3D morphology characterization of graphite and its effect on the thermal conductivity of vermicular graphite iron

It is important to establish the quantitative effect of graphite's 3D morphology on the thermal conductivity of vermicular graphite iron. In the present study, X-ray tomography is utilized to investigate the 3D morphology of graphite in vermicular graphite iron with different vermicularity. A 3D finite element model was built on the basis of graphite's 3D morphology and the equivalent thermal conductivity of vermicular graphite iron can be calculated. The results show that the volume of graphite clusters in vermicular graphite iron is distributed according to y = a (1 − e−bx)c exponential function. The higher the vermicularity, the more obvious the polarization of graphite volume. Compared with vermicularity, 3D connectivity of graphite is a more appropriate characteristic parameter to investigate the thermal conductivity of vermicular graphite iron from the 3D morphology point of view.