一方向凝固したAl-Cu合金の固液界面における六角形セル, ブロークンセル形態と成長方位

抄録

Hexagonal and broken cell morphologies on the solid-liquid interface were examined in dilute Al-Cu alloys unidirectionally growing from seed crystals with growth planes {100}, {110}, {111} and various high index planes. Hexagonal cells are produced on the solid-liquid interfaces with all growth orientations investigated and are transformed to broken cells with decreasing G/RC₀. Morphologies of hexagonal cells on {100} growth interface show the most well-ordered hexagons and permit a wide range of G/RC₀. These hexagonal and broken cells unnecessarily grow parallel to the heat flow direction and deviate toward <100> direction, if the mean interface has high index orientations. The deviation is enhanced with the broken cell interface. Such a result is a sufficient evidence for the fact that these cells essentially have <100> prefered growth orientation similarly as dendrites.