TEXTURE CHANGES DURING SUPERPLASTIC DEFORMATION OF MECHANICALLY ALLOYED ALUMINUM IN90211

Superplastic deformation of mechanically alloyed aluminium IN90211 was studied by texture analysis. The textures in three deformed specimens were investigated as a function of strain using the three-dimensional crystal orientation distribution functions (CODFs). The results for t he two superplastically deformed specimens (425-degrees-C, strain rate of 1 s-1, stress near 50 MPa, and 475-degrees-C, initial strain rate of 77 s-1, about 110 MPa) indicate that at strains below about 2.0, th e specimen deforms by grain-boundary sliding and single (or double) sl ip, and at larger strains the deformation is dominated by grain-bounda ry sliding, multiple slip and some recrystallization. At 475-degrees-C , 330 s-1, and stress near 160 MPa, the specimen was above the superpl astic regime, and the resulting texture changes with deformation were markedly different from superplastic results, and quite unusual.