Development of a high amorphous content Zr-based metallic glass coating by L-PBF for biomedical Applications

Zr-based metallic glasses (MGs) have garnered significant attention as promising biomedical coating materials. Laser powder bed fusion (L-PBF) technology was employed to fabricate Zr 55 Cu 30 Ni 5 Al 10 MG coatings on a 316 L stainless steel (316LSS) substrate. Benefiting from the high forming accuracy and ultrahigh cooling rates characteristics of L-PBF, a Zr-based MG coating with a high amorphous content exceeding 80% was successfully fabricated. This value substantially exceeds the benchmark achieved by conventional laser cladding for the same systems. Furthermore, the process achieved excellent metallurgical bonding while maintaining a significantly low dilution rate in the range of 8.43% to 13.86%, which mitigates the degradation of glass-forming ability (GFA) typically caused by substrate elemental diffusion. Due to high amorphous content and molding quality, L-PBF Zr-based MG coatings not only enhance the hardness from (282.67 Hv) to (561 Hv), but also improve the corrosion resistance (I corr decreases from 1.02 × 10 −5 A/cm 2 to 2.56 × 10 −8 A/cm 2 in the Hanks’ solution and I corr decreases from 1.53 × 10 −5 A/cm 2 to 2.58 × 10 −7 A/cm 2 in the Artificial saliva) of substrates, which is superior to reported Zr-based MG coatings prepared by other laser-fabricated methods. This study demonstrates that L-PBF provides a viable approach for developing high-performance MG coatings.