Investigation of gum metal coating on Ti6Al4V plate by direct laser deposition

Two layers of Ti-36Nb-2Ta-3Zr-0.30 (wt%, gum metal) were deposited on the Ti6Al4V substrate by direct laser deposition. The microstructures, mechanical properties and corrosion resistance of the cladding layer were investigated. The results show that the single beta phase columnar with different orientation was obtained in the second cladding layer, and a large amount of alpha '' martensites exist in the first cladding layer. The absence of the toxic elements of Al and V in the second cladding layer indicates gum metal coating can promote the long-time performance of Ti6Al4V. Nanoindentation tests show that the elastic modulus is about 75GPa at the surface of gum metal coating, decreased by about 40% compared with the Ti6Al4V substrate. The corrosion resistance of Ti6Al4V is improved by the formation of beta phase on the coating. Ti6Al4V coated with gum metal by direct laser deposition can be regarded as a potential candidate to integrate the advantages of the two Ti-base alloys for application in the biomedical field.