The optimal temperature for copper brazing in a furnace is usually between 1,100 and 1,500℉. However, it is important to note that the temperature may vary depending on the specific copper alloy being brazed.
Before brazing copper, the furnace atmosphere should be slightly positive when using hydrogen. To prevent contamination of the furnace internals, the furnace is first evacuated to a low pressure of 10-2 to 10-4 mbar (10-2 to 10-4 Torr) to remove residual air. The temperature is then raised to approximately 955°C (1750°F) to allow outgassing and remove any surface contamination. Finally, the furnace is heated to the brazing temperature, which is normally 1100–1120°C (2000–2050°F), under an inert-gas partial pressure up to 1 mbar (0.75 Torr) to inhibit evaporation of the copper.
The furnace temperature should be gradually increased to the brazing temperature, usually between 500°C and 1200°C, to ensure proper heat distribution and minimize thermal stresses. The brazing temperature should be maintained for a specified amount of time to allow the filler metal to melt, flow, and wet the base metals, creating a strong joint.
After the brazing process is complete, the furnace should be slowly cooled to room temperature to minimize thermal stress and distortion. The parts can then be removed from the furnace and inspected for quality. If necessary, post-brazing treatments such as heat treatment, machining, or surface finishing may be performed to achieve the desired properties and appearance.
It is important to carefully control the levels of hydrogen, oxygen, and water vapor in the furnace during reducing atmosphere brazing. Proper cleaning of the parts before brazing is crucial to ensure they are free of oxides, contaminants, and oils. The furnace cycle, including ramping and stabilization, is also critical to the success of the brazing operation.
For vacuum brazing of copper or copper-base alloys, the brazing temperatures are typically in excess of 1085°C (1985°F). Vacuum brazing temperatures are usually 'high', usually exceeding 1000°C (1832°F), which provides an opportunity to perform heat treatments as part of the brazing process.
In summary, the temperature for copper brazing in a furnace should be between 1,100 and 1,500℉, with specific temperature ranges depending on the copper alloy. The furnace atmosphere should be slightly positive when brazing with hydrogen, and careful control of hydrogen, oxygen, and water vapor levels is important. Proper cleaning of the parts and careful furnace cycle control are also critical for successful brazing.
Looking for high-quality laboratory equipment for copper brazing? Look no further than KINTEK! Our range of furnaces and brazing equipment ensures optimal temperature control and atmosphere for efficient and precise brazing. Trust KINTEK for all your copper brazing needs. Contact us today for a quote!
