摘要
为了提高电动机用激光选区熔融(SLM)制备Ti6Al4V合金的拉伸力学综合性能,通过控制变量的方式研究Ar气流量对其微观组织和拉伸力学性能的影响。研究结果表明:所有Ti6Al4V合金都形成了α’白色组织,控制Ar气流量为6 L/min有助于马氏体发生原位分解。此时形成了大量的α’组织以及部分α与β相,所有组织的宽度都接近0.5μm。在Ti6Al4V合金中形成了具有密排六方晶格的α组织,在SLM成形阶段存在大量α’组织转变成(α+β)结构的情况。Ar气流量为6 L/min下合金达到了更高延伸率。当能量密度增大到6 L/min之后,靠近撕裂棱区域产生了数量更多的韧窝,表明提高能量密度能够优化合金韧性,此时断口组织上产生韧窝没有出现解离面。该研究对优化SLM制备钛合金的工艺参数具有一定的理论意义。
Ti6 Al4 V alloy coatings,an advanced electric motor material,were synthesized by selective laser melting(SLM) of Ti6 Al4 V powder on Ti-alloy substrate.The influence of the Ar flow-rate on the microstructures and tensile properties was investigated with X-ray diffraction,scanning electron microscopy and tensile measurement.The results show that Ar flow-rate had a major impact.To be specific,white α’-phased tissues formed in laser melted Ti6 Al4 V alloy,and a flow-rate of 6 L/min promoted in-situ decomposition of martensite.As the Ar flow-rate increased,the elongation ratio changed in an increase-decrease mode,maximizing at 6 L/min,and the yield/tensile strengths varied slightly.Laser melting turned a large amount of α-phased hcp-structured tissue,0.5 μm in width,into some(α+β)-phased clusters.An increasing dimple-density formed around tearing ridges at 6 L/min,indicating the peak of elongation ratio;and no cleavage plane appeared near the fractures.
作者
张鹏举
齐冠然
卢金生
Zhang Pengju;Qi Guanran;Lu Jinsheng(Department of Equipment Engineering,Henan Institute of Architectural Technology,Zhengzhou 450064,China;Zhengzhou Machinery Research Institute co.、LTD.,Zhengzhou 450001,China)
出处
《真空科学与技术学报》
EI
CAS
CSCD
北大核心
2020年第8期791-794,共4页
Chinese Journal of Vacuum Science and Technology
基金
NSFC-河南联合基金重点项目(U1804254)。
