Quenching phase changes studied

Three papers have been published recently which attempt to describe the underlying physical mechanisms for the peculiar behavior in the simulated phase changes. Amar and Berry have recently applied the steepest-descent quench technique to the study of the melting transition in tt. The four isomers reported by Hoare and for Af = 7 were observed in the... 

The martensite transformation of stainless steels under stress at low temperature has been extensively studied [ ]. The purpose of this investigation has been to obtain systematic information on this phase change in an alloy (18 Ni, 10 Cr, C < 0.03%, quenched) under continuous constant stress at 20° and 77 °K. 

Wilkes and Emerson (97) studied the time-dependent behavior of a polyester polyurethane (MDI-BD based 40% hard segment) which was heated to 160°C for 5 min, then rapidly quenched to room temperature. To monitor changes in phase separation, SAXS intensity values (at a fixed angle) were recorded as a function of time. Furthermore, the elastic modulus and soft-segment Tg were followed with time. The results, shown in Figure 14, reveal an approximately exponential decay toward equilibrium with a good correlation between properties (Tg and modulus) and structure (inferred by SAXS intensities). 

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