Wear Rate

Nowadays, polycrystalline diamond compact (PDC) cutters performance dropped and affects the performance of drilling efficiency. The objective of this project is to investigate the effect of PDC cutters geometry and optimize their geometry features. An intensive study in PDC cutters geometry would help complete the section with high penetration and low wear rate. Relatively deepened analysis was carried out and come out with four important geometries features that can help in improving the penetration and reduce wear rate. They are chamfer angle, back rake angle, side rake angle and diameter. An appropriate optimization method that effectively controls all influential geometries factors during PDC cutters manufacturing is therefore critical. By adopting L9 Taguchi OA, the simulation experiment is conducted by using explicit dynamics finite element analysis (FEA). A1B1C3D1 are identified as the optimal geometry. The set of optimum geometries is identified as the following: chamfer ang...

In this research, the mechanical properties (microhardness and wear) of Al-8Si-3Cu-2Zn nanocomposites with 0, 2, and 5% by weight of tungsten disulfide nanoplates have been investigated. The studied nanocomposite was produced through mechanical grinding and hot pressing at a temperature of 510 degrees Celsius. The microstructures of powders before and after mechanical grinding and sintered samples were studied through electron microscopy (SEM). By examining the worn surfaces after the wear test by electron microscope, the cause of weight loss was investigated. The results show that by adding tungsten disulfide nanoplates up to 5% by weight, the microhardness of the samples increases more than twice and from 50 Vickers for Al-8Si-3Cu-2Zn to 101 Vickers for Al-8Si.-3Cu-2Zn nanocomposite reaches -5%WS2. According to the results of the wear tests, the wear rate for Al-8Si-3Cu-2Zn-5%WS2 will decrease by 32% %, compared to the Al-8Si-3Cu-2Zn alloy background. Therefore, Al-8Si-3Cu-2Zn-5%WS2 nanocomposite can be used as a self-lubricating nanocomposite with favorable wear properties.

моделирование организационно-технологиЧеских и техниЧеских структур сборки машиностроительных изделий Сборка сложных машиностроительных изделий в условиях мелкосерийного производства характеризуется низким уровнем достоверности технологических решений. Это связано с невозможностью поиска оптимальных вариантов технологических процессов для заданных организационно-технических условий производства из-за сложности как объекта сборки, так и средств, которые при этом применяются. Одним из путей преодоления этих проблем является имитационное трехмерное моделирование производственной среды. ключевые слова: сборка, моделирование, технологическая операция, сборщик, семантическая сеть.

моделирование организационно-технологиЧеских и техниЧеских структур сборки машиностроительных изделий Сборка сложных машиностроительных изделий в условиях мелкосерийного производства характеризуется низким уровнем достоверности технологических решений. Это связано с невозможностью поиска оптимальных вариантов технологических процессов для заданных организационно-технических условий производства из-за сложности как объекта сборки, так и средств, которые при этом применяются. Одним из путей преодоления этих проблем является имитационное трехмерное моделирование производственной среды. ключевые слова: сборка, моделирование, технологическая операция, сборщик, семантическая сеть.

Abrasive wear is one of the prime and mostly costly causes of secondary failure in the design and operation of mechanical machines and equipment. Wear limits must be known and measured to assure quality and durability of products by an experimental process to determine an optimum material composition. The development of wear monitoring systems for industrial processes is well recognised in the industry due to the continued demand for improved product quality and productivity. In this paper, a novel method of wear rate identification, based on a Support Vector Machine (SVM) is proposed. SVM is used to relate the wear rate and technological parameters of the wear resistant drip moulding. The SVM model for determining the wear rate of white iron casting with a low chromium content, was trained and tested by using the existing exploitation data from the Bor Flotation Plant, Serbia. The simulated results of wear prediction show that the accuracy rate of the SVM is 97%.

La presente investigación se originó con el objetivo de diseñar un \emph{software} con Matlab que permita calcular la velocidad de desgaste abrasivo de engranajes rectos y helicoidales de perfil evolvente. Donde, las generalidades no estudiadas sobre el diseño de engranajes han generado consecuencias negativas en la funcionalidad y fallas catastróficas que han producido paras improvistas de procesos mecánicos, por lo cual entender las causas de los mismos se vuelve fundamental. El cálculo del desgaste abrasivo de los pares tribológicos en maquinaria pesada dependerá del grado de trituración o tamaño de las partículas abrasivas, la dureza, el material del engrane base, el régimen de lubricación y las condiciones geométricas que determinen la naturaleza del contacto tribológico, así como el tiempo y velocidad de uso de la maquinaria pesada. Inicialmente, se establece el entorno teórico que compone el estudio basado en los principales componentes como engranajes, lubricación, el acero,...

The optimization of wear rate of the nanocomposites with A356 aluminium alloy matrix, reinforced with silicon carbide nanoparticles, was performed through the analysis of the following influences: wt% of the reinforcement, normal load and sliding speed. The nanocomposites were produced by the compocasting process with mechanical alloying preprocessing (ball milling). Three different amounts of SiC nanoparticles, with the same average size of 50 nm, were used as reinforcement, i.e. 0.2, 0.3 and 0.5 wt%. Tribological tests were performed on block-on-disc tribometer (line contact) under lubricated sliding conditions, at two sliding speeds (0.25 and 1 m/s), two normal loads (40 and 100 N) and at sliding distance of 1000 m. Analysis of variance (ANOVA) was applied to determine the influence of different parameters on wear value of tested nanocomposites. It was noticed from ANOVA analysis that normal load, with 33.39%, is the most significant factor affecting the wear rate of nanocomposites. The amount of reinforcement, with 28.90%, also has a significant influence on the wear rate, while the influence of sliding speed, with 23.82%, is smaller. It was found that the prediction of wear rate, by using regression model and Taguchi analysis, were close to the experimental values.

The Al-Si alloy with near eutectic composition has been conventionally used as a piston material for automobile applications. It is required to possess high abrasive wear resistance for enhanced life of the engine. The alloy is known to have fairly good wear resistance due to increased percentage of silicon present in fine form. In the present investigation, Al-SiC particulate composites have been studied for their wear resistance against emery paper (400 grit SiC particles) counterface and a comparison has been made with existing piston alloy i.e. Al-Si alloy. The Al-SiC composites have been prepared using Liquid Metallurgy technique employing 2124 Alalloy as the base material with 10 and 20 % SiC particulates by weight. The abrasive wear study has been conducted on a Pin on Disc machine. The wear rate in terms of weight loss per unit sliding distance as well as the volumetric wear rate have been obtained for the Al-SiC composites. The characteristics of worn surface were investigated using SEM. The composites are found to possess very high wear resistance as compared to Al-Si piston alloy. The results have been discussed and important conclusions are outlined.

The Al-Si alloy with near eutectic composition has been conventionally used as a piston material for automobile applications. It is required to possess high abrasive wear resistance for enhanced life of the engine. The alloy is known to have fairly good wear resistance due to increased percentage of silicon present in fine form. In the present investigation, Al-SiC particulate composites have been studied for their wear resistance against emery paper (400 grit SiC particles) counterface and a comparison has been made with existing piston alloy i.e. Al-Si alloy. The Al-SiC composites have been prepared using Liquid Metallurgy technique employing 2124 Alalloy as the base material with 10 and 20 % SiC particulates by weight. The abrasive wear study has been conducted on a Pin on Disc machine. The wear rate in terms of weight loss per unit sliding distance as well as the volumetric wear rate have been obtained for the Al-SiC composites. The characteristics of worn surface were investigated using SEM. The composites are found to possess very high wear resistance as compared to Al-Si piston alloy. The results have been discussed and important conclusions are outlined.

The optimization of wear rate of the nanocomposites with A356 aluminium alloy matrix, reinforced with silicon carbide nanoparticles, was performed through the analysis of the following influences: wt% of the reinforcement, normal load and sliding speed. The nanocomposites were produced by the compocasting process with mechanical alloying preprocessing (ball milling). Three different amounts of SiC nanoparticles, with the same average size of 50 nm, were used as reinforcement, i.e. 0.2, 0.3 and 0.5 wt%. Tribological tests were performed on block-on-disc tribometer (line contact) under lubricated sliding conditions, at two sliding speeds (0.25 and 1 m/s), two normal loads (40 and 100 N) and at sliding distance of 1000 m. Analysis of variance (ANOVA) was applied to determine the influence of different parameters on wear value of tested nanocomposites. It was noticed from ANOVA analysis that normal load, with 33.39%, is the most significant factor affecting the wear rate of nanocomposites. The amount of reinforcement, with 28.90%, also has a significant influence on the wear rate, while the influence of sliding speed, with 23.82%, is smaller. It was found that the prediction of wear rate, by using regression model and Taguchi analysis, were close to the experimental values.

The working hard conducts that some material suffer from lead us to protect it from corrosion and give long life. When we select protective system we shall take three points, the work place, base structure and the protective system it self. In this study, we test two types of diffusion coated by cementation (Single Aluminized Coating, Thermal Barrier Coating) at (1000 0 C) with (2,4,6 h). The up take of aluminum and coating thickness obeys the parabola rule so that the coating process obeys diffusion process and the weight gain rate increase with the temperature increased. The other objective of this study was to see the degradation behavior of the systems during thermal cycling (three hour cycles in enhanced hotsalt solution). The single aluminized has good protects while the uncoated sample failed after five cycles. The thermal barrier coating has an excellent protection during the test time because of the good adhesion of Al 2 O 3 layer.

Wear resistance is one of the important technological properties of magnesium alloys that may limit their practical applications, though limited information is available in the literature. In this study, wear behavior of ascast and hot rolled AZ31B magnesium alloy on dry-sliding conditions was investigated using a pin-on disc method. Wear rate was measured at a fixed sliding distance of 1500 m and at different sliding velocities of 0.25, 0.50, 1.00 and 2.00 m/s, as well as different applied loads of 10, 20, 40 and 80 N. Surface morphology of worn surface of the alloy was analyzed using a SEM/EDS. Hot rolled alloy exhibited a better wear resistance than the as-cast alloy due to a finer microstructure and higher hardness. Results showed that ultra-severe plastic deformation was found to be the main wear mechanism at the highest applied load and sliding velocity for the alloy at both metallurgical conditions according to wear maps.

Tribological properties of engineering components are a key issue due to their effect on the operational performance factors such as wear, surface characteristics, service life and in situ behavior. Thus, for better component quality, process parameters have major importance, especially for metal matrix composites (MMCs), which are a special class of materials used in a wide range of engineering applications including but not limited to structural, automotive and aeronautics. This paper deals with the tribological behavior of Cu-B-CrC composites (Cu-main matrix, B-CrC-reinforcement by 0, 2.5, 5 and 7.5 wt.%). The tribological characteristics investigated in this study are the coefficient of friction, wear rate and weight loss. For this purpose, four levels of sliding distance (1000, 1500, 2000 and 2500 m) and four levels of applied load (10, 15, 20 and 25 N) were used. In addition, two levels of sliding velocity (1 and 1.5 m/s), two levels of sintering time (1 and 2 h) and two sinte...

P OLYPROPYLENE/ nano-copper composites have been prepared with 0.5, 1, 1.5 and 2.5 wt.% nano-copper particles by mixing the nano-copper physically with the polypropylene granules then extruded by a twin screw extruder. A comprehensive study on these composites was conducted by measuring the material relative permittivity, electrical conductivity, thermal properties and tensile strength. The results showed a significant enhancement of the composite behavior up to 1.5 wt.% nano-particles addition. The increase of the nanoparticles up to 1.5 wt.% Cu decreases the relative permittivity and slightly increases the electrical conductivity. Finally, the fabricated composites with different nano-copper contents have large findings within different applications especially in electronics, packaging, and environmental issues.

Diamond-like carbon (DLC) films are suitable applicants for cutting tools due to their high hardness, low friction coefficient and wear rate. Doping metals in DLC films have been improved its tribological properties. In this study, titanium and tantalum doped hydrogenated DLC films were deposited by closed-field unbalanced magnetron sputtering system onto M2 high speed steels in Ar/N 2 /C 2 H 2 atmosphere. The friction and wear properties of Ti:Ta-DLC film were investigated under different tribo-test conditions including in atmospheric pressure, distilled water, commercial oil and Ar atmosphere. The coated specimens were characterized by SEM and X-ray diffraction techniques. The bonding state of CC (sp 3) and C=C (sp 2) were obtained with XPS. The tribological properties of Ti:Ta-DLC were investigated with pin-ondisc wear test. Hardness measurements performed by micro-indentation. Our results suggest that Ti:Ta-doped DLC film shows very dense columnar microstructure, high hardness (38.2 GPa) with low CoF (μ≈0.02) and high wear resistance (0.5E-6 mm 3 /Nm).

Nano-structured coatings can be used to reduce surface roughness, improved hardness and to protect against wear of the components. In this, research article the AISI 440C Stainless Steel is considered for coating Nano-particles and different materials such as Nickel, Titanium dioxide and Aluminium dioxide. The deposition of Nano-particles on piston ring by physical vapor deposition (PVD) process namely Electron Beam physical vapor deposition (EB-PVD). The surface morphology and crystallographic texture of the coatings were analyzed by means of the non-contact surface measurement device and XRD. Mechanical properties of the coated substrate namely hardness, friction and wear resistance are evaluated using micro-Vickers hardness and pin on disc test equipment. A major part of the power produced by the engine lost in overcoming friction between the reciprocating parts. Heat lost to the surroundings is a major factor reducing engine efficiency. Nano-coating can be used to reduce the sur...

On inception, 3D printed parts were typically used at prototyping stage to give the end user/customer a real world concept of how the part may appear when traditional manufacturing techniques were employed for final part fabrication. In this context, mechanical properties such as load bearing capacity or wear rate were not typically of primary concern. This paper investigates, given the advances in 3D printing technology, the potential for using 3D printed parts for high throughput embossing tools. The key mechanical properties for embossing tools are compression and wear rate. To this end, commercially available engineering grade photopolymer materials were characterised in terms of compression and wear using ASTM D695 and ASTM G99 standards respectively. Parts were fabricated via the Polyjet ink-jetting 3D printing technique using the commercially available Connex 260 from Stratasys. Given the nature of the fabrication technique, differences in compressive strength of the material based on orientation of build were also investigated.

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The surface coating is one of the novel approaches to enhance the performance and durability of the mechanical components by decreasing the wear and friction among two interacting bodies. In this study, tribological and mechanical properties of titanium nitride (TiN) coatings were investigated on the AISI 52100 bearing steel deposited by low-temperature physical vapor deposition system. Surface morphology and elemental composition of the TiN coating were analyzed by scanning electron microscope and energy-dispersive X-ray spectrum, respectively. Substrate surface roughness and coating thickness of TiN were varied for correlative analysis among adhesion, mechanical, and tribological properties. Scratch and tribo tests were performed for evaluating the adhesion and tribological properties, respectively. Samples having the substrate surface roughness (0.2 6 0.05 mm) and the coating thickness of more than 2.83 mm presented relatively better adhesion, wear resistance, and lower coefficient of friction of the TiN coating.

Notwithstanding the success of nanolayered coatings in the reduction of wear at nano-/microscales, the improvement of the wear resistance at the macroscale remains an issue. Moreover, the effects of nanointerfaces in nanolayered coatings on their macrotribological properties are not understood well. This paper reports on the engineering of nanointerfaces in diamond-like C/Cr nanolayered coatings to tailor their characteristics including the degree of intermixing, defects, and Cr growth mode. The result was the fabrication of a coating with subnanometer-thick periodic albeit discrete Cr interlayers. This was achieved using our patented deposition technique. This coating contained less interfacial defects compared to classic nanolayered coatings with continuous nanolayers and presented record-breaking wear rates at the macroscale. Finite Element analysis was performed and micropatterning strategy was used to reduce the wear rate further. Last, we report on discovery of a dimensionless parameter that can be used to predict the wear resistance of carbon-based nanolayered coatings.

A series of experimental tests were carried out to observe the deposition rates on different stainless steel substrates of different surface roughnesses under different operating conditions using a hot filament thermal chemical vapour deposition (CVD) reactor. The test parameters include gas flow rate of methane, temperature of substrate and activation heaters, distance between activation heater and substrate, pressure and duration. There are significant effects of these parameters on deposition rate of different stainless steel materials. It was found that deposition rates strongly depend on different surface roughnesses of the stainless steel substrates under different tested conditions within the observed range. Tribological properties, especially friction and wear of these stainless steel materials sliding against SS 314 under different normal loads and sliding velocities are also investigated before and after deposition. The obtained results reveal that the values of friction and wear are lower after deposition than that of before deposition.

This study assessed the influences of fluorine introduced into DLC films on the structural and mechanical properties of the sample. In addition, the effects of the fluorine incorporation on the compressive stress in DLC films were investigated. For this purpose, fluorinated diamond-like carbon (F-DLC) films were deposited on cobalt-chromium-molybdenum substrates using radio-frequency plasma-enhanced chemical vapor. The coatings were examined by Raman scattering (RS), Attenuated total reflectance Fourier transform infrared spectroscopic analysis (ATR-FTIR), and a combination of elastic recoil detection analysis and Rutherford backscattering (ERDA-RBS). Nano-indentation tests were performed to measure hardness. Also, the residual stress of the films was calculated by the Stony equation. The ATR-FTIR analysis revealed that F was present in the amorphous matrix mainly as C-F and C-F 2 groups. Based on Raman spectroscopy results, it was determined that F made the DLC films more graphitic. Additionally, it was shown that adding F into the DLC coating resulted in weaker mechanical properties and the F-DLC coating exhibited lower stress than DLC films. These effects were attributed to the replacement of strong C = C by feebler C-F bonds in the F-DLC films. F-doping decreased the hardness of the DLC from 11.5 to 8.8 GPa. In addition, with F addition, the compressive stress of the DLC sample decreased from 1 to 0.7 GPa.

La presente investigación se originó con el objetivo de diseñar un \emph{software} con Matlab que permita calcular la velocidad de desgaste abrasivo de engranajes rectos y helicoidales de perfil evolvente. Donde, las generalidades no estudiadas sobre el diseño de engranajes han generado consecuencias negativas en la funcionalidad y fallas catastróficas que han producido paras improvistas de procesos mecánicos, por lo cual entender las causas de los mismos se vuelve fundamental. El cálculo del desgaste abrasivo de los pares tribológicos en maquinaria pesada dependerá del grado de trituración o tamaño de las partículas abrasivas, la dureza, el material del engrane base, el régimen de lubricación y las condiciones geométricas que determinen la naturaleza del contacto tribológico, así como el tiempo y velocidad de uso de la maquinaria pesada. Inicialmente, se establece el entorno teórico que compone el estudio basado en los principales componentes como engranajes, lubricación, el acero,...

Cold forging processes are of great importance in production engineering due to the high material utilization and the associated energy and resource efficiency. Liquid and solid lubricants are used in order to perform cold forging processes successfully. These lubricants are often questionable due to ecological, economic, and legislative reasons. For these reasons, dry metal forming exhibits an increased research potential in surface engineering. The absence of lubricants in dry metal forming contributes significantly to the waste reduction in manufacturing processes and to the goal of a lubricant-free factory. Coated metal forming tools may enormously reduce tool and workpiece wear in cold forging or deliver special functions even in the absence of the lubricants. However, the abdication of lubricants goes along with the requirement that the dry tribological system has to withstand the increased tribological loads. In this contribution a (Cr,Al)N PVD tool coating and an in situ plasma etching process are developed to ensure a sufficient adhesion strength on the tool material X155CrMoV12 (DIN 1.2379, AISI D2). Such a plasma treatment of the substrate is necessary for the coating to withstand increased tribological tool loads in dry metal forming.

Zinc Plating (Electroplating) is one of the most used coating method in the industries. Zinc plating is widely applied to almost all the metal parts manufactured in the industry. Industries faces the problem of metal part rusting and corroding after a specific time from installation of that part, which eventually leads to replacing the part or its maintenance either of this will cause the reduction in production or will cost for the metal part replacement. In this project work I have come with a solution for the problem of rusting and corrosion by using Taguchi Optimization, OVAT followed by L-9 Orthogonal Array and ANOVA. When the part is ready it must be zinc plated or electroplated at a specific thickness which we have studied in research work by testing the various thickness of 316L SS zinc plated specimens which give us a summary of what thickness will be the best to minimize the problem of rusting, so that once a metal part is installed in a industry it will not be frequently required to be maintained or replaced which will reduce the cost to industry for the maintenance and replacement and will not hinder the production line of a specific industry.

A new type of coating is developed, which is a mechanical mixture of two different powders, namely, Ni-Cr-B-Si-Fe (PG 19N 01) and WC-Co (hard alloy). After the coatings from this mixture are deposited, their surface layer is fused with a plasma jet using an eroding electrode made of W. The additional treatment of the coatings with the plasma jet yields new phases and causes the redistribution of elements in the layer 45-60 μm deep; the percentage ratio of the phases WC, α CoCr, Co, and Ni, as well as Cr 3 Ni 2 + γ (Fe, Ni) appear ing during coating deposition also changes. The redistribution of elements occurs in the upper coating layer owing to fusion with the plasma jet. These processes yield variations in the physical-mechanical properties of the coatings, such as the hardness and elastic modulus; the coating wear rate decreases severalfold. It is found that with increasing load applied to the Berkovich pyramid the elastic modulus of the coating drops from 240 (at an indentation depth of 50 nm) to 175 GPa (at 150 nm). The elastic modulus of the substrate rises from 25 to 42 GPa. The coating hardness calculated from the loading-unloading curves is 15.3 to 10.6 GPa under increased load applied to the indentor. Specimens covered with the coating fused with the plasma jet in three passes demonstrate the lowest material wear.

Under the umbrella of Rapid-X (Udroiu & Ivan, 2008) there are some specific terms such as: Rapid Product Development (RPD), Rapid Technology, Rapid Nanotechnology, Rapid Prototyping (RP), Rapid Tooling (RT) and Rapid Manufacturing (RM). Additive manufacturing (AM) is an important component of the rapid product development process. Additive manufacturing technologies (AMT) represents a group of technologies used for building physical models, prototypes, tooling components and finished parts, all from three dimensional (3D) computer aided design (CAD) data or data from 3D scanning system. AMT involves automated fabrication of physically complex shapes directly from 3D CAD, using a layer-by-layer deposition principle. Based on AM principles, RP produces parts with limited functionality (prototypes and test parts), RM built end products and RT manufacture tools, jigs or moulds. Today's additive technologies offer advantages in many applications compared to classical subtractive fabrication methods like as milling, turning etc. Thus, parts can be formed with any geometric complexity or intricacy without the need for elaborate machine setup or final assembly. Also, AMT can lower manufacturing time of new products with 8-10 times in comparison with the conventional technologies and it reduces the costs of the products. There are a lot of additive manufacturing technologies in the world. The most popular AM technologies used worldwide are stereolithography (SL), selective laser sintering (SLS), Three dimensional printing (3DP), laminated object manufacturing (LOM), fused deposition modelling (FDM), polymer jetting (PolyJet), selective laser melting (SLM), direct metal laser sintering (DMLS), direct metal deposition (DMD), electron beam melting (EBM) and laser engineered net shaping (LENS). This chapter is focused on 3DP technologies that represent 44.3% of all additive systems installed worldwide at the end of 2005 (Wohler, 2006). The 3DP technologies (inkjet printing) can be classifying in the following main categories (Dimitrov et al., 2004): continuous printing (fused deposition modelling), drop on drop printing (polymer jetting) and drop on powder printing (3D Printing by ZCorp). The research was done under the umbrella of interdisciplinary platform PLADETINO (Platform for Innovative Technological Development), (Ivan, 2009). PLADETINO was aiming at create an interdisciplinary development and research centre regarding the innovation and the integration of the technologies of designing and manufacturing the products considering the new concepts (Rapid Manufacturing/ Prototyping, Reverse www.intechopen.com Rapid Prototyping Technology-Principles and Functional Requirements 2 Engineering, Concurrent Engineering, Virtual Engineering, Knowledge Engineering, Quality Engineering), and also the technologic management by on-line and long distance processing of data. PLADETINO is integrated in a research and multidisciplinary training unitary structure of Transilvania University of Brasov (Romania) and it is the main support of the research department D05 named Advanced Manufacturing Technologies and Systems. This research platform has developed new laboratories that allow professional education development and scientific research activities. Under the umbrella of Integrated Technologies was created a lot of laboratories, one of this being the Industrial Innovative Technologies laboratory. This platform was capable of allowing the development of new scientific research contracts with industrial companies. All of these contracts were developed within the Industrial Innovative Technologies laboratory and all of these are focused on the additive manufacturing technologies. In this chapter are presented some results obtained within the PLADETINO interdisciplinary platform. In the field of AM optimisation there are some major research directions (Berce et al., 2000; Canellidis et al., 2006; Ancau & Caizar, 2010): slicing algorithms, process parameters, surface quality, mechanical characteristics of the RP/ RM material, modelling and simulation, part orientation, packing many parts, optimal selection of AM technology etc. Because postprocessing require additional time and cost, the optimisation of AM process is an important factor. This chapter is organised in the following main paragraphs: The software input data for 3D Printing systems, 3D printing process chain, optimization of 3D printing performance within the pre-processing stage, products built by Additive manufacturing at Transilvania University of Brasov, surface quality of additive manufacturing products and conclusions.

The global thermal spray coatings market was valued at USD 10.1 billion in 2019 and is expected to grow at a compound annual growth rate of 3.9% from 2020 to 2027. Carbide coatings form an essential segment of this market and provide cost-effective and environmental friendly tribological solutions for applications in aerospace, industrial gas turbine, automotive, printing, oil and gas, steel, and pulp and paper industries. Almost 23% of the world’s total energy consumption originates from tribological contacts. Thermal spray WC-Co coatings provide excellent wear resistance for industrial applications in sliding and rolling contacts. Some of these applications in abrasive, sliding and erosive conditions include sink rolls in zinc pots, conveyor screws, pump housings, impeller shafts, aircraft flap tracks, cam followers and expansion joints. These coatings are considered as a replacement of the hazardous chrome plating for tribological applications. The microstructure of thermal spray...

Magnesium alloy AZ31B is an important lightweight, high specific strength material for new generations of energy-effective vehicles. Presently, a critical challenge that the vehicle production is facing is how to prevent the material from surface oxidation at elevated temperatures. This paper aims to investigate the effect of thermal oxidation and chemical compositions of oxides on the wear of AZ31B. The tribology experiments were conducted by a contact pair of pin-on-disc under elevated temperatures. The disc and pin were made by AZ31B and the production tooling steel 86CrMoV7, respectively. The composition and morphology of the disc surface were examined by the scanning electron microscope (SEM). It was found that the initial surface oxide film naturally formed prior to testing at room temperature (RT) was thin, compact and protective. However, the film would lose its protection capability when the temperature rose because of the thickened film layer and the emergence of the oxide nodules. At a higher temperature, the oxide nodules grew more quickly. Besides, more oxide nodules emerged, and the film started to crack as the temperature increased, leading to a higher wear rate. The friction coefficient varied at different temperatures due to the change in the dominant wear mechanism of AZ31B. The minimum wear rate was found to occur at 200 °C and the maximum at 400 °C. It was also found that the surface hardness of AZ31B decreased from 75 HV2 at 25 °C to 50 HV2 at 200 °C, and then fluctuated around 50 HV2 at higher temperatures, which further accelerated the wear process.

Experimental studies have been made to determine the oxidation be heavier of several coatings system on commercial mild steel alloy (AISI 1020). The oxidation kinetics of a single stage coating such as Aluminized and Nickel have been under)1000°C(using a thermal cyclic oxidation.The structures were studied using optical microscope to identify a phases. Most coating use to enhance the formation of protective oxid scale, in this research, the results for Nickel coating showed some reduction in resistance of)AISI 1020(alloy and It is found they follow linear rate law, but Aluminized coating using a packcementation technique, exhibited the greatest resistance to oxidation, followed parabolic law (protective oxidation behavior). because it has a good ductility and its capability to form a protective oxid Layer)Al2O3(, such Alumina scale is known as thermally and electrically insulator and characterized with slow gowning rate.

Surface metal matrix composites have been developed to enhance properties such as erosion, wear and corrosion of alloys. In this study, ~5 µm or ~75 µm SiC particulates were preplaced on a microalloyed steel. Single track surface zones were melted by a tungsten inert gas torch, and the effect of two heat inputs, 420Jmm-1 and 840 Jmm-1 ,compared. The results showed that the samples melted using 420Jmm-1 were crack-free. Pin-on-disk wear testing under dry sliding conditions were conducted. The effects of load and sliding velocity were used to characterise the performance of the crack-free samples. Microstructural and X-ray diffraction studies of the surface showed that the SiC had dissolved, and that martensite, was the main phase influencing the hardness.

Magnetron sputtered non-hydrogenated diamond-like carbon (DLC) coatings were tested against Al, Cu and Ti pins using a vacuum pin-on-disc tribometer. The objective was to compare Al, Ti, and Cu transfer to DLC coatings in air (29% RH) and an inert atmosphere (argon). In argon, a significant amount of adhesion and material transfer occurred from the Al and Ti pins to the DLC coating surfaces inflicting severe damage to the coatings. Wear and material transfer of the DLC coating against Cu were negligible in argon. Compared to tests in argon, the tribological performance of the DLC coatings against Al and Ti improved significantly in ambient air. In contrast, the wear rate of the DLC coatings against Cu was much higher in ambient air compared to that in argon.

In the present study, the Al2219, Al2219/ B 4 C & Al2219/B 4 C/MoS 2 hybrid composites are investigated under dry sliding wear test as for ASTM G 99-95 standard. Al 2219 base matrix reinforced with B 4 C & mixture of B 4 C and MoS 2 are fabricated using stir casting technique. By using pin on disc apparatus the test was conducted by taking parameters like sliding distance, sliding velocity and loads. The result reveals that the addition of B 4 C slightly reduces wear rate of composites, further B 4 C and MoS 2 reinforcement decreases the wear rate of the hybrid composites and increases the wear resistance of the composites. The wear rate decreases with increasing the % of MoS 2. At a lower sliding velocity the wear rate decreases and as the sliding velocity increases the wear rate increases. As the sliding distances and load increases the wear rate drastically increases.

In Total Joint Replacement (TJR), ceramic surfaces offer a major benefit of drastically reduced wear rates and excellent long-term biocompatibility with the bone tissue. Among the available ceramic materials for load bearing bio-implant applications, silicon carbide is superior for its better biocompatibility, which can increase the longevity of prosthetic joints. The major cause of revision surgery and implant failure is Osteolysis (aseptic loosening of the prosthetic joint). The product of bearing wear, microscopic particulate debris in the joint space leads to implant loosening. Prosthetic joint mainly consists of acetabular cup, acetabular lining and femoral head. The best material for manufacturing acetabular cup is nickel

The friction coefficient and wear behavior of 316L austenitic stainless steel and 316L steel + 8vol% TiB 2 + 1vol% B composites were investigated within a temperature range of 20°C to 800°C. The materials were prepared by the powder metallurgy method. The wear behavior was studied by using a ball-on-disc wear tester at room temperature. The surface before and after wear tests was analyzed using scanning electron microscopy (SEM). The results indicated that the friction coefficient and wear resistance of stel-8TiB 2-1B composites depend on the wear test conditions.

Electrical discharge machining (EDM) is a widely used process in the mould / die and aerospace industries. It is a process for shaping hard metals and forming deep and complex-shaped holes by arc erosion in all kinds of electro-conductive materials. The objective of this research is to study the influence of operating parameters of EDM of tungsten carbide on the machining characteristics. The effectiveness of EDM process with tungsten carbide is evaluated in terms of material removal rate, the relative wear ratio and the surface finish quality of the workpiece produced. It is observed that copper tungsten is most suitable for use as the tool electrode in EDM of tungsten carbide.

Mono composite (Al2219/6%B4C) and hybrid composites (Al2219/6%B4C/3%Gr) were developed by stir casting process. Dry sliding wear behavior of mono and hybrid composites were tested and analyzed by statistical techniques. In the present investigation an attempt has been made to study the influence of process parameter like, applied load, sliding speed and time on the wear behavior of both the composites. The obtained results indicates the hybrid composite showed better wear resistance under the parameters tested, compared to mono composite. Based on results, sliding speed and applied load were found to have more significant effect on the sliding wear of the specimens.

This paper presents the tribological properties of silicon and oxygen incorporated diamond-like carbon coatings tested in simulated body fluid and bovine serum albumin environments. The tests were performed using a ball-on-disc tribometer with an AISI316L steel counterbody. The wear tracks and wear scars were analyzed using optical microscopy and a nanoindenter. The interaction between the coating and the working environment was analyzed by Fourier transform infrared spectroscopy, whereas changes in the chemical structure before and after the tribological tests were compared with the use of Raman spectroscopy. Our study showed that the tribological parameters are governed by the presence of oxygen rather than the changing concentration of silicon. Both of the spectroscopy results confirm this statement, indicating that coatings with low concentrations of silicon and oxygen appear to be better candidates for biological applications in terms of wear resistance.

Electrical discharge machining (EDM) is a widely used process in the mould / die and aerospace industries. It is a process for shaping hard metals and forming deep and complex-shaped holes by arc erosion in all kinds of electro-conductive materials. The objective of this research is to study the influence of operating parameters of EDM of tungsten carbide on the machining characteristics. The effectiveness of EDM process with tungsten carbide is evaluated in terms of material removal rate, the relative wear ratio and the surface finish quality of the workpiece produced. It is observed that copper tungsten is most suitable for use as the tool electrode in EDM of tungsten carbide.

In the present work, Diamond-Like Carbon (DLC) films were deposited by the Microwave Electron Cyclotron Resonance/Plasma-Assisted Chemical Vapour Deposition process on 41Cr-Al-Mo7 nitrided steel using a benzene-argon gas mixture. The quality of DLC films grown on nitrided steel using different deposit conditions such as benzene flow rate, temperature and time was investigated. Microstructural analysis by Raman spectroscopy showed main G-band peaks are localised between 1564 and 1595 cm −1 , while the D-band peaks are centred at 1297 cm −1. Fourier Transform Infrared Spectroscopy showed the peaks attributed to C-H bending and stretching vibration modes are in the range of 2600-3100 cm −1. The microstructure, surface morphology and mechanical properties of the films were examined by X-ray diffraction, atomic force microscopy and use of a Vickers indenter (Zwick). The deposition parameters of the coatings have been studied and optimised to improve mechanical properties. The observed increase in adhesion is related to the formation of (Fe,Cr) 3 C, Cr 3 C 2 and Cr 23 C 6 interlayer phases. DLC films showed a better wear resistance, higher hardness and low friction coefficient compared to nitrided layers tested for comparison.

Currently, the application of diamond-like carbon (DLC) coatings for automotive components is becoming a favorable strategy to cope with the new challenges faced by the automotive industry. DLC coatings can effectively lower the coefficient of friction (CoF) and wear rate of engine components, consequently improving the fuel efficiency and durability of these components. Commercially available fully formulated lubricating oils enhance the lubrication of ferrous materials. Therefore, the interaction between nonferrous coatings (e.g., DLC) and commercial lubricating oil must be investigated. A ball-on-plate tribotester was used to run the experiments using stainless steel plates coated with amorphous hydrogenated DLC (a-C:H) and tetrahedral DLC (ta-C) sliding against a 440C stainless steel ball. Wear track was investigated by scanning electron microscopy and atomic force microscopy. Energy dispersive spectroscopy and X-ray photoelectron spectroscopy were used to analyze the tribofilms inside the wear track. Raman analysis was performed to investigate the structural change of the coatings. At high temperatures, the CoF decreases but the wear rate increases in the a-C:H and ta-C DLC-coated plates. CoF and wear rate (coated layer and counter surface) are mostly influenced by coating graphitization. Tribochemical films, such as polyphosphate glass, are formed in ta-C and act as protective layers. Therefore, the wear rate of ta-C DLC is lower than that of a-C:H DLC.

Tetrahedral amorphous carbon based coatings generally exhibit a low coefficient of friction (COF) while sliding against steel and aluminum, but their tribological properties are sensitive to the test environment. In this study, tribological behaviour of tetrahedral amorphous carbon (ta-C) and fluorinated ta-C (ta-C-F) coatings were investigated under different atmospheres including ambient air (53% relative humidity, RH) and dry N 2 (3% RH) against a steel counterface. The ta-C showed a period of low COF of 0.27 in ambient air and a C transfer layer was formed on the counterface, but the COF increased with sliding duration to~0.4 due to transfer of Fe 2 O 3 debris to ta-C surface. A high COF of~0.60 with high fluctuations occurred in dry N 2 as no carbon transfer layers were formed on the counterface. The ta-C-F coating exhibited a steady-state behaviour with low COF (μ s) values under both ambient (μ s = 0.25) and dry N 2 (μ s = 0.23) atmospheres. Formation of an F containing carbonaceous transfer layer on the counterface provided low COF for ta-C-F.

Magnetron sputtered non-hydrogenated diamond-like carbon (DLC) coatings were tested against Al, Cu and Ti pins using a vacuum pin-on-disc tribometer. The objective was to compare Al, Ti, and Cu transfer to DLC coatings in air (29% RH) and an inert atmosphere (argon). In argon, a significant amount of adhesion and material transfer occurred from the Al and Ti pins to the DLC coating surfaces inflicting severe damage to the coatings. Wear and material transfer of the DLC coating against Cu were negligible in argon. Compared to tests in argon, the tribological performance of the DLC coatings against Al and Ti improved significantly in ambient air. In contrast, the wear rate of the DLC coatings against Cu was much higher in ambient air compared to that in argon.

Magnetron sputtered non-hydrogenated diamond-like carbon (DLC) coatings were tested against Al, Cu and Ti pins using a vacuum pin-ondisc tribometer. The objective was to investigate the effect of counterface material on the tribological behaviour of the non-hydrogenated DLC coatings in air (29% RH) and an inert atmosphere (argon). In argon, a significant amount of adhesion and material transfer occurred from the Al and Ti pins to the DLC coating surfaces, increasing the coefficient of friction (COF) and inflicting severe damage to the coatings. Wear and material transfer between DLC coating and Cu were negligible in argon. Compared to the tests in argon, the tribological performance of DLC coatings against Al and Ti significantly improved in ambient air. In contrast, the wear rate of DLC coatings against Cu was higher in ambient air and its COF was similar under both conditions. In ambient air, carbonaceous layers were generated on Al and Ti but not on Cu. The adsorption of water vapour on the DLC coating surface and the formation of an easy-to-shear carbonaceous material at the sliding interface reduced the COFs and wear rates of non-hydrogenated DLC coatings in air with humidity.