极低温度超高压强下纳米多晶镍塑性变形行为与机理的分子动力学研究  

Plastic deformation behavior and mechanism of nanocrystalline nickel under ultra-low temperature and ultra-high pressure using molecular dynamics simulation

作　　者：何东 闵威 姚路 HE Dong;MIN Wei;YAO Lu(School of Mechanical and Materials Engineering,North China University of Technology,Beijing 100144,China)

机构地区：[1]北方工业大学机械与材料工程学院,北京100144

出　　处：《材料热处理学报》2021年第5期152-159,共8页Transactions of Materials and Heat Treatment

基　　金：北京市教委基本科研业务费资助项目(110052971803/030);北京市科技创新服务能力建设-基本科研业务费(110052971921/044)。

摘　　要：采用分子动力学方法研究了极低温度、超高压强条件下纳米多晶镍的塑性变形行为;利用共近邻分析(Common neighbor analysis, CNA)表征了纳米多晶镍的微观结构特征及其演化过程;结合广义层错能计算,揭示了超高压强对纳米多晶镍塑性变形机理的影响。结果表明:在0~300 K范围内,纳米多晶镍的强度随着温度的降低而提高,当温度从300 K降低到1 K时,屈服强度由2.9 GPa提高到5.1 GPa;超高压强能提高纳米多晶镍滑移开动的临界分切应力,改善位错分解与增殖的能力,进而导致其屈服强度随外界压强的升高而显著提高:当压强从0 GPa升高到10 GPa时,其屈服强度提高了44.8%。The plastic deformation behavior of nanocrystalline nickel at ultra-low temperature and ultra-high pressure was studied by molecular dynamics method, and the microstructure characteristics and evolution of the nanocrystalline nickel were characterized by means of common neighbor analysis(CNA) method. Combined with generalized stacking fault energy calculation, the effect of ultra-high pressure on the plastic deformation mechanism of the nanocrystalline nickel was revealed. The results show that in the deformation temperature range of 0-300 K, the strength of the nanocrystalline nickel increases with the decrease of temperature, and when the temperature decreases from 300 K to 1 K, the yield strength increases from 2.9 GPa to 5.1 GPa. The ultra-high pressure can increase the critical shear stress of slip of the nanocrystalline nickel, and improve the ability of dislocation decomposition and increment, and thus the yield strength increases significantly with the increase of pressure. When the pressure increases from 0 GPa to 10 GPa, the yield strength increases by 44.8%.

关 键 词：极低温度 超高压强 纳米多晶镍 分子动力学 

分 类 号：TG146.1[一般工业技术—材料科学与工程]