【作者】 杨丽娜； 刘建荣； 陈志勇； 王清江； 杨锐；

【Author】 YANG Li-na,LIU Jian-rong,CHEN Zhi-yong,WANG Qing-jiang,YANG Rui (Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China)

【机构】 中国科学院金属研究所；

【摘要】 研究了高应力水平下加载波形对Ti-60高温钛合金疲劳损伤行为的影响。结果发现:对于在峰值应力处保载2min的加载波形,试样的疲劳寿命明显低于无保载的加载波形的试样的寿命;在保载疲劳条件下,单位循环周次内材料的疲劳变形明显增大。SEM观察表明,在保载波形下,疲劳源出现在样品内部,而无保载的加载波形下疲劳裂纹源于样品次表面。TEM观察表明,在两种疲劳加载条件下,都有(1011)滑移系启动。更多还原

【Abstract】 The effect of loading waveform on fatigue damage behavior of Ti-60 alloys at high stress level was studied. The results show that,under the loading waveform with 2 min dwell at the peak stress,the fatigue life is shorter than that without dwell.The fatigue strain in a unit cycle under the dwell fatigue condition is obviously larger than that under the no-dwell fatigue condition.It is observed by SEM mat,under the dwell fatigue condition,the fatigue crack originates from the interior of specimens,while under the no-dwell fatigue condition,the fatigue crack originates from the subsurface of specimens.TEM observation indicates that,under the two loading waveforms,(1011) slip system is activated.更多还原