Fig. 1 Surface morphologies of Nb-Si pre-alloyed powders: a P1; b P2

Fig. 2 Surface morphologies of single tracks formed from P1 a and P2 b powders; c is the magnified image of the yellow rectangle in a, d is the magnified image of the red rectangle in a

Fig. 3 Width distributions of single tracks formed from P1 powders with different processing parameters (the error bars refer to standard deviation)

Fig. 4 a Cross-section morphology of single track formed from P1 powders (P = 380 W, V = 400 mm/s); b distributions of Nb, Si and Ti elements along line OA obtained using EPMA

Fig. 5 Schematic plot of contact angle (θ) and penetration depth (d) of single tracks a; penetration depth b and contact angle c on cross-sections of single tracks formed from P1 powders

Fig. 6 Cross-section morphologies of single layers formed from P1 with different hatch distances (H): a H = 50 μm; b H = 80 μm; c H = 120 μm; d H = 150 μm. The laser power is 380 W, and the scanning speed is 200 mm/s. The insets in the bottom show the macroscopic surface morphologies of the single layers processed with respective hatch distance

Fig. 7 Chemical maps of cross-sections of single layers formed from P1 with different hatch distances in sub-circular interfacial region: a BEI; b Nb; c Si; d Ti

Fig. 8 Top surface a and sectional microstructure b of cubic part built by optimized processing parameters

Fig. 9 Chemical maps of interface between Ti6Al4V substrate and Nb-Si-based alloy via SLM: a BEI; b Nb; c Si; d Ti; e Cr; f Al

Fig. 10 Distributions of Nb, Si, Ti, Cr and Al across interface between Ti6Al4V substrate and Nb-Si-based alloy via SLM

Fig. 11 Schematic diagram of SLM physical model

Fig. 12 Microstructural illustration of Nb-Si-based alloy processed by SLM on a Ti6Al4V substrate