激光重熔热喷涂涂层研究进展

Research Trends of Thermal Spray Coating by Laser Remelting

热喷涂涂层存在孔隙度高、组织不均匀、涂层与基体的结合强度差等问题;激光重熔热喷涂涂层可以减少涂层孔隙率,改善涂层微观组织,封闭涂层贯通孔隙,改善涂层与基体的结合强度,提高涂层硬度耐磨性和耐蚀性。但激光重熔会使涂层产生裂纹、成片剥落和出现孔洞;在热喷涂粉末中加入稀土元素和低熔点材料,合理控制激光工艺参数,制备梯度涂层等方法可以改善激光重熔热喷涂涂层的微观组织,提高涂层的使用性能。

The thermal spray coating has some problems, such as coating porosity, uneven microstructure, poor binding strength of the coating and the substrate. Laser remelting can reduce the coating porosity, improve the coating microstructure; close the through-pores of the coating; force the binding interface to form a metallurgical bond; improve the hardness, wear resistance and corrosion resistance of the coating. Coating cracks, coating peeling and holes are the main problems in laser remelting thermal spray coating. By using the reasonable laser parameters, adding rare earth elements and low melting point materials in the thermal spray powder and preparing gradient coating can improve the microstructure of the coating, enhance the performance of the coating.