(北京航空材料研究院, 北京100095)
摘 要: 研究了高强度钛合金Ti-10V-2Fe-3Al表面喷丸强化所产生的表面形貌、 表面粗糙度、 表面残余应力和表面层残余压应力场变化及喷丸对其拉-拉疲劳性能的影响。 结果表明: 喷丸强化可使Ti-10V-2Fe-3A钛合金的表面粗糙度减小和表面层产生一定深度的残余压应力场, 喷丸强化引起的表面完整性的改善显著提高了疲劳性能。 疲劳试验结果证实了喷丸强化不仅可以显著延长高强度钛合金Ti-10V-2Fe-3Al的拉-拉高周疲劳寿命, 而且可使1×107周次下的疲劳极限提高约30%, 且表面喷丸强化后疲劳裂纹源由多个变为一个。
关键字: 钛合金; 疲劳; 喷丸; 残余应力
in Ti-10V-2Fe-3Al titanium alloy
( Institute of Aeronautical Materials, Beijing 100095, China)
Abstract: The changes of surface topography, surface roughness, surface residual stress and compressive residual stress field caused by shot peening and their effects on tension-tension fatigue properties in Ti-10V-2Fe-3Al titanium alloy were studied. The results show that the fatigue limit for 1×107 cycles is improved by about 30% with shot peening and confirm that shot peening can improve tension-tension fatigue properties of metals. Moreover, fatigue crack source is single after shot peening. The reason why tension-tension fatigue properties of metals can be modified by shot peening is that the surface integrity such as better surface finish roughness and beneficial compressive residual stress field can be induced by shot peening.
Key words: titanium alloy; fatigue; shot peening; residual stress