激光重熔对Fe基非晶合金涂层抗冲蚀性能的影响

Effect of laser remelting on slurry erosion resistance of arc-sprayed Fe-based amorphous coating

采用YAG脉冲激光器对电弧喷涂Fe基非晶涂层进行激光重熔处理。通过X-ray、SEM、冲蚀磨损和硬度测量仪等检测手段,研究非晶合金涂层在重熔后的组织结构、硬度和抗冲蚀性能的变化。结果表明:电弧喷涂铁基非晶合金在激光重熔后发生晶化,重熔层非晶含量随功率升高而降低。激光重熔基本消除了非晶涂层的层状结构、残余的气孔和裂纹,平整了涂层表面,提高了涂层韧性,显著改善了涂层的抗冲蚀性能。对喷涂1层的非晶涂层进行重熔时,重熔层的冲蚀磨损量约为喷涂层的1/10,约为基体Q345的1/5。对喷涂5层的非晶涂层进行重熔时,选择0. 1 kW低功率有利于获得较好的抗冲蚀性能。当涂层较厚而激光重熔未熔透时,涂层内应力会随激光功率增大而升高,并导致涂层开裂。当5层非晶涂层被熔透时,抗冲蚀性能显著提高。

Arc-sprayed Fe-based amorphous coatings were remelted by YAG lasers.The microstructure,hardness and slurry erosion wear resistance of the remelted Fe-based amorphous coating were investigated by X-ray,SEM,erosion tester and hardness tester.The results show that the amorphous coating is crystallized after laser remelting,the amorphous content decreases with the increase of laser power.Laser remelting basically eliminates the laminated structure,residual pores and cracks of the amorphous coating,levels the surface of the coating,improves the toughness of the coating,and significantly improves the erosion resistance of the coating.When the 1-layer sprayed amorphous layer is remelted,the slurry erosion mass loss is about 1/10 of that of the spray coating and about 1/5 that of the base Q345 steel.When the5-layer sprayed amorphous coating is remelted,the low power of 0.1 k W is favorable to obtain better erosion resistance.When the coating is thick and the laser remelting is not enough,the internal stress in the coating will increase with the increase of laser power,which will lead to the cracking of the coating.When the 5-layer amorphous coating is fully melted,the erosion resistance of the coating is significantly improved.