Effects of lattice defects on indentation-induced plasticity initiation behavior in metals
Effects of lattice defects on indentation-induced plasticity initiation behavior in metals
复制标题
DOI：
10.1557/jmr.2012.161
复制
发表时间：
2012-07-01
影响因子：
2.7
通讯作者：
Tsuzaki, K.
中科院分区：
文献类型：
--
作者：
Ohmura, T.;Zhang, L.;Tsuzaki, K.
采用纳米压痕技术研究了压痕变形加载过程中出现的弹出现象，揭示了晶界和溶质元素等晶格缺陷对包括铁合金在内的多种金属材料的影响。加载过程中，晶界附近的弹出临界载荷P-c低于晶内，但晶界的相对硬度等于或大于晶内的相对硬度。在Fe-Si合金中，固溶Si对晶界和晶粒内部的P-c都比在无间隙钢中产生更大的增加。在具有不同晶体结构的单晶中，压头下方P-c所对应的最大剪切应力与剪切模量成正比。基于位错模型考虑了P-c的微观结构效应。
Plasticity initiation behavior that appears as a pop-in phenomenon on a loading process during indentation-induced deformation was investigated to reveal the effects of lattice defects such as grain boundary and solute element for various metallic materials including Fe alloys through instrumented nanoindentation techniques. The critical load P-c of pop-in on a loading process is lower in the vicinity of the grain boundary than in the grain interior, but the relative hardness of the boundary is equal to or greater than that in grain interior. In-solution Si produces a larger increase in the P-c for both the grain boundary and the grain interior in the Fe-Si alloy than in the interstitial-free steel. The maximum shear stress corresponding to the P-c underneath the indenter is directly proportional to the shear modulus in single crystals with various crystallographic structures. Microstructural effects on the P-c are considered based on some dislocation models.