Fig. 1. Preparation of T800 cobalt-based alloy wear-resistant block by direct laser deposition. (a) Schematic of laser direct deposition; (b) layer n scanning strategy; (c) layer n+1 scanning strategy

Fig. 2. Schematic diagram of laser direct deposition of wear-resistant blocks and orientations

Fig. 3. Microstructure of K417G substrate. (a) Low magnification OM tissue photograph; (b) high magnification OM tissue photograph; (c) high magnification SEM tissue photograph

Fig. 4. Low magnification OM photographs of laser direct deposition of T800 wear-resistant block in polished and corroded states. (a) (b) Test block 1; (c) (d) test block 2

Fig. 5. Schematic diagram of heat-affected zone of laser direct deposited T800 wear-resistant block. (a) Low magnification OM photograph; (b) high magnification OM photograph

Fig. 6. High magnification microstructure corresponding to regions 1‒7 in Fig. 4(b)

Fig. 7. EDS analysis of microstructure gradient zone

Fig. 8. Schematic diagram of variation of major elemental composition of laser direct deposited T800 wear-resistant blocks from top to substrate. (a) Test block 1; (b) test block 2

Fig. 9. Mechanism of microstructure evolution of laser direct deposited T800 wear-resistant blocks, from top to fusion line

Fig. 10. Test block 1, test block 2 and surfacing wear-resistant block for a part from top to substrate microhardness change curve

Fig. 11. Relationship between Ni element content and microhardness

Fig. 12. Schematic diagram of microstructure and compositional changes of a part surfacing T800 wear-resistant block. (a) Low magnification tissue photograph and hardness and composition test sampling area; (b) Ni element content changes curve; (c) top high magnification tissue photograph; (d) high magnification of heat-affected area tissue photograph