Abstract: Direct metal deposition (DMDtm) is used to fabricate customized three-dimensional artificial joint components, thereby leading to enormous savings in terms of labor, cost and lead-time. The DMD fabrication process is interfaced directly to digital data derived through CAT scans, MRI or X-ray topography. A computer-aided design (CAD) file is then constructed in accordance with the digital data, and a tool path is generated as a function of the CAD file. The desired implant, or a portion thereof (such as just the outer surface) is then be fabricated by depositing material increments along the tool path using direct metal deposition (DMD). The process may be used for both solid and scaffold structure suitable to bone ingrowth or ongrowth. In the preferred mbodiment, a closed-loop DMD process is used wherein the size of the increments are controlled through optical monitoring. The materials forming the implant may include one or more metals, polymers, or ceramics, including zirconia or alumina.

Abstract: The present invention incorporates one or more diode lasers for the high-power CO2 or Nd-YAG lasers currently used in closed-loop DMD systems. Being semiconductor-based, such devices are almost instantaneously responsive to the electrical input. As such, a DMD system driven by a diode laser according to the invention provides a much faster response compared to other sources. The faster response time, in turn, provides for enhanced dimensional control and capability to produce intricate components with better dimensional accuracy.

Abstract: A metal die casting apparatus preferably comprises a plunger core and a stationary core adapted to form recesses in the casting and to densify the metal to reduce shrink porosity. The cores are located at opposite sides of a die cavity and the plunger core is moveable in the direction of the stationary core to penetrate the metal while in a partially solidified, extrudable state. The cores are suitably shaped to displace metal laterally as the plunger core advances. The apparatus is particularly suited for forming a casting comprising an enlarged region intended to define a bore completely therethrough and surrounded by dense, nonporous metal.