Insight into the role of interfaces on mechanical properties of low-porosity Al/Ni compacts: Comparison of experiment and simulation

Abstract

Quasi-static uniaxial tension and compression, three-point bending, and Hopkinson bar measurements have been carried out on low-porosity Al/Ni compacts (pressed powders) as well as compacts of the constituent Al and Ni. Concurrently, mesoscale material point method (MPM) simulations of fully resolved Al, Ni, and Al/Ni compact microstructures and engineering scale MPM simulations of homogenized Al/Ni compacts have been conducted. These simulations, in conjunction with the experimental measurements, have allowed us to parameterize mesoscale particle/particle contact models and engineering scale anisotropic damage mechanics models for the materials. The goal of this coordinated experimental and simulation study of Al/Ni and its constituent materials was to better understand their mechanical properties and gain insight into the nature of Al-Ni and Al-Al interfaces in Al/Ni compacts and their impact on mechanical properties of the compacts. We found that brittle tensile failure of Al/Ni compacts was dominated by the strength of the Al-Al interface while ductile compressive behavior of Al/Ni compacts was largely determined by the behavior of the Al phase. The properties of both Al-Al interface and Al phase appear to be altered by the presence of Ni. Finally, it was found that softening resulting from shear damage offset underlying strain hardening of the Al and Ni phases during compressive loading of the Al/Ni compacts.