The strength differential (SD) effect as a function of plastic strain in SiCP reinforced Al –Cu –Mg alloy matrix composites with varying reinforcement sizes was investigated. Matrix alloy was also produced in a similar manner for comparison and designated as Control. All the materials exhibited significantly negative SD at very low plastic strains. The magnitude of the negative SD decreased and eventually became positive with increasing plastic strain. All the metal matrix composites exhibited a higher negative SD below and a higher positive SD above 0.35% plastic strain as compared to Control. The observed results were attributed to the nature, magnitude and distribution of thermal residual stresses in the matrix of MMCs and work hardening during deformation.
The authors would like to thank DRDO for the financial assistance and permission to publish and to Dr. V. V. Bhanuprasad for preparation of materials. Assistance rendered in optical and scanning electron metallography by Mr B. Venkateswara Rao and Dr. K. Muralidharan, is acknowledged.
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11 ASTM Standard E606, Annual Book of ASTM Standard, Am. Soc. Test Mater., Philadelphia, PA (1997) 523.Search in Google Scholar
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