Adjusting the microstructure of joints in laser-joined silicon carbide (SiC) devices for enhanced high temperature resistance

激光辅助焊接允许有效制造接合的基于SiC的器件，而无需对整个器件进行热处理。一般来说，连接部件的性能将受到接头的微观结构和性能的显著影响。将合成、表征和测试RE 2 O3-Al 2 O3-SiO2（RE：Sc、Yb、Ho、Dy、Y、Nd）类型的玻璃陶瓷焊料。在该项目中，将彻底研究和表征在激光加工的特定条件下接头内部的结构形成。这些调查包括基本的技术考虑，以及深入的结构，热机械，热力学和动力学分析的机制，控制焊料-SiC相互作用和结晶过程中发生的焊料材料。在此基础上，将根据各自的应用定制联合结构。在连接过程中精确控制焊接材料的结晶应该允许在高达1250 °C的温度下应用连接的器件。该项目的结果将支持用于SiC基器件气密密封的耐高温玻璃的开发。这些材料可用于微电子和传感器应用，以及用于开发医疗和光学用途的特殊玻璃，用于玻璃陶瓷环境屏障涂层，以及用于SiC、Si 3 N4和SiAlON基材料的液相烧结。

Laser-supported soldering allows the efficient manufacturing of joined SiC-based devices without thermal treatment of the complete devices. In general, the properties of joined components will be significantly influenced by the microstructure and the properties of the joint.Glass-ceramic solders of the type RE2O3-Al2O3-SiO2 (RE: Sc, Yb, Ho, Dy, Y, Nd) will be synthesized, characterized and tested. Within the project, the structure formation inside the joint under the particular conditions of laser processing will be thoroughly investigated and characterized. These investigations include fundamental technological considerations as well as in-depth structural, thermo-mechanical, thermodynamic and kinetic analyses of the mechanisms governing the solder-SiC-interaction and of the crystallization processes occurring in the solder material. On this basis, joint structures will be tailored to their respective application. Accurately controlling the crystallization of the solder materials during the joining process should allow an application of the joined devices at temperatures up to 1250 °C.The results of this project will support the development of high temperature resistant glasses for the hermetic sealing of SiC-based devices. These can be used in microelectronic and sensor applications as well as for the development of special glasses for medical and optical usage, for glass-ceramic environmental barrier coatings and for the liquid phase sintering of SiC-, Si3N4- and SiAlON-based materials.