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Item A comparative study on the wear behavior of cast and forge aged A356 alloy with addition of grain refiner and/or modifier(Trans Tech Publications Ltd ttp@transtec.ch, 2014) Mallapur, D.G.; Sondur, D.G.; Udupa, K.R.In the present work, a comparative study on the wear behavior of cast aged and forge aged A356 alloy has been investigated without and with the addition of grain refiner and modifier, under dry sliding conditions using a pin-on-disc wear testing machine. The comparison study reveals that tribological properties of A356 materials are highly influenced by T6 heat treatment process. It is found in the present study that, cast aged A356 materials possess higher wear resistance as compared to forge aged materials. Apart from this, the study also reveals that cast aged material is associated with lower frictional forces and coefficient of friction as compared to the forge aged category. It is further observed in the present investigation that abrasive wear mechanism is operative in both the categories of the materials when tested with lower load for lower sliding speed and lower distance of run. At higher values of external parameters the adhesive wear mechanism dominates the wear process. Lower values of wear properties recorded by the forge aged material are an unexpected result in the present studies. It is conceived to be due to the presence of micro cracks while forging. © (2014) Trans Tech Publications, Switzerland.Item Optimization of control factors in tribological studies for as cast and 1Hr T6 treated Al25Mg2Si2Cu4Fe alloy using Taguchi methods(Elsevier Ltd, 2018) Sondur, D.G.; Mallapur, D.G.; Udupa, K.R.In this study, using the predictive model offered by Taguchi, optimization of wear parameters was carried out. Controlling factors such as sliding speed, load and T6 heat treatment (homogenizing hours) were considered. Pin on disc type friction monitor was used for determing the volumetric wear rate under constant speed for as cast and 1Hr T6 treated conditions. The L16 orthogonal array, signal to noise ratio (S/N) and regression results were used to arrive at optimal control factor values that affect the volumetric wear rate of the alloy. Combination of the dominating control factors has been predicted using Taguchi technique. Predicted combination of control factors were found to be close to the experimental observations i.e load was found to be a dominant factor for volumetric wear rate. Also 1Hr T6 treated alloy shows a higher volumetric wear resistance as compared to as cast alloy. © 2017 Elsevier Ltd.Item Experimental optimization of volumetric wear behavioural study of as cast and 1hr homogenized Al-25Mg2Si2Cu4Ni alloy at constant speed based on Taguchi method(Elsevier Ltd, 2018) Harlapur, M.D.; Mallapur, D.G.; Rajendra Udupa, K.In the current study, an experimental optimization study on the volumetric wear behaviour of Aluminium (Al-25Mg2Si2Cu4Ni) alloy in as cast and 1Hr homogenized with T6 heat treatment is carried out at constant speed. The Pin-on-disc apparatus was used to carry out sliding wear test. Taguchi method based on L-16 orthogonal array was employed to analyze the data on the wear behaviour. Signal-to-noise ratio with the objective of smaller the better and mean of means results were used. General regression model is obtained by correlation. Lastly confirmation test was completed to make a comparison between the experimental results foreseen from the mentioned correlation. The mathematical model reveals the load has maximum contribution on the wear rate compared to speed. Scanning Electron Microscope was used to analyze the worn-out wear surfaces. Wear results show that 1Hr homogenized Al-25Mg2Si2Cu4Ni alloy samples with T6 treated had better volumetric wear resistance as compared to as cast samples. © 2017 Elsevier Ltd.Item Effect of T6 treatment on the coefficient of friction of Al25Mg2Si2Cu4Fe alloy(American Institute of Physics Inc. subs@aip.org, 2018) Sondur, D.G.; Mallapur, D.G.; Udupa, K.R.Effect of T6 treatment on the coefficient of friction of Al25Mg2Si2Cu4Fe alloy was evaluated by conducting wear test on pin on disc wear testing machine. Wear test parameters such as the load and the speed were varied by keeping one constant and varying the other respectively. It was observed that the coefficient of friction is high for as cast condition due to the brittle microstructure. After T6 heat treatment the precipitates formed such as the Chinese scripts and the Mg2Si blocks got modified that lead to improvement in the hardness and the wear resistance. This reduces the coefficient of friction. © 2018 Author(s).Item Experimental wear behavioral studies of as-cast and 5 hr homogenized Al25Mg2Si2Cu4Ni alloy at constant load based on taguchi method(American Institute of Physics Inc. subs@aip.org, 2018) Harlapur, M.D.; Mallapur, D.G.; Udupa, K.R.In the present study, an experimental study of the volumetric wear behaviour of Aluminium (Al-25Mg2Si2Cu4Ni) alloy in as cast and 5Hr homogenized with T6 heat treatment is carried out at constant load. The Pin on disc apparatus was used to carry out the sliding wear test. Taguchi method based on L-16 orthogonal array was employed to evaluate the data on the wear behavior. Signal-to-noise ratio among the objective of smaller the better and mean of means results were used. General regression model is obtained by correlation. Lastly confirmation test was completed to compose a comparison between the experimental results foreseen from the mention correlation. The mathematical model reveals the load has maximum contribution on the wear rate compared to speed. Scanning Electron Microscope was used to analyze the worn-out wear surfaces. Wear results show that 5Hr homogenized Al-25Mg2Si2Cu4Ni alloy samples with T6 treated had better volumetric wear resistance as compared to as cast samples. © 2018 Author(s).Item Experimental analysis of volumetric wear behavioural and mechanical properties study of as cast and 1Hr homogenized Al-25Mg2Si2Cu4Ni alloy at constant load(American Institute of Physics Inc. subs@aip.org, 2018) Harlapur, M.D.; Mallapur, D.G.; Udupa, K.R.In the current study, an experimental analysis of volumetric wear behaviour and mechanical properties of aluminium (Al-25Mg2Si2Cu4Ni) alloy in as cast and 1Hr homogenized with T6 heat treatment is carried out at constant load. Pin-on-disc apparatus was used to carry out sliding wear test. Mechanical properties such as tensile, hardness and compression test on as-cast and 1 hr homogenized samples are measured. Universal testing machine was used to conduct the tensile and compressive test at room temperature. Brinell hardness tester was used to conduct the hardness test. The scanning electron microscope was used to analyze the worn-out wear surfaces. Wear results and mechanical properties shows that 1Hr homogenized Al-25Mg2Si2Cu4Ni alloy samples with T6 treated had better volumetric wear resistance, hardness, tensile and compressive strength as compared to as cast samples. © 2018 Author(s).Item Experimental studies on mechanical properties of T6 treated Al25Mg2Si2Cu4Fe alloy(American Institute of Physics Inc. subs@aip.org, 2018) Sondur, D.G.; Mallapur, D.G.; Udupa, K.R.Effect of T6 treatment on the mechanical properties of Al25Mg2Si2Cu4Fe alloy was evaluated by conducting mechanical tests on test pieces using universal testing machine. Increase in the mechanical properties such as ultimate tensile strength, hardness and % elongation was observed. Microstructure characterization revealed the modification in the size and shapes of the precipitates formed during the homogenization process. This modification increases the anisotropy of the microstructure and the stresses in the as cast structure. The increase in the hardness of T6 treated alloy is due to the partial recrystallization, fragmentation and redistribution of primary Mg2Si phase, precipitation of fine θ, Q phases. The high volume fractions of uniformly dispersed hard β-particles greatly increase the flow stress and provide an appreciable impediment to plastic deformation. Thus increasing the hardness of the alloy. © 2018 Author(s).Item Influence of Ti, B and Sr on the microstructure and mechanical properties of A356 alloy(2011) Mallapur, D.G.; Kori, S.A.; Udupa, K.R.In the present investigation, the microstructural and mechanical properties study of A356 alloy have been discussed. The microstructural aspect of cast A356 alloy employed in the present study is strongly dependent on the grain refinement (Ti and B) and modification (Sr). The mechanical properties such as PS, UTS, %E, %R, YM and VHN have been investigated. This paper deals with the combined effect of grain refinement and modification, which improves the overall mechanical properties of the alloy. It is also a well-known fact that the mechanical properties of cast A356 alloy were improved by subjecting suitable melt treatment such as grain refinement, modification and mould vibration, etc. The quality of castings and their properties can be achieved by refining of ?-Al dendrites in A356 alloy by means of the addition of elements such as Ti and B which reduces the size of a-Al dendrites, which otherwise solidifies with coarse columnar a-Al dendritic structure. In addition, modification is normally adopted to achieve improved mechanical properties. Metallographic studies reveal that the structure changes from coarse columnar dendrites to fine equiaxed ones on the addition of grain refiner and further, plate like eutectic silicon to fine particles on addition of 0.20% of Al-10Sr modifier. The present result shows that a reduction in the size of a-Al dendrites, modification of eutectic Si and improvement in the mechanical properties were observed with the addition of grain refiner Al-3Ti, Al-3B and modifier Al-10Sr either individual addition or in combination. The change in the microstructure from coarse columnar ?-Al dendrites to fine equiaxed dendrites and plate like eutectic silicon to rounded particles leads to improved mechanical properties. © Springer Science+Business Media, LLC 2010.Item Influence of Ti, B and Sr on tribological properties of A356 alloy(2011) Mallapur, D.G.; Udupa, K.R.; Kori, S.A.The wear behaviour of an A356 alloy has been investigated in this paper. To understand the wear behaviour of the materials, the experiments were carried out using a pin on disc testing machine at various combinations of normal pressure, sliding speed and sliding distances. Tribological results reveal that weight loss of A356 alloy increases with increasing normal pressure and decreases with increasing sliding speed. Also, the results at microlevel revealed a structural change from coarse columnar dendrites to fine equiaxed ones on the addition of grain refiner (Al and B) and furthermore, plate-like eutectic silicon to fine particles on addition of modifier (Sr). It is further noted in the present study that addition of modifier does not disturb the influence of grain refiner and vice versa. Abrasive wear mechanism was interrupted by the formation of microwelds and later by oxidation of the Al matrix. © 2011 W. S. Maney & Son Ltd.Item Studies on the influence of grain refining and modification on microstructure and mechanical properties of forged A356 alloy(Elsevier Ltd, 2011) Mallapur, D.G.; Udupa, K.R.; Kori, S.A.Microstructure and mechanical properties of the forged A356 alloy have been investigated in this paper. Results reveals that at micro level forged structure was more refined than as in the as cast conditions. This is due to the work hardening effect, where the original structure is destroyed during the forging and recrystallization helped in creating large number of nucleating sites leading to fine grain structure. From the investigations on the mechanical properties, we deduce that the PS, UTS and hardness of forged materials are obviously higher than those of the ones treated with as cast condition without and with the addition of grain refiners and modifier. © 2011 Elsevier B.V.