Cu-Cr-Nb合金选区激光熔融工艺参数优化  

Optimization of process parameters for selective laser melting of Cu-Cr-Nb alloy

作　　者：任亚科 刘祖铭[1] 张亚洲 艾永康 叶书鹏 李建 彭伟才 REN Yake;LIU Zuming;ZHANG Yazhou;AI Yongkang;YE Shupeng;LI Jian;PENG Weicai(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China;Changsha Mitr Instrument Equipment Co.,Ltd.,Changsha 410219,China)

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083 [2]长沙米淇仪器设备有限公司,长沙410219

出　　处：《粉末冶金材料科学与工程》2022年第1期66-76,共11页Materials Science and Engineering of Powder Metallurgy

基　　金：中国工程院重点项目(2019-XZ-11);金属材料磨损控制与成型技术国家地方联合工程研究中心开放基金资助项目(HKDNM201907);粉末冶金国家重点实验室自主课题;国家重点研发计划(2016YFB0301300)。

摘　　要：采用选区激光熔融(SLM)对氩气雾化Cu-1.93Cr-0.74Nb(摩尔分数)合金粉末进行成形,研究激光功率、扫描速率和扫描间距等工艺参数对试样相对密度、熔池形貌和微观结构的影响。结果表明,SLM工艺参数对Cu-1.93Cr-0.74Nb合金相对密度、冶金缺陷和显微组织的影响呈现非线性关系。当激光功率由300 W上升至400 W时,或扫描速率由500 mm/s上升至1 100 mm/s时,成形件相对密度先升高后降低,孔洞数量和尺寸也呈现出类似的变化规律。相对密度与熔池道的连续性、孔洞数量和尺寸等密切相关。最优参数为激光功率330 W、扫描速率800 mm/s和扫描间距0.1 mm,所制备的Cu-1.93Cr-0.74Nb合金的相对密度达到99.3%,具有以大尺寸晶粒为中心,边缘分布着细小晶粒构成的双峰尺寸晶粒核壳结构和强{110}织构。织构指数和织构强度分别为9.319和7.812。Cu-1.93 Cr-0.74 Nb(mole fraction, %) alloy was prepared by selective laser melting (SLM) using Ar-gas atomized powders. The effects of laser power, scanning speed and scanning spacing on the relative density, molten pool morphology, and microstructure of as-built samples were investigated. The results show that the effects of SLM process parameters on the relative density, metallurgical defects and microstructure of as-built Cu-1.93 Cr-0.74 Nb alloy are nonlinear. The relative density of as-built sample increases first and then decreases with increasing the laser power from 300 W to 400 W, or the scanning speed from 500 mm/s to 1 100 mm/s. The number and size of pore also shows a similar change rule. The relative density is closely related to the continuity of melting pool, the number and size of pore. The relative density of as-built Cu-1.93 Cr-0.74 Nb alloy prepared by optimum parameters of the laser power of 330 W, the scanning speed of 800 mm/s and the scanning space of 0.1 mm, reaches 99.3%. It has a bimodal core-shell structure and a strong {110} texture with a large-sized grain as the center and fine grains distributed on the shell. The texture index and texture strength are 9.319 and 7.812, respectively.

关 键 词：Cu-Cr-Nb合金 选区激光熔融 工艺参数优化 显微组织 双峰尺寸晶粒核壳结构 

分 类 号：TG146.11[一般工业技术—材料科学与工程]