Influence of process parameters on the quality of bionic non-smooth coatings by laser cladding

摘要

The non-smooth surfaces on 45 steel were prepared by laser cladding with KF-300A alloy powder on the basis of the bionic non-smooth morphology of shark scales. The rib-type coatings were composed of hot-rolled steel 45 and clad layers containing hard phases such as WC/W_2C. In this paper, the influence of laser power and defocusing distance on the quality of cladding layer were investigated. The microstructure of the coatings was analyzed by scanning electron microscopy, with attached energy dispersive spectroscopy microprobe, and by X-ray diffraction. SEM inspection of the samples showed that all coatings exhibited similar phases in their microstructure, but the phases presented differ in morphology, size and distribution. Dilution and interaction zone of the coatings were also discussed in this paper. The results showed that the non-smooth coatings were crack-free and had a good metallurgical bonding with 45 steel trenches with a low dilution under the optimum laser conditions (P=700 W, f =14 mm, V=3 mm/s, continuous powder feeding voltage 2.1 V, nitrogen protection).