Study on the strain rate sensitivity of a Ni-based superalloy

Abstract

The aim of present study is to investigate the strain rate sensitivity of a Ni-based superalloy under the tensile loading. The yield strength of the alloy increases with the increasing of strain rate, especially when the strain rate is higher than 101 s-1. But with the increasing of strain rate, the fracture elongation decreases at first, then increases rapidly and shows a minimum value at the strain rate of 102s-1. The manner in which the dislocations pass through the strengthening phases may be different during the plastic deformation at different strain rates and it is the main reason of the appearance of inflection point in the change of the strength with the strain rate. The obvious increase in plasticity of the alloy at high strain rate is considered as the changing of plastic deformation mechanism due to the appearance of twining.