Plasma-chemical modification of ceramic material surface at normal pressure

Aim of project
The aim of the project is improvement of mechanical properties of ceramic materials, mainly cheap oxide ceramics, e.g. Al2O3, mainly in terms of resistance to brittle cracking. The research hypothesis is the assumption that a chemical change of the surface of single-phase oxide ceramics (e.g. MexOy → Mez(N,C,B)w) or ceramic-metallic composites (e.g. Me → Mex(N,C,B)y) and giving them nanocrystalline-amorphic structure will eliminate microcracks on their surface, introduce the state of compressive stress in the surface area and create an energy barrier limiting the development of cracks.

Another hypothesis of the project is the assumption that the modification (chemical-structural) of the surface of ceramics is obtained by its plasma-chemical treatment in non-isothermal plasma at atmospheric pressure (in the so-called corona discharge). With this the second aim of the project is connected: development of new technology of surface engineering of ceramic materials. Polycrystalline sinters Al2O3 of different grain sizes will be studied in order to enable to determine the influence of grain size on the processes of defect accumulation and strain size. Fulfillment of the scientific aims will require elaboration and construction of a highly efficient corona tube — a non-isothermal plasma generator working at atmospheric pressure.

Expected results
A material result of the research will be elaboration of technology fundamentals of improvement of mechanical properties of oxide ceramics.

Another material result of the research will be elaboration of physical-chemical fundamentals for surface engineering of ceramic materials at atmospheric pressure enhanced with nonisothermal plasma.

The research results will be documented in scientific publications, patent applications, a prototype of a laboratory non-isothermal plasma generator and preparation of two Ph.D. theses.