Shrinkage characteristics studies on conventional sintered zirconia toughened alumina using computed tomography imaging technique

Abstract

Shrinkage is an important issue during sintering of ceramics as it affects the structural and mechanical properties. In the current work, the shrinkage characteristics of sintered zirconia toughened alumina (ZTA) compact produced by conventional powder forming process was investigated by using computed tomography imaging technique. The effect of process parameters such as weight percentage of zirconia added to toughened alumina, compaction pressure, and sintering temperature on ZTA was studied. The Box–Behnken technique in response surface methodology was used to develop the experimental design to analyze the shrinkage phenomena. The sintered samples were subjected to computed tomography scan and analyzed by using MIMICS Software wherein the three dimensional shrinkage of the ZTA composites was done. The mathematical regression model relating powder forming process parameters to the shrinkage was developed. It was observed that due to the effect of gravity, shrinkage is found to be 20% in the top for 1600°C sintered sample. From the study shrinkage of the sintered ZTA was influenced by the sintering temperature. Being a non-contact type digital measurement method the odds of error created by instrument or human was avoided. Shrinkage of three directional complex shapes can also be identified effectively with the help of solid modeling packages.