The present disclosure relates, at least in part, to a surgical implant and a method for manufacturing the surgical implant. In one embodiment, the surgical implant comprises a metallic substrate； a tantalum interlayer disposed adjacent to the metallic substrate and comprising α-tantalum and amorphous tantalum； at least one DLC layer disposed adjacent the tantalum interlayer； wherein the amorphous tantalum has a phase gradient increasing from the metallic substrate side to the DLC side； wherein the DLC layer has a hardness value and an elastic modulus value； and wherein the hardness value has a gradient increasing away from the tantalum side； and wherein the elastic modulus value has a gradient from the tantalum side.
