中文摘要：

研究了喷丸强化与表面完整性对TC21钛合金疲劳性能的影响规律。利用X射线应力仪、粗糙度仪、扫描电子显微镜、显微硬度计等分析了喷丸强化对TC21钛合金表面残余应力场、表面粗糙度、表面形态特征及表面加工硬化的影响作用,探讨了喷丸强化对TC21钛合金疲劳抗力的作用机制。结果表明：优化工艺参数下的喷丸强化能够显著提高TC21钛合金的疲劳抗力,然而并不是喷丸强度越高强化效果越好,而是存在着最佳的喷丸强化参数,此条件下可获得良好的表面完整性,因而疲劳抗力亦高。过高强度的喷丸处理破坏了钛合金的表面完整性,反而损害钛合金的抗疲劳性能。因此,在喷丸强化工艺参数选取时,不宜盲目地追求过高的喷丸强度,而忽视钛合金的表面完整性。

英文摘要：

The influence of shot peening intensity,and surface integrity on fatigue properties of TC21 titanium alloy was studied to improve fatigue resistance of the high strength titanium alloy.The influence of shot peening on surface residual stress,surface roughness,surface morphology and surface hardness was studied by using X-ray diffraction analysis,surface profile measurement,scanning electron microscopy and microhardness instrument,etc.The mechanism of fatigue resistance improved by shot peening was also discussed.The results reveal that the effect of fatigue properties can be obviously improved by optimized shot peening process.But the fatigue properties is not a simple monotonic variation with shot peening intensity.The surface integrity and fatigue resistance are the most optimum in a certain shot peening parameters,while they will be decreased by exorbitant shot peening intensity.Therefore,when choosing shot peening parameters,it is blinded to merely pursue exorbitant intensity and ignore the surface integrity of metal materials.