直接堆粉预置涂层的激光熔覆显微组织研究

Research on Microstructure of Laser Cladding with Direct Pre-placed Powder Coatings

在铁基材料表面采用直接堆粉预置涂层方法制备激光熔覆层,得到了消除裂纹和孔洞的熔覆层。其显微组织主要由Fe-Ni合金、WC及Fe_(23)(C,B)_6所组成,且碳化物分布较均匀。熔覆层的显微硬度相对基体有显著提高,保留了有利于提高熔覆层性能的纳米颗粒。证明用该方法制备激光熔覆层是可行的。

The direct pre-placed powder coating method is adopted to prepare the laser cladding layer on the surlace ot terrous materials, thus obtaining a crack- and pore-free cladding coating. The microstrueture of the coating layer mainly consists of Fe-Ni alloy, WC and Fe23（C, B）6 and the carbide is distributed uniformly. The mierohardness of the layer is improved more greatly than that of the substance. The nano grains favorable for the properties of the coating are deposited. It is proven that the method is practicable in preparation of laser clad coating.