Project Title: Mechanical properties of ceramic layers under contact stresses at Ta <T<1500ºC

Acronym: MAT2003-05584

Funding Entity: Ministerio de Ciencia y Tecnología

Participating Entities:  University of Extremadura

Duration: 01/12/2003 – 30/11/2006

Budget: 150 000 €

UEX Principal Investigator (PI): Antonia Pajares

Number of researchers: 5

Abstract:

Ceramic layers are hard, wear resistant, chemically durable and suitable for operating at high temperatures; as such, they are ideal candidates for many technological applications.  However, at low temperature, ceramic materials tend to be brittle and therefore susceptible to catastrophic failure in repeated contact events, where inordinately high concentrated stresses can be generated by relatively small loads. Therefore, there is a need to study their mechanical behaviour under such loading conditions. This is especially true for multilayer systems where the number of possible damage modes is increased and the literature on the matter still scarce. Particularly, there are no systematic studies focused to analyze damage evolution and fatigue in such structures. Also, to the best of our knowledge, the issue of contact damage in ceramics at high temperature has never been addressed in the literature, where mechanical characterization of ceramics is almost exclusively limited to creep testing.

This project is the natural continuation of previous works on multilayer ceramic structures, and it is aimed to fulfil the above mentioned gaps in the literature. First, we seek to study contact damage evolution and fatigue properties in prototype multilayer structures at room temperature. Main objectives in this sense are determining which damage mode is more deleterious and which are the key features to improve damage tolerance in these structures. Secondly, we propose a detailed, study about contact damage properties of bulk ceramics at high temperature. This part of the project is certainly innovative and with clear practical interest. Also, it is an essential issue to face future works on contact properties of ceramic layers at high temperature.