抄録
Monodisperse spherical particles of Bi-12at%Sb alloy with diameter of 200μm were fabricated by the pul-sated orifice injection method (POIM), in which molten metal is injected from a small orifice by clipping action of a pressure transmitting diaphragm driven by piezoelectric actuater. The Bi-Sb alloy is a candidate material for thermoelectric cooling micr-odevices because of its excellent thermoelectric property at low temperature.
The shape of the obtained particles is spherical with small caps on their surface consisting of Bi phase with negligible Sb content. It has been found that the surface is covered with very thin oxide layer which is less than 100nm as detected by Auger electron spectroscopy. The microstructure is much fmner than that of casted material. The effect of injection atmosphere on microstructural change has been discussed on the basis of cooling rate of molten particle during injection.
