Microwave Hybrid Sintering and Soldering of Cu-Cr-W Composite Material for Reactive Power Breakers.

Over 60% of reported failures for reactive power compensation systems are given for damage to electrical circuit breaker contacts. This paper presents a study on the development of microwave technology for sintering of W-Cu-Cr alloys at 1012 °C for 65 min using 623.38 W microwave power, as well as microwave joining at 231 °C of the W-Cu-Cr composite material on body contact using 475 W microwave power for 55 s. The joined components were subjected to mechanical and electrical tests in accordance with ICE standards to validate the applied technology. Tests of connection-disconnection of the electrical contacts were carried out in accordance with the maximum number of disconnections allowed by the manufacturer (2 cycles/min): 25 s rest time and 5 s operating time under load. The components of the electrical contact after 111237 switches were analyzed under a microscope revealing a reduction of the damaged area by 27% compared with the original contact.