Process of ultrasonically soldering drawn aluminum tubing products

摘要

The ultrasonic soldering of continuously drawn coilable aluminum tube to provide soldered socket joints is improved where the tube, after continuous and sequential drawing to produce a work hardened tube, is subjected to a burnishing operation by being drawn through a burnishing die. The burnishing operation differs from the drawing operation used to produce the continuously drawn tube in that the burnishing does not substantially alter the wall thickness of the tube. The burnishing dies condition the outer tube surface to be more wettable by molten solder metal in fluxless ultrasonic soldering processes.