Improvement and metallurgy of current-related heating problem of circuit breakers made of AgSnO2 and AgCdO

Abstract

Abstract Recent developments in technology increase the application area of electronic systems used in cars and commercial vehicles day by day. Along with the increase in the features expected from the vehicles, the battery capacities required to meet the desired features also increase. Especially in commercial vehicles, high-capacity battery systems are used depending on the function of the vehicle. Circuit breaker systems providing high voltage and current are used to intervene in the event of a possible problem from the batteries. During the operation of the vehicle, heat is generated due to the high current passing through the circuit breakers. In this study, different materials and surface contact forms were examined to solve the heating problem of circuit breakers operating at high voltage and current values. AgSnO2 and AgCdO coating materials were used for surface coatings of rivets used in circuit breakers. Moreover, rivet groups with various surface contact geometries such as flat–flat and curved–flat were used for each material. After applying 24 V–250 A values to the different materials and rivets of different surface shape geometries, thermal and metallographic analyses were performed. The experimental study showed that the best thermal results under resistive load are formed by the curved–flat contact geometry of the AgSnO2 coating material.