摘要
采用钛箔作为中间层扩散连接Ti3Al与Ti2AlNb,利用SEM,EDS和XRD等分析方法发现,接头界面组织结构为Ti3Al/α+β双相组织/富B2相/Ti2Al Nb.分别研究了中间层厚度,连接温度,保温时间等工艺参数对接头界面组织形貌以及力学性能的影响.结果表明,当钛箔厚度10μm,T=900℃,t=120 min,p=5 MPa时,接头组织性能最佳.钛箔厚度增加会导致Ti,Al,Nb等元素扩散不均匀;Ti3Al/Ti2Al Nb直接固相扩散连接温度为1 000℃,加入钛中间层可将其降低至900℃,减小了高温热循环对母材性能的损伤,接头整体抗拉强度从795 MPa提升至906MPa;保温时间90~120 min可保证扩散充分连接可靠.
Ti3Al and Ti2 AlN b alloy were connected by diffusion bonding with Ti foil as interlayer. Through a number of analysis methods such as SEM,EDS and XRD,it was discovered that the typical interface structure of Ti3 Al / Ti / Ti2 AlN b joint was Ti3 Al / α-phase + β-phase / B2-rich phase / Ti2 AlN b. The effect of process parameters,including thickness of interface layer,bonding temperature and holding time,on the interface morphology and property of the joint was investigated. The results show that when the thickness of Ti foil was 10 μm,bonding temperature was 900 ℃ and holding time was 120 min,the resultant Ti3 Al / Ti / Ti2 AlN b joint had the optimized microstructure and properties. Increasing the foil thickness caused uneven diffusion of Ti,Al and Nb. The direct bonding temperature of Ti3 Al /Ti2 AlN b was 1 000 ℃,the addition of Ti foil interlayer could reduce the bonding temperature to 900 ℃. So the damage of high temperature thermal cycling to Ti3 Al alloy was decreased. The tensile strength of the joint increased from 795 MPa to 906 MPa.The holding time from 90 min to 120 min could ensure sufficient diffusion and reliable connection.
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2015年第4期5-8,70+113,共6页
Transactions of The China Welding Institution
基金
国家自然科学基金资助项目(51275135
51305102)
高等学校博士学科点专项科研基金优先发展领域课题资助项目(20112302130005)
关键词
扩散连接
钛铝合金
微观组织
性能
diffusion welding
titanium aluminum alloy
microstructure
property
