Design of gradient composites of aluminum and graphite by the centrifugal-casting method

A method of centrifugal casting of aluminum composites in a mixture with Al$_2$O$_3$ and C is proposed and proved by experiments. It is shown that there is a possibility of constructing gradients of admixtures, that is, of hardening the surface layer. It is specified how the concentration gradients are formed: the first technique is use of buoyance force and the second technique is redistribution of nuclei by size when they are exposed to rotation.