低温发泡多孔金属材料制备研究

论文总字数：22909字

摘 要

低温发泡多孔金属是为了适用于航天领域对于泡沫金属的特殊要求提出的。在具有同一般泡沫金属的性能特点的同时运用粉末冶金法在地面制备出发泡预制件，从而节省优化飞船空间体积。另外，降低了发泡预制件成功发泡制备多孔结构的温度，使其能够在发泡条件限制的太空环境进行发泡制备成品进行使用。本研究主要路线为探究合金成分，探究低温发泡剂阶段，以及探究制备工艺阶段。在不同的阶段，遇到的难题不一样。探究合金成分阶段，遇到的问题是基体氧化问题，探究发泡剂成分阶段，遇到的问题是发泡剂产气量以及产生的气体与基体发生反应的问题，研究制备工艺的过程中发现，并不是所有制备方法都适合制备适合条件的泡沫金属预制件。

根据金属熔点以及合金性能的综合考虑，课题中主要探究了泡沫锡锌合金的制备方法。首先在熔点为180-200℃的锡锌合金中进行挑选，确定了需要的合金成分。接下来比较了无机发泡剂与有机发泡剂的相关特性，选择符合实验需要的发泡剂。无机发泡剂使用氢化钛，有机发泡剂使用偶氮二甲酰胺（ADC）和五苯基四唑。然后分别用粉末冶金法、二次法、熔体发泡法制备泡沫锡锌合金，并观察了样品的横截面，初步分析孔结构，发现熔体发泡法制备出的泡沫锡锌合金孔更加均匀。从而对熔体发泡法制备的样品进行进一步分析。采用金相实验以及SEM扫描，分析微观结构的孔状态以及孔壁，同时对其进行力学性能测试，探究下一步研究的方向。

铝镁合金比锡锌合金的熔点更高，但是具有锡锌合金所不具备的强度优势。所以本课题最后进行了对泡沫铝镁合金的尝试性研究。通过对铝镁相图的研究寻找低熔点的合金成分，并且设计出合适的发泡剂以及增黏剂配比，制备出低温发泡预制件。

关键词：发泡多孔金属，发泡剂，锡锌合金，铝镁合金

Abstract

The low-temperature foaming porous metal is proposed for the special requirements of the foam metal in the aerospace field. The foamed preforms are prepared on the ground using the powder metallurgy method while having the same characteristics as the general foam metal, thereby saving the space volume of the spacecraft. In addition, the temperature at which the foamed preform is successfully foamed to produce a porous structure is reduced, so that it can be foamed to prepare finished products in a space environment where the foaming conditions are limited. The main line of this research is to explore the composition of alloys, to explore the stage of low-temperature foaming agents, and to explore the preparation process stages. In different stages, the problems encountered are different. The problem encountered in the investigation of the alloy composition stage is the oxidation of the matrix. In the phase of exploring the composition of the blowing agent, the problems encountered are the gas generation of the blowing agent and the reaction between the generated gas and the matrix. During the study of the preparation process, Not all methods of preparation are suitable for preparing suitable metal foam preforms.

According to the comprehensive consideration of the melting point of the metal and the properties of the alloy, the preparation method of the foam tin-zinc alloy is mainly investigated in the subject. First, the tin-zinc alloy having a melting point of 180-200°C was selected to determine the desired alloy composition. Next, the relative properties of the inorganic foaming agent and the organic foaming agent were compared, and the foaming agent that met the experimental requirements was selected. Titanium hydride is used as an inorganic foaming agent, and azodicarbonamide (ADC) and pentaphenyl tetrazole are used as an organic foaming agent. Then the foamed tin-zinc alloy was prepared by the powder metallurgy method, the secondary method and the melt foaming method, respectively. The cross-section of the sample was observed, and the pore structure was preliminary analyzed. It was found that the foam tin-zinc alloy prepared by the melt foaming method was even more porous. Uniform. Thus, the samples prepared by the melt foaming method were further analyzed. Metallographic experiments and SEM scans were used to analyze the pore state and pore wall of the microstructure, and at the same time, the mechanical properties were tested to explore the direction of the next research.

Aluminum-magnesium alloys have a higher melting point than tin-zinc alloys, but have strength advantages that tin-zinc alloys do not possess. So this topic finally carried on the tentative research to the foam aluminum magnesium alloy. The low-melting alloy composition was found by studying the phase diagram of aluminum and magnesium, and a suitable foaming agent and the proportion of thickening agent were designed to prepare a low-temperature foaming preform.

KEYWORDS: foamed porous metal, blowing agent, tin-zinc alloy, aluminum-magnesium alloy

目录

摘要 I

Abstract II

第1章 绪论 5

1.1 引言 5

1.2 泡沫合金简介 5

1.2.1 泡沫合金的性能 5

1.2.2 泡沫合金的应用 6

1.3 泡沫金属制备方法 6

1.3.1 熔模铸造法 7

1.3.2 渗流铸造法 7

1.3.3 气体发泡法 8

1.3.4 粉末发泡法 8

1.3.5 二次法 9

1.3.6 熔体发泡法 10

1.4 泡沫金属添加剂 10

1.4.1 发泡剂 10

1.4.2 增黏剂 12

1.5 泡沫合金发展研究状况 12

1.6 课题研究思路与研究意义 13

第2章 泡沫合金成分 14

2.1 低温合金成分选取 14

2.2 泡沫锡锌合金发泡剂的选取 15

2.2.1 介绍 15

2.2.2 无机发泡剂选择 15

2.2.3 有机发泡剂选择 16

2.3 增黏剂 18

第3章 制备泡沫锡锌合金 19

3.1 粉末冶金法制备泡沫锡锌合金 19

3.1.1 成分 19

3.1.2 实验方案 19

3.2 在锡锌合金中加入铋使用粉末冶金法制备 20

3.2.1 成分 20

3.2.2 实验方案 20

3.3 二次法制备泡沫锡锌合金 20

3.3.1 成分 20

3.3.2 实验方案 21

3.4 熔体法制备泡沫锡锌合金 21

3.4.1 成分 21

3.4.2 实验方案 21

3.5 小结 23

第4章 熔体法制备泡沫锡锌合金性能分析 24

4.1 万能试验机力学性能测试 24

4.2 孔结构分析 24

4.2.1 金相分析 24

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