Abstract:
To investigate the effect of La
2O
3 on the organization and properties of laser melting shape memory alloy coatings, a broadband laser melting technique was used to prepare a La
2O
3-doped Fe17Mn5Si10Cr5Ni shape memory alloy composite coating on the surface of 42CrMo medium carbon steel. The results of the effect of La
2O
3 on the microstructure, Vickers hardness, wear resistance, corrosion resistance and surface residual stress of the composite coatings were obtained by characterization. The results show that La
2O
3 significantly reduces the grain size, when the doping mass fraction of 0.009 grain size reaches a minimum value of 3.03 μm. The composite coating has a maximum hardness of 454.7 HV
0.2 and the lowest wear and the lowest self-corrosion current of 4.287×10
-7 A/cm
2 and the highest self-corrosion potential of -0.843 V are obtained, and the coating protection rate reaches 94.83%. La
2O
3 significantly improves the corrosion resistance of the coating. The residual stresses change from tensile to compressive stresses, with the highest residual compressive stress value of -378 MPa at Fe-Mn-Si/La
2O
3. This study provides a practical reference for the development and promotion of low-stress high-performance laser cladding coatings.