PNNL

Abstract

Nanoindentation is performed on hot isostatic pressing (HIP) Mg-Al (AM40) alloy samples prepared from high-pressure die cast (HPDC) for the purpose of characterizing the mechanical properties of the a- grains. Extracting elastic modulus and hardness from resulting load-depth curves is well established. A new inverse method is developed to extract plastic material properties as well. The method utilizes empirical yield strength-hardness relationship reported in the literature with finite element modeling of the indentation. Due to the shallow depth of the indentation, indentation size effect (ISE) is taken into account when determine plastic properties. Elastic and plastic properties are determined for a series of indents. The resulting average values and standard deviation are calculated for use as input distributions for microstructure modeling of the AM40.