Abstract
Keywords:
AZ91D alloy, Microporosity, Strain Hardening Exponent, Strain Rate Sensitivity, Micro-void, Plastic Deformation
Abstract
The tensile properties of as-cast AZ91D magnesium alloy were investigated through experimental study and numerical prediction under consideration of constitutional law. Gravity casting, which use a various shaped-molds as well as inoculation fabricated the test specimens. The tensile test was conducted at room temperature and the strain rate sensitivity was measured through incremental strain rate testing method. Even though the tensile strength and elongation has a nonlinear and a very intensive dependence upon variation of microporosity, the yield strength appeared to have a linear relationship with microporosity. The numerical prediction suggests that the effect of microporosity on fractured strength and elongation was nullified as the strain-hardening exponent and strain rate sensitivity were increased. However, the shape and distribution of micro-void may play a dominant role on the tensile plastic deformation behavior of AZ91D alloy.