Optical Dilatometry and Push-Rod Dilatometry - A Case Study for Sintering Steel and Zirconia Tapes

In this work, the sintering behavior of tapes prepared via tape casting from stainless-steel and zirconia powders is investigated by optical – as well as push-rod – dilatometry. Both methods are compared in terms of sample preparation, measurement conditions and advantages and disadvantages. The experimental work shows the advantages of optical dilatometry in characterizing of the sintering behavior of load free sintering tapes and the possibilities of simultaneous observation of sample warpage and deformation. Push-rod dilatometry requires a constant load on the sample, which influences the sintering process in the case of tapes with lower mechanical stability but has advantages because of the higher accuracy in measuring dimensional changes. In the case of warpage, the shrinkage due to sintering of the sample is superimposed by an irregular deformation process that can be separated by analytical methods. No in-plane shrinkage anisotropy of the tapes is observed for either type of tape. In the case of the push-rod dilatometer, an additional peak in the shrinkage rate is observed in the early stage of compaction and a slight shift and increased maximum of the compaction rate. This is most likely due to the effects of the contact pressure of the push-rod.