Current distribution between motor housing and electrode paste

The electrode paste is basically non-conductive before 450°C, and all current passes through the electrode shell.

At 500°C, the current through the electrode paste gradually increases. After 800°C, more than 50% of the current flows through the electrode paste. The temperature continues to rise, and with the oxidation and ablation of the electrode shell, the resistance also increases sharply, while the resistance of the electrode paste decreases correspondingly, and all the current is borne by the electrode paste.

The use of electrode paste has no obvious effect on the current distribution law at the same temperature. For example, when the standard paste is used at 500°C, 0.82% of the current flows through the electrode paste, and it is increased to 2.34% with the special paste. The standard paste is 9.63% at 600℃, and the special paste is 12%. From this point of view, the low-temperature conductivity of the special paste has not been significantly improved. Its thermal conductivity is good, it can increase the sintering temperature of the electrode, thereby improving its electrical conductivity, which is the main reason why the sealed paste is suitable for use in a sealed furnace.