钛合金低周疲劳性能研究

Research on Low Cycle Fatigue Property of Titanium Alloys

摘要:

采用轴向应变控制的方法，在Ｉｎｓｔｒｏｎ－１３４３型万能疲劳试验机上测定了ＴＡ５钛合金的低周疲劳性能数据，研究了在循环载荷下该材料的应变与寿命的关系，初步预测了ＴＡ５钛合金的低周疲劳寿命。结果表明，塑性变形是造成ＴＡ５合金疲劳损伤的根本原因；通过试验求得的该材料的应变与寿命关系曲线其对数方程为一直线ε_ｔ＝０．０２８８Ｎ~（－０．１９９７）（其中相关系数ｒ＝０．９９１４．标准差Ｓ＝０．２１５３）；ＴＡ５钛合金具有循环软化的特性；其低周疲劳断口具有明显的挤压条纹特征。

关键词:钛合金 循环载荷 低周疲劳

Abstract:

n this paper, low cycle fstigue property of Ti alloy TA5 was determined in a type of instron 1343 universal fatigue testing machine by using an axle strain controlled method.Strain-life relation of the material under cyclic loading was investigated, low cycle fatigue lifeof a Ti alloy was preliminarily predicted. Results show that the plastic deformation is the basic reason resulting in the fatigue damage of Ti alloy TA15. A logarithmic equation for strain-life curve of the material obtained by a test is linear equation:= 0.0288N -0.1997(wherecorrelation coefficient is 0. 9914, standand difference is 0.2153). Titanium alloy TA5 hascharacteristic of cyclic softening: low cycle fatigue fracture has obvious extrusion streak.

Key words:Titanium alloys TA5 cycle loading low cycle fatigue,