Effects of inclusion type and inclusion radius on deformation characteristic and failure mechanism inside monocrystalline NiFeCr alloy

Abstract

The effect of different inclusion types, inclusion radius, and strain rates (STRs) on the mechanical property, deformation behaviors, energy absorption, and failure mechanisms of NiFeCr alloy is investigated through a molecular dynamic simulation of a tensile process. The tensile strength, strain energy, and dislocation densities of the sample without and with inclusion all increase as increasing STRs. However, the tensile strength, strain energy, and dislocation densities of the sample without inclusion are all larger than those of the sample with inclusion. Moreover, Young’s modulus (E) of the none-inclusion sample is a little smaller than that of the Fe-inclusion sample while larger than that of the Ni-inclusion and Cr-inclusion samples. The results also show that the effect of inclusion radius is complex, which depends on the type of material that makes up the inclusion. E values decrease as increasing inclusion radius for all inclusion types. The phase transformations from FCC to HCP structure and the dislocation length for the none-inclusion sample are much larger than that of the inclusion samples. Besides, the nuclear deformed appears at the contact area between the inclusion and the NiFeCr workpiece and then widely develops as increasing strain. The Stair-rod and Shockley partial dislocations consider a dominant proportion for all samples.