Paper Title
Precipitation Hardening Behaviour Of Two Stage Stir Cast Al6061-Sio2 Composite

Abstract
In the present work Al6061-SiO2 composites are produced by two stage stir casting method and subsequently studied various properties. Microstructure, hardness, tensile and wear properties of Al6061 based composite reinforced with silicon oxide particles of various weight percentage (2, 4 and 6% wt.) is analyzed and presented. The aging behavior and tensile properties of the cast material were studied. Experimental results show fairly uniform distribution of the SiO2 particulates in the matrix of the Al 6061 leading to higher hardness, and tensile strength. Presence of SiO2 particles in Al6061 alloy accelerating the aging process and thus attains higher strength. These particles provide more sites for the nucleation of fine precipitates. These fine precipitates hinder the movement of dislocation and thus increases hardness as well strength of materials. After aging at 100ᴼC for Al6061/6% wt. SiO2 composite , highest strength is observed at longer duration of aging. Comparison of the characteristics study before and after heat treatment was done and it is observed that there is an improvement in hardness, tensile strength and wear resistance of both Al6061 alloy and its composites after precipitation hardening treatment. Index Terms- Al6061 Alloy, Metal Matrix Composites, Stir Casting, Precipitation Hardening