A method including: submerging a ceramic preform (10) in a layer (12) of powdered superalloy material (14), wherein the preform defines a desired shape of a channel (60, 62, 64, 78) to be formed in a layer (42) of superalloy material; melting the powdered superalloy material around the preform without melting the preform; and cooling and re-solidifying the superalloy material around the preform to form the layer of superalloy material with the preform defining the shape of the channel therein.

A method including: submerging a ceramic preform (10) in a layer (12) of powdered superalloy material (14), wherein the preform defines a desired shape of a channel (60, 62, 64, 78) to be formed in a layer (42) of superalloy material; melting the powdered superalloy material around the preform without melting the preform; and cooling and re-solidifying the superalloy material around the preform to form the layer of superalloy material with the preform defining the shape of the channel therein.

A polycrystalline composite tool component and associated methods are disclosed. In one example plurality of diamond particles are coated with a conforming catalyst metal coating and a plurality of graphene particles. Various asymmetric distributions of graphene particles are shown that provide a variety of material properties.