金属陶瓷复合涂层的激光熔覆与无裂纹的实现

Realization of laser cladding and crack-free ceramic-metal composite coatings

鉴于传统的激光熔覆金属陶瓷复合涂层技术主要存在2方面不足:其一,熔覆效率低,导致大面积熔覆时成本昂贵;其二,由于激光熔覆本身的特点,即快速加热与快速凝固,在激光熔覆过程中,热应力极易诱导熔覆层开裂。基于此,综述了国内外激光熔覆金属陶瓷复合涂层的研究进展,指出其存在的主要问题,并提出了激光感应复合快速熔覆的新方法,即感应预热基材的同时快速激光熔覆。该方法不仅可使熔覆效率大大提高而且获得了无裂纹的金属陶瓷复合涂层。

The conventional technique for the laser cladding ceramic-metal composite coating mainly has two disadvantages. Firstly, the efficiency of its powder deposition is low and it limits the cladding rate, makes the process rather expensive for cladding on large areas. Secondly, due to some inherent characteristics in laser cladding technique, such as rapid heating and rapid solidification, the residual stress induced during laser cladding could lead to the crack formation in the composite coatings. The status quo of the domestic and foreign research on laser cladding ceramic-metal composite coating technique is reviewed. The existing problems are pointed out and a new solution for laser induction hybrid rapid cladding （LIHRC） is put forward, which preheats the substrate before the laser cladding. The efficiency of this new solution is higher than that of the conventional laser cladding and crack-free ceramic-metal composite coatings prepared by LIHRC.