为了进一步提高TiAl合金表面等离子喷涂Al2O3-13%TiO2(质量分数,下同)复合陶瓷涂层的抗冲蚀性能,采用激光重熔工艺对涂层进行处理,研究了激光重熔对涂层微观组织和抗冲蚀性能的影响,并讨论了陶瓷涂层的冲蚀机理。结果表明,激光重熔处理会形成致密细小的等轴晶重熔区,导致涂层有更好的抗冲蚀性能。激光重熔试样仍表现为典型的脆性冲蚀特性,以近表面的裂纹萌生和扩展,最终导致重熔层破碎、晶粒剥离为主。
In order to improve the erosion resistance of the Al2O3-13%TiO2 composite ceramic coatings fabricated by plasma spraying on TiAl alloy surface,laser remelting experiment was carried out and the effects of laser remelting on microstructure and erosion resistance on coatings were studied.Meanwhile,the erosion mechanisms of the ceramic coatings were discussed based on the experimental results.The results show that the laser-remelted coating exhibits a compact remelted zone which is composed of fine equiaxed grains.The laser-remelted coating has better erosion resistance than the plasma-sprayed coating and shows a brittleness erosion mechanism.During erosion process,cracking occurs within region near the surface of the laser-remelted ceramic coating and that erosion occurs by removal of these small blocks.