Sintering kinetics in nonisothermal conditions

Due to heating period of samples during examinations of the sintering kinetics of materials it is, in principle, impossible to maintain isothermal conditions of the process, especially in the initial periods of time, when the most important changes in rates and degrees of sintering are taking place. For this reason, it is always vague whether the observed laws of changes in the density degree are determined by the sintering mechanism or by the heating rate of samples. The examination of the sintering kinetics in non-isothermal conditions is methodically more correct when the change in density degree and in temperature of samples is controlled. The method of analysis of the kinetics data on sintering, which is proposed, is based on this: if under some other identical conditions, the densification degree depends on the heating rate very essentially, then the rate of this process does not depend on the heating rate, because during the infinitely little interval of time dtau the process may be taken as isothermal at any rate of heating (dT/dtau). On the example of sintering Naf in nonisothermal conditions was shown the way how the calculate kinetic parameters of the sintering process, as well as to constract isothermal density curves by means of it. It was established that, in this way, the examination of the sintering kinetics in nonisothermal conditions is distinguished, apart from some insignificant difficulties, by a greater reliability of the results