二次孔挤压强化对Ti1023钛合金孔疲劳性能影响

摘要

The property of the surface layer of twice hole expansion Ti1023 alloy was analyzed by TEM, X-ray and roughness tester, and the strengthen mechanism of the bushing hole expansion was discussed. The results indicate that the roughness(Ra1. 722→0. 349μm), hardness(Hv32→38) and residual stress distribution of the hole are improved by twice hole expansion techniques,and the fret-ting wear fatigue(fatigue limits 385→619MPa)of Ti1023 alloy is improved.%采用X射线应力仪、粗糙度检测仪和透射电镜等对Ti1023钛合金孔挤压表面层性能进行对比分析，讨论带衬套孔的强化机理。结果表明：孔挤压(过盈量1%~3%)强化改善了孔壁表面粗糙度( Ra 从1.722μm降低到了0.349μm)，增加了钛合金表面硬度(Hv值从32提高到了38)，引入了残余应力场分布，从而改善了钛合金的微动疲劳性能(极限值从385 MPa提高到了619 MPa)。