中文摘要：

拉伸断裂极限值是预测零件高温裂纹的主要依据。为了研究工业纯钛在高温拉伸下的断裂极限,采用理论模型和试验相结合的方法,通过GFL(Gleeble fracture limit)试验测得工业纯钛在不同温度下的真应力-应变曲线,并利用真应力-应变曲线求得工业纯钛的断裂极限值,分析了温度和应变速率对断裂极限值的影响。结果表明,温度和应变速率对断裂极限值有较大影响。温度升高使断裂极限增加,在应变速率为0.1 s-1下随着温度从800℃升高到1000℃,断裂极限值从1.798增加到2.343;在900℃相同温度下,随着应变速率从0.01 s-1的提高到1 s-1,断裂极限值从2.496降低到1.745。

英文摘要：

Tensile fracture limit is the main index of high temperature crack prediction during industrial processing .A combining method of theory model and experiment processing was adopted to study the tensile fracture limit of commercial pure titanium ( CP-Ti ) at high temperature.By means of GFL (Gleeble fracture limit) test, the true stress-strain curve was obtained and the fracture limits were figured out.The effect of strain rate and temperature on the fracture limit was analyzed .The results show that the strain rate and temperature have significant influences on the fracture limit .The fracture limit always increases with the temperature increasing , under the strain rate of 0.1 s-1 , the fracture limit increases from 1.798 to 2.343 when the temperature raises from 800 ℃ to 1000 ℃.Under the temperature of 900 ℃, the fracture limit decreases from 2.496 to 1.745 when the strain rate increases from 0.01 s-1 to 1 s-1 .