Sheng Li
,
Yu-Zeng Chen
,
Yu-Ke Cao
,
Feng Liu
金属学报(英文版)
doi:10.1007/s40195-016-0367-4
It is well known that, in kinetics, the interaction between dislocations and interstitial solute normally exerts strong solute drag effect on dislocations, leading to strong solution hardening of the metals. However, due to the low mobility of interstitial solute in many metals, thermodynamic aspect of the interaction between dislocations and interstitial solute is often unobservable and omitted. It will be shown in this article by reviewing the H-induced behaviors in metal-H systems, especially the recent progress in Pd-H system that, when the interstitial solute atoms are highly mobile and able to collect in the vicinity of mobile dislocations easily, the scenario will be remarkably different. The interaction between dislocations and these highly mobile interstitial solute atoms, in thermodynamics, will reduce the line energy of dislocations and will facilitate the generation of dislocations, leading to an increase in dislocation density and an enhanced strain hardening of metals upon plastic deformation.
关键词:
Plastic
,
deformation
,
Dislocation
,
Interstitial
,
solute
,
Strengthening
,
mechanism
,
Thermodynamics
Ming-Zhen Wei
,
Zhen-Hua Cao
,
Xiang-Kang Meng
金属学报(英文版)
doi:10.1007/s40195-016-0377-2
In this work, we have investigated the mechanical properties of Cu/Ta, Ag/Cu and Ag/Nb multilayers with different heterogeneous interfaces. The results suggest that when individual layer thickness (h) is larger than 5-10 nm, the hardness/strength of three different multilayer systems has the similar length scale effect with decreasing layer thickness, while when h ≤ 5 nm, the three multilayer systems show remarkably different plastic deformation behaviors. The strength curves exhibit the variation trends of unchanging, softening and increasing corresponding to Cu/Ta, Ag/Cu and Ag/Nb multilayers, respectively. The microstructure analysis shows that three kinds of multilayers have totally different interfacial structures, which lead to the different strengthening or softening mechanisms.
关键词:
Metallic
,
multilayers
,
Plastic
,
deformation
,
Interfacial
,
structures
,
Strengthening
,
mechanism
Jinyu GUO
,
Ke WANG
,
Lei LU
材料科学技术（英）
High density nano-scale deformation twins were introduced in the surface layer of Cu sample by means of surface mechanical attrition treatment (SMAT) at room temperature. The Cu sample with deformation twins shows a yield strength of about 470 MPa in tension tests. The significant strengthening may be attributed to the effective inhibition of slip dislocations by abundant twin boundaries.
关键词:
Copper
,
表面机械研磨
,
变形孪晶
,
强化
