新型高强亚稳β钛合金电子束焊接接头组织与力学性能  

Microstructure and Mechanical Properties of the Electron Beam Welded Joint of a New High-Strength Metastable Beta Titanium Alloy

作　　者：张新全 李金山[1,3] 陶曼飞 陈彪 ZHANG Xinquan;LI Jinshan;TAO Manfei;CHEN Biao(State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi'an 710072,China;The First Aircraft Institute of AVIC,Xi'an 710089,China;Innovation Center NPU Chongqing,Chongqing 401135,China)

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072 [2]中航工业第一飞机设计研究院,陕西西安710089 [3]西北工业大学重庆科创中心,重庆401135

出　　处：《铸造技术》2023年第5期411-418,共8页Foundry Technology

基　　金：国家自然科学基金(52274367)。

摘　　要：以新型高强亚稳β钛合金Ti-4Al-5Mo-5Cr-5V-1Nb(Ti-45551)为研究对象,分别对20 mm厚锻态、固溶态和固溶时效态钛合金板材进行电子束焊接,研究了不同母材状态下电子束焊接接头的显微组织和力学性能。结果表明,3种焊件熔合区均为粗大β柱状晶,固溶态+焊接(SW)条件下焊接接头各区域均无α相,而锻态+焊接(FW)和固溶时效态+焊接(AW)条件下随着距离焊缝中心越远,热输入能量越低,在热影响区有残余α相(ghostαphase)存在,并随着距离焊缝中心越远,“ghostαphase”含量增多。3种焊接接头抗拉强度和塑性相近,分别约为760 MPa和7.5%,归因于熔合区均形成粗大柱状β晶组织,应变在该区域集中,导致焊件强度下降,最终在熔合区断裂。A new high-strength metastableβtitanium alloy Ti-4Al-5Mo-5Cr-5V-1Nb(Ti-45551)was studied by electron beam welding on forged,solid-solution and solid-solution aged titanium alloy plates with a thickness of 20 mm.The microstructure and mechanical properties of electron beam welding joints under different base metal states were studied.The results show that the fusion zone of the three kinds of welds consists of coarseβcolumn crystals,and noαphase exists in each region of the welded joint under the condition of solid solution+welding(SW),while the ghostαphase is found in the heat affected zone due to the heat input energy decreaseing with the distance from the weld center under the conditions of forging+welding(FW)and solid solution aging+welding(AW).The content of the"ghostαphase"increases with the distance from the weld center.The tensile strength and plasticity of the three welded joints are similar,approximately 760 MPa and 7.5%,respectively,which is attributed to the formation of a coarse columnarβcrystal structure in the fusion zone,and the concentration of strain in the zone,resulting in a decline in the strength of the welded parts and finally fracture in the fusion zone.

关 键 词：Ti-45551合金 电子束焊接 母材状态 组织 力学性能 

分 类 号：TG146.73[一般工业技术—材料科学与工程]