Stress-strain response in skin and core regions of die cast magnesium alloy AM60B determined from spherical microindentation

Spherical indentation testing is used to analyze the dependence of the mechanical properties upon local microstructure of the highpressure die cast magnesium alloy AM60B. Indentation testing is performed on two samples from the skin and the core regions of the die-casting. The difference in the indentation stress-strain flow curve between the skin and the core, and comparisons with results from uniaxial tensile testing are analyzed. It was found that results from the skin region compare well with the tensile stress-strain flow curve, while results from the core region produce a different strain hardening coefficient and a lower stress at each loading level. This study indicates that the skin region controls the flow properties of tensile samples cut from AM60B die-castings.