Sr-modified hypoeutectic Al-Ni filler alloy

30% higher fluidity

Sr segregation at dendrite boundaries and Al4Sr formation significantly improve fluidity without notably altering the eutectic temperature.

Hari, Vigneshwar · McDonald, S. D. · Qu, Dongdong · Tan, Xin F. · Dong, Xu · Zherui, Tong · Nogita, Kazuhiro

Journal of Alloys and Compounds 2025

Specifications

Fluidity increase

{'zh': '30', 'en': '30'} %

Reduction in median cross-sectional area fraction of Al dendrites

{'zh': '26', 'en': '26'} %

Advantages

30% higher fluidity

The reduction in dendrite size allows the molten alloy to flow more easily, which is beneficial for filling complex brazing gaps.

Dendrite refinement

The median cross-sectional area fraction of Al dendrites decreases by 26%, indicating significant refinement, which may contribute to the fluidity improvement.

Eutectic temperature unchanged

The eutectic temperature is not significantly affected, so the alloy can be used at brazing temperatures similar to those for the original Al-Ni alloy.

Applications

• Aluminum alloy brazing：As a filler metal, improved fluidity enables better filling of brazed joints.
• Aerospace structural joining：In aerospace structural brazing, better fluidity aids in joining complex shapes.
• Heat exchanger manufacturing：In heat exchanger manufacturing, higher fluidity can improve brazing quality in narrow channels.