日本金属学会誌

J. Japan Inst. Metals, Vol. 36, No. 12 (1972),
pp. 1232-1237

Microstructures of Unidirectionally Solidified Ternary Eutectic Alloys Containing the Al-Si System

Ishi Miura1 and Hitoshi Hamanaka1

1Institute for Medical and Dental Engineering, Tokyo Medical and Dental University, Tokyo

Abstract:

Ternary eutectic alloys containing the Al-Si system were unidirectionally solidified, and the effect of the third element or the third phase on the growth morphology of Si in the Al matrix was studied in comparison with those of Al-Si binary eutectic alloys. Growth mechanism of Si is largely influenced by the shape of the solid-liquid interface, which is thought to be effected by the growth habit of the third phase in ternary eutectics. In Al-Si- β (Fe, Si, Al) ternary eutectics, the β phase has a higher entropy of fusion and the solid-liquid interface becomes planar, so the Si phase grows with a platelet or radial section due to the {111} twin. On the other hand, in Al-Si-CuAl2 ternary eutectics, the CuAl2 phase has a lower entropy of fusion, so the solid-liquid interface is uneven and Si grows with a preferred < 100 > fiber texture as in Al-Si binary eutectics. Although the growth of the Si phase in ternary eutectics seems to be surpressed by the third elements, the effect of them is not clear. It is thought that the third elements in liquid phase have an effect on the growth mechanism of the Si phase in cooperation with the growth of the third phase.


(Received 1972/8/4)

Keywords:


PDF(Free)PDF (Free)     Table of ContentsTable of Contents

Please do not copy without permission.