喷雾干燥法制备球形喷涂钼粉及烧结工艺的研究

Study on Fabrication of Spherical Thermal Spraying Molybdenum Powders by Spray Drying and Sintering Process

本文采用球磨工艺制备钼粉料浆,通过喷雾干燥法制备球形团聚钼粉,然后经过保护气氛脱脂烧结制备出球形喷涂钼粉,同时对烧结前后球形钼粉的松比、流动性及组织形貌进行了表征与分析。结果表明,料浆与钼粉颗粒尺寸的均匀性、粘结剂、固含量以及球磨时间密切相关,合适的固含量和粘结剂含量、较长的球磨时间下可以获得具有较好形貌和完整性的球形钼粉;在喷雾干燥的过程中,转速是影响球形钼粉颗粒大小的很重要因素;在保护气氛脱脂烧结过程中,烧结温度对钼粉的松装密度及流动性影响较大,提高烧结温度是改善钼粉松比及流动性的主要途径。

Spherical molybdenum powders for thermal spraying have been fabricated by ball milling, spray drying method and protective atmosphere skim sintering process. The apparent density and microstructure of molybdenum powders have been characterized and analyzed in this paper. The experimental results show that the slurry can be compacted by the uniformity of molybdenum powder particle, the composition homogeneity of slurry and solid content. Powders with high solid content and long ball mixing time can bring to good morphology and integrity. Sintering temperature has a great infl uence on the apparent density and fl owability of molybdenum powders, so improving sintering temperature is the major solution to improve those characters.