2014 年 64 巻 5 号 p. 191-194
An aluminum alloy hollow extrusion made with a porthole-die has a few seam welds. It is known that the deformation behavior of a weld region is different from that of a non-weld region at room temperature. In the present study, the influence of a seam weld on the high temperature deformation of a 6N01 aluminum alloy extrusion bar was investigated. The elongation of the alloy with the seam weld was significantly lower than that of the alloy without it. This was because the alloy with the seam weld started local necking at a very early stage of deformation. An orientation analysis with an electron backscatter diffraction suggested that a difference in recrystallization texture between weld and non-weld regions would accelerate the start of local necking.