METALLIC COATINGS ON METALLIC SUBSTRATES

摘要

Porous titanium coatings have been produced on Ti-6A1-4V substrates by electrophoretic deposition of TiH2 powder suspensions, followed by vacuum sintering at 850°C. The use of titanium hydride resulted in lower sintering temperatures as compared to pure titanium powders and this allowed maintaining the a-ß microstructure and mechanical properties of the substrate material. Pure Ti coatings with thicknesses varying from 10 µm to over 500 µm, a porosity ranging from 37 to 52 % and a surface roughness from 1.6 to 4.9 µm have been produced. The process allows to control the thickness and porosity of the coating. Metal coatings with metals of the group consisting of Ti, Zr, Mg5 Hf, Ta, Nd, Nb, Mn, and Mo with thicknesses varying from 1µm - 90 µm, from 2 µm - 90 µm or from 2 µm - 1000 µm and a porosity ranging from 0 to 70%, preferably from 2 to 70% and more preferably from 45 to 70 % are achievable by this process. It even is possibly to produce coatings that have a porosity of only 0-5 % porosity. Adhesion testing of the coatings showed a tensile bond strength that is higher than 22 MPa.