Investigation of nanomechanical properties of Ni-Mn based Heusler alloys using nanoindentation technique

Abstract

Abstract Studies on mechanical properties of Ni-Mn based Heusler alloys are lacking which limits their use for practical applications. In the present work, nanomechanical analysis of ternary Ni-Mn-Sn and Ni-Mn-Al Heusler alloys were performed using nanoindentation test. Dense pellet specimens of selected 15 hr mechanical alloyed ball milled powder samples were prepared by consolidation, sintering and polishing processes. Load-displacement curves were obtained from a typical nanoindentation test by penetrating the indenter tip into the prepared pellet specimens surface with a prescribed loading and unloading data using Oliver-Pharr method of analysis to determine elastic modulus and hardness. The average elastic modulus and harness of Ni-Mn-Al alloy found more than Ni-Mn-Sn alloy. Also, the effects of sintering temperatures on the densities of pellet specimens were observed which showed that higher sintering temperatures are required to achieve the homogeneity and reduce the porosity of specimen.