Effect of magnesium on the properties of ultrafine grained aluminum processing through equal channel angular pressing (ECAP)

Abstract

Equal channel angular pressing (ECAP) was carried out at room temperature and at 100 °C to refine the grain size of two different aluminium alloys, AA-5050 and AA-5754. AA-5050 contains 1.5 % magnesium and AA-5754 contains 3.3 % magnesium. Optical light microscopy revealed that ultra-fine grain sizes are attained in both alloys. Tensile and compression tests at room temperature shows that the strength increases with an increase in the number of passes but the elongation to failure is decreased. Special attention was paid to the tension and compression asymmetry of the both alloys and it found that the yield strength in the case of tension is almost 25-30 % higher in both alloys. The maximum yield strength observed in AA-5050 after 4 passes during tensile test is 450 MPa at 100 °C while in compression is 356 MPa. In case of AA-5754 this value is 445 MPa in tension and 372 Mpa in compression.