摘 要

W-Cu复合材料综合了W、Cu双方各自的优点，在具有高强度、高硬度、高密度这些特性的同时，还拥有良好的延展性、导电性和导热性，同时具备可控的热膨胀系数，极具发展潜力。

而W-Cu梯度复合材料连续改变了W和Cu两种不同金属的各种物理性质或力学性质，一端表现出W或W合金的性质，另一端表现出Cu或Cu合金的性质，然后在其中添加过渡层，使其内部界面减小细化，在宏观上表现消失，从而获得材料性能呈连续平稳变化的W-Cu复合材料。

梯度材料的制备有多种方法，其中，流延成型工艺拥有配置简单、可连续操作、生产效率快、自动化水平高、工艺稳定等各种优点，是一个制备梯度功能复合材料的好方法。在过去，流延成型工艺主要用于陶瓷的制备，不用于制备金属膜片的主要原因在于金属颗粒的粒径与密度大，在制备过程中容易发生沉降。但随着现在超细金属粉体制备技术的提升，流延成型工艺也可以用于制备金属材料。

而流延成型技术的关键环节有流延浆料的配置与膜带的制备。本文以W-Cu流延浆料及其流延膜带为研究对象，采用真空球磨混料的混合工艺制备出流延浆料，并对流延浆料进行了流变性测试及分析，同时对流延膜带的微观形貌进行了观测和能谱分析。实验中通过改变黏结剂PVB的分子量与金属粉料的固相含量进行对比，研究粘度、剪切应力、物相分布等与它之间的关系。

结果表明，实验中每一次的流延浆料都能很好的满足流延的粘度条件。当固相含量从60wt%升至70wt%时，两种分子量PVB的浆料在粘度上均发生突变，粘度从99.51mPa·s和140.43mPa·s快速上升至146.01mPa·s和233.43mPa·s。其流变特性也随之发生变化，流变模型从假塑性流体变为宾汉姆流体。流延浆料流延得到的流延膜带致密性良好，伴随着固相含量的增加不断变得致密，正反面分布中W表现良好，Cu在固相含量突变点前中沉降明显，突变点后分布良好，其中在70wt%时W、Cu的分布均一性均为最佳。在粉料的含量控制上，当粉料固相含量为60wt%时，原料成分的控制表现的最好。

关键词：流延成型；W-Cu；梯度材料；流变性

Abstract

W-Cu composite material is the material shared the advantages of both the W and the Cu , such as high density, strength, hardness and great ductility, electrical and thermal conductivity , and of course, the low thermal expansion coefficient and other properties . It is very great.

W-Cu gradient composite continuous change of various physical properties and mechanical properties of W and Cu two different metals. On one terminal, the material shows the properties of W or W alloy, and on the other terminal, it show the properties of Cu or Cu alloy. And then between then, a transition layer is added on, in which the internal interface decreases or disappear in the macro performance of refinement. In the end, we obtain W-Cu composites with stable and continuous change properties.

The tape casting technology has the advantages of simple equipment, continuous operation process , high production efficiency, automation, stable and so on. It is the best technology for making multilayer structure materials. In the past, the tape casting process is mainly used for the production of ceramics. The main reason for not using tape casting technology fabricating metal diaphragm material is its own property: the metal powder has large particle size and higher density, and as a result, the settlement phenomenon is easy to happen during the process of tape casting. But with the development of metal powder preparation technology, we can also use tape casting to make metal material .

The essential part are the fabrication of W-Cu slurry and W-Cu cast film. This paper takes W-Cu casting slurry and cast film as research object, using vacuum ball celling technology to product the slurry. On the other hand, rheological test and analysis for the slurry, add on microscopic morphology observation and energy spectrum analysis to the cast film make more data.

The results show that the slurry of every experiment can meet the casting viscosity conditions beautifully. When the solid content increased from 60wt% to 70wt%, viscosity of two kinds of molecular weight PVB both have swift growth. The viscosity increased rapidly from 99.51mPa·s and 140.43 mPa·s to 146.01 mPa·s and 233.43 mPa·s, The rheological characteristic have a change at the same time. The rheological model changes from pseudoplastic fluid to Bingham fluid. Cast film casting slurry obtained with good compactness. With the increase of solid content, it becomes dense. W performs well in positive and negative distribution. Cu has obvious settlement before the sudden change, before which the viscosity changes slowly and after changes fast, and after it the distribution of Cu has a good performance. It is worth noting that at 70wt%, W and Cu showed the best uniform distribution. On the content control of powder, when the solid content of powder is 60wt%, the control performance of the ingredients is the best

Key Words：tape cast; W- Cu; gradient material; rheology

目录

摘要 I

Abstract II

第一章 绪论 1

1.1 W-Cu复合材料 1

1.2 梯度功能材料 2

1.3 流延成型工艺 2

1.3.1 流延成型工艺介绍 3

1.3.2 流延成型工艺分类 3

1.4 本文选题意义与研究内容 4

1.4.1 选题意义 4

1.4.2 研究内容 5

第二章 实验与测试 5

2.1 实验原料 6

2.2实验方法 9

2.3 测试方法 11

第三章 测试结果分析 13

3.1 流延浆料分析 13

3.1.1 W-Cu浆料粘度值分析 13

3.1.2 W-Cu浆料时间稳定性分析。 15

3.1.3 W-Cu浆料剪切变稀特性分析 16

3.1.4 W-Cu浆料流体动力学模拟 18

3.2 流延膜带分析 20

3.2.1W-Cu流延膜带表面致密性分析 20

3.2.2 流延膜带表面均一性 24

3.2.3 粉料吸附均一性分析 25

第四章 全文总结与展望 26

4.1 全文总结 26

4.2 工作展望 26

参考文献 27

致谢 28

第一章 绪论

W和Cu是我国常见的两种金属材料，其中，W拥有较高的硬度、密度和熔点以及较低的热膨胀系数，常温下不受空气侵蚀。W-Cu复合材料的主要用途是制备超硬模具、灯丝以及制备高速切削合金钢，同时也用在一些光学仪器和化学仪器。我国是世界上最大的W储藏国。而Cu是一种柔软的金属，拥有较好的延展性以及较高的导电性、导热性，所以在电子、电气元件以及电缆中有较为广泛的应用，同时可以在多次回收后不损失其机械性能，因此也广泛应用于机械冶金等行业。表1-1是W和Cu的一些物理性质^[1]。

表1-1 W和Cu的一些物理性质

1.1 W-Cu复合材料