一种Ti_3Al基合金高周疲劳特性的研究

STUDY ON THE HIGH CYCLE FATIGUE OF Ti_3 Al BASED ALLOY

本文研究了Ｔｉ－２５Ａｌ－１０Ｎｂ－３Ｖ－１Ｍｏ（ａｔ－％）合金（简称ＴＤ２合金）棒材、饼材和环形件三种类型的组织及其室温、６５０℃、７００℃的高周疲劳性能。结果表明，ＴＤ２合金具有较高的高周疲劳性能。应用ＳＥＭ，对不同组织在室温和高温下的断口特征进行了分析，用ＴＥＭ观察了疲劳试样上的位错形貌，讨论了ＴＤ２合金疲劳裂纹荫生机制。

In this paper, the high-cycle fatigue properties of Ti-25Al-10Nb-3V-1Mo(at-%)alloy(designated asTD2 alloy),with three different microstructures of its bar, disc and ring, were studied at room tempera-ture, 650℃ and 700℃,The results indicated that This alloy possessed considerable high-cycle fatiguestrength. The dislocation morphology and fractograph of its fatigue specimens with different microstructureswere examined with TEM and SEM. Meanwhile,fatigue crack intiation and growth mechanism of TD2 al-loy was discussed.The conclusion of this work might be helpful to apply Ti3Al matrix alloy as parts beingworked in fatigue stress.