Bonding graphite to copper can be achieved through brazing, a high-temperature joining process that uses a filler metal (braze alloy) to join the materials.
Brazing involves heating the materials to a temperature above the melting point of the braze alloy but below the melting point of the graphite and copper. The molten braze alloy flows into the joint gap by capillary action and solidifies to form a strong metallurgical bond. Because graphite is a non-metal and copper is a metal, special braze alloys containing active elements like titanium are often used to promote wetting and bonding to the graphite surface.
Studies investigating the bonding of copper to pyrolytic graphite using specific braze alloys have determined optimal parameters for achieving the best bond. The reference indicates that different braze alloys require distinct temperature and time profiles.
Optimal Brazing Parameters
Based on the referenced studies, the best results for bonding copper to pyrolytic graphite were observed under the following conditions:
| Braze Alloy | Temperature | Time | Result |
|---|---|---|---|
| Ti-Cu-Sil | 900° C | 5 min | Best Bond |
| Ti-Cu-Ni | 980° C | 2 min | Best Bond |
These findings highlight that the choice of braze alloy significantly influences the required bonding temperature and duration to achieve an optimal joint between copper and graphite. Using these specific alloys and precise process control is key to successfully bonding these dissimilar materials.
