论文总字数：19021字

摘 要

Ti-2Fe 合金是一种近年来被开发的新型钛铁合金， Ti-2Fe合金的成本远低于传统的TC4合金，从而使Ti-2Fe合金的实用性更加广泛。不仅如此，该合金材料通过加入少量的 Fe 元素，不仅可以起到提高合金的力学性能，同时还可以使其热加工性能有效地改善，从而提高合金的综合性能。

为了获取不同温度与压缩速率下的应力应变曲线，本文使用Gleeble3800热压缩模拟机，对Ti-2Fe合金进行了不同温度跟应变速率的热压缩实验。通过分析应力应变曲线得到了Ti-2Fe在热压缩过程中的数学模型，找到适合该合金的本构方程,进而确定合金的最佳热加工工艺。本论文中取得的主要研究成果和结论如下：

（1）通过对原始金相组织的观察，得到了Ti-2Fe合金的原始组织特征，发现其组织为经典的网篮状组织，包含了初生α相、片状α相、微量的晶间β相及微量析出物。

（2）其流变应力曲线呈典型的单峰流变特征，且峰值应力随温度的增加而逐渐减少，而随应变速率的减慢而增加。

（3）Ti-2Fe合金本构方程的建立依赖于含Arrhenius项的Z参数模型，该方程的精准度较高，预测值与实验数据的相关系数分别是0.981，能较好地代表Ti-2Fe合金在高温变形过程中的流动行为。

关键词：钛合金 本构方程 相组成 热变形行为

Study on Microstructure and Hot Deformation Behavior of New Ti-2Fe Alloy

Abstract

In recent years, Ti-2Fe alloy has attracted much attention because of its low price and good mechanical properties. The traditional TC4 alloy is more expensive.The research found that the addition of a small amount of iron element has improved the mechanical properties of titanium alloy and its hot working performance, which makes the titanium alloy better meet our application needs.In order to understand the thermal deformation behavior of this new alloy, we conducted multiple thermal compression deformation experiments on it by changing the temperature and strain rate. The instrument used was a GLEEBLE3800 thermal compressor.After obtaining the stress-strain curves of the alloy under different conditions, we used the Arrhenius equation proposed by Sellars and Tegart, and obtained its constitutive equation by calculation, allowing us to describe its thermal deformation behavior.We got the following conclusion:

1. Through the observation of the original metallographic structure, the original structure characteristics of the Ti-2Fe alloy were obtained, and the structure was found to be a classic basket-like structure, including the grain boundary α phase, lamellar α phase, a trace amount of intragranular β phase and little precipitates.
2. Its rheological stress curve shows a single peak rheological characteristic, and its peak stress is affected by temperature and strain rate.
3. The Ti-2Fe alloy constitutive equation is established according to the Z-parameter model with Arrhenius terms. The equation has a high accuracy.The correlation coefficients between the experimental data and the predicted values are 0.981, which indicates that the constitutive equation can better represent its high-temperature rheological behavior.

Keywords: Titanium alloy Constitutive equation Phase composition Thermal deformation behavior

目 录

摘 要 I

Abstract II

第一章 绪论 1

1.1引言 1

1.2钛合金简介 1

1.2.1钛合金发展 1

1.2.2钛合金的应用 2

1.2.3钛合金的分类 3

1.3钛合金中的常见添加元素 3

1.4钛合金的热变形实验 5

1.5研究本课题的意义 5

第二章 实验材料与方案 7

2.1实验材料 7

2.2实验方案 7

2.3实验仪器 7

2.4实验过程 8

2.4.1试样的金相制备与显微组织观察 8

2.4.2热压缩实验 9

第三章 实验结果与讨论 11

3.1 Ti-2Fe合金的组织特征 11

3.2 Ti-2Fe合金的热塑性性能 12

3.2.1 Ti-2Fe合金的流变应力曲线 12

3.2.2 变形温度对Ti-2Fe流变应力的影响 12

3.2.3 变形速率对Ti-2Fe流变应力的影响 13

3.2.4 Ti-2Fe合金的线性本构方程 14

第四章 实验结论 17

参考文献 18

致 谢 22

第一章 绪论

1.1引言

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