EQUAL CHANNEL ANGULAR PRESSING OF A TWO-PHASE ALLOY Mg-8Li-1Al II. Room Temperature Tensile Properties of the Alloy Processed by ECAP

Measurement of room temperature tensile properties of Mg-8Li-lAl (mass fraction, %) alloy processed by equal channel angular pressing (ECAP) shows that the strength and elongation increase simultaneously with increasing the passes of ECAP. To ECAP 1, 2, 3 and 4 passes, the corresponding yield stresses and elongations of the alloy are 169, 185, 196, 198MPa and 12%, 14%, 25%, 27% respectively. The analysis of the microstructures reveals that ECAP process could not only refine the α and β phases, but also improve the homogeneity of a phase microstructure and increase the misorientations between grains in both phases. This kind of grain boundaries which are in non-equilibrium state and with relatively large rnisorientation might stimulate new deformation modes, such as grain boundary sliding or grain rotation during the room temperature tensile tests, as a result, the ductility of the alloy was improved.