• Nowak, Krzysztof

Abstract

<jats:p> Deterioration of the materials, particularly metals under environmental conditions such as high temperature, alternating loading and chemical aggression is an example of processes which happen on the microstructure levels but project themselves upon macroscopically observed behaviour of materials and structures. This connection between both levels of observation was obvious to many researches, even if they aimed at macroscopic description on the level of continuum mechanics. The wisdom of micro- and macro-coupling was induced by a very complex nature of microstructural processes which demonstrated themselves as transgranular or intergranular failures, just to mention two typical modes of creep failure. The gap between micro- and macro-world was a challenge to both material science and mechanics societies throughout the second half of 20th century. A proposed method to cover this gap for polycrystalline materials is based on Cellular Automata (CA) technique well suited to be used on the microscopic level and giving responses relevant to macroscopic observations. It allows for microstructure modelling to distinguish grains and grain boundaries. Once it is done, a cellular automaton can be attributed to the Representative Volume Element (RVE) and failure mechanism described on the basis of appropriate transition rules. Examples of transgranular and intergranular creep damage growth are demonstrated. This procedure can be extended over the feedback from micro-level to macro-level leading to the formation of so-called CAFE technique. </jats:p>

Topics

• impedance spectroscopy
• grain
• creep
• cellular automata