Professor Pol Duwez of the California Institute of Technology, Pasadena,
USA, developed a method in 1960 to solidify metallic melts at cooling
rates exceeding about 105 K/sec. It was shown that under these
non-equilibrium conditions it was possible to obtain supersaturated
solid solutions, metastable crystalline inter- mediate phases and even
amorphous phases under appropriate quench- ing conditions and for
suitable alloy compositions. Subsequently, several other techniques have
also been developed to achieve these non-equilibrium effects. A common
feature of all these rapid quench- ing techniques ow collectively
referred to as splat quenching, liquid quenching, melt quenching or
liquisoi quenching) is that quenching is carried out from the liquid
state at very high cooling rates. However, the shape and size of the
quenched product may be different depending on the technique employed.
The method of melt spinning- in which a continuous stream of liquid jet
is impinged against a conducting wheel rotating at a high speed - has
become the most popular since long and continuous ribbons of uniform
cross section can be obtained. Although started only about 20 years ago,
the rapid quenching technique has come to be established as a standard
method to produce metastable effects. The activity in this area is now
world-wide as evidenced by the organization of three international
conferences devoted exclusively to this topic. The first one was held in
Brela, Yugoslavia (1970), the second in Massachusetts, Cambridge, USA
(1975) and the third at Sussex, UK (1978).