In recent years, with the continuous improvement of market performance requirements for circuit breakers, many circuit breaker manufacturers are developing circuit breakers with higher electrical endurance, such as 250A MCCB, and some manufacturers' requirements for electrical endurance reach 8000 times. In the electrical endurance test, the arc usually erodes the static contact more, so it is necessary to improve the performance of the static contact, thereby improving the electrical endurance of the circuit breaker. AgWC(12)C(3) electric contacts are manufactured by powder metallurgy sintering process, powder production and sintering are the key processes affecting its performance.

    AgWC(12)C(3) samples prepared by different granulation processes have little difference in hardness and density, but great difference in resistivity and flexural strength.

    For example, three kinds of granulation processes, such as burnt powder granulation, mixed glue granulation and dry granulation:

    ① The difference in density and hardness is not large, but the difference in resistivity and flexural strength is obvious, the comprehensive performance comparison, dry granulation is better than mixed granulation, mixed granulation is better than burnt powder granulation.

    ② The electric endurance difference is obvious, dry granulation is better than mixed granulation, mixed granulation is better than burnt powder granulation.

    ③ Compared with burnt powder granulation, the electrical resistivity of AgWC(12)C(3) contact prepared by dry granulation is reduced by about 9.7%, the flexural strength is increased by about 23%, and the electrical endurance is increased by more than 78%.

——The content of the article comes from the Internet