摘要
采用120～130Hz的频率测试Ti-600合金光滑试样室温高周轴向应力疲劳性能。结果表明,应力比(R)为0.1时,合金的疲劳强度为475MPa,与IMI834合金相当;合金内含有较细小、薄片状的、互相交错排列的α+β相,这种细小的α+β相间的层状组织对于阻止疲劳裂纹的扩展和提高疲劳裂纹寿命有重要作用;疲劳裂纹扩展阶段,应力同为600MPa时,疲劳寿命为8.61×105的合金试样比寿命为1.78×106的疲劳条纹间距宽;合金内稀土相的尺寸由几个μm到0.2μm变化,合金中未观察到与稀土相颗粒有关的裂纹萌生。
High cycle fatigue（HCF） of Ti-600 alloy was tested at a frequency of 120-130 Hz and load ratio R of 0.1.The results show that the HCF strength for the alloy at ambient temperature is 475 MPa,comparable with that of IMI834 alloy.The observed high tensile strength and high HCF strength is attributed to its overlapping fine and thin-plate-like α＋β phase microstructure.The propagating region of the fatigue crack for the as-annealed composite is regular and wide,which contribute to its improved HCF strength and prolonged fatigue crack propagation life.The distance between two fatigue stripes for the sample fractured at 8.61 105 cycles is wider than that of the sample failed at 1.78 106 cycles,indicating that their propagation resistance for fatigue cracks is smaller.The average grain size of rare earth phases ranges from several micrometers to 0.2 m,and no cracks corresponding to rare earth particles are initiated.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2011年第7期1202-1205,共4页
Rare Metal Materials and Engineering
基金
国家"973"计划资助项目(2007CB613807)
国家科技支撑计划资助项目(2007BAE07B01)
关键词
高温钛合金
Ti-600合金
疲劳强度
疲劳裂纹
稀土相
high temperature Ti alloys
Ti-600 alloy
fatigue strength
fatigue cracks
rare earth phases
