温度和轧制方向对TC1合金板材疲劳行为的影响

摘要

为了确定试验温度和轧制方向对TC1钛合金板材的高周疲劳寿命及断裂行为的影响,针对平行于和垂直于轧制方向的TC1钛合金板材在不同试验温度下进行了应力控制的拉-拉疲劳试验,并对相应的疲劳断裂机制进行了分析.结果表明,平行于和垂直于轧制方向的TC1钛合金板材的疲劳极限及其在相同外加应力下的疲劳寿命均随着试验温度的升高而降低;相同试验温度下,垂直于轧制方向的TC1钛合金板材的疲劳极限和疲劳寿命均高于平行于轧制方向的TC1钛合金板材.在应力控制的高周疲劳加载条件下,轧制态TC1钛合金板材的疲劳裂纹均以穿晶方式萌生于疲劳试样表面,并以穿晶方式扩展.%In order to identify the influence of testing temperature and rolling direction on the high-cycle fantigue life and fracture behavior of TC1 titanium alloy plate,the stress-controlled tension-tension fatigue tests for TC1 alloy plates both parallel and perpendicular to rolling direction were conducted at different temperatures.And the corresponding fatigue fracture mechanism was analyzed.The results show that for TC1 alloy plates both parallel and perpendicular to rolling direction,the fatigue limit and fatigue lives at the same imposed stress decrease with increasing the testing temperature.At the same temperature,the fatigue limit and fitigue lives of TC1 alloy plate perpendicular to rolling direction are higher than those of TC1 alloy plate parallel to rolling direction.Under the stress-controlled high-cycle fatigue loading condition,the fatigue cracks initiate and propagate in a transgranular mode for the rolled TC1 titanium alloy plate.