论文总字数：18638字

摘 要

钛合金是一种具有优良的综合性能的合金。这使得钛合金在许多方面都得到高度的重视和广泛的应用，无论是军事工业还是民用领域。然而钛合金的应用存在着成本过高的困难。所以，目前，研发低成本钛合金不仅是一个产业需要也是一个研究热点。本次课题以Ti-3.5Fe-0.15B钛合金为研究对象。采用的仪器有光学金相显微镜(OM)，X射线衍射仪(XRD)和扫描电子显微镜(SEM)等。这比较全面地研究了普通退火对钛合金的相组成及微观组织的影响，明确微观组织的演变机制与普通退火的关系；并通过硬度和室温拉伸性能等测试来分析探讨了普通退火对合金的物理机械性能的影响。研究结果表明：

（1）Ti-Fe-B合金退火前的微观组织为典型的片层状组织。并且晶粒内局部具有网篮组织特征，合金的相组成为α相和β相两相。在普通退火热处理后，α相含量减少，α相宽度下降，β相含量增加。

（2）Ti-Fe-B合金在普通退火后，其维氏硬度由287.49上升至301.53。室温抗拉强度由688MPa下降至649MPa，屈服强度由152MPa上升至637MPa。断后伸长率由22.0%下降至21.0%；这是由于合金中，因为滑移距离增大降低材料强度与固溶强化作用增强基体的强度，在本实验中，前者的效果占据主导地位导致的。

（3）通过对Ti-Fe-B合金的拉伸断口形貌观察，普通退火后的韧窝更大，说明了普通退火后，合金的塑性有了改善。

（4）本文最后得到普通退火对合金组织演变和性能变化影响的规律，在普通退火后，合金α相的含量下降，α相宽度降低，β相含量上升。合金的维氏硬度和塑性有了提高，合金的强度略微降低。

关键字：钛合金 低成本 普通退火 组织演变 机械性能

The effect of general annealing technology on the organization and mechanical properties of Ti-Fe-B

ABSTRACT

Titanium alloy is a kind of alloy with excellent comprehensive properties. It makes the titanium alloy have been valued highly and used widely in many aspects, whether it is military industry or civilian areas. However, the application of titanium alloy has a problem because of high cost. Therefore, the current research and development of low-cost titanium alloy is not only an industry need, but also a research hotspot. The subject was studied with Ti-3.5Fe-0.15B titanium alloy. The instruments are such as optical metallographic microscope (OM), X-ray diffractometer (XRD) and scanning electron microscope (SEM). This paper studies the effect of general annealing on the composition and microstructure of titanium alloy, and makes clear the relation between the evolution mechanism of microstructure and general annealing. The effect of general annealing on the physical mechanical properties of the alloy was analyzed by the test of hardness and temperature tensile property.

The results showed:

(1)The microstructure of the Ti-Fe-B alloy is the typical laminar tissue. In addition, it has the characteristics of the basket-weave microstructure, and the composition of the alloy is α and β.After general annealing heat treatment, the α phase decreases, the breadth of α decreases, and the β phase content increases.

(2)After the general annealing of the Ti-Fe-B alloy, its vickers hardness increased from 287.49 to 301.53.Room temperature tensile strength reduced from 688MPa to 649MPa, and its yield strength increased from 152MPa to 637MPa.The elongation rate dropped from 22.0% to 21.0%. Because the sliding distance increases in strength of materials and solid solution strengthening effect to enhance the strength of the matrix, in this experiment, the result of the effect of the former dominated.

(3) After the general annealing of the Ti-Fe-B alloy was observed by the tensile fracture of the Ti-Fe-B alloy. We can know that the plasticity of the titanium alloy is improved after the general annealing.

(4) Finally, the paper get general annealing on the microstructure evolution and performance change rule. After general annealing, the α phase decreases, the breadth of α decreases, β phase content increased. The hardness and plasticity of the alloy are improved, and the strength of the alloy is slightly lower.

Key words: Titanium alloy; Low cost; General annealing; Microstructure evolution; Mechanical properties

目 录

摘要…………………………………………………………………………………I

ABSTRACT………………………………………………………………………II

1. 绪论………………………………………………………………………1

1.1钛及钛合金的概述…………………………………………………………1

1.1.1钛及钛合金的应用与发展史…………………………………………1

1.1.2低成本钛合金的概述…………………………………………………1

1.1.3钛合金成本高昂的分析………………………………………………2

1.1.4降低钛合金成本的方法………………………………………………3

1.2添加的合金元素对钛合金的影响…………………………………………4

1.2.1添加铁元素对钛合金的影响…………………………………………5

1.2.2添加硼元素对钛合金的影响…………………………………………5

1.3钛合金的退火工艺…………………………………………………………5

1.4研究目的和方法……………………………………………………………6

第二章 实验方法………………………………………………………………7

2.1实验方案……………………………………………………………………7

2.2实验材料及制备……………………………………………………………7

2.2.1钛合金成分分析………………………………………………………7

2.2.2 DSC实验 ……………………………………………………………8

2.2.3钛合金热处理实验……………………………………………………9

2.3微观测试分析 ……………………………………………………………10

2.3.1金相试样的制备与观察 ……………………………………………10

2.3.2合金物相分析实验 …………………………………………………10

2.3.3拉伸断口形貌观察 …………………………………………………10

2.4力学性能测试 ……………………………………………………………10

2.4.1显微硬度测试 ………………………………………………………10

2.4.2拉伸性能测试 ………………………………………………………11

第三章 普通退火对钛合金组织的影响 …………………………………12

3.1金相组织分析 ……………………………………………………………12

3.2合金物相分析 ……………………………………………………………13

3.3本章总结 …………………………………………………………………14

第四章 普通退火对钛合金力学性能的影响 ……………………………15

4.1显微硬度分析 ……………………………………………………………15

4.2拉伸测试分析 ……………………………………………………………15

4.3拉伸断口形貌分析 ………………………………………………………16

4.4本章总结 …………………………………………………………………17

第五章 结论与展望 ……………………………………………………………19

参考文献 …………………………………………………………………………20

致谢…………………………………………………………………………………21

1. 绪论

1.1钛及钛合金的概述

1.1.1钛及钛合金的应用与发展史

请支付后下载全文，论文总字数：18638字