Al-4.5%Cu合金のディスク及びプリデンドライトの結晶方位について

抄録

  The crystallographic orientation of discs and predendrites formed in the surface layer of Al-4.5%Cu alloy ingots was examined by X-ray diffraction and etch pit technique. Predendrites grow from the outer surface of hemispherical discs. Triangle and square etch pits are observed on the planes of the discs parallel and vertical to the chilled surface and on the plane at 45° to the chilled surface respectively. The plane indices in the directions parallel and vertical to the chilled surface are (111). The X-ray diffraction also confirms these facts. The predendrite preferably grows in the <100> direction. Etch pits are not revealed by etching in the region between disc and predendrite.