Casting core for casting molds and method for the production thereof

A casting core for casting molds, the casting core comprising ceramic particles bound with a silica sol, wherein the casting core has a pore structure comprising pores, and an average pore size of the pores increases at least in sections from an outside to an inside in the casting core:

• wherein the casting core comprises a core center, which contains ceramic particles bound with a silica sol, and at least one core shroud which is arranged around the core center and which contains ceramic particles bound with a silica sol, wherein the core center has a pore structure in which the average pore size of the pores increases from the outside to the inside in the casting core, wherein the at least one core shroud has a pore structure in which the average pore size of the pores increases from the outside to the inside in the casting core, and wherein the average pore size of the pores in an outer region of the core center is less than the average pore size of the pores in an inner region of the core shroud.