摘要：

The capillary shape instabilities associated with ribbon or finite plate dispersoids are described and documented with experimental evidence from three composite systems: (1) drawn castings of CuFe containing ribboned Fe fibers (14.3 vol.% Fe), (2) rolled liquid-phase sintered NiW alloys containing elliptic W plates (48 vol.% W), (3) rolled “hypoeutectic” NiW alloys containing W blades which occupy 17% of the eutectic microconstituent's volume. The primary instabilities observed include cylinderization via edge recession, boundary splitting via the thermal grooving of internal boundaries, and edge spheroidization via the ovulation of ridges formed by edge recession. For a given plate-shaped dispersoid, the dominant instability is determined by cross sectional aspect ratio (width/thickness) and, when internal boundaries are present, the ratio of the internal boundary's energy to that of the phase interface.

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