investigation of effective parameters on graphite distribution in fgm structure of a356/al2o3/gr composite

In this study, a hybrid aluminum/alumina/graphite composite was prepared using the horizontal centrifugal casting method, and the microstructure and distribution of alumina and graphite particles in the radial direction of the sample cross-sections were investigated. the distribution of graphite and alumina particles resulted in the formation of a functionally graded material (fgm) structure along the cross-section length. due to the centrifugal force, graphite particles were separated in the inner part of the sample, while alumina particles gradually increased from the inner to the outer region. samples with 3, 5, and 7% volume fractions of graphite particles added to the melt were obtained using mold rotation speeds of 1000 rpm, 1500 rpm, and 2000 rpm, and the formation of an internal graphite-rich zone was examined. in all samples, a 3% volume fraction of alumina particles was used, and the effect of the presence of alumina particles on the distribution of graphite particles was studied. optical microscopy (om) was used to investigate the microstructure and distribution of graphite and alumina particles. increasing the amount of graphite from 3 to 7% volume fraction increased the collision and interaction between graphite particles, resulting in a thicker inner graphite-rich layer. increasing the mold rotation speed initially led to an increase in the thickness of the inner layer and then resulted in a decrease. the presence of alumina particles prevented the complete separation of graphite particles in the inner region and led to a more uniform distribution.