Studies on Mechanical Properties and Tribological Characteristics of LM25- Graphite- Silicon Carbide and LM25-Flyash- Silicon Carbide - Hybrid MMCa??s

摘要

Hybrid MMC’s have various advantages over conventional metals. Aluminum has a wide advantage in research field which is used as base metal in many MMC’s. Aluminum LM25 is used as base metal in this work. The studies were done using graphite and flyash by varying the percentage of Silicon Carbide and aluminum LM25 as base metal. Graphite and flyash are added for 2 % of aluminium weight seperately and Silicon carbide is varied for 2, 4, 6 and 8% weight of aluminium. The low density of Aluminum and hardness of Silicon carbide and graphite, and affinity of Flyash in Aluminum was to be evaluated as a hybrid structure. The mechanical properties such as tensile strength, Hardness and wear rate were increased after alloying with Graphite and Silicon carbide up to certain percentage. The primary advantage of the hybrid composite is the low density that is obtained after alloying. AlSiCFA is a lightweight material with a density one third of that of Cu alloys. The 2% SiC and 2% Graphite is the best combination of reinforcements that could be integrated in aluminum for best results. The hardness of the material increases with the combination of 2% addition of SiC and Graphite. The Silicon Carbide and Fly ash addition increases the tensile strength, hardness and wear resistance, but only up to a particular composition. The 2% SiC and 2% Fly ash is the best combination of reinforcements that could be integrated in aluminum for best results. The highest wear rate was measured in 8% SiC. Here the hardness of the alloy makes it unable to bear the wear. The AlSiCG and AlSiCFA hybrid composite materials preparation was cost effective and provides high performance related properties after testing for their mechanical behavior. The MMC’s were tested for the evaluationof composite materials ability to replace existing advantages of aluminium LM25. Also to evaluate the hybrid reinforcement property of composites for their better useage.