激光选区熔化Ti-1023合金微观组织及力学性能研究  

Research on Microstructure and Mechanical Properties of Ti-1023 Alloy by Selective Laser Melting

作　　者：杨子威 徐俊强 郭顺[1,2] 武文迪 周琦 Yang Ziwei;Xu Junqiang;Guo Shun;Wu Wendi;Zhou Qi(School of Materials Science and Engineering,Nanjing University of Science and Technology,Nanjing 210094,Jiangsu,China;Key Laboratory of Controlled Arc Intelligent Additive Manufacturing Technology,Ministry of Industry and Information Technology,Nanjing 210094,Jiangsu,China)

机构地区：[1]南京理工大学材料科学与工程学院,江苏南京210094 [2]工业和信息化部可控电弧智能增材制造技术重点实验室,江苏南京210094

出　　处：《中国激光》2023年第24期172-180,共9页Chinese Journal of Lasers

基　　金：国家自然基金(52105367)。

摘　　要：采用真空电弧熔炼(VAM)和激光选区熔化(SLM)技术制备了Ti-1023合金试样,并对其组织性能进行了测试分析。结果表明:SLM快速冷却条件抑制了β→α的相变过程,形成了全β相组织,而VAM试样由α+β双相组织构成。虽然SLM样品缺少高硬度α相,但快速冷却条件带来的高密度位错阻碍了位错运动,使得其屈服强度与VAM试样相近。α/β相界面会阻碍位错滑移,从而导致塑性降低,而SLM试样全β相组织可避免α/β界面的产生,并在变形中产生了应力诱导马氏体相变,使得断裂延伸率提升至VAM试样的5倍以上。Objective Metastable β titanium alloy has a high melting point,high activity,low thermal conductivity,and high deformation resistance.However,traditional manufacturing methods face several problems when dealing with the complex components of metastable β titanium alloys,such as numerous processes,long cycles,high cost,and low yield.Laser selective melting(SLM) is a new manufacturing technology that uses a laser as the heat source to melt metal powders layer-by-layer to manufacture solid parts.Owing to its super-complex structure forming ability,high material utilization rate,and rapid prototyping manufacturing ability,SLM provides an excellent solution for the manufacturing of titanium alloy parts with complex structures in aerospace.For the initial manufacturing process of metastable β titanium alloy,the cooling rate range of SLM is 103-108 K/s-1,while that of traditional vacuum arc melting(VAM) is 101-102 K/s-1.Non-equilibrium solidification resulting from rapid cooling is advantageous for grain refinement.The grain sizes of the SLM samples are significantly smaller than those of the VAM samples,and the grain size has a significant impact on their mechanical properties.The VAM Ti-1023 alloy is used to simulate the as-cast microstructure of a Ti-1023 alloy.The differences in the microstructures and mechanical properties of the SLM and VAM Ti-1023 alloys are compared.The effects of rapid cooling conditions on the microstructure and properties of Ti-1023 alloy are systematically studied and provide a theoretical basis for the additive manufacturing of complex components of metastable β titanium alloy.Methods The SLM samples are fabricated using the Ti-1023 alloy powder prepared by gas atomization through laser selective melting.Figure 1 illustrates the morphology and particle size of the Ti-1023 powder.A laser metal powder 3D printer is used to produce the SLM samples.The laser spot diameter is 70 μm,and 20 mm×20 mm×10 mm blocks are directly deposited on a commercial Ti-6Al-4V substrate as shown in Fig.2(a)

关 键 词：激光技术 TI-1023 激光选区熔化 真空电弧熔炼 微观组织 力学性能 

分 类 号：TG456.7[金属学及工艺—焊接]