丝束同轴束源模式对电子束熔丝增材制造TC11钛合金组织及力学性能的影响  

Effect of Coaxial Beam Wire Source Mode on Microstructure and Mechanical Properties of TC11 Titanium Alloy Fabricated by Wire-Fed Electron Beam Additive Manufacturing

作　　者：王壮 权银洙 石毅磊 桑兴华 许海鹰 杨光 杨波 齐铂金[2] Wang Zhuang;Quan Yinzhu;Shi Yilei;Sang Xinghua;Xu Haiying;Yang Guang;Yang Bo;Qi Bojin(AVIC Manufacturing Technology Institute,Beijing 100024,China;School of Mechanical Engineering and Automation,Beihang University,Beijing 100191,China;Unit 93160 of the PLA,Beijing 100076,China;School of Materials Science and Engineering,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]中国航空制造技术研究院,北京100024 [2]北京航空航天大学机械工程及自动化学院,北京100191 [3]中国人民解放军93160部队,北京100076 [4]南京理工大学材料科学与工程学院,江苏南京210094

出　　处：《稀有金属材料与工程》2024年第10期2941-2951,共11页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(52075024);广东省重点领域研发计划(2018B090904004)。

摘　　要：粗柱状β晶粒中存在的针状α'马氏体是电子束熔丝增材制造(EBAM)TC11钛合金较差延展性的主要原因。为实现高强韧TC11钛合金的工程制造,采用丝束同轴电子束熔丝增材制造(C-EBAM),通过提升EBAM过程中电子束、丝材以及基材相互作用状态,改善了熔池热分布。进一步从组织结构、晶粒形貌以及力学性能等方面对EBAM与C-EBAM试样进行了详细比较。讨论了两者丝材过渡状态对工艺稳定性的影响、马氏体相变过程以及拉伸性能差异性与各向异性的原因。结果表明:C-EBAM试样在较低的冷却速率下,从β相场缓慢冷却的途径和原位马氏体分解获得了强韧层状α+β微观结构,Al元素几乎无蒸发。与EBAM试样相比,C-EBAM试样中沉积方向塑性的提高可归因于双层微观结构、不连续α相晶界。这为进一步优化束源特性指明了方向。The presence of needle-likeα′martensite within the coarse columnarβgrains is the primary reason for the poor ductility of TC11 titanium alloys produced by wire-fed electron beam additive manufacturing(EBAM).To enable the engineering fabrication of high-strength and high-ductile TC11 titanium alloys,a novel coaxial beam wire-EBAM(C-EBAM)process was developed,which could enhance the interaction between the electron beam,wire,and substrate,thereby improving the thermal distribution within the melt pool.Comparison between EBAM and C-EBAM samples was conducted,in terms of microstructures,grain morphologies,and mechanical properties.The impact of wire transition states on process stability,martensitic transformation,and the anisotropy of tensile properties was explored.The results reveal that C-EBAM facilitates the formation of strong lamellarα+βmicrostructure with minimal evaporation of Al elements,which is achieved through slow cooling within theβphase field and in situ martensite decomposition.Compared with EBAM,the enhanced ductility by C-EBAM is attributed to the development of the bi-lamellar microstructure and discontinuousαgrain boundaries.

关 键 词：电子束熔丝增材制造 丝束同轴 TC11钛合金 显微组织 力学性能 

分 类 号：TG146.23[一般工业技术—材料科学与工程] TG439.3[金属学及工艺—金属材料]