ベリリウムの腐食像

抄録

Flake-beryllium lump melted and solidified in a beryllia crucible in vacuum was cut, polished, and ethced with hydrochloric acid. Regular- and irregular-shaped etch pits and a characteristic striated structure were observed. The regular-shaped pits were needle-shaped, rectangular or hexagonal. Stereographic projection analysis, using the back-reflected X-ray patterns and microphotographs of twins and slip lines on the surface of specimens, indicated that the grain surface with hexagonal pit corresponded to the (0001) basal plane, that the sides of the hexagon were parallel to the a-axes, that is, were formed by intersection of (0001) and {10\={1}0} planes, and that the striation is the intersection of {10\={1}0} prismatic planes. Therefore, it was deduced that the major exposed plane by etching, e.g. the facet of rectangular pit, is one of {10\={1}0} planes and the minor one is (0001) plane. As etching proceeds, the etched area of the grain surface which was favorably oriented to produce the striated structure propagated more rapidly than that of other grain surface.