Oxidation Behaviour of Si3N4-Based Ceramics; Studied by the Thermogravimetric Method
1993 (English)In: Thermochimica Acta, ISSN 0040-6031, Vol. 214, no 1, 27-31 p.Article in journal (Refereed) Published
The oxidation curves of three different Si3N4-based ceramics are presented. In most cases, the obtained weight gain curves do not follow the parabolic rate law (ΔW/Ao)2 = Kpt + B. If crystallization occurs in the formed oxide scale during the experiment, the amorphous cross section area, A, through which oxygen most easily diffuses will decrease with time. With a function A(t), which describes the time dependence of the decrease of A, incorporated into the parabolic rate law one obtains a new rate law which reads ΔW/Ao = aarctan√bt +c√t. It is shown that all oxidation curves can be explained within the framework of this rate law in combination with the parabolic rate law.
Place, publisher, year, edition, pages
1993. Vol. 214, no 1, 27-31 p.
IdentifiersURN: urn:nbn:se:liu:diva-60870DOI: 10.1016/0040-6031(93)80033-7OAI: oai:DiVA.org:liu-60870DiVA: diva2:359606