ZrO_2纳米粉等离子喷涂层制备研究

Study on Fabrication of Zirconia Nanopowder plasma-Sprayed Coating

经二次造粒的纳米ZrO2 为喂料制备了等离子喷涂层。X衍射物相分析、SEM形貌观察表明 ,涂层主要以四方相和立方相构成 ,含有少量的单斜相 ;在喷涂过程中粉末熔化状况良好 ,涂层含有网状微裂纹。用金相法测定了涂层孔隙率 ,与普通ZrO2 等离子喷涂层相比 ,涂层致密度显著提高。在模拟熔炼条件下 ,对涂层进行了真空热震试验 ,涂层均能经受一次真空热震而涂层完好。单斜相含量较低、具有一定孔隙率和均匀网状微裂纹的涂层 ,经二次真空热震后 ,涂层仍处于完好状态。

The plasma-sprayed coating was fabricated with nanostructured zirconia feedstock, and the coating was characterized by XRD and SEM. The result indicats that the coating mainly contain tetragonal and cubic phase, and a small amount of monoclinic zirconia; the morphylogy show that the melting of powder was good, and coating have net microcracks. The porosity of coating was determined by metallographic method. The coating fabricated by nanostructured zirconia has higher density comparing to the micrometer zirconia. Thermal shock test in vacuum was done under modelling melting conditions, the coating could resistant to thermal shock in vacuum furnace for one time. After the second thermal shocking, the coating which has some porosity and uniform net microcrack is complete still.