Fig. 1. Transport diagram of heterogeneous alloy powder, as well as morphology and particle size distributions of two kinds of powders. (a) Schematic diagram of synchronous delivery of heterogeneous alloy powder; (b) micro-morphology of Ti6Al4V powder; (c) particle size distribution of Ti6Al4V powder; (d) micro-morphology of Ni_55.5Ti_44.5 powder; (e) particle size distribution of Ni_55.5Ti_44.5 powder

Fig. 2. Gradient compositional design of Ti6Al4V/NiTi heterogeneous alloy prepared by in-situ additive manufacturing

Fig. 3. XRD spectra and macroscopic morphology of Ti6Al4V/NiTi composites thin-walled samples with 11 compositional ratios. (a) XRD spectra; (b) macroscopic morphology

Fig. 4. Microstructures of Ti6Al4V/NiTi composites thin-walled samples with different composition ratios

Fig. 5. Elemental mass fraction changing of Ti6Al4V/NiTi thin-walled samples with different composition ratios

Fig. 6. In-situ gradient additive manufacturing of Ti6Al4V/NiTi heterogeneous functional materials. (a) Macroscopic morphology of formed part; (b) planer surface and partial enlargement of gradient transition zone of formed sample

Fig. 7. EDS line scan results near Ti6Al4V/NiTi gradient alloy interfaces. (a) Interfaces 1 and 2; (b) interface 3; (c) interface 4; (d) interface 5

Fig. 8. Schematic diagram of microhardness measurement points and distribution of measurement results for Ti6Al4V/NiTi gradient alloy. (a) Schematic diagram of sampling measurement points; (b) distribution of microhardness measurement results

Table 1. Process parameters corresponding to different composition ratios

Table 2. SEM observation and EDS analysis of Ti6Al4V/NiTi gradient alloy