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

在各种应用中，传统的金属材料无法满足机械和热性能以及耐腐蚀性的不断提高的要求。由于这一事实，使用高性能的部分或全部陶瓷材料和韧性金属支撑件的组合变得越来越重要。为了创建具有特定性能的高强度接头，通常需要使用基于熔合的工艺来连接这些部件。在这里，钎焊被广泛应用。阻碍所产生的接头的全部潜力的使用的困难是钎焊期间残余应力的独特发展。这是所用材料的热膨胀系数通常显著不同的结果。为了获得应力的降低，使用韧性填充金属。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释放残余应力，并具有足够的韧性以产生高强度接头。这些要求可以通过可硬化合金来满足，只要存在可用的合适合金并且已知和理解可硬化机制。拟议的工作的主要任务是在钎焊的背景下，可硬化合金的分析。与这种合金的铸造相反，显微组织演变经历了复杂得多的过程。尤其是多组分体系中的扩散动力学现象，更是需要深入研究的问题。为此，将对选定的合金进行单独分析，与一个基材以及整个接头相互作用。使用这种尝试可以识别和确定基板对硬化行为的影响。所获得的知识将在项目的最后阶段应用于连接应用相关的组件，以揭示新合金的潜力，并将其与传统的填充金属进行比较。这两个调查的结果相结合，提供了一个深刻的科学基础，可能面向应用的发展所描述的特殊应用的填充金属。

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.