High strength welding of NiTi and stainless steel by impact: Process, structure and properties

•Vaporizing Foil Actuator Welding was used to weld NiTi and stainless steel for the first time.•Variations of impact angle and velocity are well connected to the high spatial variations of structures.•Transmission Electron Microscopy shows that amorphization occurred at the NiTi-SS interfaces and the NiTi side.•Thermo-Calc calculations predict a high glass forming potential in the resulting multi-component alloy.•NiTi/SS impact welds exhibit much higher joint efficiency than traditional welding technologies.