Al-Ni-Co微细球形粉末的制备及SLM成形研究

采用气雾化(IGA)制备了Al-Ni-Co粉末，初筛后的最大粉末粒径小于150μm。分别采用霍尔流速计、XRD、SEM、VSM等测试方法研究了不同粒径范围Al-Ni-Co微粉的微观形貌、相成分、磁性能等。研究表明：微粉的球化率在95%左右；50～80μm范围微粉的流动性相对最好；20μm以下微粉因为粒径偏小，成分偏析较为严重；80～150μm微粉因为粒径过大，表面吸附卫星小颗粒，粗糙度较差；Al-Ni-Co微粉的磁性为软磁，相组成为AlNi和FeCo相。综合比较微观结构、相成分及粉末占比量，选取20～80μm的Al-Ni-Co微粉采用SLM法制备了6组Al-Ni-Co圆柱形磁体，热处理后磁体的密度、磁性等综合性能达到铸造Al-Ni-Co磁体的性能水平。

Micro-scale powder of Al-Ni-Co alloy and its SLM 3D-printed magnets

Al-Ni-Co powder was prepared by inert gas atomization(IGA),and the maximum particle size of the powder was less than 150 μm after the initial screening.The morphology,phase composition and magnetic properties of Al-Ni-Co powder with different particle size range were studied by hall flowmeter,XRD,SEM and VSM.The results showed that the spheroidization rate of the powder was about 95%.The fluidity of micro-powders in the range of 50~80 μm is relatively the best.Due to small particle size,the composition segregation of micro-powders under 20 μm is serious;80~150 μm micro-powders’ s surface adsorps satellite small particles,the roughness is poor;the magnetism of Al-Ni-Co powder is soft one,and the phases are AlNi and FeCo.Six groups of Al-Ni-Co cylindrical magnets were prepared by SLM method with 20~80 μm Al-Ni-Co micro powder.The density and magnetic properties of the magnets after heat treatment reached the performance of the cast Al-Ni-Co magnets,which indicated that SLM could be used to prepare 3 D-printed Al-Ni-Co magnets.