An amorphous state is defined by the absence of crystalline structure showing long range order with regular atom positions. In the solidification process when rapid cooling from a melt occurs, molecular mobility within a material is hindered before re-alignment into a more thermodynamically favourable crystalline state occurs.
Specialist rapid cooling facilities are required for most metal melts to solidify fast enough to remain amorphous and then only thin wire or ribbon can attain this state.
The Process
PSI’s IN-Roquench incorporates a rotating hollow rim with coolant,normally water, held by centrifugal forces against the internal surface of the rim. With the casting wheel set to a predetermined speed coolant is introduced into its rim. A charge of alloy is melted within a silica crucible, the end of which has been drawn down to provide an orifice of suitable dimensions.
This outlet is positioned at variable distances and angles to the surface of the moving water and the melt is ejected over a period of a few seconds to cast a fine stream of liquid metal into the water. Melt ejection is provided by the application of inert gas pressure to the silica tube, driving a filament of molten metal into the coolant which quenches it to solid and carries it away.
Technology You Can Trust
PSI are experienced in the design and fabrication of
vacuum-based rapid solidification technology having,
over twenty years, constructed systems for melt spinning,
planar flowcasting, wire casting and cold crucible melting
by induction,electric arc and electron beam in water-cooled copper.