Improving fatigue performance of Ti-6Al-4V alloy via ultrasonic surface rolling process  

作　　者：Chengsong Liu Daoxin Liu Xiaohua Zhang Dan Liu Amin Ma Ni Ao Xingchen Xu 

机构地区：[1]Corrosion and Protection Research Laboratory,Northwestern Polytechnical University

出　　处：《Journal of Materials Science & Technology》2019年第8期1555-1562,共8页材料科学技术（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (No. 51771155)

摘　　要：The effect of a gradient nanostructured(GNS) surface layer obtained by ultrasonic surface rolling process(USRP) on the fatigue behavior of Ti-6Al-4V alloy has been studied in this paper. Microstructure, surface topography, surface roughness and residual stress measurements were performed to characterize the surface under different conditions. Rotating bending fatigue tests were carried out to evaluate the fatigue behavior of different treatments. The results present a remarkable fatigue performance enhancement for the Ti-6Al-4V alloy with a GNS surface layer obtained by application of USRP with respect to the untreated condition, notwithstanding its considerable surface roughness due to severe ultrasonic impacts and extrusions. Mechanical surface polishing treatment further enhances the beneficial effects of USRP on the fatigue performance. The significantly improved fatigue performance can mainly be ascribed to the compressive residual stress. Simultaneously, the GNS surface layer and surface work hardening have a synergistic effect that accompanies the effect of compressive residual stress.The effect of a gradient nanostructured(GNS) surface layer obtained by ultrasonic surface rolling process(USRP) on the fatigue behavior of Ti-6Al-4V alloy has been studied in this paper. Microstructure, surface topography, surface roughness and residual stress measurements were performed to characterize the surface under different conditions. Rotating bending fatigue tests were carried out to evaluate the fatigue behavior of different treatments. The results present a remarkable fatigue performance enhancement for the Ti-6Al-4V alloy with a GNS surface layer obtained by application of USRP with respect to the untreated condition, notwithstanding its considerable surface roughness due to severe ultrasonic impacts and extrusions. Mechanical surface polishing treatment further enhances the beneficial effects of USRP on the fatigue performance. The significantly improved fatigue performance can mainly be ascribed to the compressive residual stress. Simultaneously, the GNS surface layer and surface work hardening have a synergistic effect that accompanies the effect of compressive residual stress.

关 键 词：ULTRASONIC SURFACE rolling process Fatigue COMPRESSIVE residual stress Gradient nanostructured SURFACE layer TI-6AL-4V alloy 

分 类 号：TG[金属学及工艺]