Fig. 1. IN718 superalloy and 316L stainless steel abrupt gradient material. (a) Simulated sample; (b) fabricated sample

Fig. 2. Content of Fe and Ni elements in the abrupt gradient material

Fig. 3. Change of element content near the interface of the abrupt gradient material. (a) Interface morphology; (b) element content

Fig. 4. Distribution of elements in the micro region at the interface of the abrupt gradient material. （a）SEM morphology; (b) electron image; (c) Ni element distribution; (d) Fe element distribution

Fig. 5. Microstructures near the interface of the abrupt gradient material

Fig. 6. EDS analysis of different microstructures near the interface. (a) IN718 matrix; (b) 316L matrix; (c) Laves phase; (d) (Ti,Nb)(C,N)

Fig. 7. Change rule of microhardness near the interface

Fig. 8. Relationship among the forming process, element content and microhardness near the interface. （a） Morphology analysis; (b) longitudinal section and cross section; (c) microanalysis