Lomové chování keramického Al2O3/ZrO2 laminátu s tenkými vrstvami

Fracture behaviour of alumina and zirconia thin layered laminate

článek v časopise - ostatní, Jost

en

Laminates with strong bonds between thin layers were examined in this work to explore the influence of developed internal stresses on the fracture behaviour. A set of laminates having different level of internal stresses were prepared. Alumina and zirconia were the model materials for evenly alternating layers. The electrophoretic deposition technique was used for manufacturing of the laminates. The basic mechanical properties as elastic modulus and flexural strength were determined for all prepared materials. The crack propagation changes due to effect of internal stresses, elastic mismatch and surface effects were investigated using modified single edge notched beam technique. An extensive fractographical analysis of fracture surfaces was undertaken using laser confocal microscopy. The changes of the crack direction when crack propagates through alternating layers under different angels were described. Further, the effect of the internal stresses level within individual layers was reported.

V této práci byly zkoukmany lamináty s tenkými vrstvami z hlediska popsání vlivu vnitřních napětí na lomové chování. Byl připraven soubor laminátů s různou hodnotou vnitřních napětí. Jednotlivé alternující vrstvy sestávaly z oxidu hlinitého a oxidu zirkoničitého. Pro přípravu laminátů byla použita metoda elektroforetické depozice. Pro všechny připravené materiály byly určeny základní mechanické vlastnosti jako modul pružnosti a ohybová pevnost. Charaktrizace změny šíření trhliny způsobená vnitřními napětími byla zkoumána pomocí SENB technikou. Pro fraktografickou analýzu byl použit laserový konfokální mikroskop. Z těchto údajů byly popsány změny šíření trhlin zkrze objem vrstevnatých materiálů. V práci je také popsán efekt vnitřních napětí v jednotlivých vrstvách.

Laminates with strong bonds between thin layers were examined in this work to explore the influence of developed internal stresses on the fracture behaviour. A set of laminates having different level of internal stresses were prepared. Alumina and zirconia were the model materials for evenly alternating layers. The electrophoretic deposition technique was used for manufacturing of the laminates. The basic mechanical properties as elastic modulus and flexural strength were determined for all prepared materials. The crack propagation changes due to effect of internal stresses, elastic mismatch and surface effects were investigated using modified single edge notched beam technique. An extensive fractographical analysis of fracture surfaces was undertaken using laser confocal microscopy. The changes of the crack direction when crack propagates through alternating layers under different angels were described. Further, the effect of the internal stresses level within individual layers was reported.

Keramiky, Lamináty, Šíření trhliny, Vnitřní napětí, Lomové chování

Ceramics; Laminates; Crack propagation; Internal stresses; Fracture behaviour

2012

01.07.2012

0955-2219

32

9

2057–2061

5