Project Title: Mechanical response of prototype multilayer materials under contact stresses
Funding Entity: Junta de Extremadura
Participating Entities: University of Extremadura
Duration: 14/12/2000 – 14/12/2003
Budget: 20 344.26 €
UEX Principal Investigator (PI): Antonia Pajares
Number of researchers: 4
Coating certain materials with ceramic layers has important technological applications. Common examples are cutting tools, thermal barrier coatings, car windscreens, dental restorations, etc. In these and many other applications, the multilayer structures are subjected to high contact stresses, limited to small regions. Although multilayer structures are known to be more tolerant to contact damage than any of the constituent materials, they are also prone to new fracture modes that can cause premature and catastrophic failure of the system. Therefore, it is necessary to identify and characterize damage modes in model multiplayer systems. The main objective of this research project was to identify and analyze contact damage in multilayer structures with an external ceramic, and therefore brittle, layer. After this first step, our interest was focused on the prevention of catastrophic failure in this structures. For this purpose, we obtained general analytical expressions relating the critical loads to initiate each mode with characteristic parameters of the structures (i.e. layer thicknesses, elastoplastic properties of constituent materials, etc.).