Micromechanical Behavior of Single‐Crystal Superalloy with Different Crystal Orientations by Microindentation

Abstract

In order to investigate the anisotropic micromechanical properties of single-crystal nickel-based superalloy DD99 of four crystallographic orientations, (001), (215), (405), and (605), microindentation test (MIT) was conducted with different loads and loading velocities by a sharp Berkovich indenter. Some material parameters reflecting the micromechanical behavior of DD99, such as microhardnessH, Young’s modulusE, yield stressσy, strain hardening componentn, and tensile strengthσb, can be obtained from load-displacement relations.HandEof four different crystal planes evidently decrease with the increase ofh. The reduction ofHis due to dislocation hardening whileEis related to interplanar spacing and crystal variable.σyof (215) is the largest among four crystal planes, followed by (605), and (001) has the lowest value.nof (215) is the lowest, followed by (605), and that of (001) is the largest. Subsequently, a simplified elastic-plastic material model was employed for 3D microindentation simulation of DD99 with various crystal orientations. The simulation results agreed well with experimental, which confirmed the accuracy of the simplified material model.

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

“…To fully calculate the ability of the different crystalline Nibased single-crystal alloy materials to resist deformation caused by impact loading from fragments, it is necessary to analyse the nano-hardness of the materials. [31][32][33] According to Newton's third law, every force is accompanied by an equal reaction force. The impact load on the substrate can be calculated according to the magnitude of the penetration force.…”