摘要
A modified surface layer was formed on Ti-6Al-4V alloy by wet peening treatment. The variations of the residual stress,nano-hardness and microstructure of the modified layer with depth from surface were studied using X-ray diffraction analysis,nano-indentation analysis, scanning electron microscopy and transmission electron microscopy observations. The results show thatboth the compressive residual stress and hardness decrease with increasing depth, and the termination depths are 160 and 80 μm,respectively. The microstructure observation indicates that within 80 μm, the compressive residual stress and the hardness areenhanced by the co-action of the grain refinement strengthening and dislocation strengthening. Within 80–160 μm, the compressiveresidual stress mainly derives from the dislocation strengthening. The strengthened layer in Ti-6Al-4V alloy after wet peeningtreatment was quantitatively analyzed by a revised equation with respect to a relation between hardness and yield strength.
采用湿喷丸处理方法在Ti-6Al-4V 合金表面制备了改性层.利用X 射线衍射技术、纳米压痕技术、扫描电镜以及透射电镜对合金改性层的残余应力、硬度以及显微组织随深度的变化进行研究.结果表明,改性层的残余压应力和硬度均随深度增加而减小,影响深度分别为160 和80 μm.通过显微组织观察发现,在80 μm 深度范围以内,残余压应力和硬度的增加是由细晶强化和位错强化共同主导的;在80-160 μm 深度范围内,残余压应力由位错强化主导.通过对硬度与屈服关系的公式进行修正,深入研究了Ti-6Al-4V 合金湿喷丸处理后的强化层.
基金
Project(51405059)supported by the National Natural Science Foundation of China
Project(2014M551074)supported by the China Postdoctoral Science Foundation
Project(NCET-10-0278)supported by the Program for New Century Excellent Talents in University
