Hydrothermal Surface Modification of a Low Modulus Ti-Nb Based Alloy

Abstract:

A low modulus near b type titanium alloy (Ti-25Nb-3Zr-2Sn-3Mo, or TLM alloy) was subjected to hydrothermal treatments with a urea solution at different temperatures followed by heat treatment. The surface structure, the chemical composition, adhesion and hydrophilicity of the treated TLM alloy were investigated by SEM, XRD, XPS, Rockwell-C indentation test and contact angle measurement. The results show that nanosheet films of ammonium titanate can be formed at 105 and 120 °C, while the nanoparticle film of anatase TiO2 containing Nb2O5 is formed at 150 °C on the alloy surface. The subsequent annealing heat treatment at 400 °C can decompose the ammonium salts and crystallize titania. The obtained oxide films have a good adhesion. The duplex treatment has enhanced the hydrophilicity of the TLM alloy, and it would be good for its biocompatibility.

Key words:titanium alloy; biomaterials; hydrothermal; TiO2; hydrophilicity