Dendritic Growth Directions of Chromium and Zinc in Solidified Cu - 2.3%Cr and Zn - 3.8%Al Alloys
이용기Yong Gi Lee, 이상헌Sang Heon Lee, 김경현Kyung Hyun Kim, 이동녕Dong Nyung Lee
Abstract
This study is concerned with the halo formation and the shape of dendrites of chromium primary phase in the solidified Cu 2.3%Cr alloy and the dendritic growth directions of zinc during solidification of the Zn-3.8%Al alloy. Cu-Cr hypereutectic alloys show the well developed copper halo around chromium primary phase, because the coupled zone is skewed to the chromium side of the phase diagram. In nf-nf type eutectic system, the coupled zone is skewed due to the large difference of melting temperature between α phase and β phase. The shapes of chromium primary phase imply that <111> directions are the preferred growth directions in chromium dendrites. These directions minimize the strain energy in the dendrite arm. The dendritic growth direction of zinc has been found to be the primary <0001> and secondary <101 ̄0> directions. The results have been explained based on the factors suggested by the present anthers.