Effects of Cooling Rate on Solidification Microstructure of ZK60 Magnesium Alloy
In this paper, the influence of the cooling rate on the solidified structure of ZK60 Mg alloy has been studied by means of Gleeble-1500D thermal simulation instrument. The result showed that the grain size and grain shape depended on the cooling rate, Primary Dendrite Arm Space ( λI ) and Secondary Dendrite Arm Space ( λII) sharply decreased with the increasing of solidifying cooling rate (v) in the range of experimental cooling rate (0.2~100K/s). When superheat was constant, the empirical formulas of the relation between λI λII and v was obtained. In addition, the dependence between micro-hardness (HV) and Secondary Dendrite Arm Space ( λII) for ZK60 casting alloy was proved to be similar with Hall-Petch formula. The empirical formula for λII-HV has been proposed.
W.Ke, E.H.Han, Y.F.Han, K.Kainer and A.A.Luo
C. M. Yang et al., "Effects of Cooling Rate on Solidification Microstructure of ZK60 Magnesium Alloy", Materials Science Forum, Vols. 488-489, pp. 295-298, 2005