Effect of La2O3 on Microstructure and Properties of Laser Cladding SMA Coating on AISI 304 Stainless Steel

Known as having a stress self-accommodation characteristic, the laser cladding shape memory alloy (SMA) coatings have been widely used in material failure repair. Nevertheless, their further development is greatly limited by low microhardness (250 HV0.2) and corrosion resistance. Benefiting from capability of refined grain adjusted microstructure, rare earth oxides play key role improving properties materials. Herein, to improve anti-corrosion SMA coatings, different amounts La2O3 were doped coating. The influence doping on phases, size was studied. SMA/La2O3 composite coating explored 3.5 wt.% sodium chloride solution. Results showed that significantly refined. When with 0.9 wt.%, refinement rate reaches 19%. Furthermore, based Hall–Petch effect, increased 450 HV0.2. At same time, enhanced due smaller fewer defects.