中国激光, 2019, 46 (10): 1002002, 网络出版: 2019-10-25
热处理对选区激光熔化CoCrW合金组织及显微硬度的影响 下载: 993次
Effect of Heat Treatment on Microstructure and Microhardness of CoCrW Alloys Processed by Selective Laser Melting
激光技术 选区激光熔化 热处理 显微组织 显微硬度 laser technique selective laser melting heat treatment microstructure microhardness
摘要
采用选区激光熔化(SLM)技术技术制备了成形良好的块状CoCrW合金,研究了热处理工艺对CoCrW合金相组成、组织及显微硬度的影响。通过JMATPro软件模拟计算了CoCrW合金的平衡相图;利用X射线衍射分析仪、扫描电子显微镜、显微硬度计对热处理前后合金的相组成、组织、显微硬度进行了测试。结果表明:SLM制备的原始试样主要由γ相以及少量ε相组成,热处理后大量的γ相转变为ε相,且有块状、条状析出相产生;在较低的热处理温度下,熔合线处析出相的尺寸较大,与其他部位的区别比较明显;随着热处理温度升高,晶粒长大,晶界处析出相(δ相)长大,且与熔合线处的差别减小;热处理后,CoCrW合金的显微硬度有所降低,其中1100 ℃水冷试样硬度的降幅最大。
Abstract
Well formed bulk CoCrW alloys are fabricated by selective laser melting (SLM) and the effect of the heat treatment process on the phase composition, microstructure, and microhardness of the CoCrW alloy is studied. The equilibrium phase diagram of CoCrW alloy is simulated and calculated by JMATPro software, and the X-ray diffractometer, scanning electron microscopy, and microscopic hardness tester are used to test the phase composition, microstructure, and microhardness of the CoCrW alloy before and after heat process. Results show that the original SLM sample mainly comprises γ phase and a trace amount of ε phase. After heat treatment, a large portion of γ phase is transformed into ε phase, and the lump- and strip-like precipitate phases are produced. The size of the precipitated phase at the fusion line is large under low temperature heat treatment, and it is clearly different from those of other regions. The grain boundary and grain size of the precipitated δ phase grow with the increasing heat treatment temperature. Simultaneously, the difference in the precipitated phase size at the fusion line decreases. The microhardness of the CoCrW alloy decreases after heat treatment, especially for heat treatment at 1100 ℃ followed by water cooling.
尹燕, 康平, 肖梦智, 张瑞华, 路超, 张圆, 屈岳波. 热处理对选区激光熔化CoCrW合金组织及显微硬度的影响[J]. 中国激光, 2019, 46(10): 1002002. Yan Yin, Ping Kang, Mengzhi Xiao, Ruihua Zhang, Chao Lu, Yuan Zhang, Yuebo Qu. Effect of Heat Treatment on Microstructure and Microhardness of CoCrW Alloys Processed by Selective Laser Melting[J]. Chinese Journal of Lasers, 2019, 46(10): 1002002.