高温热暴露对Ti60钛合金高周疲劳性能的影响
Effect of high temperature thermal exposure on high cycle fatigue performance of Ti60 titanium alloy
张少平 1郭会明 1赵子博 2吴晨 1田伟 1钟燕 1徐建伟 3曾卫东3
作者信息
- 1. 中国航发四川燃气涡轮研究院,四川成都 610500
- 2. 中国科学院金属研究所,辽宁沈阳 110016
- 3. 西北工业大学材料学院,陕西西安 710072
- 折叠
摘要
研究了高温热暴露对Ti60钛合金室温旋转弯曲高周疲劳性能的影响,通过分析试样的表面特征和内部组织,阐明了疲劳性能变化的原因.结果表明,600℃×100 h热暴露后合金的室温强度升高、塑性下降,室温旋转弯曲高周疲劳强度由470 MPa提升至543.3 MPa.疲劳性能的变化是由表面特征和内部组织变化共同引起的,热暴露导致试样表面产生由TiO2及Al2O3组成的氧化膜,表面粗糙度增加、质量变差,对疲劳性能产生不利影响;同时,热暴露致使合金中α2相和硅化物的析出数量增加,且尺寸增加,析出相的变化使得合金强度增加,并进一步提升疲劳强度.综合两方面作用,析出相对旋转弯曲高周疲劳强度的提升强于表面粗糙度增加所产生的不利影响,是疲劳性能提高的主要因素.
Abstract
Effect of high temperature thermal exposure on high cycle fatigue performance of Ti60 titanium alloy during room temperature rotational bending was studied.By analyzing the surface characteristics and internal structure of the samples,the reasons for the changes in fatigue performance were explained.The results show that after thermal exposure at 600 ℃ for 100 h,the room temperature strength of the alloy increases while the plasticity decreases,and the high cycle fatigue strength during the room temperature rotating bending increases from 470 MPa to 543.3 MPa.The changes in fatigue performance are caused by both surface characteristics and internal structural changes.Thermal exposure leads to the formation of an oxide film composed of TiO2 and Al2O3 on the surface of the specimen,resulting in an increase in surface roughness and a decrease in surface quality,which has an adverse effect on the fatigue performance.At the same time,thermal exposure causes an increase in the precipitation amount and size of α2 phase and silicides in the alloy,and the change in precipitates leads to an increase in the strength of the alloy and further enhances its fatigue strength.Taking into account both factors,the improvement of rotational bending high cycle fatigue strength caused by precipitated phases is larger than the adverse effects caused by surface roughness increase,which is the main factor for the improvement of fatigue performance.
关键词
Ti60钛合金/热暴露/高周疲劳性能/析出相/表面特征Key words
Ti60 titanium alloy/thermal exposure/high cycle fatigue performance/precipitation/surface characteristics引用本文复制引用
基金项目
"两机"专项基础研究(J2019-VI-0005-0119)
出版年
2024
NETL
NSTL
万方数据