Resistance welding a porous metal layer to a metal substrate

摘要

An apparatus and method are provided for manufacturing an orthopedic prosthesis by resistance welding a porous metal layer of the orthopedic prosthesis onto an underlying metal substrate of the orthopedic prosthesis. The resistance welding process involves directing an electrical current through the porous layer and the substrate, which dissipates as heat to cause softening and/or melting of the materials, especially along the interface between the porous layer and the substrate. The softened and/or melted materials undergo metallurgical bonding at points of contact between the porous layer and the substrate to fixedly secure the porous layer onto the substrate.

主权项

1. A method of manufacturing an orthopedic prosthesis comprising the steps of:
providing a metal substrate; providing a previously-manufactured porous metal layer having a manufactured thickness, the previously-manufactured porous metal layer having a porosity of 55% to 90%; positioning the previously-manufactured porous metal layer against the metal substrate to form an interface between the previously-manufactured porous metal layer and the metal substrate, wherein said positioning generates a net contact area of 15% to 25% between the previously-manufactured porous metal layer and the metal substrate at said interface; applying a weld pressure holding the previously-manufactured porous metal layer against the metal substrate, wherein said weld pressure is at least 100 psi (0.7 MPa) but less than 3,000 psi (20.7 MPa), and wherein said net contact area is maintained despite applying said weld pressure; and directing an electrical current to the interface between the previously-manufactured porous metal layer and the metal substrate to resistance weld the previously-manufactured porous metal layer to the metal substrate while maintaining the manufactured thickness of the previously-manufactured porous metal layer.