Mechanical fatigue detection on ceramic materials

It is well known that ceramic materials are highly susceptible to environme ntal assisted subcritical crack growth. Ln addition, this subcritical crack growth could be also related to cyclic loading (mechanical fatigue). This type of behaviour is not observed either in glasses nor in traditional cera mics. However this phenomena is clearly active in many advanced ceramics. T he aim of this work is to obtain a procedure for detecting the presence of cyclic fatigue in ceramic materials. This procedure attempts to obtain cycl ic fatigue life estimations and to compare it with the static loading exper imental results. Through this comparisons it is possible to asses whether t he cyclic fatigue is acting or not. Finally some calculations are conducted in ceramic materials (alumina, mullite and ZTA) with natural and indentati on flaws.