A medical implant is disclosed. The medical implant includes: a first biocompatible metal forming a substrate (210, 310, 410), a second biocompatible metal diffused into the first biocompatible metal to form an biocompatible alloy surface (220, 314, 414), the alloy surface further including a diffusion hardening species, wherein the diffusion hardening species may be carbon, nitrogen, oxygen, boron, or any combination thereof. A method of forming a medical implant is also disclosed. The method includes the steps of: providing a first biocompatible metal or alloy that forms a substrate (210, 310, 410), providing a second biocompatible metal or alloy, diffusing the second biocompatible metal into the first biocompatible metal to form an alloy layer (220, 314, 414), removing excess second metal material from the substrate to expose the alloy layer, and diffusion hardening the alloy layer.