A casting method for forming an article, comprising: introducing a first material into a mold, the first material being introduced in a molten state, the mold being arranged and disposed to distribute the first material to form a first region of the article; subjecting the first material to a first condition suitable for growing a first grain structure; growing the first grain structure from a first portion of the first material, forming the first region of the article while maintaining a second portion of the first material in the molten state; introducing a second material into the mold to form a second region of the article, the second material being introduced in the molten state, the second material being compositionally distinct from the first material; forming a hybridized material by intermixing a first portion of the second material with the second portion of the first material; subjecting a second portion of the second material to a second condition suitable for growing a second grain structure, the second grain structure being distinct from the first grain structure; and growing the second grain structure from the second portion of the second material, forming the second region of the article, the first region and the second region being integrally formed as a single, continuous article with a hybridized region formed from the hybridized material and disposed between the first region and the second region, wherein introducing at least one of the first material and the second material includes introducing at least one hard-to-weld, HTW, alloy; wherein the at least one HTW alloy is one of: René 108, GTD 111, GTD 444, René N2, and Inconel 738. introducing a first material into a mold, the first material being introduced in a molten state, the mold being arranged and disposed to distribute the first material to form a first region of the article; subjecting the first material to a first condition suitable for growing a first grain structure; growing the first grain structure from a first portion of the first material, forming the first region of the article while maintaining a second portion of the first material in the molten state; introducing a second material into the mold to form a second region of the article, the second material being introduced in the molten state, the second material being compositionally distinct from the first material; forming a hybridized material by intermixing a first portion of the second material with the second portion of the first material; subjecting a second portion of the second material to a second condition suitable for growing a second grain structure, the second grain structure being distinct from the first grain structure; and growing the second grain structure from the second portion of the second material, forming the second region of the article, the first region and the second region being integrally formed as a single, continuous article with a hybridized region formed from the hybridized material and disposed between the first region and the second region, wherein introducing at least one of the first material and the second material includes introducing at least one hard-to-weld, HTW, alloy; wherein the at least one HTW alloy is one of: René 108, GTD 111, GTD 444, René N2, and Inconel 738.