Investigation of precipitation-hardenable-, copper-base-alloys, for brazing of materials with highly different coefficients of thermal expansion.

研究可沉淀硬化的铜基合金，用于钎焊热膨胀系数差异很大的材料。

• 批准号: 281583335
• 负责人: Professor Dr.-Ing. Wolfgang Tillmann
• 金额: --
• 依托单位: Lehrstuhl für Werkstofftechnologie (LWT)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/281583335?language=en
• 关键词: Investigation; precipitation; hardenable; copper; base

In various applications, the rising requirements concerning the mechanical and thermal properties as well as corrosion resistance cannot be met by conventional metallic materials. Due to this fact, the use of combinations of high-performance partially or fully ceramic materials and ductile metal supporters becomes increasingly important. In order to create high-strength joints with specific properties it is often necessary to join these parts with a fusion based process. Here, brazing is broadly applied. A difficulty, which hinders the use of the full potential of the created joints, is the distinctive development of residual stresses during brazing. This is the result of the often significantly different coefficients of thermal expansion of the used materials. To obtain a reduction of the stresses, ductile filler metals are used. However, these alloys possess only limited strength against external forces. Consequently, an ideal filler metal should be both ductile enough to relax residual stresses and tough enough to create high-strength joints. These requirements can be met by hardenable alloys, as long as there are suitable alloys available and the metallurgic mechanisms are known and understood. The main task of the proposed work is the analysis of hardenable alloys in the context of brazing. Contrary to the casting of such alloys, the microstructural evolution undergoes much more complex processes. Especially the diffusion-kinetics phenomena in multi-component system have to be considered intensively. To do so, selected alloys will be analyzed on their own, in interaction with one substrate as well as in the whole joint. The effects of the substrates on the hardening behavior can be identified and determined using this attempt. The gained knowledge will be applied in the final stages of the project to join application-related components in order to reveal the potential of the new alloys and compare it to conventional filler metals. The combination of the results of both investigations provides a profound scientific fundament for possible application-oriented development of filler metals for the described special applications.

在各种应用中，传统金属材料无法满足对机械性能、热性能以及耐腐蚀性能不断提高的要求。由于这一事实，高性能部分或全部陶瓷材料与延展性金属支撑件的组合使用变得越来越重要。为了制造具有特定性能的高强度接头，通常需要通过基于熔合的工艺来连接这些部件。在这里，钎焊被广泛应用。阻碍充分发挥所创建接头潜力的一个困难是钎焊过程中残余应力的明显发展。这是由于所用材料的热膨胀系数通常存在显着差异的结果。为了减少应力，使用延展性填充金属。然而，这些合金仅具有有限的抵抗外力的强度。因此，理想的填充金属应具有足够的延展性以松弛残余应力，并且足够坚韧以形成高强度的接头。只要有合适的合金可用并且冶金机制是已知和理解的，可硬化合金就可以满足这些要求。拟议工作的主要任务是在钎焊背景下分析可硬化合金。与此类合金的铸造相反，微观结构的演变经历了更加复杂的过程。特别是多组分体系中的扩散动力学现象必须得到深入考虑。为此，将对选定的合金进行单独分析、与一种基材的相互作用以及整个接头的相互作用。通过这种尝试可以识别和确定基材对硬化行为的影响。所获得的知识将应用于项目的最后阶段，以连接与应用相关的组件，以揭示新合金的潜力并将其与传统填充金属进行比较。两项研究结果的结合为针对所述特殊应用的填充金属的可能的面向应用的开发提供了深刻的科学基础。