Mechanical and Manufacturing Engineering

Fourier transform infrared spectroscopy (ETIR) of a ferroelectric liquid-ciystalline material: 4-(3)-(S>methy1-2..(S) chloropentanoyloxy-4'-octyloxy-biphenyl has been investigated in the wavenumber range 450-4000 cm for various temperatures and as a function of direct bias voltage in its SmC* phase. Samples prepared in both homeotropic and homogeneous alignments have been studied. The order parameter was calculated for several isolated JR vibrations which are characteristic of different parts and orientations ofmolecules. The dependence ofthe molecular tilt angle on direct bias voltage and temperature has similar characteristics to those Obtained from electro-optic measurements.

Microcavity structures are designed to enhance the interaction of light with matter. Wavelength-scale structures that confine light can be used to make highly efficient micro-lasers and sensors. Planar, spherical, and cylindrical geometries have all been developed to make efficient micro-resonators. Among these devices, the microcylindrical or microcapillary dielectric resonators have generated significant interest due to their small size and material compatibility with telecommunication optical fibers. 1 The cylindrical cavity format is also compatible with a large variety of sensing modalities such as immunoassaying and molecular diagnostic assaying. Recent efforts to develop efficient micro-tube emitters focused on optical modes that are concentrated at the surface of dielectric materials. The main physical phenomenon exploited for this development is grazing-incidence total internal reflection of light resulting in 'whispering-gallery' modes (WGMs). In these modes, light propagates in planes near the surface, with integer numbers of wavelengths along closed circumferential trajectories. The high degree of confinement of light in WGM results in a high resonance quality factor (Q). Experimentally, the most widely-studied configuration of thin-wall microtube cavities is the microcapillary filled with a highly luminescent dye solution. Both diameter (typically 50-200µm) and wall thickness can be controlled by the etching of commercially-available glass samples in an HF-water solution. 2 However, the short-distance evanescent field in these microcavities and the limited photostability of dye molecules are retarding factors for potential applications. In the small-size regime (with diameters less than 10µm), semiconductor microdisks of finite height-micropillars-have been widely used as a tool to control spontaneous emission and confine photons in three dimensions. The evanescent field in

This study investigated the effects of selected casting methods on mechanical behaviour of Al-Mg-Si alloy. The casting methods used were spin, sand and die casting, these were done with a view to determine which of the casting methods will produce the best properties. The pure aluminium scrap, magnesium and silicon were subjected to chemical analysis using spectrometric analyzer, thereafter the charge calculation to determine the amount needed to be charged into the furnace was properly worked out and charged into the crucible furnace from which as-cast aluminium was obtained. The mechanical properties of the casting produced were assessed by hardness and impact toughness test. The optical microscopy and experimental density and porosity were also investigated. From the results it was observed that magnesium and silicon were well dispersed in aluminium matrix of the spin casting. It was observed from visual examination after machining that there were minimal defects. It was also observed that out of the three casting methods, spin casting possesses the best mechanical properties (hardness and impact toughness).

Aluminum alloy finds strong suitability in automotive, sporting, goods aerospace,
and weight reduction industries. Its blend of lightweight attributes and robust
strength make it well-suited for crafting lightweight components and structures
while upholding overall strength and performance standards. In this research,
AA6061-T4 alloy chips underwent a recycling process involving hot extrusion
followed by Equal Channel Angular Pressing. The influence of various routes and
varied numbers of cycles on microstructure and mechanical characteristics were
examined utilizing a die featuring angles of 90° and 20°. Two routes, BC and C,
were scrutinized, and the outcomes displayed significant enhancements in
properties for the recycled chips after the hot extruded and ECAP techniques. After
the fourth run, route BC exhibited a maximum Ultimate tensile strength of 265
MPa, peak yield strength of 149 MPa, and an elongation to failure of 46%.
Meanwhile, the corresponding values for route C were 238 MPa, 136 MPa, and
41%, respectively. For two routes, BC and C, every pass led to elevated strength
and hardness while also contributing to increased elongation to failure. The
microstructures and mechanical characteristics of the ECAPed samples surpassed
those of the extruded sample. The routes and pass numbers substantially impacted
the microstructures and mechanical properties of the solid-state recycled AA6061-
T4 alloy chip specimens. Scanning electron microscopy pictures showcased a
honeybee-type pattern following ECAP through route BC, signifying the final
stages of grain refinement. At the same time, the initial sample exhibited a fracture
tendency with a mix of brittleness and ductility.

The mechanical, chemical and physical property of Alkaleri fireclay was investigated for its appropriateness for refractory application. The chemical composition was performed and analyzed using the X-ray fluorescence (XRF) spectrometer Bench top XRF analyzer technique. Chemical property result indicated that the clay contained 67.4 % silica (SiO 2), 30.06 % aluminum (Al 2 O 3), and other impurities. The clay was subjected to mechanical activation through sintering process at varied sintering temperatures of 900 °C, 1000 °C, 1100 °C and 1200 °C. At the best sintering temperature of 1200 °C, the cold crushing strength (CCS) was 17.82 MPa, in the physical properties; apparent porosity was 22.8 %, bulk density was 1.8 g/cm 3 , and firing shrinkage was 8.9 %. The Alkaleri clay belongs to alumino-silicate fireclay group and therefore, suitable materials for refractory application of ladle, kiln dryer, boilers, cook stoves, furnace lining and bricks.

Since the hotel operates from November 2015 until July 2018 the occupancy room level has always changed inconsistently. The purpose of this study is to analyze the current marketing strategy and to find out more appropriate strategies in increasing occupancy rooms based on the online travel agent market segment at Whiz Prime Hotel Pajajaran Bogor. The analysis was carried out through IFE matrix analysis, EFE matrix, IE matrix, SWOT matrix, and QSPM matrix. The results showed that the condition of the marketing strategy with IE matrix analysis was in a position of growth and development with the meeting point value of IFE 335 and EFE 376. In this position the strategy that must be carried out is market penetration, market development, product development, forward integration, and backward integration. Based on SWOT matrix analysis the strategy that must be done is to display complete information, add hotel facilities, improve product and service quality, and improve the quality of human resources. The results of the analysis using the QSPM matrix show that the most appropriate strategy carried out by Whiz Prime Hotel Pajajaran Bogor is to improve product and service quality.

There are various types of reinforcements used in the development of aluminium based metal matrix composites. It was observed that by the use of ceramic particles, mechanical characteristics such as hardness and tensile strength were enhanced. However, density and cost was also increased. Groundnut shell is waste product that produces lots of soil pollution. By utilizing ground nut shell ash as reinforcement material with aluminium, mechanical properties can be improved. Further, density and cost of composite can be reduced. The aim of this review article is to study the influence of various types of reinforcements in the fabrication of composites with enhanced mechanical properties.

This study was a comparative study on the effect of the flux produced from coconut and eggshell powders during arc-welding of mild steel. An arc welding machine and flux prepared from agrowastes were employed for the study. The Flux compositions used for the 5 welded groups include 100% Eggshell, 100% Coconut shell, 70% Eggshell with 30% Coconut shell, 30% Eggshell with 70% Coconut shell and finally, normal convectional flux for control experimentation. Tensile test shows that the 100% egg shell powder as flux had the highest tensile strength with 850 N at maximum tensile compare with 70% Egg shell, normal flux, 30% Coconut shell and 100% Coconut shell that returned values of 847, 785, 750 and 712 N respectively. Samples welded using 100% Eggshell developed flux produced the highest Brinell Hardness Value of 125.25 BHN at the welded joint compared to results from other flux types. Tensile results shows that welded joints formed by 100% Eggshell flux had the highest Maximum Tensile Stress (MTS) of 850.2 N compared with others having lower values of MTS and can last longer when load bearing properties is considered. Hence, flux developed from 100% Eggshell is recommended for use as substitute for the conventional flux.

In this study, AZ91C magnesium matrix in-situ nano-composites reinforced with oxide particles were produced by the addition of 2 % of mass fractions of silica nanoparticles to the melt using the stir-casting method. For this purpose, nano-silica powder was mixed in molten AZ91C by a special procedure and stirred for 15 min at 750°C and cast in a preheated die at 720°C. Control samples were also cast under the same conditions. Improved microstructure, reduced porosity and increased hardness, tensile strength and yield strength of the composite sample were revealed by microstructural and mechanical investigations. The hardness, yield strength and tensile strength values increased from 65 BHN, 82 MPa and 165 MPa for the monolithic samples to 77 BHN, 97 MPa and 175 MPa for the in-situ formed cast composites. Microstructural and EDS analyses suggested the in-situ formation of Al2O3, MgAl2O4 and MgO oxide particles by in-situ reaction of the Al, Mg and SiO2 in the melt. Keywords: AZ91C alloy, in-situ cast nano-composite, silica nanoparticles, mechanical properties V {tudiji so bili izdelani AZ91C nanokompoziti in situ, na podlagi magnezijeve matrike in oja~ani z oksidnimi delci z dodatkom 2 % nanodelcev silicija za topljenje, z uporabo metode litja z me{anjem. Za ta namen je bil nanosilicijev prah zme{an v raztopljen AZ91C s posebno metodo in nato 15 min me{an na 750°C in lit v predogretem modelu na 720°C. Preizku{anci so bili ravnotako liti v enakih pogojih. Izbolj{ana mikrostruktura, zmanj{ana poroznost in pove~ana trdota, napetostna trdnost in napetost vzorcev kompozita so bili odkriti s preiskavami mikrostrukture in z mehanskimi preiskavami. Vrednosti trdote, napetosti te~enja in natezne napetosti so se pove~ali iz 65 BHN, 82 Mpa in 165 MPa in za monolitne vzorce na 77 BHN, 97 MPa in 175 MPa za in situ formirane lite kompozite. Mikrostrukture in EDS-analize so predlagale in situ formacijo Al2O3, MgAl2O4 in MgO oksidne delce z in situ reakcijo Al, Mg in SiO2 v topljenem. Klju~ne besede: AZ91C zlitina, in situ litje nanokompozitov, nanodelci silicija, mehanske lastnosti

Aluminum 6061 is a heat-treated, extruded alloy used for various engineering and structural components such as wings and fuselage of aircraft, railings, window frames, driveshaft and valves, etc. Al-6061 is widely used amongst its 6000 aluminum series because of its outstanding properties like medium to high strength, excellent environmental resistance, low density, high elongation at break and superior machinability. This paper aims to review the mechanical, tribological and microstructural characterization of stir cast Al-6061 metal/matrix composites (MMCs). In this review article an attempt has been made to demonstrate the effect of different reinforcements on metallurgical behavior of Al-6061 MMC. The particulates reinforcements like SiC, Al 2 O 3 , Gr, B 4 C, TiC, fly ash, bagasse ash and red mud were dispersed with Al-6061 alloy through stir casting route as single, dual and triple reinforcements. The experimental results showed significant improvement in tribological and mechanical properties of Al-6061 MMC as compared with Al-6061 alloy. The overall characterizations of Al-6061 MMC are summarized with key findings, which will provide a methodical approach for researchers in selecting optimized parameters for the fabrication of aluminum-based MMC.

Today's composite research has been focused on developing lighter and cheaper materials. Out of many available ceramic reinforcements, fly-ash has been used as a cheaper reinforcement available in abundant quantity. Use of fly-ash will be helpful in reducing the cost of metal composite and weight also. Use of fly-ash as particle reinforcement will utilize a large amount of a waste material. The present work deals with the development of Aluminium Matrix composites using aluminium alloy AA6061 as matrix, Al 2 O 3 and fly ash as reinforcing material; fabricated by stir casting technique. The effects on properties of these materials investigated by adding fly ash. This investigation shows that with the addition of fly ash Micro hardness, Rockwell hardness increases however density decreases. The microstructures of specimen of composites also have studied by optical microscopy. The microstructure reveals the fairly uniform distribution of reinforcement particles in the aluminium 6061 matrix.

The effect of double thermal ageing treatment (DTAT) on the hardness, impact and tensile properties of Al-Cu-Mg/rice husk ash composite produced by double stir casting method has been studied. From the results obtained, DTAT samples showed better hardness, impact and tensile properties as compared with the STAT samples. These significant improvements were evidenced in the DTAT for 5 h (with a hardness value of 81.3 HRB) and DTAT for 4 h with impact strength of 72 kJ/m 2 and Ultimate tensile strength of 129.797 N/mm 2 respectively. The Microstructural analysis revealed that more precipitates were formed and more evenly distributed in the DTAT than STAT. It can be deduced that the thermal treatment has improved the mechanical properties of the composite studied under this condition.

This article provides an intensive review of the past and current research work on the solid-state recycling of light metals. The review includes an experimental aspect of the relevant works that clearly clarify the effects of several critical factors noted as chip preparation, reinforcing phases, die geometry, process parameter selection and performance of miscellaneous methods over the quality of the extruded profiles. Likewise, reviews of numerical and analytical works on the solid-state recycling were presented to understand the strengthening phenomena of chip-based billet through the plastic deformation. Finally, concluding remarks underline challenges of direct recycling method and subsequently highlight the potential future work on making the method as a promising alternative for sustainable manufacturing agenda.

Alternating typical primary aluminium production with recycling route should benefit various parties, including the environment since the need of high cost and massive energy consumption will be ruled out. At present, hot extrusion is preferred as the effective solid-state recycling process compared to the typical method of melting the swarf at high temperature. However, the ideal properties of extruded product can only be achieved through a controlled process used to alter the microstructure to impart properties which benefit the working life of a component, which also known as heat treatment process. To that extent, this work ought to investigate the effect of extrusion temperature and ageing time on the hardness of the recycled aluminium chips. By employing Analysis of Variance (ANOVA) for full factorial design with centre point, a total of 11 runs were carried out randomly. Three dissimilar extrusion temperatures were used to obtain gear-shape billet. Extruded billets were cut and ground before entering the treatment phase at three different ageing times. Ageing time was found as the influential factor to affect the material hardness, rather than the extrusion temperature. Sufficient ageing time allows the impurity atoms to interfere the dislocation phenomena and yield great hardness. Yet, the extrusion temperatures still act to assist the bonding activities via interparticle diffusion transport matter.

Solid-state recycling of light metals reinforced inclusions through hot Equal Channel Angular Pressing (ECAP) is performed to directly recycle metal scraps and reduce cost of material in engineering applications. The ECAP is one of the most important method in severe plastic deformation (SPD) that can convert light metals into finished products. This paper reviews several experimental and numerical works that have been done to investigate the effects of the ECAP parameters such as die angles, material properties, outer corner angle, friction coefficient, temperature, size of chips, pressing force, ram speed and direct effects of number of passes on the strain distributions. It also includes the performance enhancement of aluminium matrix composite reinforced ceramic-based particles that derived from direct recycled aluminium chips for sustainable manufacturing practices.

In this contribution, researchers have provided a summary of the agricultural and industrial waste recoveries to be deployed as the composite reinforced materials. It covers the work of previous researchers related to this area and addressed the key challenge to overcome for further development and advancement. The major contributions of this work were a comprehensive review on a wide variety of Sever Plastic Deformation (SPD) techniques implementation in development of the waste materials based reinforced metal matrix composite. The waste materials can be derived from either industrial or natural sources. Also, it discusses the range of Metal Matrix Composites (MMCs) applications in engineering and related manufacturing techniques with further emphasized on the process parameters which directly determine the material properties. Some useful suggestions were proposed to the industrialists, academicians and scientists to further improve the performance aspect of MMCs for commercialization reason. Furthermore, industrial and natural waste enhancement materials have been strongly proposed because of their higher reinforced content particulates such as alumina (Al2O3) and silica (SiO2). Also, the mechanical and physical properties are directly influenced by the size, shape and weight-volume fraction of the composites as same as the potential reactions between matrixes/reinforced materials interface.

This paper presents the evaluation of surface roughness and roughness profiles when machining carbon steel under wet conditions with low and high cutting speeds. The workpiece materials and cutting tools selected in this research were AISI 1045 carbon steel and canela carbide inserts graded PM25, respectively. The cutting tools undergo machining tests by CNC turning operations and their performances were evaluated by their surface roughness value and observation of the surface roughness profile. The machining tests were held at varied cutting speeds of 35 to 53 m/min, feed rate of 0.15 to 0.50 mm/rev and a constant depth of cut of 1 mm. From the analysis, it was found that surface roughness increased as the feed rate increased. Varian of surface roughness was suspected due to interaction between cutting speeds and feed rates as well as nose radius conditions; whether from tool wear or the formation of a built-up edge. This study helps us understand the effect of cutting speed and feed rate on surface integrity, when machining AISI 1045 carbon steel using carbide cutting tools, under wet cutting conditions.

This study was a comparative study on the effect of the flux produced from coconut and eggshell powders during arc-welding of mild steel. An arc welding machine and flux prepared from agrowastes were employed for the study. The Flux compositions used for the 5 welded groups include 100% Eggshell, 100% Coconut shell, 70% Eggshell with 30% Coconut shell, 30% Eggshell with 70% Coconut shell and finally, normal convectional flux for control experimentation. Tensile test shows that the 100% egg shell powder as flux had the highest tensile strength with 850 N at maximum tensile compare with 70% Egg shell, normal flux, 30% Coconut shell and 100% Coconut shell that returned values of 847, 785, 750 and 712 N respectively. Samples welded using 100% Eggshell developed flux produced the highest Brinell Hardness Value of 125.25 BHN at the welded joint compared to results from other flux types. Tensile results shows that welded joints formed by 100% Eggshell flux had the highest Maximum Tensile Stress (MTS) of 850.2 N compared with others having lower values of MTS and can last longer when load bearing properties is considered. Hence, flux developed from 100% Eggshell is recommended for use as substitute for the conventional flux.

In this work, the effect of adding pumice powder to recycled beverage cans as reinforcement from 2 to 8 wt% in steps of 2 wt% was investigated. Manual stir casting technique was employed. Some mechanical (rockwell hardness, impact strength, tensile strength) and physical (density) properties were determined using standard methods. At 8 wt% pumice addition, an increment of 11.08% and 28.39% on hardness and tensile strength, respectively of the unreinforced recycled beverage can were recorded. However, the impact strength was reduced by 24.24%. The density was reduced by 39.51% compared to the unreinforced recycled aluminum. This composite material would find relevant applications in the development of light weight materials.

The paper is concerned with an analysis of utility and fatigue properties of industrially produced aluminium alloy, specifically EN AW 6061 (AlMg1SiCu), reinforced with the particles of SiC. The following properties were subject to evaluation: microstructure and sub-structure, mechanical characteristics. All of these mechanical properties in pre-and post-equal channel angular pressed (ECAP) state have been studied. The hardness was evaluated by Vickers hardness test at the load of HV10. The significant part the thesis was devoted to the fatigue properties at cyclic load in torsion. The presented results demonstrate well that the combination of fractography and microscopy can give a significant contribution to the knowledge of initiation and propagation crack in the aluminium alloy.

This study was a comparative study on the effect of the flux produced from coconut and eggshell powders during arc-welding of mild steel. An arc welding machine and flux prepared from agrowastes were employed for the study. The Flux compositions used for the 5 welded groups include 100% Eggshell, 100% Coconut shell, 70% Eggshell with 30% Coconut shell, 30% Eggshell with 70% Coconut shell and finally, normal convectional flux for control experimentation. Tensile test shows that the 100% egg shell powder as flux had the highest tensile strength with 850 N at maximum tensile compare with 70% Egg shell, normal flux, 30% Coconut shell and 100% Coconut shell that returned values of 847, 785, 750 and 712 N respectively. Samples welded using 100% Eggshell developed flux produced the highest Brinell Hardness Value of 125.25 BHN at the welded joint compared to results from other flux types. Tensile results shows that welded joints formed by 100% Eggshell flux had the highest Maximum Tensile Stress (MTS) of 850.2 N compared with others having lower values of MTS and can last longer when load bearing properties is considered. Hence, flux developed from 100% Eggshell is recommended for use as substitute for the conventional flux.

Compared to the recycling process by remelting, hot extrusion significantly reduces the energy consumption and CO2 emission and ensures good mechanical and microstructural properties. This study investigates the effects of reinforcing aluminium AA6061 chips with mixed boron carbide (B4C) and zirconia (ZrO2) particles by employing a design of experiment (DOE) under 550 °C processing temperature and three hours preheating time. The findings showed that compressive strength (CS) and hardness increased with up to 5% added particles, and beyond 5%, the yielded values decreased because of materials agglomeration. However, the decreasing density was dependent on the addition of ZrO2 particles. The distribution of particles with different volume fractions of mixed particles was investigated by employing SEM, AFM, and EDS tests. Thus, the process can produce a net shape structure that utilises material-bonding consolidation to provide sufficient support to reuse the recovered materials in en...

Recycle aluminium has been mixed with palm oil fly ash based on fraction weight of overall weight of palm oil fly ashes to aluminium recycle. The ratios discussed on this paper are 0%, 3% 6%, 9%, 12% and 15%. The samples have been developed via sand casting method. The result shows that the best composition has been achieved when we added 3% of palm oil fly ashes, with the new composite aluminum have a highest hardness with the value of 119.7HV, with the Modulus of raptured of 7.71Mkg/m2  

Silica plays an important role in aluminium-based materials. However, role of silica in aluminium matrix composite is not clear so far. In the present study, pure silica was successfully extracted from rice husk by thermal and chemical treatments. The extracted silica had undergone FESEM, FTIR, and XRD for characterizing the purity of silica particles. The results showed that the obtained silica particles were highly pure. The rice husk-extracted pure silica was used as reinforcement in graphite/aluminium matrix hybrid composites. Composites were made using powder metallurgy process followed by sintering. Reinforcements of silica and graphite in aluminium matrix composites were done at different compositions to control the hardness in order to improve machinability. The aluminium matrix hybrid composites had shown excellent physical, mechanical, and thermal properties in terms of surface strength along with light mass as well as controlled thermal conductivity. The hardness of the hybrid composites had increased significantly compared to the single phase aluminium and also was controlled by the combined effect of added silica nanoparticle and graphite flake as reinforcements. Beside mechanical properties, these hybrid composites showed significantly desired thermal properties, particularly lower thermal expansion than that of pristine aluminium. Hence, the newly developed rice husk-extracted pure silica reinforced graphite/aluminium matrix hybrid composites can be used as potential materials for various advanced applications including microelectronic devices, engine piston, and automobile components.

The equal channel angular pressing (ECAP) method is used in this work to treat the Al-Zn-Mg-Cu alloy. As the most promising severe plastic deformation (SPD) technique, equal channel angular pressing (ECAP) has received extensive research in recent years. Hardness test, compression test, electrical conductivity, and surface studies were used to look into how an ultra-fine grained (UFG) industrial aluminum alloy that was made by equal channel angular pressing (ECAP) for one pass strengthened its mechanical characteristics and electrical conductivity. The product has been annealed for three hours at 415 0 C; Experimental research is done to determine how aluminum alloy 7075's electrical conductivity and material characteristics are impacted by the rate of severe plastic deformation (SPD) during equal channel angular pressing (ECAP). According to the results, the ECAP will increase compressive strength from 145 to 295.5 N/mm 2 at the same strain in 0.016 seconds after one pass, Hardness increases progressively until 295.5 N/mm 2 is reached as its highest value, then it gradually decreases. The percentage increase in hardness was 50.9% at a strain rate of 0.016s-1. ECAP method is frequently used to raise the yield strength of the aluminum alloy 7075 by 204 % while simultaneously reducing the rate of strain at a compressive strength of 145 N/mm 2 from 0.016 to 0.008s-1. With just one pass, IACS of the alloy as received and after Escaping both showed an improvement in electrical conductivity from 30.8% to 43.5%., ECAP increases electrical conductivity by 29.2% with a strain rate of 0.016s-1 .

The equal channel angular pressing (ECAP) method is used in this work to treat the Al-Zn-Mg-Cu alloy. As the most promising severe plastic deformation (SPD) technique, equal channel angular pressing (ECAP) has received extensive research in recent years. Hardness test, compression test, electrical conductivity, and surface studies were used to look into how an ultra-fine grained (UFG) industrial aluminum alloy that was made by equal channel angular pressing (ECAP) for one pass strengthened its mechanical characteristics and electrical conductivity. The product has been annealed for three hours at 415 0 C; Experimental research is done to determine how aluminum alloy 7075's electrical conductivity and material characteristics are impacted by the rate of severe plastic deformation (SPD) during equal channel angular pressing (ECAP). According to the results, the ECAP will increase compressive strength from 145 to 295.5 N/mm 2 at the same strain in 0.016 seconds after one pass, Hardness increases progressively until 295.5 N/mm 2 is reached as its highest value, then it gradually decreases. The percentage increase in hardness was 50.9% at a strain rate of 0.016s-1. ECAP method is frequently used to raise the yield strength of the aluminum alloy 7075 by 204 % while simultaneously reducing the rate of strain at a compressive strength of 145 N/mm 2 from 0.016 to 0.008s-1. With just one pass, IACS of the alloy as received and after Escaping both showed an improvement in electrical conductivity from 30.8% to 43.5%., ECAP increases electrical conductivity by 29.2% with a strain rate of 0.016s-1 .

Biomass ash generated in thermal power plants as a material, could be a valuable supply of many oxides like SiO2, Al2O3, Fe2O3 and CaO. These oxides will function a helpful preliminary supply for glass production. The glass system ready during this project is Borate-Zinc-Biomass ash (BZB) and Borate-Zinc-Rice husk ash (BZR) glass by exploring biomass ash as glass former. The progressive addition of biomass ash to the current system of glass was created to study its effect on the chemical and physical properties of the parent glass. Ultrasonic measurements were performed by pulse-echo method. The densities of the ready samples were measured to justify the packing arrangements of the constituent chemical compound. The variations in densities and ultrasonic velocities of the ready samples containing progressive fly ash contents were correlate and mentioned. The values of elastic moduli (including Young's modulus, coefficient of elasticity, shear modulus and Poisson's ratio) were compared with those on paper calculated.

Biomass ash generated in thermal power plants as a material, could be a valuable supply of many oxides like SiO2, Al2O3, Fe2O3 and CaO. These oxides will function a helpful preliminary supply for glass production. The glass system ready during this project is Borate-Zinc-Biomass ash (BZB) and Borate-Zinc-Rice husk ash (BZR) glass by exploring biomass ash as glass former. The progressive addition of biomass ash to the current system of glass was created to study its effect on the chemical and physical properties of the parent glass. Ultrasonic measurements were performed by pulse-echo method. The densities of the ready samples were measured to justify the packing arrangements of the constituent chemical compound. The variations in densities and ultrasonic velocities of the ready samples containing progressive fly ash contents were correlate and mentioned. The values of elastic moduli (including Young’s modulus, coefficient of elasticity, shear modulus and Poisson’s ratio) were compar...

The die-casting process is a metal casting processes that utilize metal molds or permanent dies. In this work, the effect of varying percentage increase in reinforcement on some mechanical properties of aluminum alloy composites was obtained by the die cast process. The process was applied to produce various casts using aluminum alloy as the metal matrix and sawdust as the reinforcement at 5%, 10% and 15% by weight. Aluminum Scrap was sourced and sent for elemental characterization at Engineering Materials Development Institute (EMDI), Akure Nigeria. Tensile and hardness test were the mechanical tests carried out on the different samples of the cast. The elemental characterization test result showed that, the composition of the aluminum alloy used is Al-8.1%Mg-0.4%Fe-0.2%Zn. Results showed that at 10% by weight of reinforcement, the average tensile strength of the composite had the highest value while the lowest tensile strength was recorded at 15% by weight of reinforcement. At 15% by weight of reinforcement, the average hardness of the composite had the highest value while the lowest hardness was recorded at 5% by weight of reinforcement. Results were compared with the works of Ranjit et al. (2020) and Belete et al. (2013) and it was concluded that the results obtained from this work are adequate and significant for use.

CuO-ZnO ceramic composites have been obtained by pressing conventional method. The composite materials are CuO and ZnO powders with ratio in mass composition of CuO and ZnO are 75%:25%, 80%:20%, 85%:15%, 90%:10% and 95%:5%. The samples were made by three steps. The first step, CuO and ZnO powders are sieved with particle size of 100 mesh. Then, both of powders are mixed until homogeneous for 5 minutes with dry mixing method. The second step, the homogeneous powders are fabricated with pressure at 300 MPa for 10 minutes to form a pellet. The last step, the pellet was burned by furnace at temperatures 800 o C, 900 o C and 1000 o C for 3 hours. Each sample that has been burned was characterized by physical properties (density), morphological analysis (SEM), mechanical properties (compressive strength and hardness) and crystalline structural analysis (XRD). The results of characterization show that optimum ratio in mass composition of CuO and ZnO is 95%:5% at 1000 o C temperature. It has the highest density of 9.205 g/cm 3 while the highest of compressive strength is 218.799 MPa, the highest hardness is 1816.920 MPa and morphological structures are evenly distributed.

In order to investigate the effect of nano-alumina on the microstructure and mechanical properties of Al/nanoAl2O3 composite, an innovative method was used in stir casting to avoid agglomeration and segregation of particles. Different volume fraction of nano-alumina particles were incorporated into the aluminum A356 alloy by a mechanical stirrer and cylindrical specimens at different temperatures were cast and tested. The microstructural characterization of the composite samples showed uniform distribution of reinforcement, grain refinement of aluminum matrix, and presence of the minimal porosity. The effects of Al2O3 particle content and casting temperature on the mechanical properties of the composites were investigated. Based on experiments, it was revealed that the presence of nanoAl2O3 reinforcement led to significant improvement in hardness, UTS and ductility. This combination of enhancement in UTS and ductility exhibited by nanoAl2O3 reinforced aluminum is due to uniform dist...

In this analysis, Aluminum 6063 (AA6063) is used as matrix material and sugarcane bagasse ash (SCBA) is used as reinforcement material and combinedly cast to produce Metal Matrix Composite (MMC). Particle size of reinforcement is 75µm with varying composition from 0% to 3% is fabricated by stir casting technique. The effect of percentage reinforcement on the particle dispersion and strength of MMC's are studied. The microstructures were examined under optical microscope. Cast composites were characterized for mechanical properties with respect to wt. percentage of SCB and it is observed that the hardness and tensile strength were increased as reinforcement increased. The dry sliding wear behavior of the cast composites were studied using pin on disc apparatus. Experiments were conducted varying the loads from 2kg to 3 kg, for a constant distance of 5000m and constant sliding speed of 500 rpm. Sliding wear resistance has been increased for reinforced alloy as compared to AA6063 alloy and also resistance increased as reinforcement increased.

In this analysis, Aluminum 6063 (AA6063) is used as matrix material and sugarcane bagasse ash (SCBA) is used as reinforcement material and combinedly cast to produce Metal Matrix Composite (MMC). Particle size of reinforcement is 75μm with varying composition from 0% to 3% is fabricated by stir casting technique. The effect of percentage reinforcement on the particle dispersion and strength of MMC's are studied. The microstructures were examined under optical microscope. Cast composites were characterized for mechanical properties with respect to wt. percentage of SCB and it is observed that the hardness and tensile strength were increased as reinforcement increased. The dry sliding wear behavior of the cast composites were studied using pin on disc apparatus. Experiments were conducted varying the loads from 2kg to 3 kg, for a constant distance of 5000m and constant sliding speed of 500 rpm. Sliding wear resistance has been increased for reinforced alloy as compared to AA6063 a...

The main objective of this study is to investigate the electrical properties of Sn–3.0Ag–0.5Cu solder joint with the incorporation of carbon nanotube instead of solder bulk. Sn–3.0Ag–0.5Cu solder paste with the incorporation of carbon nanotube up to 0.04 wt% was fabricated by using mechanical mixing method. Fabricated solder pastes were then soldered on printed circuit board via reflow soldering at 260°C peak temperature. Electrical resistivity of Sn–3.0Ag–0.5Cu-carbon nanotube solder joints was measured by the four-point probe method at room temperature. Microstructure properties were observed by optical microscope and field emission scanning electron microscope. Electrical resistivity of Sn–3.0Ag–0.5Cu solder joint was found to increase with the incorporation carbon nanotube up to 0.03 wt% and slightly decrease at 0.04 wt%. Incorporation of carbon nanotube in the solder matrix apparently changes the microstructure of Sn–Ag–Cu solder alloys. Microstructural observation found that e...

This study presented the ballistic properties and impact strength of the aluminum alloy AA 7075-reinforced nano-SiC composites, which were produced by stir-squeeze casting and forging processes. Ballistic tests revealed that the samples met the National Institute of Justice (NIJ) Type II standard, except for samples that were not forged. The other characteristics examined were microstructural observations analyzed using optical and scanning electron microscopes. As a result of the pinning effect, the microstructure of the samples showed a decrease in grain size as the SiC content increased, except for samples with over 0.25 vf% of nano-SiC. This effect was observed in samples with and without forging. The forging process decreased grain size further, affecting ballistic and mechanical properties. The addition of 0.3 vf% nano-SiC improved the ballistic properties and impact strength, resulting in the highest impact value of 7.7 J, despite higher values of the average ballistic diameter of perforation (about 4.7 mm) and average indentation depth (about 17.22 mm) measured on this sample.

In the previous decades, manufactured filaments, for example, glass or carbon strands have been utilized to strengthen composites of polymer. Be that as it may, with the developing worldwide ecological concerns, moderate biodegradability is their drawback [6]. In this way, researchers are finding other conceivable ways to deal with enhance polymeric composites biodegradability. Natural fiber bio-composites have many advantages, including low costs, sustainability, renewability, good formability, good thermal insulation, eco-friendly, lightweight, processability,

Waste sugarcane bagasse-ash and graphite utilizing as reinforcement in fabricating of an aluminium alloy (Al-7075) based matrix hybrid composites. The aluminium matrix hybrid composites have been fabricated by stir-casting method at 750°C. Casting was developed in circular metal mould having 5 circular slots of diameter of 21 mm and length of 250 mm. Adding bagasse-ash with varying reinforcement of three cases, in first case 2% constant with varying graphite 1%, 3%, and 5%, in second case 4%, and in third case 6% constant with varying same graphite percentage. The effect of the reinforcement has been performed through various mechanical tests. The mechanical properties measuring such as Brinell hardness and tensile strength of both the samples have been prepared as per the ASTM E23 and E8 standards. Results give out that there will be greater effect of reinforcing different bagasse-ash in aluminium alloy matrix hybrid composites. In the third case more enhanced mechanical properties have been achieved as compared to case one and two of bagasse-ash combination. It shows that the selection of bagasse-ash as reinforcement has one of the most significant criteria for the fabrication of aluminium matrix hybrid composites.

M etallic chips formed during machining are generally recycled by melting and casting. This procedure results in oxidation of the materials and degradation of the material properties. Additionally, the aforementioned procedure requires high energy consumption and the emission of harmful gases. Additionally, these processes are inefficient and expensive (Gronostajski et al, 1997). It has been reported (Lazzaro and Vittori, 1992) that the process of melting aluminum alloy chips results in 10% burning and 10% slag formation. Additionally, the direct conversion of aluminum chips into compact metal results in 40% material savings, 26-31% energy savings and 16-60% labor savings (Chmura and Gronostajski, 2006). Solid state recycling is an effective and energy efficient process due to the prevention of oxidation compared with melting processes. Solid state recycling was first proposed by Nakanishi et al. (1995) for recycling magnesium alloy chips and scrap. Lee et al. (1995) and Liu et al. (2002) also conducted research on AZ91D and AZ80 magnesium alloys using solid state recycling. In

In this study, the low-velocity impact behavior of porous metal matrix composites (MMCs) has been investigated. The MMCs consisting of spheroidal cast iron chips (GGG-40) and bronze chips (CuSn10) were produced by hot isostatic pressing. The MMCs were produced with different CuSn10 contents as 90-80-70-60%. The hot isostatic pressing was performed under three different pressures and temperatures. The produced MMCs were exposed to low-velocity impact loading under 2 m/s by using a drop weight test stand. The test results were compared with the bulk CuSn10 and bulk GGG-40, separately. The test results revealed that hot-isostatic-pressed MMCs can successfully represent bulk material properties when subjected to low-velocity impact loading even these MMCs have porosity 2-8%. Keywords Low-velocity impact Á Recycling Á Isostatic hot pressing Á Metal matrix composites (MMCs)

Due to their excellent thermal conductivity, lightweight, and ease of processing, aluminum alloys are the material of choice for piston manufacture in internal combustion engines. Nanoparticles (NPs) of alumina (Al2O3) with a size of 25 nm were incorporated into an aluminum piston alloy to examine the effect of the NP addition on wear resistance and fatigue behavior. The stir casting method has been utilized to manufacture experimental samples of the composite material by altering the particle weight ratio of aluminum to the matrix alloy to 2, 4, and 6 wt%. The surface morphology of the samples has been examined using an electronic scanning microscope. The results of the wear and fatigue tests indicate that the addition of Al2O3 to the composite enhanced its fatigue resistance and wear strength, with the exception of 6 wt% weight ratio. The best improvement in wear resistance and fatigue strength occurs at 4 wt% Al2O3 particles, which are 12.13 and 67.5%, respectively, more signific...

is present investigation focusing on preparation of Al-based hybrid composites in which Al6082 is engaged as the main alloy reinforced with two reinforcements of ZrSiO₄/TiC. e combination of the stir-squeeze process helps to make di erent specimen by change of four parameters such as stir speed, stir time, reinforcements, and squeeze pressure. In this process, two reinforcements are reserved as constant about 7.5 wt%. e four levels of each parameter are stir speed (

The main objective of this research is to analyze the strategy of developing the footwear business. Case studies were carried out at CV Hikmah Shoes Bogor. The initial analysis was carried out by identifying the business of the ongoing CV Hikmah shoe model and analyzing the external and internal scope to identify problems that occurred in the company. The descriptive method used to identify CV Hikmah Shoes Bogor using, Internal Factor Matrix (IFE) and External Factor Evaluation (EFE) used to analyze internal and external factors at CV Hikmah Shoes Bogor. SWOT matrix selected to determine the strategy to be implemented and Quantitative Strategy Planning Matrix (QSPM) is used as a process to determine strategic priorities for the company. The results of the SWOT Matrix in this study produced six alternative strategies which were chosen as development strategies at CV Hikmah Shoes Bogor. The best strategy is taken in developing the footwear business strategy, maximizing promotion and marketing using social media or e-commerce and continuing with the improvement business KEY WORDS: IFE, EFE, QSPM, SWOT Matrix ANALIZA STRATEGIEI DE DEZVOLTARE A AFACERILOR ÎN DOMENIUL ÎNCĂLŢĂMINTEI FOLOSIND ANALIZA QSPM ŞI SWOT REZUMAT. Obiectivul principal al acestei cercetări este de a analiza strategia de dezvoltare a afacerilor în domeniul încălţămintei. S-au efectuat studii de caz asupra companiei CV Hikmah Shoes Bogor. Analiza iniţială a fost efectuată prin identificarea strategiei de afaceri actuale asupra modelelor de încălţăminte CV Hikmah şi prin analizarea cadrului intern şi extern pentru a identifica problemele apărute în cadrul companiei. Pentru a identifica strategia companiei CV Hikmah Shoes Bogor s-a utilizat metoda descriptivă prin evaluarea factorilor interni (IFE) şi evaluarea factorilor externi (EFE) în vederea analizării acestor factori în cadrul companiei. S-a selectat analiza SWOT pentru a determina strategia care urmează să fie pusă în aplicare şi s-a utilizat matricea planificării strategice cantitative (QSPM) ca proces de determinare a priorităţilor strategice pentru companie. Rezultatele analizei SWOT din acest studiu au generat şase strategii alternative selectate ca strategii de dezvoltare a companiei CV Hikmah Shoes Bogor. S-a ales cea mai bună metodă pentru elaborarea strategiei de afaceri în domeniul încălţămintei, maximizarea promovării şi marketingului prin utilizarea reţelelor sociale sau a comerţului electronic şi continuarea îmbunătăţirii afacerii. CUVINTE CHEIE: IFE, EFE, QSPM, analiza SWOT ANALYSE DE LA STRATEGIE DE DEVELOPPEMENT DES AFFAIRES DANS LE SECTEUR DE LA CHAUSSURE UTILISANT L'ANALYSE QSPM ET SWOT RÉSUMÉ. L'objectif principal de cette recherche est d'analyser la stratégie de développement des affaires dans le secteur de la chaussure. Des études de cas ont été réalisées chez l'entreprise CV Hikmah Shoes Bogor. L'analyse initiale a été réalisée en identifiant la stratégie d'affaires en cours pour les modèles chaussure de CV Hikmah et en analysant la portée externe et interne pour identifier les problèmes survenus dans l'entreprise. Pour identifier la stratégie de l'entreprise CV Hikmah Shoes Bogor on a utilisé la méthode descriptive en évaluant les facteurs internes (IFE) et les facteurs externes (EFE) afin d'analyser ces facteurs au sein de l'entreprise. L'analyse SWOT a été choisie pour déterminer la stratégie à mettre en oeuvre, tandis que la matrice de planification stratégique quantitative (QSPM) a été utilisée comme processus de détermination des priorités stratégiques de l'entreprise. Les résultats de l'analyse SWOT de cette étude ont généré six stratégies alternatives retenues comme stratégies de développement de l'entreprise CV Hikmah Shoes Bogor. La meilleure méthode a été choisie pour développer la stratégie commerciale de la chaussure, maximiser la promotion et le marketing grâce à l'utilisation de réseaux sociaux ou de commerce électronique et continuer à améliorer l'entreprise.

In this study, the micro-mechanisms involved in fatigue crack propagation are investigated qualitatively in a Al/Al 2 O 3 /SiC hybrid metal matrix composite (MMC) and the results are compared with Al 2 O 3 fibre reinforced MMC and monolithic Al alloy. The three-point bending fatigue test was carried out in a rectangular notched specimen and crack propagation was monitored until the fracture of the specimen. The crack profile on the surface of the specimen was analyzed via optical microscope. The fracture surface and the crack-path profile in the fracture surface were analyzed by scanning electron microscopy (SEM) and three dimensional (3D) surface analysis respectively. The hybrid MMC shows higher crack propagation resistance than that of fibre reinforced MMC and Al alloy in the low ∆K region. In the threshold region, the crack in hybrid MMC is directed by the reinforcement-matrix debonding, followed by void nucleation in the Al alloy. Additionally, the crack propagation in the stable-crack-growth region is controlled by reinforcement-matrix interface debonding caused by the cycle-by-cycle crack growth along the interface, as well as by the transgranular fracture of particles and fibres. The presence of large volumes of inclusions and the microstructural inhomogeneity reduces the area of striation in hybrid MMC, leading to unstable fracture.

Snailshells and discarded aluminium based alloys have low economic values and are mostly considered as environmental pollutants. However, recycling them for further application in material processing can create significant economic value. Snailshell particles are known for their hardness, and thus useful as good alloying element for aluminium based pistons. In this paper, the potential of snailshell particles as reinforcement agent in Al/snailshell particulate composites is reported. Snailshell particles of weight fraction ranging from 16 to 48 wt.% and size of 200, 400 and 600 μm were added to aluminium obtained from discarded aluminum pistons during casting. The microstructures of the composites were examined under optical metallurgical microscope. The tensile strength and hardness were measured based on the experiments conducted using Box Behnken design. The results showed that, at 48 wt.% and 600 μm particle size, the tensile strength and hardness are maximum (236 MPa and 48.3 HRF, respectively) compared to the tensile strength of 92.4 MPa and hardness of 29.2 HRF for the unalloyed samples. These increments are attributed to the uniform distribution of snailshells in the ductile aluminum matrix. It is concluded that both the tensile strength and hardness are significantly enhanced, and snailshells can be used as a low-cost reinforcement for engineering applications.

This paper describes the influence of deformation by equal-channel angular pressing (ECAP) on the solid particle erosion resistance of the AlSi7Mg0.3 alloy and AlSi7Mg0.3 based composite material reinforced with the addition of 4 % of fly ash (FA) particles. Both, alloy and composite samples were produced using the compo-casting method. The samples have been subjected to ECAP in multiple passes with the rotation of samples around the vertical axis for the angle of 90° after each pass. Particles of silicon carbide (SiC) have been used as erodent while their impact angle was varied (30° and 90°). Observed samples of AlSi7Mg0.3 alloy generally showed higher wear resistance at 90° angle where material fatigue predominates, than at a 30° angle where abrasion-related phenomena predominate. On the other hand, AlSi7Mg0.3 based composite material exhibited erosion wear at 30° angle less than at 90° angle after one ECAP pass. Evaluation of the erosion resistance has been made based on mass and volume loss. After two passes of ECAP, the matrix structure of the AlSi7Mg0.3 based composite material, as well as that of the AlSi7Mg0.3 alloy was improved from the aspect of erosion resistance.

Aluminium alloy is the most favourable material based on the various properties and economic factors. Always there are so many researches going on based on the enhancement of the material properties with various combinations and the various materials mixing rate depending upon the availability. ese researches were focused on the augmentations of the properties, and then the corresponding properties can be used in the various applications depending upon the results. In this study, the AA6066 aluminium alloy composites were created with the magnesium oxide and coal ash with a variety of grouping. e specimens were named as AAMgOCA 1 to AAMgOCA 6 with respect to the volume concentration composition. en, the composites were tested to identify the impact on various strengths such as yield strength, ultimate tensile strength, shear strength, and flexural strength. ese strengths were compared with the two conditions of the composites such as annealed and heat-treated conditions. AAMgOCA 3 has the greatest results in heat-treated condition when compared with the annealed condition.

A336.0 aluminum alloy used to fabricate hybrid composites using rice husk ash (RHA) and MgO particles as reinforcement. The influence of the particles on the wear behavior of A336.0 aluminum alloy as a matrix that reinforced with MgO and RHA was investigated. Firstly, the rice husk burned at 700°C and then heat treated at 1100°C for 2 hrs. The ash characterized by X-ray florescence and X-ray diffraction. Less than 53 and 125 micron are the particle sizes of MgO and RHA respectively. The hybrid composites manufactured using stir casting method in two steps. A336.0 aluminum alloy reinforced with 4:0, 3:1, 2:2, 1:3 and 0:4 of RHA: MgO with 10 wt% total reinforcement phase. Optical microscope and X-ray diffraction were used to characterize the prepared hybrid composites. Dry sliding wear, hardness, apparent density, percentage of porosity and coefficient of friction were examined. Results indicated that porosity, apparent density and hardness enhanced with increasing MgO, while increasi...

In this paper Hydrated Mg-Al-silicate ceramic particles are used as reinforcement to fabricate a low density, low cost metal matrix composite (MMC) with Al6063 (Aluminum Alloy) as base metal via the stir casting technique is explored. Weight percentages of the reinforcements used to fabricate different density composites are 1, 2, 3, 4, and 5. The microstructures as observed by Olympus optical microscope and SEM revealed a uniform mixture of the particles and the matrix material. The density has been reduced by about 20% and porosity is increased by 16% when compared to pure Al6063 for 5% weight addition of the reinforced particles. Impact energy absorption has increased by 2 times as compared to pure Al6063 Alloy as measured by Izod impact test. The compressive stress strain curves at strain rate of 0.1mm/sec for 5% addition shows a plateau region over a wide strain rate which emphasizes the potential use of the composite for energy absorption application. The plateau stress is 50MPa and energy absorbing capacity is 22.5MJ/m 3 for 5% weight addition. Moreover the plateau stress 50Mpa is maintained over a strain range of 20-50% hence the composite is promising for energy absorbing applications.

This paper presents the effects of adding TiO 2 , CuO, and SiO 2 (1 wt%) nanoparticles on the microstructure and mechanical properties of Al-10 wt% Zn alloy. A set of composite alloys was produced by incorporating SiO 2 , CuO, and TiO 2 nanoparticles to the Al-10 wt% Zn alloy. Optical microscope (OM), scanning electron microscope (SEM) fitted with an Energy Dispersive Spectroscope (EDS), and X-ray diffraction (XRD) were used to investigate the microstructure of these alloys. The mechanical properties of the composite solders were assessed using the Vickers hardness tests. After a solution heat treatment at 500 K for 2 h, samples were immediately aged at 373 to 473 K for 2 h, followed by water quenching at 300 K. The experimental data indicated that Al-10 wt% Zn-1wt% SiO 2 samples had the highest hardness values among all investigated composite alloys. The calculated porosity percentages of the composite alloys revealed that the Al-10 wt% Zn-1 wt% SiO 2 samples had the lowest percentage. This finding can be attributed to the fact that these samples demonstrated the highest hardness values. The hardness of all composite alloys decreased with increasing the aging temperature with anomalous behavior at 443 K, where they had abnormally high values. The observed differences in the mean crystallite size, lattice strain, and dislocation density of the composite alloys, calculated from XRD data with increasing aging temperature, are attributed to the precipitation in Al-Zn alloys. The calculated values of the stress exponent and activation energy of composite alloys may be associated with grain boundary diffusion (GBD) as the dominant operating mechanism.