Microstructure, multi-phase and corrosion resistance of amorphous phase reinforced multi-layer fabricated by laser beam

Abstract

Abstract The Fe-Cr-B-Si deposited layers were prepared on the titanium alloy by the laser melting deposition (LMD) or the laser cladding (LC) technology. The microstructure of the clad layer and the deposition bulk was characterized by the scanning electron microscopy, transmission electron microscopy and electron-backscattered diffraction. The single clad layer was primarily composed of the amorphous phase (APs), the fraction of APs decreased with increasing of the LMD layer thickness due to the heat accumulation, producing the crystalline phases. Parts of the nanocrystalline phases (NPs) were produced due to the characteristics of a laser-induced pool (LIP), producing the deposition bulk with the good metallurgy bond between the adjacent laser fabricated layers. The corrosion resistance of the deposition bulk was enhanced due to the production of the oxides and hydroxides, forming a passive film to enhance the corrosion resistance.