Comparative Study on the Activity of GaF₃ and Ga₂O₃ Nanoparticle-Doped CsF-AlF₃ Flux for Brazing 6061 Al/Q235 Steel Joints

• Published in: Crystals
• Main Authors: Zhen Yao, Songbai Xue, Junxiong Zhang
• Format: Article
• Language: English
• Published: MDPI AG 2020-06-01
• Subjects: spreadability; wettability; GaF₃; Ga₂O₃; CsF-AlF₃ flux
• Online Access: https://www.mdpi.com/2073-4352/10/6/498
• ISSN: 2073-4352

The effect of trace amounts of GaF₃ and Ga₂O₃ nanoparticles on the wettability and spreadability of CsF-AlF₃ flux matched Zn-15Al filler metal were comparatively studied on 6061 aluminum alloy and Q235 low-carbon steel. The experimental results indicate that appropriate amounts of GaF₃ and Ga₂O₃ added into the flux could significantly promote the Zn-15Al filler metal to wet and spread on the surface of 6061 aluminum alloy and Q235 low-carbon steel. The optimum ranges for GaF₃ and Ga₂O₃ were 0.0075–0.01wt.% and 0.009–0.01 wt.%, respectively. Comparative analysis showed that the activity of CsF-AlF₃ flux bearing GaF₃ was higher than that bearing Ga₂O₃. The reason for this is that the former flux has a stronger ability to remove oxides of the base metal and reduce the interfacial tension of the molten filler metal and the base metal.