线能量密度对内燃机用激光增材Ti2AlNb合金组织及力学性能的影响  

Effect of Linear Energy Density onthe Microstructure and Mechanical Properties of Laser Additive Manufactured Ti2AlNb Alloy for Internal Combustion Engine

作　　者：王红伟[1] 尹冠飞[1] 李峰[2] 白含岭 Wang Hongwei;Yin Guanfei;Li Feng;Bai Hanling(School of Automotive Engineering,Henan Vocational and Technical College,Zhengzhou 450046,Henan,China;School of Mechanical Engineering,Henan Polytechnic University,Wuxi 214122,Jiangsu,China;Zhengzhou Yutong Bus Co.,Ltd.,Zhengzhou 450061,Henan,China)

机构地区：[1]河南职业技术学院汽车工程学院,河南郑州450046 [2]河南理工大学机械工程学院,江苏无锡214122 [3]郑州宇通客车股份有限公司,河南郑州450061

出　　处：《应用激光》2023年第1期52-58,共7页Applied Laser

基　　金：河南省高等学校人文社会科学研究项目(2021-ZDJH-0181)。

摘　　要：选择内燃机用Ti2AlNb锻造试样作为测试材料,对其实施送粉激光增材处理并测试不同激光能量密度下的熔覆组织特性,分析试样结合区的力学特性变化。研究结果表明:线能量密度为100 J/mm时,下部基材区形成与锻态基材同样的组织结构;顶部区域中存在对沉积层形成穿透的β柱状晶。下部区域存在等轴形态与片层状两种α相;中部包含了等轴与片层状α相,β相内还存在次生α相,该相数量随线能量密度提高而增长;上部结合区中形成魏氏组织,在β晶粒中存在α片层组织。提高线能量密度后,试样拉伸强度与屈服强度减小,而延伸率变大。线能量密度为100 J/mm时,形成力学性能最优的结合区组织,获得最大拉伸与屈服强度。试样拉伸断口存在剪切唇以及韧窝形貌,发生了韧性断裂。The Ti2AlNb forging sample used for internal combustion engine was selected as the test material.The powder feeding laser additive treatment was applied to the sample.The microstructure characteristics of cladding under different laser energy densities were tested,and the mechanical properties of the bonding zone of samples were analyzed.Results show that when the linear energy density is 100 J/mm,the microstructure of lower substrate is the same as that of the forged substrate.There areβcolumnar crystals in the apical region that penetrate into the sedimentary layer.There are twoαphases in the lower region,i.e.,equiaxed and lamellar.There are equiaxed and lamellarαphases in the middle part,and secondaryαphases in theβphase.The number ofαphases increases with the increasing of linear energy density.There areαlamellar structures in theβgrains.When the linear energy density is increased,the tensile strength and yield strength decrease,while the elongation increases.When the linear energy density is 100 J/mm,the microstructure of the bond zone with the best mechanical properties is formed,and the maximum tensile and yield strength is obtained.There are shear lip and dimple morphology in the tensile fracture of the specimen,and the ductile fracture occurs.

关 键 词：激光增材制造 线能量密度 结合区 显微组织 力学性能 

分 类 号：TG146[一般工业技术—材料科学与工程]