Ti_2AlNb相合金Ti-22Al-25Nb的TLP扩散连接  

The TLP Diffusion Bonding of Ti_2AlNb-Based Alloy Ti-22Al-25Nb

作　　者：邹贵生[1] 白海林[1] 谢二虎[1] 吴爱萍[1] 王庆[1] 任家烈[1] 

机构地区：[1]清华大学教育部先进成形制造重点实验室,北京100084

出　　处：《稀有金属材料与工程》2008年第12期2181-2185,共5页Rare Metal Materials and Engineering

基　　金：清华大学基础研究基金项目(Jcqn2005011)

摘　　要：以Ti-15Cu-15Ni合金薄带作中间层,用Gleeble1500D热-力学模拟试验机对Ti2AlNb相合金Ti-22Al-25Nb进行TLP扩散连接。研究了连接参数对接头组织演变、元素分布、接头强度及其断裂特征的影响。结果表明,接头形成过程由5个阶段组成,Nb是接头成分均匀化的扩散主控元素。适当延长保温时间和适当提高连接温度有利于获得组织与成分均匀的高强接头。保温结束后接头快速冷却时,其连接区室温组织为B2相;而采用慢冷工艺有利于促进高温β相的相变从而改善连接区组织,室温组织为B2相基体和少量α2、O相。连接温度和保温时间分别为990℃和90min且采用慢冷工艺时,接头的室温和650℃抗拉伸强度分别为1041MPa和659MPa,分别达到原始母材强度的95%和81%,明显高于采用快冷工艺的接头强度。Ti2AlNb-based alloy Ti-22Al-25Nb was joined with the transient liquid phase （TLP） diffusion bonding using the Ti-15Cu-15Ni film as interlayer on a thermal-mechanical simulator Gleeble 1500D. The effects of bonding parameters on the joint features such as microstructures, element distribution, tensile strength and fracture characteristics have been investigated. The formation of a joint consists of five steps, and Nb is the mainly controlling diffusion element to the formation of composition-homogenous bonding zone. A suitably long holding time and high bonding temperature are beneficial to the formation of joints with homogeneous compositions and high strength. The bonding zone of joint with a rapid cooling technology after dwelling at bonding temperature is composed of pure B2 phase. A slow cooling technology is beneficial to promoting the phase transformation of the high-temperature phase β and thus modifying the microstructures of the joints, and the bonding zone is composed of matrix B2 and a small amount of α2 and O. The tensile strengths at room temperature and 650 ℃ of the joint that was performed under the conditions of bonding temperature 990℃ for 90 min with a slow cooling technology, reached up to 1041 MPa and 659 MPa, which are equal to that of 95 % and 81% of base material themselves, respectively, obviously higher than the strengths of joints with a rapid cooling technology.

关 键 词：Ti2AlNb相合金 TLP扩散连接 显微组织 

分 类 号：TG453.9[金属学及工艺—焊接]