Research On Deformation Mechanism And Constitutive Equations Of Nickel-Based Intermetallic Compound IC10 Alloy

IC10 alloy is one of the Ni₃Al-based high temperature alloys, which is applied in the hot parts of aviation engine because of its excellent high temperature mechanical performance. In this article,constant deformation rate tensile tests at different temperature are conducted and TEM is applied to research the change of dislocation type and density in microscopic level in order to analyze the deformation mechanism. The function of dislocation density and strain is established and applied in the constitutive equations which is verified by numerical simulation. The main work and conclusions are as follows:1.Macro-mesoscopic mechanical property test on IC10 alloy is carried out. Constant deformation rate tensile tests with 10-4/s strain rate are conducted at 700 ? and 900 ? and TEM. is applied to observe the specimens at different strain. The conclusion is that strain hardening is the main characteristic of the alloy tested at 700 ? and numerous parallel straight screw dislocation with1 2[1 ???0] burgers vector and other types of dislocations are observed. Strain hardening in early deformation and subsequent strain softening is the characteristic of the alloy tested at 900? and the dislocation wall consists of two groups of parallel edge dislocations is observed.2.Research on the deformation mechanism of IC10 alloy and evolution of dislocation density is conducted. The conclusion is that dislocation density increases in the whole deformation process and tends to saturate at 700?. Besides, dislocation cell, stacking fault, dislocation circle and K-W lock are observed. Dislocation density increases first and then decreases and stabilizes finally at 900 ?.Many subgrains are observed and some of them coalesce. The dislocations piled up in the cell wall rearrange and absorb new dislocation to form subboundary.3.The function of dislocation density and strain is applied to improve the rate-dependent constitutive equations. Numerical simulation technique is developed. The simulation results at the temperature of 600? and 700? coincide with the tests mainly and average errors are around 3%.