Engineers can now create rapid prototypes in cobalt chromium, a widely used alloy in orthopedic implants in Europe.
The ASTM F-75 Cobalt Chromium alloy from Stratasys Inc., Minneapolis, is for use with the company's Arcam EBM (electron-beam melting) systems.
EBM fabricates solid metal parts through a patented CAD-to-Metal process. Parts are built in layers from metal powder. Each successive layer forms when an electron beam melts the metal powder in the geometry defined by the CAD file. The process is under high vacuum and thus creates fully dense parts that contain no imperfections that could cause oxidation. EBM also eliminates the time, cost, and challenges typically associated with machining and investment casting. Stratasys is the exclusive North American distributor of EBM rapid-manufacturing and prototyping systems.
ASTM F-75 Cobalt Chromium is a candidate for biomedical and aerospace parts that need high strength, low weight, and resistance to wear and corrosion. In Europe the alloy serves in total-hip or knee arthroplasty, as well as in metal-on-metal bearings in total-hip arthroplasty.
Says Kirby Quirk of Stratasys, "Cobalt-chromium parts made using Arcam EBM can be produced three-to-five times faster than other metal additive-fabrication methods."
In addition to F-75 Cobalt Chromium, EBM parts can be made in Ti6AI4V titanium (the most widely used titanium alloy), and Ti6AI4VELI, which features improved ductility and fracture resistance at low temperatures.