The AA7075 composites reinforced with 3, 6, and 9 volume fractions (vol.%) of ZrB2 particles have... more The AA7075 composites reinforced with 3, 6, and 9 volume fractions (vol.%) of ZrB2 particles have been successfully fabricated using in situ fabrication method. In this technique, the inorganic salts K2ZrF6 and KBF4 were added to the molten aluminum and retained the melting at 900∘C to form the required vol.% of ZrB2 particles. The aluminum-reinforced metal matrix composites (MMCs) are commonly known as aluminum matrix composites (AMCs). This work carries the effects of various wire electrical discharge machining (WEDM) input process parameters like pulse-on-time ([Formula: see text]), pulse-off-time ([Formula: see text]), wire feed rate (WFR), and gap voltage (GV) on the output responses such as material removal rate (MRR), surface roughness (SR), and Kerf-width ([Formula: see text]) of the fabricated AA7075/(3, 6, and 9) vol.% ZrB2 in situ AMCs. Based on Taguchi’s L9 orthogonal array method, the design of experiments (DoE) was used to carry out the operations on the fabricated AMC...
Many researchers have attempted to join Aluminum Matrix Composites (AMCs) using traditional fusio... more Many researchers have attempted to join Aluminum Matrix Composites (AMCs) using traditional fusion welding processes resulting in the formation of porosity, segregation, coarse microstructure, brittle intermetallic compounds and corrosion of ceramic particles. Friction Stir Processing (FSP) is the latest solid-state technique to achieve the homogeneous dispersion of reinforcement particles in the friction stir processed zone of AMCs [M. Shamanian, E. Bahrami, H. Edris and M. R. Nasresfahani, Surf. Rev. Lett. 25 (2018) 1950010]. The most widely used reinforcing material since the inception of FSP is inorganic (metallic) powders such as silicon carbide, titanium alloy, graphene, iron, stainless steel, nitrides and oxides, and fewer works have been reported on organic powders (i.e. bioprocessing using agro-waste powders) such as fly ash, palm kernel shell ash, coconut shell ash and rice husk ash [O. M. Ikumapayi, E. T. Akinlabi, S. K. Pal and J. D. Majumdar, Procedia Manuf. 35 (2019) 9...
The moving parts of any mechanism and machine parts are always subjected to a significant wear du... more The moving parts of any mechanism and machine parts are always subjected to a significant wear due to the development of friction. It is utmost important aspect to address the wear problems in present environment. But the complexity goes on increasing to replace the worn out parts if they are very precision. Technology advancement in surface engineering ensures the minimum surface wear with the introduction of polycrystalline nano nickel coating. In this study, tribological behavior of the nano nickel coating developed through pulsed electro deposition technique has been investigated. The nano structured coated specimen were admitted for pin and disc method of wear testing. The nature of wear has been examined over the surface of the specimen through Atomic Force Microscope (AFM) in order to validate the prior results. The results yielded from pin and disc and AFM registered the negligible deviations.
AA7075/ZrB2 Aluminium Matrix Composites (AMCs) were successfully fabricated using the in-situ fab... more AA7075/ZrB2 Aluminium Matrix Composites (AMCs) were successfully fabricated using the in-situ fabrication method. The inorganic salts (K2ZrF6 and KBF4) reacted with molten aluminium at 900 °C and formed ZrB2 inside the melt itself. AMC castings were obtained in different volume fractions (0, 3, 6 and 9%) of ZrB2. The dry sliding wear behaviour of AA7075/ZrB2 in-situ AMCs was evaluated using pin-on-disc wear apparatus. The wear experiments were executed as per Design of Experiments (DoE). The effect of wear parameters such as sliding velocity, sliding distance, content of ZrB2 and normal load on wear rate was analyzed. It was evident that ZrB2 particles influenced the wear resistance of fabricated AMCs. The worn surfaces revealed an increase in number of cracks when sliding velocity, sliding distance and normal load increased. The worn surface of AA7075/ZrB2 AMCs was observed using Field Emission Scanning Electron Microscopy (FESEM). The wear rate was decreased and the corresponding wear resistance was increased when the volume fraction of ZrB2 particles increased in the fabricated AMCs.
Oesophageal atresia (EA) and tracheoesophageal fistula (TEF) is one of the congenital anomaly occ... more Oesophageal atresia (EA) and tracheoesophageal fistula (TEF) is one of the congenital anomaly occurring in the newborns with the incidence of 1 in 2500 births seen worldwide. A retrospective review of newborns admitted to Hospital Sultanah Bahiyah (HSB) from 1st January 2000 to 31st December 2009 was done. The objective was to look at the influence of birth weight, time of surgical intervention, presence of other congenital anomaly and presence of preoperative pneumonia to the immediate outcome (mortality) of the surgery. There were 47 patients with oesophageal atresia, out of which 26 (55%) were males and 21 (45%) females. The distribution of patients by race were 34 Malays (72%), 9 Chinese (19%) and 4 Indians (9%). The birth weight of the babies range from 0.8 kg to 4.0 kg and there was a significant association with the outcome of the surgery (p< 0.05). Most of the babies (20) were operated within 24 hours of presentation but there was no significant association to the outcome...
UNIT III DIMENSIONAL ANALYSIS 9 Dimension and units: Buckingham's П theorem -Discussion on dimens... more UNIT III DIMENSIONAL ANALYSIS 9 Dimension and units: Buckingham's П theorem -Discussion on dimensionless parameters -Models and similitude -Applications of dimensionless parameters.
The AA7075 composites reinforced with 3, 6, and 9 volume fractions (vol.%) of ZrB2 particles have... more The AA7075 composites reinforced with 3, 6, and 9 volume fractions (vol.%) of ZrB2 particles have been successfully fabricated using in situ fabrication method. In this technique, the inorganic salts K2ZrF6 and KBF4 were added to the molten aluminum and retained the melting at 900∘C to form the required vol.% of ZrB2 particles. The aluminum-reinforced metal matrix composites (MMCs) are commonly known as aluminum matrix composites (AMCs). This work carries the effects of various wire electrical discharge machining (WEDM) input process parameters like pulse-on-time ([Formula: see text]), pulse-off-time ([Formula: see text]), wire feed rate (WFR), and gap voltage (GV) on the output responses such as material removal rate (MRR), surface roughness (SR), and Kerf-width ([Formula: see text]) of the fabricated AA7075/(3, 6, and 9) vol.% ZrB2 in situ AMCs. Based on Taguchi’s L9 orthogonal array method, the design of experiments (DoE) was used to carry out the operations on the fabricated AMC...
Many researchers have attempted to join Aluminum Matrix Composites (AMCs) using traditional fusio... more Many researchers have attempted to join Aluminum Matrix Composites (AMCs) using traditional fusion welding processes resulting in the formation of porosity, segregation, coarse microstructure, brittle intermetallic compounds and corrosion of ceramic particles. Friction Stir Processing (FSP) is the latest solid-state technique to achieve the homogeneous dispersion of reinforcement particles in the friction stir processed zone of AMCs [M. Shamanian, E. Bahrami, H. Edris and M. R. Nasresfahani, Surf. Rev. Lett. 25 (2018) 1950010]. The most widely used reinforcing material since the inception of FSP is inorganic (metallic) powders such as silicon carbide, titanium alloy, graphene, iron, stainless steel, nitrides and oxides, and fewer works have been reported on organic powders (i.e. bioprocessing using agro-waste powders) such as fly ash, palm kernel shell ash, coconut shell ash and rice husk ash [O. M. Ikumapayi, E. T. Akinlabi, S. K. Pal and J. D. Majumdar, Procedia Manuf. 35 (2019) 9...
The moving parts of any mechanism and machine parts are always subjected to a significant wear du... more The moving parts of any mechanism and machine parts are always subjected to a significant wear due to the development of friction. It is utmost important aspect to address the wear problems in present environment. But the complexity goes on increasing to replace the worn out parts if they are very precision. Technology advancement in surface engineering ensures the minimum surface wear with the introduction of polycrystalline nano nickel coating. In this study, tribological behavior of the nano nickel coating developed through pulsed electro deposition technique has been investigated. The nano structured coated specimen were admitted for pin and disc method of wear testing. The nature of wear has been examined over the surface of the specimen through Atomic Force Microscope (AFM) in order to validate the prior results. The results yielded from pin and disc and AFM registered the negligible deviations.
AA7075/ZrB2 Aluminium Matrix Composites (AMCs) were successfully fabricated using the in-situ fab... more AA7075/ZrB2 Aluminium Matrix Composites (AMCs) were successfully fabricated using the in-situ fabrication method. The inorganic salts (K2ZrF6 and KBF4) reacted with molten aluminium at 900 °C and formed ZrB2 inside the melt itself. AMC castings were obtained in different volume fractions (0, 3, 6 and 9%) of ZrB2. The dry sliding wear behaviour of AA7075/ZrB2 in-situ AMCs was evaluated using pin-on-disc wear apparatus. The wear experiments were executed as per Design of Experiments (DoE). The effect of wear parameters such as sliding velocity, sliding distance, content of ZrB2 and normal load on wear rate was analyzed. It was evident that ZrB2 particles influenced the wear resistance of fabricated AMCs. The worn surfaces revealed an increase in number of cracks when sliding velocity, sliding distance and normal load increased. The worn surface of AA7075/ZrB2 AMCs was observed using Field Emission Scanning Electron Microscopy (FESEM). The wear rate was decreased and the corresponding wear resistance was increased when the volume fraction of ZrB2 particles increased in the fabricated AMCs.
Oesophageal atresia (EA) and tracheoesophageal fistula (TEF) is one of the congenital anomaly occ... more Oesophageal atresia (EA) and tracheoesophageal fistula (TEF) is one of the congenital anomaly occurring in the newborns with the incidence of 1 in 2500 births seen worldwide. A retrospective review of newborns admitted to Hospital Sultanah Bahiyah (HSB) from 1st January 2000 to 31st December 2009 was done. The objective was to look at the influence of birth weight, time of surgical intervention, presence of other congenital anomaly and presence of preoperative pneumonia to the immediate outcome (mortality) of the surgery. There were 47 patients with oesophageal atresia, out of which 26 (55%) were males and 21 (45%) females. The distribution of patients by race were 34 Malays (72%), 9 Chinese (19%) and 4 Indians (9%). The birth weight of the babies range from 0.8 kg to 4.0 kg and there was a significant association with the outcome of the surgery (p< 0.05). Most of the babies (20) were operated within 24 hours of presentation but there was no significant association to the outcome...
UNIT III DIMENSIONAL ANALYSIS 9 Dimension and units: Buckingham's П theorem -Discussion on dimens... more UNIT III DIMENSIONAL ANALYSIS 9 Dimension and units: Buckingham's П theorem -Discussion on dimensionless parameters -Models and similitude -Applications of dimensionless parameters.
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