This paper investigates the effects of ultrasonic shot peening (USP) on surface morphology, microstructure, and residual stress field distribution of TC17 alloy under different process parameters. The aim is to reveal the surface strengthening mechanism of TC17 alloy caused by USP. The results suggest that the use of the 2.5 mm projectile diameter leads to an increase in surface roughness, plastic deformation, and a deeper grain refinement layer compared to the 1.5 mm projectile diameter. Additionally, it results in a greater depth of the compressive residual stress layer and maximum compressive residual stress. The crack initiation sites under two projectile diameters are located below the compressive residual stress layer. The USP treatment introduces compressive residual stress on the surface, inhibiting the initiation of surface cracks, and the deeper compressive residual stress layer offsets the early fatigue failure caused by higher roughness.

中文翻译：

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TC17合金超声波喷丸表面强化效果

本文研究了不同工艺参数下超声喷丸（USP）对TC17合金表面形貌、显微组织和残余应力场分布的影响。目的是揭示USP引起TC17合金表面强化的机制。结果表明，与 1.5 mm 弹丸直径相比，使用 2.5 mm 弹丸直径会导致表面粗糙度、塑性变形增加和更深的晶粒细化层。此外，它还导致压缩残余应力层的深度更大以及最大压缩残余应力。两个弹丸直径下的裂纹萌生部位均位于残余压应力层下方。 USP处理在表面引入残余压应力，抑制表面裂纹的萌生，更深的残余压应力层抵消了较高粗糙度引起的早期疲劳失效。