Research On Constitutive Model Of Alloy IC10 Based On The Characteristics Of Microstructure

Nickel-based super-alloy IC10 is applied widely in industry because of their superior resistance to creep and fatigue at high temperatures.The mechanical properties of the material are greatly influenced by its microstructure,but the research on the mechanical properties of IC10 alloy is basically stucked in the macroscopic test as well as the study of the characteristics of microstructure are less.Scanning electron microscopy was used in this article to observe the material microstructures,and the statistical distribution of the typical microscopic geometric parameters was studied.The representative volume element is established by using the method of completely random and combination cell.Based on crystal plasticity theory,a multiscale constitutive model was established respectively from the single cell(unit cell)scale and the representative volume element(RVE)which considered the interaction of the dislocations density and microstructure.The numerical simulation method was developed by finite element software ABAQUS.At last,the influence of microscopic geometric parameters on the properties of materials were studied.The main research work includes:1.The microstructures of alloy IC10 were observed by SEM.Three microscopic geometric parameters were proposed to describe the microstructure of alloy IC10.Based on the statistical analysis,the volume fraction of the precipitate was obtained and the probability distribution of the precipitate size and the shape parameter were determined.2.Combined the theory of crystal plasticity,the microscopic constitutive model and numerical simulation method were established by considering the effects of microstructure and the evolution rules of dislocation density during the deformation based on the unit cell which containing the basic composition of the material.The stress-strain curves of alloy IC10 under uniaxial tensile load at 600? were simulated.It shows that the predicted results are in good agreement with the experimental results,which verifies the validity of the constitutive model and numerical simulation technique.The influence of typical micro geometric parameters on the mechanical properties of the material was studied by using the unit cell model.3.The microscopic constitutive model and numerical simulation method were established based on the RVE,and the representative volume element for finite element analysis was established by the method of completely random and combination cell based on the micro geometric parameters of materials.The stress and strain response of the material in the inhomogeneous distribution of the precipitate was studied,and the influence of the variation of the micro geometric parameters on the RVE was discussed.It is found that the stress of the precipitate is higher than the matrixs',and the maximum stress is located at the interface.The stress of the small precipitate is higher than the larger one,and the stress values of of narrow matrix channels is higher than the open area of the matrix.