Studies on Al6061-SiC and Al7075-Al₂O₃ Metal Matrix Composites

G. B. Veeresh Kumar, C. S. P. Rao, N. Selvaraj, M. S. Bhagyashekar

Department of Mechanical Engineering, Don Bosco Institute of Technology, Bangalore,Karnataka, India..
Department of Mechanical Engineering, National Institute of Technology, Warangal, (A.P),India..
Research Scholar, National Institute of Technology, Warangal, (A.P), India & Department of Mechanical Engineering, S B M Jain College of Engineering, Jain University,Jakkasandra (P), Kanakapura (T), Ramanagara (D)-562 112, Karnataka, India..

DOI: 10.4236/jmmce.2010.91004                

Abstract

The aluminum based composites are increasingly being used in the transport, aerospace, marine, automobile and mineral processing industries, owing to their improved strength, stiffness and wear resistance properties. The widely used reinforcing materials for these composites are silicon carbide, aluminum oxide and graphite in the form of particles or whiskers. The ceramic particles reinforced aluminum composites are termed as new generation material and these can be tailored and engineered with specific required properties for specific application requirements. Particle reinforced composites have a better plastic forming capability than that of the whisker or fiber reinforced ones, and thus they have emerged as most sought after material with cost advantage and they are also known for excellent heat and wear resistance applications. In this paper it is aimed to present the experimental results of the studies conducted regarding hardness, tensile strength and wear resistance properties of Al6061-SiC and Al7075-Al₂O₃ composites. The composites are prepared using the liquid metallurgy technique, in which 2-6 wt. %’age of particulates were dispersed in the base matrix in steps of 2. The obtained cast composites of Al6061-SiC and Al7075-Al₂O₃ and the castings of the base alloys were carefully machined to prepare the test specimens for density, hardness, mechanical, tribological tests and as well as for microstructural studies as per ASTM standards. The SiC and Al₂O₃ resulted in improving the hardness and density of their respective composites. Further, the increased %’age of these reinforcements contributed in increased hardness and density of the composites. The microphotographs of the composites studied revealed the uniform distribution of the particles in the matrix system. The experimental density values were agreed with that of the theoretical density values of the composites obtained using the rule of mixture for composites. The dispersed SiC in Al6061 alloy and Al₂O₃ in Al7075 alloy contributed in enhancing the tensile strength of the composites. The wear factor K obtained using computerized pin on disc wear tester with counter surface as EN31 steel disc (HRC60) and the composite pin as specimens, demonstrated the superior wear resistance property of the composites.

Keywords

Al6061-SiC, Al7075-Al₂O₃, Metal Matrix Composites, Density, Microstructure, Hardness, Mechanical properties, Wear Factor.

Conflicts of Interest

The authors declare no conflicts of interest.

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