Plastic deformation of a model material containing soft spheroidal inclusions: spheroidal graphite cast iron

摘要

The plastic deformation of a soft inclusion-containing material usually results in mechanical anisotropy due to the non-uniform deformation of the matrix. The soft inclusions are normally assumed to change shape but offer little or no restraint to the manner in which the matrix deforms. An attempt was made here to test this assumption by studying the plastic deformation of a model material containing soft spheroidal inclusions in order to observe the relationship between the local matrix deformation, the inclusion deformation, and the gross mechanical shape change of the composite material. A ferritic spheroidal graphite iron was chosen as the model material. Thus, cylindrical specimens of spheroidal cast iron were compressed and the deformation of the inclusions and the overall matrix deformation were measured from observations on the longitudinal sections of the specimens using image analysis. A deformation ratio (K) of the inclusions to the matrix was derived. The measured deformation values agreed well with those predicted.