two ways to sinter electronic sintered graphite mold

Two ways to sinter electronic sintered graphite mold

Graphite die characteristics
     In the mechanical industry, graphite materials are used as molds for pressure casting, centrifugal casting and hot extrusion of superhard alloy. Graphite molds can be used for train wheels and fine parts. Graphite mold can be used repeatedly. The castings after demoulding have high finish, and some can be used without further processing.
     It has advanced graphite processing equipment and profound production technology. The processing equipment now includes special graphite CNC processing centers, CNC milling machines, CNC lathes, large sawing machines, imported grinding machines and other special graphite CNC processing centers.
Electronic sintered graphite mould
     There are two sintering methods for hot pressing electronic sintering graphite mold: resistance heating method and medium frequency induction heating method. We know that when sintering by resistance heating method, the outer mold temperature is lower, and the cutter head and inner mold temperature are higher. The uneven temperature distribution determines the location of die damage.
1. Surface oxidation and cracks: due to the lack of maintenance of reducing atmosphere during hot pressing sintering and the direct touch of graphite and air, surface oxidation will inevitably occur at high temperature. The higher the temperature, the faster the oxidation speed; The ore mold is gradually consumed, leaving only part of carbon and ash, which can be found at the practical production site. After a period of time, pores and toner will occur on the surface of the die.
2. Fracturing: the reason for this damage is that the side plate of the diamond bit is not tightly clamped, resulting in unbalanced pressure drop on the head and transverse shear force.
3. Crushing: the electronic sintered graphite mold directly touches the matrix powder containing diamond. The touch surface is under high voltage. The hardness difference between diamond and electronic sintered graphite mold is too large. Pits will occur on the surface of the die touching the East-West end of the diamond.
4. Type of impact damage: in the sintering process, the matrix powder enters the oxidation gap of the electronic sintering graphite mold in the molten state, resulting in the adhesion between the East and West ends and the mold, making it difficult to demould. Repeated tapping of the die will demould the die, resulting in edge defects and metal pits.
5. The wear size of electronic sintered graphite die is very poor: some matrix powder will be extruded to the die surface in the molten state to adhere to the graphite material. Before the next use of the mold, the metal residue must be removed manually, which leads to the shape and size of the mold out of tolerance.

Post time: Nov-25-2021
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