An insert for a drill bit may include a substrate; a working layer of polycrystalline diamond material on the uppermost end of the insert, wherein the polycrystalline diamond material includes a plurality of interconnected diamond grains; and a binder material; and an inner transition layer between the working layer and the substrate, wherein the inner transition layer is adjacent to the substrate; wherein the inner transition layer has a hardness that is at least 500 HV greater than the hardness of the substrate.