含孔钛合金扩散连接止焊层合板裂纹扩展特性试验  

Crack Growth Characteristic for Diffusion Bonded Laminates of TC4 Titanium Alloy with Localized No-Welded Area

作　　者：贺小帆[1] 刘彦毛[1] 刘文珽[1] 孙彦鹏[2] 王向明[2] 

机构地区：[1]北京航空航天大学航空科学与工程学院,北京100191 [2]沈阳飞机设计研究所,沈阳110035

出　　处：《航空材料学报》2011年第5期77-81,共5页Journal of Aeronautical Materials

基　　金：航空基金(2010ZA51002);973项目(613658);中央高校基本科研业务费专项资金

摘　　要：带有局部圆形止焊区的钛合金扩散连接层合板能够改善层合板在拉-拉疲劳载荷作用下的裂纹扩展性能,为了研究止焊区尺寸对裂纹扩展寿命的影响,采用3mm,2mm,3mm厚钛合金板材通过扩散连接成8mm厚层合板,层合前预留12mm,15mm止焊区,并加工成含中心6mm孔的板状试件,进行了两类试件在含标识载荷的等幅载荷下的疲劳试验。通过断口判读裂纹形态和尺寸,得到裂纹扩展(a,N)数据,建立了裂纹扩展da/dN-a曲线,对裂纹扩展行为进行了对比。结果表明,裂纹扩展可分为3个阶段;止焊区尺寸对止焊区内裂纹扩展行为无明显影响,但随着止焊区尺寸的增加,止焊区边界附近和越过边界后的裂纹扩展速率有减缓趋势。To research the crack growth characteristics of diffusion bonded laminates with localized no-welded region of TC4 titanium alloy,the fatigue tests for 8mm thick TC4 three-layer diffusion bonded laminates with localized 12mm and 15mm no-welded area were conducted under the constant amplitude fatigue stress of R=0.093 inserted with marker load of R=0.7.The crack growth（a,N） data were obtained by QF.The analysis on the failure surface shows the crack growth could be divided into three phases.The contrast on the da/dN-a curves of those coupons shows that the crack growth characteristic in the no-welded area has no difference,the crack growth rate of the 15mm no-welded area is lower than that of 12mm no-welded area in the welded boundary area.

关 键 词：钛合金 扩散连接 层合板 裂纹扩展 

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] TG146.2[一般工业技术—材料科学与工程]