典型医用钛合金材料电子结构及力学性能研究

Electrical and mechanical properties of typical medical metal materials

随着科技的飞速发展,在二十一世纪的今天,许多金属运用于现代医学领域;其中钛及其合金因其高强度、低弹性模量、生物相容性好等优势,而占据医用金属材料的半壁江山。二氧化钛(TiO2 )由于其具有优异的能带结构、较好的化学稳定性、较高的催化性以及较低的价格,从而使其在体外辅助治疗材料方面应用最为广泛。本文基于密度泛函理论的第一性原理赝势法对不同结构的TiO2和二元β型钛合金(Ti-Mo)的电学参数(禁带宽度、态密度)和力学性能(弹性常数、弹性模量)进行了理论模拟计算。计算结果表明金红石型TiO2是禁带宽度为2.03eV的直接半导体;锐钛矿型TiO2是禁带宽度2.15eV的间接半导体。对Ti15Mo1、Ti9Mo7、Ti1Mo15三种Ti-Mo合金的计算结果表明,随着Mo元素的增加,Ti-Mo合金的β稳定性提升,弹性模量B、E、G均有所增加。

With the rapid development of science and technology, in the twenty-first Century, many metals were used in the field of modern medicine, in which titanium and its alloys occupy half of the medical metal materials because of their advantages of high strength, low modulus of elasticity and good biocompatibility. Titanium dioxide(TiO2) is the most widely used in vitro assisted treatment materials because of its excellent band structure, good chemical stability, high catalytic activity and low price. Based on the density functional theory, the first principle pseudopotential method is used to simulate the electrical parameters(forbidden band width, state density) and mechanical properties(elastic constants and elastic module) of different structures of TiO2 and two element beta titanium alloy(Ti-Mo). The results show that rutile TiO2 is a direct semiconductor with a band gap of 2.03 eV, and anatase TiO2 is an indirect semiconductor with a band gap of 2.15 eV. The calculation results of three Ti-Mo alloys of Ti15 Mo1, Ti13 Mo3 and Ti11 Mo5 show that the stability of Ti-Mo alloy increases with the increase of Mo element, and the modulus of elasticity of B, E and G all increase.