The magnesium alloy was processed by equal-channel angular pressing for up to 8 passes at 473K, and the evolution of strength and microstructural parameters were determined using hardness testing and X-ray line profile analysis. The results showed the sub-grain size and twin boundary density increase between 1 and 2 passes and then decrease, the dislocation density continuously decreased up to 8 passes and the measured microhardness remains reasonably constant between 1 and 8 passes of equal-channel angular pressing. The results were interpreted using a model based on the additive effects of the dislocation density and an average size factor incorporating the effects of both the twin and the sub-grain boundaries.

The Contributions of Grain Size, Dislocation Density and Twinning to the Strength of a Magnesium Alloy Processed by ECAP. L.Balogh, R.B.Figueiredo, T.Ungár, T.G.Langdon: Materials Science and Engineering A, 2010, 528[1], 533-8