MICROSTRUCTURE AND TEXTURE OF COMMERCIAL PURITY ALUMINUM STRIPS PRODUCED BY MELT DIRECT ROLLING

The microstructure and texture of the aluminum strips produced by the melt direct rolling (MDR) method are inhomogeneous in the direction of strip thickness. The subsurface layer (about 30% thickness of the str ips) shows fine and equiaxed grains formed by geometric dynamic recrys tallization and has a strong shear texture ([110]//RD fiber texture in cluding {111}[110] and {001}[110] orientations), while the center laye r shows elongated grains and has a typical rolling texture. This inhom ogeneity is due to large shear deformation induced by friction during rolling. Near the surface, the microstructure shows no remarkable chan ges during annealing below 673 K, but the relative intensities of {111 }[110] and {113}[110] orientations increase. Relatively large (r) over bar and very large Delta r are obtained from the tensile tests of the MDR strip and they vary with the textures depending on annealing temp eratures. The present study has clarified that the MDR method is usefu l to develop the {111} texture in aluminum strip by introduction of la rge shear deformation during rolling.