TC4和TC4-DT钛合金耐久性及损伤容限性能对比研究  

Comparative Study on Durability and Damage Tolerance of TC4 and TC4⁃DT Titanium Alloys

作　　者：江旭来 王勇军 张立新 JIANG Xulai;WANG Yongjun;ZHANG Lixin(Chengdu Aircraft Design&Research Institute,Chengdu 610041,China)

机构地区：[1]成都飞机设计研究所,四川成都610041

出　　处：《飞机设计》2024年第5期12-17,共6页Aircraft Design

摘　　要：随着军用飞机上越来越多的结构件使用损伤容限型钛合金(TC4-DT),对于TC4-DT和TC4钛合金的耐久性和损伤容限性能对比研究就变得十分迫切。为了对比2种材料的疲劳性能,构建了基于局部应力-应变法的裂纹萌生寿命预测模型和基于Walker公式和Willenborg迟滞模型的裂纹扩展寿命预测模型。采用单片双孔试验件开展了随机谱下的疲劳试验,验证了该方法的正确性。采用同样方法对TC4和TC4-DT在等幅谱下的疲劳全寿命试验结果进行了分析,并计算了典型试验件在300~400 MPa应力水平随机谱下使TC4-DT材料裂纹萌生寿命增加到TC4水平所需增重百分比,使TC4材料裂纹扩展寿命增加到TC4-DT水平所需增重百分比。TC4-DT材料在裂纹扩展寿命上的优势并不如TC4材料在裂纹萌生寿命上的优势明显,飞机结构应该综合考虑耐久性和损伤容限设计准则来对TC4和TC4-DT的选用做出权衡。As more and more structural parts of military aircraft utilized damage tolerance titanium alloy(TC4⁃DT),it is very urgent to compare the durability and damage tolerance of TC4⁃DT and TC4 titanium alloy.In order to compare the fatigue life characteristics of the two materials,a crack initiation life prediction model based on local stress⁃strain method and a crack propagation life prediction model based on Walker formula and Willenborg model were introduced.A fatigue test of double⁃hole coupon under random spectrum is carried out to verify the correctness of the method.By using the same method,the fatigue test of TC4 and TC4⁃DT titanium alloy under constant amplitude spectrum was analyzed.The percentage of weight gain required to increase the crack initiation life of TC4⁃DT material to the level of TC4 and the percentage of weight gain required to increase the crack propagation life of TC4⁃DT material to the level of TC4⁃DT at 300~400 MPa stress level under random spectrum were calculated.It is concluded that the superiority of TC4⁃DT material in crack growth life is not as obvious as that of TC4 material in crack initiation life.For the aircraft structure,both durability and damage tolerance design criteria should be taken into consideration to make a choice between TC4 and TC4⁃DT.

关 键 词：TC4 TC4-DT 耐久性 损伤容限 裂纹萌生寿命 裂纹扩展寿命 重量对比 

分 类 号：V215.5[航空宇航科学与技术—航空宇航推进理论与工程]