ABSTRACT
Due to the limitation of casting technique, conditions and material property, micro voids and other defects are inevitably and randomly existed among the whole structure. As a typical foundry structure which has complicated shape, cylinder head always undertake high thermo-mechanical loads. There is no doubt that the condensed and large-area appeared casting defects will apparently influence the material’s mechanical performance. However, microscopic voids which are sometimes being neglected could also become a disturbing part of the structure’s life period, even though these micro-defects has the characters of uncontrollable, hard-detectable and disperse distribution. How to incorporate the effects of micro-defects on the overall macroscopic behavior has become more and more serious to the engineering designers.
