激光增材连接TC4-DT钛合金的组织及力学性能  

Structure and mechanical properties of TC4-DT titanium alloy by laser additive joining

作　　者：高旭 沈淑馨 何蓓 汤海波 GAO Xu;SHEN Shuxin;HE Bei;TANG Haibo(National Engineering Laboratory of Additive Manufacturing for Large Metallic Components,Beihang University,Beijing 100191,China;School of Materials Science and Engineering,Beihang University,Beijing 100191,China;Research Institute for Frontier Science,Beihang University,Beijing 100191,China)

机构地区：[1]北京航空航天大学大型金属构件增材制造国家工程实验室,北京100191 [2]北京航空航天大学材料科学与工程学院,北京100191 [3]北京航空航天大学前沿科学技术创新研究院,北京100191

出　　处：《材料工程》2023年第5期27-35,共9页Journal of Materials Engineering

基　　金：国家科技重大专项(2019-Ⅶ-0004-0144);国家自然科学基金(52101033)。

摘　　要：采用激光增材连接技术对“X”型坡口TC4-DT钛合金锻件进行连接,利用OM和SEM对连接后TC4-DT钛合金基材、热影响区和连接区三个区域的宏微观组织形貌进行表征分析;采用维氏硬度计测量三个区域的显微硬度;采用万能试验机和摆锤冲击仪对不同取样类型的试样进行室温拉伸和冲击实验。结果表明:激光增材连接区与基体形成致密的冶金结合;显微硬度分布从基材到连接区呈递增趋势;随着拉伸试样中连接区占比的降低,TC4-DT钛合金的强度表现为先升高后降低,而塑性却呈现降低的趋势;冲击韧性a kU均在55 J/cm^(2)以上,U型缺口开口方向对连接区冲击韧性影响较大,对结合区冲击韧性无明显影响。TC4-DT titanium alloy forgings with X-type groove were joined by laser additive joining technology.OM and SEM were used to characterize the macro and micro morphology of TC4-DT titanium alloy base metal,heat affected zone and joining zone.The microhardness of the three regions was measured by Vickers hardness tester.The tensile and impact tests of different samples were carried out at room temperature with universal testing machine and pendulum impactor.The results show that there is a dense metallurgical bond between the joining zone and the base metal.Distribution of microhardness from the base metal to the joining zone shows an increasing trend.The strength of TC4-DT alloy increases first and then decreases with the decrease of the proportion of the joining zone in tensile specimen,while the plasticity decreases.The impact toughness a kU is above 55 J/cm^(2).The position of U-shaped notch opening has a great effect on the impact toughness of the joining zone but not the bond zone.

关 键 词：激光增材连接 TC4-DT钛合金 显微组织 力学性能 

分 类 号：TG115[金属学及工艺—物理冶金]