Patent ID: 6908520

Claim:
A process for producing an aluminum alloy hollow material comprising: homogenizing an aluminum alloy ingot containing about 0.8 to about 1.5 wt % Mn; and port hole extruding the ingot to produce a hollow material, wherein said homogenizing of the ingot is carried out by maintaining the ingot at a first temperature of 500-630° C. for more than zero but not more than about 24 hours, cooling the ingot down to a second temperature of 400-500° C. at a cooling velocity of not more than 100° C./hr, and maintaining the ingot at said second temperature for about 4 to 48 hours, wherein the processing is performed such that a difference in electric conductivity of individual portions in a lengthwise direction of the hollow material is not more than 1.0 IACS %, and such that an electric conductivity value becomes at least 39.0 IACS %.