增材制造TiNi记忆合金结构及其变形行为的研究

论文总字数：32760字

摘 要

TiNi合金因其具有形状记忆效应而在各个领域获得广泛应用。由于成形和加工困难以及智能材料特性会因再加工而丢失等问题，使得TiNi合金的使用仅限于丝材和棒材等最基本的形式，严重限制了这种智能材料的广泛和深入的应用。

本文的研究目标是通过采用送丝方式的层流等离子体增材制造设备打印出钛镍合金构件,并进一步使其具备形状记忆效应。本文对增材制造设备所用钛镍合金丝和打印样品热处理前后状态的分析，以及对打印样品形状记忆处理方式的研究结果表明：经约束的钛镍合金丝在450℃时效处理后相转变更充分，出现形状记忆效应；打印的钛镍合金致密性优良，在实验温度区间（0-100℃）不发生相转变；打印的钛镍合金微观组织特点和取向性随着所处样品区域而呈现规律性变化；时效处理不能改善打印的钛镍合金微区成分不均，但能使样品在实验温度区间（0-100℃）发生相转变且随着时效时间延长相变更明显；固溶处理可以使打印的钛镍合金成分均匀化的同时给予其双程形状记忆效应中的低温相形状，固溶后的时效可以给予其双程形状记忆效应中的高温相形状，进而使样品展现出良好的双程形状记忆效应。

关键字：钛镍合金，增材制造，形状记忆效应，热处理

Abstract

Nickel-titanium alloy is widely used in various fields because of its shape memory effect.Due to the difficulties in forming and processing and the loss of intelligent material properties due to reprocessing, the use of nickel-titanium alloy is limited to the most basic forms such as wire and bar, which seriously limits the wide and deep application of this intelligent material.

The aim of this paper is to print out the nickel-titanium alloy components by laminar plasma additive manufacturing equipment with wire feeding and further make them have shape memory effect.In this paper, the state analysis of nickel-titanium alloy wire used in additive manufacturing equipment and printed sample before and after heat treatment, as well as the research results of shape memory treatment of printed sample show that: the phase transformation of restrained nickel-titanium alloy wire is more sufficient after aging treatment at 450℃, and the shape memory effect appears;The printed nickel-titanium alloy has excellent compactness and does not undergo phase transformation in the experimental temperature range (0-100 ° C);The microstructure and orientation of the printed nickel-titanium alloy change regularly with the sample area;The aging treatment can not improve the uneven composition of the printed nickel-titanium alloy micro-region, but can make the phase transformation of the sample in the experimental temperature range (0-100 °C) and with the aging time extension, phase transformation is more obvious;Solid solution treatment can homogenize the components of the printed nickel-titanium alloy and give the shape of the low-temperature phase in the two-way shape memory effect at the same time, and the aging after solid solution can give the shape of the high-temperature phase in the two-way shape memory effect, so that the samples show good two-way shape memory effect.

KEY WORDS: nickel-titanium alloy, additive manufacturing, shape memory effect, heat treatment

目 录

摘要 .............................................................................................................................................Ⅰ

Abstract .....................................................................................................................................Ⅱ

第一章 绪论 ..............................................................................................................................1

1.1钛镍形状记忆合金 ..................................................................................................1

1.1.1形状记忆合金及形状记忆效应 ...............................................................1

1.1.2钛镍合金 ...................................................................................................2

1.1.3钛镍合金主要加工方法 ...........................................................................4

1.2金属增材制造技术 ..................................................................................................4

1.2.1金属增材制造技术及分类 .......................................................................4

1.2.2关键技术问题及应用 ................................................................................5

1.3增材制造钛镍形状记忆合金结构 ...........................................................................5

1.3.14D打印技术及优势 ...................................................................................5

1.3.2钛镍记忆合金增材制造研究现状 ............................................................6

1.4选题背景与意义 .......................................................................................................9

1.5本文研究内容 ...........................................................................................................9

第二章 实验材料及方法 .........................................................................................................11

2.1实验设备 .................................................................................................................11

2.2实验材料 .................................................................................................................11

2.3研究方法 .................................................................................................................12

第三章 TiNi形状记忆合金丝材研究 ....................................................................................14

3.1原始丝材状态分析 .................................................................................................14

3.2丝材热处理后状态分析 .........................................................................................16

3.2.1热处理对TiNi丝材相组成的影响 ........................................................16

3.2.2热处理对TiNi丝材相转变的影响 ........................................................18

3.3丝材热处理后的变形行为 .....................................................................................18

第四章 增材制造对样品状态的影响 ....................................................................................20

4.1打印样品参数设置 .................................................................................................20

4.2不同工艺参数对样品致密度的影响 .....................................................................21

4.3 不同工艺参数对样品相组成的影响 ...................................................................21

4.4 不同工艺参数对样品相变行为的影响规律 .......................................................23

4.5 打印样品的微观组织分析 ...................................................................................23

第五章 增材制造样品的形状记忆处理研究 ........................................................................28

5.1不同时效时间对打印样品状态的影响 ................................................................28

5.2样品双程形状记忆效应处理分析 ........................................................................33

5.2.1固溶处理对样品相组成的影响 .............................................................33

5.2.2固溶和时效对样品相转变的影响 .........................................................34

5.3双程形状记忆效应的变形行为 ............................................................................34

第六章 总结................................................................................................................................36

参考文献 ..................................................................................................................................37

致谢 ..........................................................................................................................................39

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