Mechanical properties and bioactive surface modification via alkali-heat treatment of a porous Ti–18Nb–4Sn alloy for biomedical applications

Abstract

A porous Ti–18 at.%Nb–4 at.%Sn (hereafter, Ti–18Nb–4Sn) alloy was prepared by powder metallurgy. The porous structures were examined by scanning electron microscopy and the phase constituents were analysed by X-ray diffraction. Mechanical properties of the porous alloy were investigated using a compressive test. To enhance the bioactivity of the alloy surface, alkali-heat treatment was used to modify the surface. The bioactivity of the pre-treated alloy sample was investigated using a biomimetic process by soaking the sample into simulated body fluid (SBF). Results indicate that the elastic modulus and plateau stress of the porous Ti–18Nb–4Sn alloy decrease with decreasing relative density. The mechanical properties of the porous alloy can be tailored to match those of human bone. After soaking in SBF for 7 days, a hydroxyapatite layer formed on the surface of the pre-treated porous Ti–18Nb–4Sn alloy. The pre-treated porous Ti–18Nb–4Sn alloy therefore has the potential to be a bioactive implant material.