A novel Ni2MnCuSnAl0.1 multi-principal element alloy coating to enhance the wear resistance and corrosion resistance of Mg-Li alloy.

[Display omitted] • A multi-step ultrasonic assisted laser cladding for Mg-Li alloy was proposed. • A metallurgical Ni 2 MnCuSnAl 0.1 MPEA coating was prepared on Mg-Li alloy. • Typical gradient microstructure was obtained in Ni 2 MnCuSnAl 0.1 MPEA coating. • The corrosion-resistance and wear-resistance of Mg-Li alloy were improved. The evaporation and dilution of substrate are the key deficiencies that limit the performance of laser-cladded coatings on Mg-Li alloys (or Mg alloys). In order to overcome these drawbacks, in this work, a novel Ni 2 MnCuSnAl 0.1 multi-principal element alloy (MPEA) coating and a multi-step ultrasonic assisted laser cladding technique were proposed. Dense metallurgical Ni 2 MnCuSnAl 0.1 MPEA coatings were successfully synthesized on Mg-Li alloy. Typical gradient microstructure of low-diluted layer, diffusive layer and interfacial layer were obtained in the coating. The low-diluted layer was composed of BCC solid solution, Ni 2 MnAl and Ni 2 MnSn while the diffusive layer and interfacial layer showed an interactive microstructure of Mg-CuMg 2 eutectic, Ni 2 MnAl, Li 2 MgSn/SnMg 2 and Mg/Mg-Li substrate. The corrosion potential of Ni 2 MnCuSnAl 0.1 MPEA coating (-108 mV SHE) was 1283 mV SHE higher than that of Mg-Li alloy (-1391 mV SHE), while the corrosion current density of the coating (5.85 × 10−7 A·cm−2) was about three orders of magnitude lower than that of Mg-Li alloy (1.12 × 10−4 A·cm−2). The micro-hardness gradually increased from the substrate to the coating, and the average micro-hardness of the coating was ~ 541.2 HV 0.2 , which is about 10 times higher than that of Mg-Li alloy (~57.8 HV 0.2). The wear resistance of Mg-Li alloy was also improved approximately 10 times by cladding Ni 2 MnCuSnAl 0.1 MPEA coating. [ABSTRACT FROM AUTHOR]