Effects of pre-compression on the microstructure, mechanical properties and corrosion resistance of RE65Co25Al10 (RE = Ce, La, Pr, Sm and Gd) bulk metallic glasses

• Multicomponent RE65Co25Al10 (RE = Ce, La, Pr, Sm and Gd) BMG was designed and prepared.
• Effects of pre-compression for the RE65Co25Al10 BMG have been investigated.
• Pre-compression induces the change of microstructure or partial crystallization of BMGs.
• Pre-compression obviously enhances the mechanical property and corrosion resistance.
• RE-based BMG composite processes the excellent compressive fracture strength and HV.

The effects of the pre-compression treatment at room temperature on the microstructure, mechanical properties, and corrosion resistance of the RE65Co25Al10 (RE = Ce, La, Pr, Sm and Gd) bulk metallic glasses (BMGs) in the seawater solution have been investigated. The results indicate that the pre-compression treatment induces the microstructure changes or partial crystallization, which can significantly improve the thermal stability and the mechanical properties of the RE65Co25Al10 BMGs. The BMG-based composite with nanocrystals under the pre-compression stress of 450 MPa shows the excellent mechanical properties with the compressive fracture strength of 832 MPa and microhardness of 261 HV, while the BMG pre-compressed by the stress of 250 MPa exhibits the enhanced corrosion resistance in the seawater solution, as indicated by the low corrosion current density and high corrosion potential. However, the corrosion resistance of the RE65Co25Al10 BMG composite pre-compressed under the stress of 450 MPa does not perform as well as this of the specimen pre-compressed under the stress of 250 MPa. Moreover, the discussion has been made based on the short-range order (SRO), free-volume content, and nanocrystal precipitation under the pre-compression treatment. The proper pre-compression design can be beneficial for improving the practical application of the RE-based BMGs.