(1. 昆明理工大學 材料科學與工程學院，昆明 650093；
2. 昆明貴金屬研究所，昆明 650106)
摘 要: 鈦合金以其優(yōu)良的生物相容性和綜合力學性能成為當前生物醫(yī)用材料的研究熱點，本文采用密度函數(shù)理論方法對不同固溶度的Ti1-xTax合金的能量、晶體結(jié)構(gòu)、電子結(jié)構(gòu)和力學性質(zhì)進行全面、系統(tǒng)的理論計算和分析，并通過電子結(jié)構(gòu)的分析研究了相關(guān)力學性質(zhì)變化的內(nèi)在機理。結(jié)果表明：Ti1-xTax合金體系在固溶度x=0~0.125區(qū)間內(nèi)六方密排相為主，在其他固溶度下則兩種相同時存在。兩種晶體結(jié)構(gòu)Ti1-xTax合金的晶格常數(shù)平均值、晶胞體積和體積模量隨著固溶度x的增加按一階Vegard規(guī)律線性增加。Ti1-xTax合金體系的穩(wěn)定性、體彈模量、彈性模量和剪切模量的變化均與對應的電子結(jié)構(gòu)密切相關(guān)，在不同固溶度區(qū)間呈現(xiàn)不同的變化規(guī)律。
關(guān)鍵字: Ti-Ta合金；晶體結(jié)構(gòu)；電子結(jié)構(gòu)；力學性質(zhì)；密度泛函理論計算
（1. Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming 650093, China;
2. Kunming Institute of Precious Metals, Kunming 650106, China）
Abstract:The excellent biocompatibility and comprehensive mechanical properties of medical titanium alloy have become the focus of current research. In this paper, the energy, crystal structure, electronic structure and mechanical properties of Ti1-xTax alloy with different solid solubility were calculated and analyzed comprehensively and systematically by using density function theory method. The results show that the Ti1-xTax alloy is dominated by the hexagonal close packing phase in the range of solid solubility of x=0-0.125, while the other two phases exist simultaneously. The lattice constant average value, crystal cell volume, and volume modulus of the two Ti1-xTax alloys increase linearly with the enhancement of solid solubility x according to the first-order Vegard law. The stability, body elastic modulus, elastic modulus and shear modulus of the Ti1-xTax alloys are all closely related to the corresponding electronic structure, showing different variation rules in different solid solubility intervals.
Key words: Ti-Ta alloys; crystal structure; electronic structure; mechanical properties; DFT calculations
