|
6010 |
|
Wednesday, May 22, 2019, Saal Brüssel 5:00 PM Brazing of ceramic and glass |
|
Brazed metal-ceramic components for space applications |
|
Hans Rudolf Elsener* / EMPA, Switzerland Lars Jeurgens / EMPA, Switzerland Tobias Burgdorf/ EMPA, Switzerland Bastian Rheingans/ EMPA, Switzerland Stefan Brüngger/ University of Bern, Switzerland Daniele Piazza/ University of Bern, Switzerland Peter Wurz/ University of Bern, Switzerland |
|
Within the framework of the ESA mission JUICE (JUpiter ICy moons Explorer) ion optical metal-ceramic components were developed and manufactured for a time-of-flight mass spectrometer. Compared to previous space missions (Rosetta, BepiColombo or Luna), the requirements and performance of such scientific instruments have increased continually. Throughout the last two decades, many skills for metal-ceramic brazing and coatings were developed and optimized at Empa. Most of these procedures could be re-used or had to be modified only. In all cases, the chemical composition of the coating with subsequent heat treatment was the key point for a strong metal-ceramic joint or use as a diffusion barrier. The ion source main structure (body) is a high precision brazed construction consisting of a stack of concentric metal electrodes and insulating ceramic rings. Molybdenum copper high performance composites (Mo85Cu15) were used for the electrodes. The combination of these two materials results in thermal expansion characteristic similar to that of the alumina insulators. TiAlN was used as a diffu-sion barrier for the gold coated Mo85Cu15 electrodes. The upper part of the ion source consists of two laser cut alumina plates which were screen printed on both sides with different pastes. Several electrodes, double grid, outer grid and heater were integrated into the patterned ceramic plates with different joining techniques. |