Evaluation of Mechanical and Tribiological Characteristics of LM-13 Hybrid Al-Metal Matrix Composites

LM-13 used for piston and applications where thermal stresses are more. This alloy can withstand higher temperatures and loads. It has good wear resistance properties and machinability. In this experimental study, Al alloy LM13-SiC & MoS2 & Graphite hybrid composites were produced by stir casting method using Sic powder as reinforce particles with 150-micron average diameter and Al alloy as the matrix metal. The melt composites were stirred, then casted into a metallic mold. Different samples of 0, 2.5, 5 and 7.5 weight percent of Sic with constant weight percentage of MoS2 and graphite were prepared. The casted composite specimens were machined as per test standards. Effects of weight percent of Sic particles on hardness, tensile strength and compressive strength of prepared composites have been investigated. The highest tensile and compressive strengths were achieved in the specimen containing 5%, 7.5 weight percent of SiC, which shows an increase in comparison with the unreinforced Al alloy. It has been observed that addition of Sic particles significantly improves hardness, tensile strength, and compressive strength properties as compared with that of unreinforced matrix. Wear and corrosion rate were minimum obtained with the ratio of 5% & 7.5 weight percent of Sic.