Influence of Excess Volumes Induced by Re and W on Dislocation Motion and Creep in Ni-Base Single Crystal Superalloys: A 3D Discrete Dislocation Dynamics Study

被引：6

作者：

Gao, Siwen ^{[1
]}

Yang, Zerong ^{[1
]}

Grabowski, Maximilian ^{[1
]}

Rogal, Jutta ^{[1
]}

Drautz, Ralf ^{[1
]}

Hartmaier, Alexander ^{[1
]}

机构：

[1] Ruhr Univ Bochum, Interdisciplinary Ctr Adv Mat Simulat, D-44801 Bochum, Germany

来源：

METALS | 2019年 / 9卷 / 06期

关键词：

superalloy; excess volume; solute atom; dislocation dynamics; creep; DFT; TOTAL-ENERGY CALCULATIONS; LOW-STRESS CREEP; HIGH-TEMPERATURE; TRANSITION-METAL; NICKEL; RHENIUM; CLIMB; MICROSTRUCTURE; SIMULATIONS; SEGREGATION;

D O I：

10.3390/met9060637

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

A comprehensive 3D discrete dislocation dynamics model for Ni-base single crystal superalloys was used to investigate the influence of excess volumes induced by solute atoms Re and W on dislocation motion and creep under different tensile loads at 850 degrees C. The solute atoms were distributed homogeneously only in gamma matrix channels. Their excess volumes due to the size difference from the host Ni were calculated by density functional theory. The excess volume affected dislocation glide more strongly than dislocation climb. The relative positions of dislocations and solute atoms determined the magnitude of back stresses on the dislocation motion. Without diffusion of solute atoms, it was found that W with a larger excess volume had a stronger strengthening effect than Re. With increasing concentration of solute atoms, the creep resistance increased. However, a low external stress reduced the influence of different excess volumes and different concentrations on creep.

引用

页数：15