Investigation Of Shear Band Formation For In-Situ Magnesium Metal Matrix Composites During Hot Compression

Document Type : Primary Research paper


1 Department of Metallurgical Engineering PSG College of Technology Coimbatore 641004, Tamil Nadu, INDIA

2 Department of Materials Engineering Indian Institute of Science Bengaluru 560012, Karnataka, INDIA


Twinning and dynamic recrystallization are believed to be the two major contributors for
shear band formation in polycrystalline magnesium. In this present work, we have
proposed an empirical relationship to determine the criteria for shear band formation
based on work-hardening values derived from true stress-true strain curves. In-situ
magnesium metal matrix composites were subjected to hot compression tests at strain rate
ranges of 1 x 10-3 to 1 s-1 and from temperature ranges of 150 to 350 oC. We show that if
the ratio of work hardening or work-softening rate to maximum work hardening rate
reduces below -0.02, then the shear bands nucleate within the grain matrix and propagate
along the direction having maximum shear stress. On the other hand, if this ratio exceeds
0, no shear band formation occurs within the composites. However, when temperature
approaches 350 oC, activation of non-basal slip systems suppresses the severity of twinning
by enhancing the plastic flow across the several grains, which eventually leading to
produce deformation bands rather than shear bands.