A nickel-based superalloy part includes a nickel-based superalloy substrate, and a metal sublayer covering the substrate, wherein the metal sublayer includes a first and a second layer, the first layer being located between the substrate and the second layer, the first layer including a first -Ni.sub.3Al phase and a second -Ni phase, the second layer including a first -Ni.sub.3Al phase, a second -Ni phase and a third -NiAl phase, the average atomic fraction of aluminum in the second layer being strictly greater than the average atomic fraction of aluminum in the first layer.

A nickel-based superalloy part includes a nickel-based superalloy substrate, and a metal sublayer covering the substrate, wherein the metal sublayer includes a first and a second layer, the first layer being located between the substrate and the second layer, the first layer including a first -Ni.sub.3Al phase and a second -Ni phase, the second layer including a first -Ni.sub.3Al phase, a second -Ni phase and a third -NiAl phase, the average atomic fraction of aluminum in the second layer being strictly greater than the average atomic fraction of aluminum in the first layer.

A part includes a three-dimensional porous metallic workpiece printed via an additive manufacturing process and subsequently subjected to a diffusion-based process to convert at least a portion of the porous metallic workpiece to a ceramic workpiece or an intermetallic workpiece.

A part includes a three-dimensional porous metallic workpiece printed via an additive manufacturing process and subsequently subjected to a diffusion-based process to convert at least a portion of the porous metallic workpiece to a ceramic workpiece or an intermetallic workpiece.