Volume 2, Issue 10 (November 2005)
Metallurgical Attachment of a Porous Tantalum Foam to a Titanium Substrate for Orthopedic Applications
A porous tantalum foam (Trabecular Metal™) has been successfully attached to a titanium substrate for an orthopedic acetabular cup application by two different methods: sintered powder processing and diffusion bond processing. A metallurgical evaluation of the interfaces between the tantalum foam and the titanium substrates has been performed, as well as long-term corrosion immersion tests to evaluate the susceptibility of the materials and design to crevice corrosion attack. The sintered powder attachment method used sprayed titanium powder at the interface between the tantalum foam and the titanium substrate. The assembly is sintered at high temperature to form a metallurgical bond between the sintered titanium powder and the titanium substrate and a predominately mechanical interlock between the sintered powder and the tantalum foam. The diffusion bond attachment process used time, pressure, and temperature to form a metallurgical bond between the tantalum foam and the titanium substrate by solid state diffusion. Both methods formed acceptable bond strengths with no evidence of corrosion attack from the corrosion immersion tests.