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
王壮 1权银洙 2石毅磊 1桑兴华 3许海鹰 4杨光 3杨波 3齐铂金5
作者信息
- 1. 中国航空制造技术研究院,北京 100024;北京航空航天大学机械工程及自动化学院,北京 100191
- 2. 中国人民解放军93160部队,北京 100076
- 3. 中国航空制造技术研究院,北京 100024
- 4. 中国航空制造技术研究院,北京 100024;南京理工大学材料科学与工程学院,江苏南京 210094
- 5. 北京航空航天大学机械工程及自动化学院,北京 100191
- 折叠
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.
Abstract
The presence of needle-like α'martensite within the coarse columnar β grains 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 lamellar α+β microstructure with minimal evaporation of Al elements,which is achieved through slow cooling within the β phase 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 discontinuous α grain 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Key words
wire-fed electron beam additive manufacturing/coaxial beam wire/TC11 titanium alloy/microstructure/mechanical property引用本文复制引用
基金项目
国家自然科学基金(52075024)
广东省重点领域研发计划(2018B090904004)
出版年
2024
NETL
NSTL
万方数据