Abstract
In this paper, a supercell modeling of secondary orientation was established using 90 cubic mosaic units made up of γ’ phase embedded in γ matrix, in accordance with an actual structure of Ni-based single crystal superalloys (NSCS). The effects of secondary orientation on the deformation behavior and microstructure evolution of NSCS under uniaxial tensile were studied by a three-dimensional molecular dynamics (MD) simulation. Simulation results showed that secondary orientation had a significant effect on mechanical properties of NSCS, that is, a big fluctuation was found in tensile strength which dropped down almost 50% from a peak (corresponding to the secondary orientations of 18° and 45°) to a trough (those of 34° and 63°). Mechanisms of secondary orientation affecting the deformation behavior were further discussed systematically. The deformation of NSCS under uniaxial tensile was a process tending towards amorphization of microstructure, together with the dislocation formation, merging and break-up. On a micro viewpoint, this work for us will be useful to apprehend the tensile deformation conduct of NSCS.
Funder
Science and Technology on Advanced High Temperature Structural Materials Laboratory, AECC Beijing Institute of Aeronautical Materials, China
Subject
General Materials Science,Metals and Alloys