Fluxless ultrasonic soldering of aluminum tubes

Claim 1

A method of fluxless joining of aluminum tubes comprising: 1 bringing into socket engagement a male and female aluminum tube member to provide a lapped socket joint configuration, the annular gap between said male and female members being 0.002 to 0.006 inch substantially around the entire periphery of said gap, the joint being oriented in a substantially vertical direction with the entrance to the female member pointing substantially upwardly, 2. positioning at the said upwardly facing entrance end of said female portion a supply of joining filler alloy, 3. bringing said joint and said filler alloy to joining temperature which melts the joining alloy but not the aluminum tube members, 4. applying to said joint at said joining temperature positive multi-directional ultrasonic energY pulses to cause cavitation of said molten filler alloy thereby to cause said filler alloy to disrupt the oxide coating and to wet the metal surfaces of said members engaged in said joint to progressively form a connecting bridge between said surfaces, and 5. solidifying said filler alloy.

Claim 2

A method of fluxless joining of aluminum tubes comprising: 1 bringing into socket engagement a male and female aluminum tube member to provide a lapped socket joint configuration, the annular gap between said male and female members being 0.002 to 0.006 inch substantially around the entire periphery of said gap, the joint being oriented in a substantially vertical direction with the entrance to the female member pointing substantially upwardly, 2. positioning at the said upwardly facing entrance end of said female portion a supply of joining filler alloy, 3. bringing said joint and said filler alloy to joining temperature which melts the joining alloy but not the aluminum tube members, 4. applying to said joint at said joining temperature positive multi-directional ultrasonic energY pulses to cause cavitation of said molten filler alloy thereby to cause said filler alloy to disrupt the oxide coating and to wet the metal surfaces of said members engaged in said joint to progressively form a connecting bridge between said surfaces, and 5. solidifying said filler alloy.