The aluminum alloy welded joint and aluminum alloy board basic material null for the welded joint

摘要

PROBLEM TO BE SOLVED: To provide a 6000 series aluminum alloy joint, especially of excess Si type or the like, for preventing bottom of a lateral part from cracking, and to provide a base metal sheet of aluminum alloy for weld joint. ;SOLUTION: The weld joint is manufactured by means of welding a base metal sheet of a 6000 series aluminum alloy. The base metal sheet of the aluminum alloy is characterized by crystal grains which have a shape extended to a transversal direction against a weld line, the aspect ratio (r_l/r_t, where r_l is a mean particle diameter in the transverse direction against the weld line, and r_t is a mean particle diameter in a sheet thickness direction) of 2 or more, and a mean particle diameter r_t of 100 μm or less.;COPYRIGHT: (C)2003,JPO