Evaluation Of Microstructure And Mechanical Properties Of As Cast Aluminium Alloy 7075 And Zro2 Dispersed Metal Matrix Composites
Metal matrix composites offer designers many added benefits as they are particularly suited for applications
requiring good strength at high temperature, good structural rigidity, dimensional stability and light weight. The trend is
towards safe usage of the MMC parts in the automobile engines, which works particularly at high temperature and pressure
environments. Particles reinforced MMCs has been the most popular over the last three decades. Among the MMCs ceramic
reinforces Aluminum. MMCs have most popular families. Although incorporation of the second phase into matrix material
can enhance the physical and mechanical properties of the base metal, it could also significantly change the wear behavior.
This paper aims the examination on effect of reinforced particles Zirconium-di-oxide on hardness and wear of aluminum
alloy7075 (AA7075) and its composites which is produced by stir casting method. The castings produced were machined
and samples were fabricated by varying weight percentage of the reinforced particles as 0-8 Wt.% in the step of 2Wt.% in
volume. SEM and microstructural studies were carried out on AA7075 and its composites. Microstructural study reveals
uniform scattering of reinforcement in as cast and AA7075 composites. Substantial improvement in hardness and coefficient
of friction was found with increase in Zirconium-di-oxide particles in weight percentage of compositesin both with
and without heat treatment. Also the wear diminished with increased weight percentage of reinforcement in the composites
in both with and without heat treatment in different quenching media.
Keywords- MMC, Zirconium-di-oxide, SEM, Heat treatment, hardness, Adhesive wear.