摘要
针对航空钛合金零件在加工过程中存在的抗疲劳性能不足等问题,提出了通过旋转超声铣削技术改善表面残余应力,从而提高钛合金抗疲劳性能。重点开展了旋转超声铣削钛合金残余应力以及疲劳寿命试验研究,并且通过扫描电镜对钛合金疲劳断口进行了观察。研究结果表明,与普通铣削相比,旋转超声铣削后钛合金表面残余压应力显著提高,疲劳试验结果表明旋转超声铣削最大可提高钛合金疲劳寿命25%。经疲劳断口观察,旋转超声铣削减少了裂纹源,降低了疲劳条纹宽度,有效地抑制了疲劳裂纹扩展。
Regarding the problem of aero titanium alloy parts'lacking fatigue resistance in the process of machining,it is proposed to improve the surface residual stress by rotary ultrasonic milling in order to improve the fatigue resistance performance of aviation titanium alloy materials.Experiments were carried out to study the residual stress and fatigue life of titanium alloy during rotary ultrasonic milling,with the fatigue crack observed through SEM.Results shows that,compared with conventional milling,the surface residual compressive stress of titanium alloy significantly increases after rotary ultrasonic machining.Fatigue experiment shows that the fatigue life of titanium alloy can be extended by 25%maximally during rotary ultrasonic machining.Through fatigue crack observation,it's found that ultrasonic machining reduces the number of crack initiations and the width of fatigue stripe,thus effectively inhibiting fatigue crack growth.
作者
苗迪迪
郑达
郑侃
薛枫
Miao Didi;Zheng Da;Zheng Kan;Xue Feng(Nanjing University of Science and Technology,Nanjing 210094,China;AVIC Shenyang Aircraft Design Institute,Shenyang 110035,China)
出处
《航空科学技术》
2020年第6期73-77,共5页
Aeronautical Science & Technology
基金
航空科学基金(20171659001)。
关键词
TC4钛合金
旋转超声铣削
残余应力
疲劳寿命
疲劳断口
TC4 titanium alloy
rotary ultrasonic milling
residual stress
fatigue life
fatigue fracture
作者简介
苗迪迪(1996-)男,硕士。主要研究方向:旋转超声加工技术。Tel:18323241683,E-mail:18323241683@163.com;郑侃(1983-)男,博士,副教授。主要研究方向:旋转超声加工技术。Tel:13655194980,E-mail:zhengkan@njust.edu.cn。
