2-24. Diffusion dynamics analysis of laser selective melting process of elemental powder blender

Su Hang Hou Yaqing Zuo Qianlong Ying Hua

1 . Beijing MATDAO Technology Co., Ltd, Beijing 100081, China
2 . Chongqing ADRAYN Technology Co., Ltd, Chongqing 401329, China

Abstract: Elemental powder blender 3D printing technology uses mixing powder of pure elements or simple alloy as raw material. It can omit the melting and milling process, complete the metallurgical process directly during printing. Compared with traditional 3D printing method, it can be one of the most important directions in future so as to shorten the production process and reduce the type of metal powder. This article propose the technical principal on direct elemental powder blender of SLM process. The feasibility of the technology is confirmed by diffusion simulation of Fe-Ni alloy system during their molten state. The results show that the improvement of element diffusion efficiency and composition homogenization can be achieved substantially by increasing peak laser temperature, molten state period, reducing metal powder particle and adding a subsequent high-temperature heat treatment. The results of SEM and EDS experiments show that increasing peak laser temperature, molten state period can effectively improve the diffusion efficiency, which is consistent with the calculated results.

Keywords:Selective laser melting; Diffusion dynamics; Elemental powder blender; 3D printing; 

元素粉末混合 3D 打印的扩散动力学分析及试验验证

苏航 侯雅青 左乾隆 应华

1.北京钢研新材科技有限公司，北京 100081 2.重庆安德瑞源科技有限公司，重庆 401329

摘要: 元素粉末混合 3D 打印，即采用纯元素或简单合金粉末混合进行 3D 打印，可以省略冶 炼和制粉流程，在打印中直接完成冶金过程，相比传统基于均质金属粉末的 3D 打印，流程 大大缩短、粉末种类大大减少，具有重要发展价值。本文针对 SLM 打印过程，提出了元素金 属粉末直接 3D 打印冶金的技术原理，并以 Fe-Ni 合金为例进行了元素打印过程和后处理的 扩散动力学分析。计算表明，通过提高 SLM 脉冲峰值温度、延长熔态时长、减小合金粉末粒 径、增加后续高温热处理等方法可以大幅提高打印过程中的元素扩散效率，实现成分均匀化。 SEM 和 EDS 实验结果显示提高 SLM 脉冲峰值温度、延长熔态时长确实能有效提高扩散效率， 与计算结果吻合。

关键词:激光选区熔融;扩散动力学;元素粉末;3D 打印