Surface characterization of Ti–7.5Mo alloy modified by biomimetic method

Abstract

Titanium and its alloys have been used in dentistry due to their excellent corrosion resistance and biocompatibility. It was shown that even a pure titanium metal and its alloys spontaneously form a bone-like apatite layer on their surfaces within a living body. The purpose of this work was to evaluate the growth of calcium phosphates at the surface of the experimental alloy Ti–7.5Mo. We produced ingots from pure titanium and molybdenum using an arc-melting furnace. We then submitted these ingots to heat treatment at 1100 °C for one hour, cooled the samples in water, and cold-worked the cooled material by swaging and machining. We measured the media roughness (Ra) with a roughness meter (1.3 and 2.6 μm) and cut discs (13 mm in diameter and 4 mm in thickness) from each sample group. The samples were treated by biomimetic methods for 7 or 14 days to form an apatite coating on the surface. We then characterized the surfaces with an optical profilometer, a scanning electron microscope and contact angle measurements. The results of this study indicate that apatite can form on the surface of a Ti–7.5Mo alloy, and that a more complete apatite layer formed on the Ra = 2.6 μm material. This increased apatite formation resulted in a lower contact angle.