| Customization: | Available |
|---|---|
| Customized: | Non-Customized |
| Certification: | CE, ISO |
| Shipping Cost: | Contact the supplier about freight and estimated delivery time. |
|---|
| Payment Methods: |
|
|---|---|
| Support payments in USD |
| Secure payments: | Every payment you make on Made-in-China.com is protected by the platform. |
|---|
| Refund policy: | Claim a refund if your order doesn't ship, is missing, or arrives with product issues. |
|---|
Suppliers with verified business licenses
Audited Supplier Audited by an independent third-party inspection agency
Specification material
Plate: 316 stainless steel, plate size is 389mm × 270 mm; solder: 99% pure copper solder, sheet (δ=0.3mm), brazing method: high vacuum brazing furnace. The vacuum degree is 1*10-2Pa, and the brazing temperature is 1130ºC.
Selection of brazing temperature
For stainless steel, the brazing heating temperature should not be too high. When the brazing temperature is higher than 1150ºC, the strength and heat treatment performance of stainless steel will be affected, and when it stays at 500~750ºC, chromium carbide will precipitate along the grain boundary, which is prone to intergranular corrosion. When selecting solder and process parameters, prolonged heating above 1150°C should be avoided. Therefore, the brazing temperature was set at 1130°C.
Selection of vacuum solder
Vacuum brazing requires long-term maintenance of high vacuum, so the brazing filler metal with low vapor pressure should be selected. In the process of device manufacturing, the device is subjected to long-term high temperature (above 500 ºC) baking exhaust, and the brazed joints made of dissimilar materials are prone to large thermal stress. Therefore, the brazed joints are required to have sufficient mechanical strength and the ability to release stress.
Copper-based solder has low vapor pressure, good high temperature strength, good wettability to various metals, and moderate price, so it should be the first choice. It is worth noting that the pure copper solder must be made of oxygen-free copper, otherwise it is difficult to ensure the air tightness of the brazing seam. When pure copper is used as solder, it needs to be brazed in a protective atmosphere and vacuum, and the temperature is 1100~1150ºC. At this temperature, the internal stress of the device has been eliminated, and because the device is heated as a whole, the thermal stress is small, and the weldment will not crack.
Copper-based solders are available in powder, filament and flake form. Among them, powdered solder has a large surface area, many surface oxides, and poor wettability during brazing, so it is not suitable for use. The sheet brazing filler metal can be well wetted in the molten state, and can ensure a certain flatness and density. Therefore, 99% pure copper, flake (δ=0.3mm) is selected as the solder.
Flux is generally not used during vacuum brazing. When the brazed joint is cooled with the furnace, argon is used as a protective gas at an appropriate time.
){kind=link}