Laser Powder Deposition of Titanium - Tantalum Alloys Structured Interfaces for Use In Orthopedic Devices

Tantalum has increased biocompatible and osseointegrative properties compared to other metals but is prohibitively expensive for use as a bulk implant material.  Bonding a functional tantalum surface to a titanium orthopedic device is inherently difficult because of the small difference between the melting temperature of tantalum, 3017°C, and the boiling point of titanium, 3287°C.  LASER Powder Deposition (LPD) is a fusion operation using a Nd:YAG laser piped through a 10μm optical fiber to melt a small volume of substrate into which metal powder is sprayed; achieving high temperature with a high solidification rate.  Using LPD to deposit tantalum powder onto a Ti-6Al-4V substrate produces a bulk substrate of unaffected titanium, a solid solution layer of tantalum stabilized β-titanium, and a structured porous surface layer of pure tantalum with pore size of 350 - 500 μm.