Controlled-rate thermal analysis - Study of the process of super hard material debinding

Binder burnout has been carried out by a controlled heating programme which depends on the composition of the binder system used. The present paper gives the principle of constant decomposition rate thermogravimetry, which falls within controlled-rate thermal analysis, and the advantage of this technique when evolved gas analysis is used in discriminating the process of super hard material burnout by comparison with the conventional linear heating method is described. In this technique, the sample temperature is varied to maintain a constant rate of mass loss by control of the heating of the infrared image furnace. Since the constant decomposition rate control (CDRC) allows a much better control of the sample environment, which generally depends on the rate of gas evolution, it is possible for uniform conditions to exist throughout the sample, and the total burnout time can be reduced considerably without crack formation. The efficiency of this CDRC was proved by the obtained temperature vs. time curve and SEM observations of the heat-treated sample after the debinding process.