Reactive metallic microparticles for thermal joining applications

由铝（Al）和镍（Ni）组成的反应系统具有独特的能力，当暴露于外部能源时，可在几毫秒内产生高达1500 °C的反应温度。该热反应能量可用于通过焊接、粘结或粘合进行连接。这些系统仅以纳米箔的形式可商购获得。用于接合工艺的纳米箔存在若干不利的特性，包括材料的脆性性质和应用于平面几何形状的限制。为了解决这些限制，本研究项目的目标是开发和表征一种新的，更灵活的形式，在连接应用中应用Al-Ni系统的有益反应特性，即微粒。为了便于在生产工程中通过Al-Ni颗粒进行连接，我们采用了整体方法。对反应性微粒的湿化学和机械合成的详细研究提供了基础。为了获得对热连接应用的深刻工艺理解，在通过微波能量激活反应之前、期间和之后，对反应性微粒的性质进行表征。所确定的影响和相互依存关系允许得出关于两种不同合成路线的结论，并形成工艺行为建模的基础。

Reactive systems consisting of aluminium (Al) and nickel (Ni) have the unique ability to generate reaction temperatures of up to 1500 °C for a few milliseconds when exposed to an external energy source. This thermal reaction energy can be used to join via welding, bonding, or adhesion. These systems are commercially available only in the form of nanofoils. There are several disadvantageous characteristics of the nanofoils for joining processes, including the brittle nature of the material and the limitation of applications to planar geometries. To address these restrictions, the objective of this research project is to develop and characterize a new, more flexible format of applying the beneficial reaction properties of Al-Ni systems in joining applications, namely microparticles. To facilitate joining via Al-Ni particles in production engineering, a holistic approach is pursued. Detailed investigations on wet-chemical and mechanical synthesis of reactive microparticles provide the basis. In order to attain profound process understanding for thermal joining applications, reactive microparticles are characterized regarding their properties prior to, during, and after the activation of the reaction via microwave energy. The identified effects and interdependencies allow to draw conclusions about the two distinct synthesis routes and form the basis for the modelling of process behaviour.