Investigation of the microstructure and phase evolution across multi-material Ni50.83Ti49.17-AISI 316L alloy interface fabricated using laser powder bed fusion (L-PBF)

• Laser-powder bed fusion (L-PBF) fabrication of functionally graded nickel-titanium (NiTi)-AISI 316L material demonstrated. Excellent bonding between NiTi and AISI alloys controlled via complex bands multi-material layers. Phase microstructural evolution through the L-PBF settings. Multi-material phase microstructure formation/evolution mechanisms elucidated. This study evaluates additively manufactured (AM) Nickel Titanium (NiTi) alloy, across interface with stainless steel build plate, in order to understand processing parameter (input power, layer thickness scan speed), composition, interrelationships necessary achieve excellent 316L. The effect process parameters utilised was characterised using Scanning Electron Microscope (SEM), Backscatter Diffraction (EBSD), X-ray diffraction (XRD), Energy-dispersive spectroscopy (EDX). SEM/EBSD results demonstrated, for first time, that close comprised martensite, austenite Fe phases, sequentially arranged a layered sandwich pattern direction. complexity bonding. influenced diffusion behaviour concentration elements found at interface. rate Ti NiTi-316L 3.05 × 10 - 6 m 2 / s 3.27 8 , respectively, representing 93.27-fold increase. observed is related generated chemistry thermomechanical history strain resulting from process.