多孔YSZ涂层的制备和可磨耗性

Abradable properties of porous YSZ coatings

采用等离子喷涂方法在Ni718合金表面制备氧化钇稳定氧化锆(YSZ)涂层,通过在YSZ喷涂粉末中分别加入10%,30%和50%(质量分数,%)表面包覆Ti O2的聚苯酯材料,涂层平均孔隙率从原来的2.1%分别提高到12.3%,28.5%和29.7%,孔隙的平均直径从原来的4.2μm分别变为14.4,18.5和25.4μm.随着孔隙的增多,涂层的表面洛氏硬度下降,同时涂层在刮磨过程中的摩擦力和摩擦系数下降.当孔隙率由2.1%上升到30%左右时,涂层在刮磨过程中的磨耗质量上升3倍左右,相对应的转动销质量损失下降约50%.结果表明,孔隙率的提高使得涂层的可磨耗性上升.

In order to obtain an abradable seal coating which is used in high temperature,a porous yttria-stabilized zirconia( YSZ) coating was deposited by the plasma spraying technology. The coating porosity achieved to 2. 1% merely by utilizing commercial YSZ powder. A polyester powder coated by TiO 2was blend into the YSZ powder to increase the porosity of the coating. It was shown that the coating porosity increased to12. 3%,28. 5% and 29. 7% when the mass percent of the coated polyester powder got up to 10%,30% and 50%,respectively. Then the mean diameter of the pore in coatings reached to14. 4,18. 5 and 25. 4 μm respectively as well. The decreasing hardness was presented with the increase of coating porosity. The higher porosity aroused lower friction force and coefficient in an abrasion condition. The weight loss of the coatings increased by about 3 times with the porosity increasing to about 30% from2. 1%,and the weight loss of the rotated pins decreased by50%. Thus it can be seen,the abradable property of YSZ coatings can be improved through a porosity promoting process.