SCALING LAW OF IRREGULAR EUTECTIC IN DIRECTIONAL SOLIDIFICATION

The profile features of the solidifying interface of the irregular Al-Si eutectic duringdirectional solidification are studied by numerically solving a nonlinear coupling equation ofdirectional solidification of this eutectic.The critical splitting point of the solidifying interfacecoincides with the maximum value of its position and corresponds to the marginal stabilitypoint.Argument is presented that the interlamellar spacing for local regular structure selectsthe critical splitting state of the α(Al)-liquid interface as its operating point,and the oper-ating point of the average interflake spacing for the irregular structure is the critical splittingstate of the β(Si)-liquid interface.The scaling laws derived,which have the more generalforms than the classic Jackson-Hunt scaling,gained support from the experimental results.