摘要
针对航空发动机在腐蚀环境下存在的超高周疲劳问题,先对TC17钛合金进行加速腐蚀处理,然后应用超声疲劳试验系统在室温下研究了腐蚀对TC17钛合金超高周疲劳性能的影响,最后观察了疲劳断口形貌。结果表明:在疲劳循环大于107周次时,腐蚀与未腐蚀的试样都会发生疲劳断裂,并不存在明显的疲劳极限;腐蚀后钛合金的疲劳强度略有降低,且随着载荷循环周次的增加,其S-N曲线更接近未腐蚀钛合金的;腐蚀后钛合金的疲劳源位于表面,氧化膜破坏导致的点蚀是疲劳裂纹于表面萌生的主要原因。
Aiming at solving the problem of very high cycle fatigue for the aero-engine in the corrosive environment,accelerated corrosion treatments were performed on TC17 titanium alloy,and the effect of corrosion on very high cycle fatigue properties of TC17 titanium alloy was studied by using the ultrasonic fatigue testing system at room temperature.The experimental results indicate that the pre-corrosion and without-corrosion specimens tested to failure in the range above 107 cycles did not show obvious fatigue limit and express the fatigue fracture.The fatigue strength reduced a little for the pre-corrosion specimen,and the S-N curves were much close to each other for the two kinds of specimens with the increase of the cyclic number.The fatigue sources were all located at the surface of specimens after corrosion,the pitting caused by destructive oxidation film was the main reason of fatigue cracks initiation on the surface.
出处
《机械工程材料》
CAS
CSCD
北大核心
2014年第11期76-79,94,共5页
Materials For Mechanical Engineering
