Study On The Mechanism Of Radiation Damage Of Ni-Based And W-Based Concentrated Solid Solution Alloys

After a long period of accumulation and evolution,the point defects produced by irradiation will seriously affect the microstructure of materials,and then lead to changes in macroscopic mechanical properties and electrical properties of materials.Therefore,it is of great significance to study the radiation damage process of materials and the factors affecting radiation damage for guiding the design of radiation-resistant materials.In this paper,the cascade collision process of Ni-based and W-based single-phase solid solution alloys at the initial stage of irradiation damage and the effects of different factors on irradiation-induced point defects and clusters were studied by molecular dynamics simulation.In addition,the mechanical behavior and change mechanism of W-Ta alloy after irradiation were also investigated in detail.Specific research contents are as follows:(1)Based on the empirical potential molecular dynamics method,the effects of the Primary Knock-on Atom(PKA)energy,alloy element composition and temperature on irradiation damage of Ni-based single-phase solid solution alloy were studied.It was found that when the number of components and temperature are the same,with the increase of PKA energy,the number of point defects increases,and defect recombination first decreases and then increases,Increasing the number of components will increase the recombination rate of dislocated atoms,and then increase the radiation resistance of materials.Elevating temperature will also increase the recombination rate of dislocated atoms,but has little effect on NiCuFe alloy.(2)The effects of PKA energy and Ta concentration on the early defect evolution of W-Ta single-phase solid solution alloy were studied.It was found that the number of point defects,small clusters and the recombination rate of dislocated atoms increase with the increase of PKA energy.By changing Ta content,it is found that Ta content has little effect on residual defects and recombination rate of dislocated atoms in W-Ta alloy,which indicates that Ta content has little effect on radiation resistance of the alloy.(3)The effect of irradiation on the mechanical properties of W-Ta alloy was studied.The results showed that the Young's modulus and yield stress of W-Ta alloy decrease after irradiation,and decrease proportionally with the increase of PKA energy.With the increase of Ta content,the Young's modulus and yield stress of W-Ta alloy firstly increase,and reach the peak when Ta content is 20%.The Ta content continued to increase,and the Young's modulus and yield stress decreased linearly,and finally fell below the pure W level.By analyzing the dislocations after irradiation,it is found that the number and length of dislocations increase with the increase of strain,and 1/2<111>dislocation lines are the main part.Figure[24]Table[6]Reference[102]...