Carbide-tipped Gear Hob Vacuum Brazing

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Cemented carbide has small specific heat capacity and poor thermal conductivity. Especially when brazing large pieces of cemented carbide, the heating rate should be controlled, generally not exceeding 10°C/min, to ensure that the heat can be transferred in time and the thermal stress caused by uneven expansion Time to release. The residence time at the brazing temperature should be able to make the internal and external temperature of the brazing seam basically the same, and the alloying effect of the brazing seam is sufficient to obtain a high-strength joint.

Controlling the cooling rate after brazing is the main measure to avoid cracks in the brazing seam or cemented carbide. Usually, the cooling rate is reasonably selected according to the type and quality of the cemented carbide.

Vacuum brazed M16 carbide gear hobs. When this kind of gear hobbing cutter is processing hard-toothed gears, scraping can be used instead of grinding. Its structure is to insert and weld a hard alloy at the negative rake angle of the gear cutter body. The material of the cutter body is 40Cr, and the hard alloy is YT0.5. Cut the solder and place it between the cutter body and the blade.

The high-temperature brazing furnace of SIMUWU vacuum furnace, the working area can be customized according to the customer’s output, and the maximum temperature of 1300C can meet the customer’s requirements.

The blade is fixed on the cutter body with a fixture, and the contact part between the fixture and the part is coated with resisting flux, and put into a vacuum furnace. Vacuumize to 5*10-2Pa in the cold state, heat to 1000C at a rate of 450C/h, fill the furnace with high-purity argon, the pressure in the furnace is 2~3Pa, and stabilize for 30~40min to make the temperature inside and outside the knife uniform, and then Heat to 1120+5C at a rate of 250C/h, keep warm for 15±2min, turn off the power and cool down to below 900C with the pressure in the furnace (2~3Pa), fill high-purity argon again to raise the pressure in the furnace to 4*10- 4Pa, cool down to below 400C, increase the filling amount of argon, so that the pressure rises to 8*10-4Pa, start the fan to stir the argon, cool to below 65C and take out the furnace. It is strictly forbidden to collide with the hobbing cutter after it comes out of the furnace, and it is naturally cooled in the air to completely shrink the cutter body before disassembling the fixture. Otherwise, the fixture is easily damaged.

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