Brazing characteristics of vertical joints with silver copper eutectic alloy Ag72Cu28 for RFQ section brazing stage
摘要
A radio-frequency quadrupole (RFQ) is a critical component in particle accelerator technology, and section brazing is a crucial fabrication process in this context. This study investigates the brazing characteristics of vertical joints created using Ag72Cu28 metal filler in a high-vacuum environment. Experimental specimens were prepared with copper plates and brazed at temperatures ranging from 778 to 805° C to analyze the melting behavior of the filler. X-ray computerized tomography (CT) scans revealed that the filler begins to melt at 782° C and that complete melting occurs at 784° C. It was found that maintaining temperatures of above 780° C for at least 17 min ensures optimal bonding, while temperatures below this can result in incomplete melting and potential vacuum leaks. Conversely, excessively high temperatures can cause filler overflow and require additional machining. This study provides critical insights regarding the precise temperature control required for successful RFQ section brazing, addressing the challenges of vacuum leaks and incomplete filler melting. These findings offer practical guidelines related to the minimum brazing temperature and brazing time for improving RFQ manufacturing reliability, particularly for vertical joint configurations.