【摘要】 采用等离子喷涂技术在TC4钛合金表面制备了常规Metco130陶瓷涂层及纳米结构Al₂O₃-13wt%TiO₂涂层,并利用CO₂激光器对涂层进行了激光重熔,采用X射线衍射分析（XRD）、扫描电镜分析（SEM）、微区成分分析（EDAX）及维氏硬度试验研究了激光重熔前后涂层的组织性能变化。结果表明,等离子喷涂涂层与基体形成了较好的机械结合,但涂层中存在孔隙,激光重熔后,重熔层与基体形成了良好的冶金结合,其组织结构更为均匀而致密。采用谢乐公式估算了重熔后涂层中各相的平均粒径,结果表明,等离子喷涂纳米结构的涂层在激光重熔后仍然处于纳米结构。另外,选择合理的激光工艺参数,涂层的硬度得到了较大提高。更多还原

【Abstract】 Conventional Metco130 ceramic coatings and nanostructured Al₂O₃-13wt%TiO₂ coatings have been successfully fabricated by plasma spraying on a titanium alloy （TC4）.A CO₂ laser has been used to remelt the plasma sprayed coatings.The phase constitution, microstructure characterization,composition and microhardness of the as-sprayed and laser remelted coatings were investigated by means of X-ray diffraction （XRD）,scanning electron microscopy （SEM）,energy-dispersive analysis of X-rays （EDAX） techniques and hardness testing,respectively.It was found that the as-sprayed coatings maintained good mechanical boning to the substrate,though there were some pores in the coating.After laser remelting,the remelted coatings possessed a more homogeneous microstructure,less porosity,and an excellent metallurgical bonding to the substrates.The average grain size in the remelted coatings was evaluated using Scherrer Equation.The results show that the plasma sprayed nanostructured coatings still keep nanostructured after laser remelting.The microhardness of the coatings could be increased using optimized laser remelting parameters.更多还原