TC4金字塔点阵结构的激光焊接及其平压性能  

Manufacturing Process and Compression Performance of TC4 Pyramid Lattice Structure with LaserWelding

作　　者：刘玮 王辉 褚兴荣[1] 王延刚[1] 高军[1] LIU Wei;WANG Hui;CHU Xingrong;WANG Yangang;GAO Jun(School of Mechatronics and Information Engineering,Shandong University(Weihai),Weihai 264209,China)

机构地区：[1]山东大学(威海)机电与信息工程学院,威海264209

出　　处：《材料研究学报》2021年第8期623-631,共9页Chinese Journal of Materials Research

基　　金：山东省自然科学基金(ZR2019MEE008);山东省重点研发计划(2019TSLH0103)。

摘　　要：基于用高温节点下压法成形的TC4钛合金芯体,用面芯激光焊接制备了钛合金金字塔点阵结构。用响应曲面法优化激光焊接参数,实现了点阵结构面芯连接,分析焊接节点的微观组织并进行了点阵结构平压实验。结果表明:激光功率对焊接效果有显著的影响。点阵结构面芯激光焊接的优化工艺参数为:上面板的焊接功率为1.4 kW,下面板的焊接功率为1.2 kW,离焦量为30 mm,停留时间为1 s。在激光焊接热影响区发生了马氏体转变,分布着大量的针状马氏体;熔焊区的组织为粗大β相+针状α相。在焊接节点处,从熔焊区到母材的显微硬度随着马氏体相的减少而降低。根据平压实验结果分析了金字塔点阵结构变形和破坏的规律,桁架杆失效断裂发生在热影响区。用激光焊接制备的TC4钛合金点阵结构,其平压强度为3.09 MPa,平压模量为153.25 MPa。Based on the TC4 Ti-alloy core formed by alternating pin-press method at high-temperature,the laser welding connection process of the panel and the core was investigated in order to manufacture the pyramid lattice structure of Ti-alloy.The laser welding parameters were optimized by response surface method,the plane and core of lattice structure were connected,the microstructures of welding joints were examined,and the compression performance of lattice structure was investigated.The results show that the laser power has the most significant influence on the welding result.The optimized parameters of laser welding of lattice structure face core were as follows:welding power of upper panel was 1.4 kW,welding power of lower panel was 1.2 kW,defocusing quantity was 30mm,and residence time was 1 s.The martensite transformation of Ti-alloy occurred,and a large number of acicular martensite phases distributed in the heat affected zone of laser welding.The microstructure of welding zone was coarseβphase and acicularαphase.The microhardness decreased from the weld zone to the base metal in the welding joints with the decreasing of martensite phase.Based on the compression process recorded by the camera the deformation and failure process of the pyramid lattice structure were analyzed.The failure fracture of truss rod occurred in the heat-affected zone.The compression pressure strength and modulus of the TC4 Ti-alloy lattice structure manufactured by laser welding were 3.09 MPa and 153.25 MPa,respectively.

关 键 词：金属材料 金字塔点阵结构 激光焊接 微观组织 平压性能 

分 类 号：TG430.40[金属学及工艺—焊接]