1994 Volume 44 Issue 4 Pages 229-233
Aging characteristics of Mg-9mass%Al alloy have been investigated by means of hardness measurement and microstructure observation with optical and electron microscopy. Hardness increased by about HV30 with aging time at temperatures between 403-473K. The hardness increase was found to be caused by the continuous and discontinuous precipitation. The TTT diagram for the phase decomposition was determined from the hardness curves, the nose temperature being 523K. The initiation and growth of the grain boundary reaction occur in competition with well-advanced continuous precipitation process. The apparent activation energy for grain boundary reaction is also described.
