A FAST-FIRING SHRINKAGE RATE-CONTROLLED DILATOMETER USING AN INFRARED IMAGE FURNACE

A novel dilatometer design is described for performing rate controlled sintering experiments on powder compacts. Previous rate controlled sintering systems, which control the shrinkage of a sintering compact, possessed only limited shrinkage rate control and shrinkage profile complexity due to the high thermal mass of conventional furnaces and dilatometers. The instrument described in this work features an infrared imaging furnace and a low thermal mass dilatometer assembly which together provide a very rapid temperature response. The system is capable of heating and cooling ceramic samples at up to 500-degrees-C/min. Shrinkage control is accomplished using a modified, computer interfaced proportional-integral-derivative algorithm, and tests on glass-alumina composite samples demonstrated excellent shrinkage control with differences routinely less than 0.2% between the set point and actual shrinkage.