等离子喷涂ZrO_2层经激光再熔后的组织变化

STRUCTURAL CHANGE OF PLASMA SPRAYED ZrO_2 COATING AFTER LASER REMELTING

本文研究了等离子喷涂ZrO_2陶瓷层的激光再熔化处理经激光再熔化处理的ZrO_2涂层致密、无孔隙,但熔化层有裂纹在ZrO_2中添加适量的SiO_2,降低了熔化层在冷却时的热应力,有效抑制裂纹的产生经激光再熔化处理后的陶瓷展和粘结层之间的结合为冶金结合;粘结尾和基材的冶金结合层厚度明显增加;随着激光功率的增加,陶瓷层、粘结层以及一定厚度的基材发生熔化。

An improvement on the properties of plasma sprayed ZrO_2 ceramic coating by laser remelting treatment has been observed by TEM, SEM, EPMA and X-ray diffraction analysis. After laser remelting, the ZrO_2 coating changes its structure into more dense and nonporous, and more stable to thermal failure and cracking if a suitable SiO_2 doped. The bonding of laser remelted ZrO2 ceramic coating together with adhesion layer is found to be of metallurgical nature. The thickness of adhesion layer and metallurgical bonding interface may be evidently increased. With the increase of the laser output, the ceramic coating, adhesion layer and a certain depth of substrate surface are able to be fused. A liquid Zr6Fe3o phase may be formed between ceramic coating and adhesion layer.