Field of Expertise: Advanced Material Science | |
Friction Stir Welding of Aluminium-SiC MMC boxes for astronautics For astronautic applications, light-weight boxes to protect and carry electronic equipment need to be sealed. The main requirements on the components are low thermal expansion, gas tightness and corrosion resistance. The common material for such a application is a metal matrix composite (MMC). This MMC consists of an Al alloy matrix with 12-15 vol.%- SiC particle reinforcement. The electronic components inside the boxes during sealing withstand temperatures of only about 180°C. Due to the boundary conditions gas tightness and low heat input, Friction Stir Welding (FSW) might be a alternative to the employed joining techniques vacuum brazing or resistance welding. Because of the SiC particles a high wear resistance of the tool has to be ensured. Therefore a WoC-tool was used. For the FSW-process itself the T-Joint is the most appropriate Joint geometry in respect to the box design. The geometry of the lid has to ensure the backing system for the stirzone inside the box. A successful weld of the box was done after a joint geometry optimization. The examination of the welded box concerning gas tightness and corrosion resistance is in progress. |