摘要
本文研究了氢处理对铸造钛合金的低周疲劳寿命及断裂韧性的影响,发现经氢处理后铸造钛合金粗大的魏氏组织转变成细小的等轴组织,其应变低周疲劳寿命大大延长,在低周疲劳过程中,应变量较小时,试样出现循环硬化现象,而在应变量较大时,出现循环软化现象,氢处理后材料的断裂形式由脆性断裂转为韧性断裂;断裂韧性提高。
This paper prcsents the results of an investigation of the influence of hydrogen treatment on the low cycle fatigue life and fracture toughness of Ti-6AI-4V cast alloy The coarse widmanstatten micrcstructure of the cast titanium alloy was bro- ken up into a very fine equiaxed microstrueture after hydrogen treatment.The strain LCF life of the cast alloy refined by hydrogen treatment was greatly increased.The results of LCF test showed that the cyclic hardening is assoc- iated with the low strain amplitudes and the cyclic softening with the high strain amplitudes.After hydrogen treatment the brittle fracture morphology of specimen as cast transformed into ductile one,and the fracture toughness is improved.
关键词
氢处理
钛合金
疲劳
寿命
断裂
hydrogen treatment
cast titanium alloy
fatigue life
fracture toughness
