等离子喷涂用纳米MoO_(3)-Bi_(2)O_(3)复合粉体的制备  

Preparation of nano-structured MoO_(3)-Bi_(2)O_(3) composite powder for plasma spraying

作　　者：孙航 贾均红 杨杰[1] 何乃如 杨鑫然 蔡粮臣 SUN Hang;JIA Junhong;YANG Jie;HE Nairu;YANG Xinran;CAI Liangchen(School of Mechanical and Electrical Engineering,Shanxi University of Science and Technology,Xian 710021,China;Lanzhou Institute of Chemical Physics,Chinese Academy of Sciences,Lanzhou 730000,China)

机构地区：[1]陕西科技大学机电工程学院,陕西西安710021 [2]中国科学院兰州化学物理研究所,兰州甘肃730000

出　　处：《中国粉体技术》2021年第6期29-36,共8页China Powder Science and Technology

基　　金：国家自然科学基金项目,编号:51675508;陕西省重点研发计划项目,编号:2019GY-173。

摘　　要：通过高能球磨、喷雾造粒结合热处理的方法制备了可用于等离子喷涂的MoO_(3)-Bi_(2)O_(3)(简称MB)纳米团聚复合粉体,采用激光粒度仪、霍尔流量计、高分辨场发射扫描电镜、X-射线衍射仪等方法考察球磨浆料中MB粉体的质量分数与热处理温度对复合粉体粒径分布、致密度、球形度、松装密度及流动性的影响,并在室温到800℃对该粉体所制得涂层的摩擦性能进行测试。结果表明,通过机械球磨和喷雾造粒获得粒径为33.77~54.96μm的MB纳米复合粉体;随着球磨浆料中MB粉体的质量分数的增加,喷雾造粒所得粉体形貌逐渐趋于规则球形,粒径分布先变窄再变宽,发现球磨浆料中MB粉体合适的质量分数为35%,但所得颗粒结构较为疏松不致密;实验发现,复合粉体的最佳热处理温度为500℃,此时粉体松装密度为1.98 g·cm^(-3),50 g粉体所需的流动时间为25.97 s,粒径为39.26~51.62μm,热处理过程中未发生固相反应产生新相;复合涂层在400℃时摩擦系数低至0.2,在600℃时磨损率低至9.28×10^(-5)mm^(3)/(N·m)。MoO_(3)-Bi_(2)O_(3)(MB)nano-agglomerated composite powders for plasma spraying were prepared by high-energy ball milling and spray granulation combined with heat treatment.Using laser particle size analyzer,hall flowmeter,high-resolution field emission scanning electron microscope,X-ray diffractometer and other methods to investigate the effect of the mass fraction of MB powder in the ball mill slurry and the heat treatment temperature on the particle size distribution,density,sphericity,bulk density and fluidity of the composite powder.The friction performance of the coating made of the powder was tested at room temperature to 800℃.The results showed that MB nano-structure composite powders with particle size distribution ranging from 33.77μm to 54.96μm were obtained by mechanical ball milling and spray granulation.With the increase of the mass fraction of MB powder in the ball-milling slurry,the morphology of the powders obtained by spray granulation gradually tended to be regular spherical,and the particle size distribution first narrowed and then widened.It was found that the suitable mass fraction of MB powder in the ball-milling slurry was 35%,but the structure particles of the powders obtained were loose and not dense.The results show that the optimal heat treatment temperature of the composite powder is 500℃,when the loose density is 1.98 g/cm^(3),the flow time of 50 g powder is 25.97 s,the particle size distribution is 39.26~51.62μm,and no new phase is generated by solid phase reaction.The coating is as low as 0.2 at 400℃,and the wear rate is as low as 9.28×10^(-5) mm^(3)/(N·m)at 600℃.

关 键 词：高能球磨 喷雾造粒 热处理 纳米结构 等离子喷涂 

分 类 号：TG174.44[金属学及工艺—金属表面处理]