真空气雾化法制备AlSi10Mg粉末参数优化及打印态组织性能研究

目的 探究利用真空气雾化法制备AlSi10Mg球形粉末过程中各参数对粉末质量的影响，以得到最佳的制粉工艺参数。以制备的粉末进行增材制造，研究块体组织及其力学性能。方法 针对制备的球形粉末，采用扫描电镜(SEM)观察粉末的球形度及其内部组织。通过分析球形粉末的平均粒径与粒度分布区间总结最优制粉参数。针对以球形粉末增材制造出的沉积态样品，采用X射线衍射仪(XRD)、扫描电镜(SEM)研究其微观组织形貌并通过拉伸试验研究其力学性能。结果 真空气雾化法制备出的粉末表面光洁且球形度良好，同时粉末平均粒径随雾化压力的增大呈现先减小后增大的趋势并在4.0 MPa时粒径最小，且与环孔喷嘴相比，环缝喷嘴制备出的粉末粒径更小。粉末内部组织由胞状晶与树枝晶构成。通过SLM制备的沉积态样品组织以沿沉积方向的枝晶为主，该样品的力学性能较优异，断裂方式主要为沿晶断裂。结论 在使用真空气雾化法制备增材制造用球形粉末时，应选择4.0 MPa的气雾化压力并选择环缝喷嘴，方能得到质量最佳的球形粉末。

Optimization of Parameters and Printed Microstructure and Properties of AlSi10Mg Powder Prepared by Vacuum Atomization Method

The work aims to explore the influence of various parameters on the quality of AlSi10Mg spherical powder prepared by vacuum atomization method to obtain the optimal powder making process parameters, and at the same time, conduct additive manufacturing with the prepared powder to study the block structure and mechanical properties. A scanning electron microscopy (SEM) was used to observe the sphericity and internal structure of the prepared spherical powder. The optimal milling parameters were summarized by analyzing the average particle size and particle size interval of spherical powder. The microstructure and morphology of the deposited samples printed in spherical powder 3D were studied using X-ray diffraction (XRD) and a scanning electron microscopy (SEM), and their mechanical properties were studied through tensile tests. The surface of the powder prepared by vacuum atomization method was smooth and had good sphericity. At the same time, the average particle size of the powder showed a trend of first decreasing and then increasing with the increase of atomization pressure, and the particle size was the smallest at 4.0 MPa. Moreover, the powder particle size prepared by the annular gap nozzle was smaller than that prepared by the annular hole nozzle. The internal structure of the powder was composed of cellular crystals and dendrites. The microstructure of the deposited samples prepared by SLM was mainly composed of dendrites along the deposition direction, with excellent mechanical properties. The fracture mode was mainly intergranular fracture. To prepare spherical powder for additive manufacturing using vacuum atomization method, a atomization pressure of 4.0 MPa and a circumferential nozzle should be selected to obtain the best quality spherical powder.