Mechanical behaviour and microstructural evolution of Ni-based single crystal alloys under shock loading†

Abstract

Engine turbine blades are subjected to high-temperature and high-speed fragment impacts during use, and the ability of the blades to resist shocks affects their reliability. At present, there are few studies on the ability to withstand shocks of Ni-based single crystal alloys, especially with regards to their mechanical behaviour and microstructural evolution under shock loading. The solutions to the above problems can further help us understand the mechanisms of the mechanical responses and microstructural evolution of Ni-based single crystal alloys under shock loading. Thus, we study the mechanical behaviour and microstructural evolution characteristics of Ni-based single crystal alloys with different crystal orientations under shock loading using molecular dynamics simulations. We find that the (001) phase interface has the strongest impediment ability due to its dislocation network structure and the expansion of dislocations, which lead to the greatest reinforcing effect on the matrix. The penetration force of the (001) phase interface is the greatest with fragment penetration. Moreover, the energy dissipation capacity of the (001) phase interface is the highest with fragment penetration because it has the strongest resistance to shock loading. The second highest is the (110) phase interface, and the minimum dissipation capacity comes from the (111) phase interface. This study has an important theoretical significance for the in-depth understanding of the failure mechanisms of Ni-based single crystal alloys under shock loading.

Abstract

Through molecular dynamics simulations, we find that the (001) phase interface has the strongest resistance to shock loading.