In Situ Observation during Copper Alloy Brazing Using an X-Ray System

Abstract:

In general, a flux is used to braze a copper alloy. In many cases, when the molten brazing filler metal spreads in the set joint gap, vaporised flux and its residue are produced, and defects (mainly voids) are formed. Voids, which are formed on the brazed layer, cause deterioration in the strength and other properties. However, with conventional evaluation methods (e.g. ultrasonic or X-ray radiography tests), the behaviour of the molten brazing filler metal during the brazing process cannot be visually observed from the outside of the joint. Therefore, the void formation process cannot be clarified. To improve the quality of the brazed layer, it is necessary to elucidate the mechanism of void formation. The purpose of this study is to observe the behaviour of the molten brazing filler metal by performing an X-ray radiography test at the same time as brazing and to study how to reduce voids. In this study, a brass specimen was brazed with a Cu–P-based brazing filler metal. The specimen was brazed by heating in an electric furnace, and the specimen was irradiated with X-rays. The state where the molten brazing filler metal spread into the gap was photographed as the transmission image. Thereafter, the behaviour of the molten brazing filler metal was analysed.

• Periodical: Materials Science Forum (Volume 1016)
• Pages: 911-916
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.1016.911
• Online since: January 2021
• Authors: Hirokazu Miura*, Hiroki Okada, Yasuyuki Miyazawa, Fumio Kanasaki
• Keywords: Brazing, Copper Alloy, EPMA, Filler Metal, Void, X-Ray Radiography

References

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