R. W. Smith, Materials Resources International, Lansdale, PA; R. Redd, S-Bond Technologies, LLC, Lansdale, PA

Summary: New alloys have been developed that permit the joining of aluminum, copper and aluminum to copper in protective furnace atmospheres with the use of flux. The alloys are based on Sn-Ag-Ti active solder technology and have been specially formulated to permit furnace reflow joining of aluminum and/or copper at 500°C (932°F). The new alloy’s joining temperatures are 50 – 60°C lower than commercially available Al-based braze filler metals and would permit the repair of conventionally brazed aluminum structures, reduced distortion in joining of large aluminum structures, and conduct braze joining of aluminum without having to use dedicated aluminum brazing furnaces. The authors will present the alloy and processing steps, show the metallurgical structures and report on the tensile properties of the joints. The results of joints made various brazing atmospheres (N2, Ar, and vacuum) and conducted with varying furnace cycles will also be reviewed.