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Vacuum Heat Treatment Furnace

Vacuum Sintering Furnace

Vacuum Brazing Furnace

Vacuum Brazing Process For High-pressure Turbine Blades

The high-pressure one-stage turbine blades for aero-engines are made of nickel-based casting alloys K38G and CH3030. It is required to braze a cover plate to restrict the cooling air flow on the blade crown. The brazing filler metal is BNi79CrSiBCo adhesive tape brazing filler metal with a thickness of 0.1mm.

The vacuum brazing process is as follows: the blade and cover are first degreasing in the trichloroethylene vapor tank. The leaves are washed in a 30% (NaOH + C6H1107Na) solution at 95C for 2 minutes, then washed in cold water; then washed in a 25% HNO solution at room temperature for 5 minutes, then rinsed with hot water and dried in an oven at 150~200C for 30 minutes . Use adhesive tape solder to clamp between the blade and the cover plate, use the adhesive to locate at two points, and install it in a ceramic fixture to keep the blade surface to be brazed at a level
Brazing process parameters: cold vacuum degree 8X10-3Pa, heating to 450°C at a rate of no more than 300C/h, stable for 20 min, so that the binder volatilizes completely, and the vacuum in the furnace can be restored to the cold state The degree of vacuum. Then heat to 950C at a rate of 800C/h and stabilize for 30mins or longer to make the temperature uniform and restore the vacuum in the furnace; then heat to 1190+10° at a rate of 450°C/h, and keep it for 1 hour to make the solder and The base material fully diffuses each other to obtain the joint of the solid solution tissue. Vacuum cooling from 1190C to 950C, then fill with high-purity hydrogen, and start the fan to speed up the cooling to below 150C.