Abstract

Tantalum (Ta) is a remarkable biological substance, with excellent corrosion resistance and biocompatibility. However, pure Ta coatings do not possess sufficiently high mechanical properties, especially wear resistance. To improve the wear resistance of Ta, Ta₂O₅ reinforced Ta-based coatings were fabricated on Ta substrates using laser cladding with a direct pre-placed powder method. The microstructure of the coating was primarily the result of a monotectic reaction and can be interpreted using the Ta-O phase diagram. The results suggested that Ta-Ta₂O₅ graded coatings can be fabricated on Ta substrates by controlling the amount of melting of the Ta substrate and/or adjusting the oxygen level of the processing chamber during laser cladding. The corrosion and wear resistances of the composite coating were higher than those of the uncoated Ta material when free corrosion potential, corrosion current density and wear track width were considered.