Effect of twinning on the flow behavior during strain path reversals in two Mg (+Al, Zn, Mn) alloys

Strain path change tests (uniaxial tension followed by compression) were employed to investigate the effect of the twins formed during extension on the subsequent compression behavior. Higher yield stresses were observed during compression after prior extension than when no prestraining was used. This contrasts sharply with the equivalent behavior reported in the literature when compression precedes extension. The peak strain in compression was increased by tensile prestraining and it was noted that the presence of twins has a greater influence on the compression flow stress than the grain size.