Al_2O_3弥散强化316L不锈钢粉末的高速火焰喷涂

High velocity oxy-fuel spraying of Al_2O_3 dispersion strengthened 316L stainless steel powders

采用高能球磨工艺制备了Al2O3弥散强化316L不锈钢喷涂粉末,并进行高速火焰喷涂(HVOF)试验。研究了弥散强化粉末及其喷涂层的微观组织结构和硬度。采用销-盘磨损试验机测试了涂层的耐磨性能。结果表明,球磨加工后,Al2O3颗粒尺寸大多小于1μm,由微米级、亚微米级及纳米级粒子组成并均匀分布在316L不锈钢基体粉末中。随着球磨时间的增加,粉末的显微硬度提高。喷涂后球磨粉末的微观组织结构基本不变,喷涂层的硬度比对应球磨粉末硬度低,其耐磨性明显优于单纯不锈钢粉末涂层。

The high energy ball milling technique is an effective method for producing metal matrix composites.Al_2O_3 dispersion strengthened 316L stainless steel powders were prepared using high energy ball milling process.The milled powders were sprayed using a high velocity oxy-fuel spraying process.The microstructure and microhardness of the milled powders and corresponding coatings were investigated.The abrasive wear resistance of the coatings was evaluated using pin-on-disk tests.It was found that most of the Al_2O_3 particles distributed uniformly in 316L stainless steel matrix after milling had smaller size than 1 μm,and consisted of micron-sized particles,sub-micron sized particles and nano-scale particles.The microhardness of the milled powders increased with increasing milling time.No obvious change of the microstructure of the milled powders after spraying was observed.However,the coatings were softer than the milled powders,and the composite coatings were much more wear resistant than the single matrix material coatings.