摘要
研究了喷丸强化对TC17钛合金表面完整性及疲劳寿命的影响。采用表面粗糙度仪、扫描电子显微镜、X射线残余应力测试仪、显微硬度计等分析了弹丸种类和喷丸强度对表面粗糙度、残余应力场、显微硬度场和微观组织的影响;在旋转弯曲疲劳试验机上测试了喷丸强化后的疲劳寿命,探讨了表面完整性与疲劳寿命的内在联系及作用机制。结果表明:喷丸强化后TC17钛合金表面粗糙度为0.5~1.0μm,残余压应力层为100μm左右,最大残余压应力位于表面下30μm处,表面出现加工硬化,晶粒发生了压缩变形;与未喷丸试样相比,玻璃丸对疲劳寿命的提升幅度最大,陶瓷丸次之,铸钢丸最小。喷丸强化提高疲劳寿命的机制归结于引入较深的残余应力层、较高的表面硬化程度和表层晶粒的细化。
The effect of shot penning on the surface integrity and fatigue life of TC17alloy was investigated.The effectof shot type and shot peening intensity on surface roughness,residual stress,microhardness,and microstructure wasanalyzed by using surface roughness tester,a scanning electron microscopy,X-ray diffraction residual stress analyzer,microhardnessinstrument,etc.The fatigue life before and after shot peening was tested by rotating bending fatigue testingmachine.The relationship between surface integrity and fatigue life was discussed.Results show that surface roughness(Ra)of0.5~1.0μm was obtained after shot peening,the thickness of compressive residual stress layer was approximately100μm,and the maximum compressive residual stress was located at about30μm depth beneath the surface,work hardening andgrain deformation were observed.Compared with the fatigue life of untreated specimens,the longest fatigue life is obtainedwhen utilizing glass shot,then utilizing ceramic shot,last utilizing cast steel shot.The mechanism of improving fatigue lifeafter shot peening is due to the induced deep compressive residual stress layer,high surface hardening degree and surfacegrain refinement.
作者
张少平
谈军
谭靓
姚倡锋
ZHANG Shaoping;TAN Jun;TAN Liang;YAO Changfeng(AECC Sichuan Gas Turbine Research Establishment, Chengdu 610500, China;AECC Aviation Power Co., Ltd., Xi’an 710021, China;Key Laboratory of Contemporary Design and Integrated Manufacturing Technology, Ministry of Education,Northwestern Polytechnical University, Xi’an 710072, China)
出处
《航空制造技术》
2018年第5期89-94,共6页
Aeronautical Manufacturing Technology
