Analysis of the whole process of electrode paste sintering

The whole process of electrode paste sintering can be divided into three main stages, although these stages do not have clear boundaries in the roasting process, but can be divided according to the ambient temperature and location. The whole process is carried out without external pressure, relying only on the weight of the electrode paste itself.

(1) Softening stage: In this stage, the solid electrode paste begins to melt, the resistance becomes larger, the compressive strength decreases, and the electrode paste finally becomes completely liquid. The ambient temperature at this stage rises from 25 ° C to 120~200 ° C, about 500mm above the conductive jaw plate.

(2) Volatilization stage: At this time, the electrode paste is completely melted, the internal flow fills the gap, and the product quality becomes more uniform. At the same time, the electrode paste began to volatilize significantly and gradually thickened, the resistance continued to decrease, and the volatilization was violently mushy. At this stage, the ambient temperature rises from 120~200 ° C to 650~750 ° C, about the half-ring position.

(3) Sintering stage: In this stage, a small amount of volatiles continue to volatilize, and begin to further sintering, electrical conductivity is greatly improved, forming a hard whole. The height of complete sintering is located 200~400mm below the conductive frontal plate, and the ambient temperature at this stage rises from 650~750 ° C to 900~1000 ° C.

It should be noted that due to the gradual loss of electrodes caused by electrode surface oxidation, furnace reaction and arc combustion, it is necessary to control sintering according to the loss situation, and put the sintered electrode into the furnace to maintain the appropriate working length and position.