论文总字数：19945字

摘 要

ABSTRACT II

第一章 绪论 2

1.1 研究背景及研究意义 2

1.2 钛合金固溶强化研究现状 2

第二章 研究方案 2

2.1 研究方法 2

2.1.1 理论背景 2

2.1.2 工具软件介绍 2

2.2 计算流程 2

2.2.1 构建超胞模型 2

2.2.2 驰豫计算 2

2.2.3 静态计算（scf计算） 2

2.2.4 差分电荷密度计算（chgdiff计算） 2

2.2.5 态密度计算（dos） 2

2.2.6 力学弹性常数计算 2

第三章 结果及分析 2

3.1 驰豫结构分析 2

3.2 力学弹性常数 2

3.2.1 杨氏模量、剪切模量和泊松比 2

3.2.2 计算结果分析 2

3.3 电子结构分析 2

3.3.1 态密度计算结果 2

第四章 总结与展望 2

4.1 总结 2

4.2 展望 2

参考文献 2

致谢 2

固溶元素对α-Ti力学性质的影响机制

摘 要

钛金属自从发现以来就一直受到人们的关注，而钛合金更是广泛运用于人们的日常生产生活中。钛及钛合金具有耐腐蚀，耐热性好，比强度很高，高比强度的特点。现在钛合金的主要用途是在1.以航空航天领域为主的飞机、火箭中，2.船舶耐腐蚀的应用，3.生物医用钛合金，4.汽车工业。然而在众多钛合金中，固溶元素对钛合金力学性质的影响尚不全面，而本文运用第一性原理计算方法，研究、探索了Cr，Mo，Nb元素对α-Ti力学性质的影响机制。本课题对含Cr，Mo，Nb的钛合金进行第一性原理计算，测定其基本物理性质以及对Cr，Mo，Nb元素影响力学性质机制进行研究。希望能够加深相关钛合金的力学性质变化机理研究及预测钛合金性能，寻找性能变化规律，提供研发新钛合金材料思路。第一性原理计算方法是从电子运动的层次研究材料的结构和相关性能。可以根据很少几个基本的物理参数得到科学的结果，计算结果较符合现象背后的物理本质。主要结论如下：

（1）Ti-Cr、Ti-Mo、Ti-Nb钛合金的固溶比例达到25at%时，发现Ti-Cr稳定性最大，而Ti-Mo次之，Ti-Nb最小。

（2）Ti-Cr、Ti-Mo、Ti-Nb等的力学性质变化，Ti-Nb体模量B、弹性模量E、剪切模量G、泊松比最大、Ti-Cr次之，Ti-Mo最小。

（3）固溶原子周围电子减少，聚集在Ti原子和固溶原子之间，这表示Ti原子和固溶原子形成了金属键，共用电子对。

关键词：第一性计算原理 α-型钛合金 力学性质 固溶

Effect Mechanism of Solid Solution Elements on α-Ti Mechanical Properties

ABSTRACT

Titanium metal has been receiving people's attention since its discovery, and titanium alloys are widely used in people's daily production and life. Titanium and titanium alloys have the characteristics of corrosion resistance, good heat resistance, high specific strength and high specific strength. At present, the main uses of titanium alloys are in 1. aerospace-based aircraft and rockets, 2. the application of corrosion resistance in ships, 3. biomedical titanium alloys,4. automobile industry. However, in many titanium alloys, the influence of solid solution elements on the mechanical properties of titanium alloys is not comprehensive, and the first-principles calculation method used in this paper has studied and explored Cr. The influence mechanism of Mo and Nb elements on the mechanical properties of α-Ti. In this subject, first-principles calculations are performed on titanium alloys containing Cr, Mo, and Nb to determine their basic physical properties and the mechanism of the influence of Cr, Mo, and Nb elements on mechanical properties. I hope to deepen the research on the mechanism of mechanical properties change of titanium alloys and predict the properties of titanium alloys, look for the law of property changes, and provide ideas for the development of new titanium alloy materials. The first-principles calculation method is to study the structure and related properties of materials from the level of electronic motion. Scientific results can be obtained based on a few basic physical parameters, and the calculation results are more in line with the physical essence behind the phenomenon. The main conclusions are as follows:

(1) When the solid solution ratio of Ti-Cr, Ti-Mo, Ti-Nb titanium alloy reaches 25at%, it is found that Ti-Cr is the most stable, followed by Ti-Mo, Ti-Nb is the smallest.

(2) The mechanical properties of Ti-Cr, Ti-Mo, Ti-Nb, etc. change, Ti-Nb bulk modulus B, elastic modulus E, shear modulus G, Poisson's ratio maximum, Ti-Cr second , Ti-Mo is the smallest.

请支付后下载全文，论文总字数：19945字