特殊粒径分布球形Ni粉的制备及SLM工艺性能研究  

Preparation and Performance of Spherical Ni Powder with Special Particle Size Distribution for SLM Processing

作　　者：张亚娟 李亚楠 宋晓艳[1] 王海滨[1] 侯超[1] 聂祚仁[1] ZHANG Yajuan;LI Yanan;SONG Xiaoyan;WANG Haibin;HOU Chao;NIE Zuoren(Key Laboratory of Advanced Functional Materials,Education Ministry of China,College of Materials Science and Engineering,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学材料科学与工程学院新型功能材料教育部重点实验室

出　　处：《材料导报》2020年第6期114-119,共6页Materials Reports

基　　金：国家自然科学基金创新研究群体资助项目(51621003)~~

摘　　要：3D打印复杂三维结构的Ni基合金时表面易产生突起而粗糙,难以获得致密的打印组织。基于此,本研究采用低温喷雾干燥与热处理相结合的新方法,制备得到了物相纯净、球形度高、流动性好的具有粒径单峰和双峰分布的两种选区激光熔化(SLM)用球形Ni粉。结果表明:粒径双峰分布的Ni粉具有更大的比表面积和更高的堆积密度以及更高的导热系数;在打印过程中,可以吸收更多的激光能量形成更宽的致密熔道,无球化现象;粒径单峰分布的Ni粉打印件表面有少量球化颗粒和微裂纹生成,硬度和模量随压入深度的增加而逐渐下降;粒径双峰分布的Ni粉打印件的相对密度达到99.8%,硬度和模量随压入深度的增加而趋于稳定,其塑性较粒径单峰分布Ni粉打印件提高了30%。Based on the technical characteristics of selective laser melting(SLM),a novel method combining low temperature spray-drying with heat treatment was developed,and two kinds of Ni powders with single-peak and bimodal distribution of particle size,high purity,good sphericity,high flowability were prepared.It is found that the Ni powder with bimodal particle size distribution has higher specific surface area and apparent density,leading to absorb more laser energy and higher thermal conductivity.As a result,wider melting channels were formed in the printing process and the spheroidization phenomenon was eliminated.However,a small amount of spheroidization particles and micro cracks occurred on the surface of the printed bulk material prepared by the Ni powder with single-peak distribution of particle size,exhibiting decreased hardness and modulus with the increasing indentation depth and poor mechanical properties.The relative density is achieved as 99.8%at the printed bulk material prepared by the Ni powder with bimodal distribution of particle size and the hardness and modulus tend to be a stable value with increasing indentation depth.In addition,its plasticity increased by 30%than that of the printed bulk material prepared by the Ni powder with single-peak distribution of particle size.

关 键 词：选区激光熔化 粒径双峰分布 松装密度 导热系数 

分 类 号：TG123[金属学及工艺—金属学]