Fatigue Behavior of Fly ash reinforced in LM6 Aluminum Metal Matrix Composite

Abstract

This dissertation describes the fatigue behavior investigation carried on MMC, in which LM6 aluminum form metal matrix and fly ash act as reinforcement. The MMC was obtained by liquid metallurgy and continuous stir casting process. The variation of fatigue behavior with varying volume percentage of reinforcement (i.e. 0 Vol%, 2.5 Vol%, 5 Vol%, 7.5 Vol%, 10 Vol% 12.5 Vol% and 15 Vol%) was studied using rotating bending fatigue test machine of the constant bending moment type.During the fatigue test, with increase in volume percentage of fly ash reinforcement from 0 Vol% to 10 Vol% there is an increase in the number of cycles to failure in MMC from 0.11× Cycles to 0.88× Cycles, but with further increase in the Vol % of reinforcement from 10 Vol% to 15 Vol%
there is a decrease in the number of cycles required for failure to 0.13× Cycles.When these failure samples are subjected to microstructure analysis in metallurgical microscope, it revealed uniform dispersion of fly ash particulate as per volume percentage,further optical study of the micro structural analysis after failure of composites was conducted using SEM which suggested that, there is an addition in the brittle nature of MMCs with the addition of fly ash after 10 volume percent.It was  easoned out that fly ash can be used as support in aluminum composite, composite give better fatigue life than LM6 Al alloy and this MMC can be utilized as a replacement for materials used automobile industry to produce engine blocks, pistons etc.