Originally Published EMDM
March/April 2003
INDUSTRY NEWS
Amorphous Metal Pairs Strength with Processing EaseImagine a metal alloy whose strength exceeds that of steel and titanium, but that can be processed like a plastic. Sound far-fetched? Not to the people at
Liquidmetal Technologies (Tampa, FL, USA). A zirconium-based alloy marketed by the company exhibits 2.5 times the strength of some titanium alloys and twice the strength-to-weight ratio of some aluminiums. In addition to these exceptional characteristics, the alloy can be cast into net-shape forms that significantly reduce the need for secondary finishing processes.
The secret to this innovation lies in the alloy’s amorphous structure that eliminates the inherently weak spots found at molecular grain boundaries. “All metals have an amorphous structure in their liquid state,” says vice president of medical products Barry Canon. “But our alloy retains this characteristic in its solid state, essentially making it like a metallic glass.” Other physical benefits that result from this amorphous structure include a 2% elasticity and twice as much hardness as some stainless steels.
The absence of phase transformation during solidification also holds benefits for processing. With a lower melting point than its constituent elements, the zirconium alloy can be cast into net-shape parts without voids or defects, reducing the need for costly finishing and machining operations. Because the alloy does not crystallize, the surface finish of parts made from it is also smoother and more consistent than that of some die castings.
Combine all of these characteristics with biocompatibility and resistance to corrosion and wear and it is easy to see why some companies are seeing applications for the alloy in the medical field. Surgical Specialties Corp. (Reading, PA, USA), for instance, began producing ophthalmic scalpel blades using Liquidmetal technology in the third quarter of 2002. Another company, Depuy Orthopedics Inc. (Warsaw, IN, USA), recently began using the alloy to produce knee-replacement devices. Other possible product applications include pacemaker casings and medical instruments.
For more information, contact Liquidmetal Technologies at 100 N. Tampa St., Ste. 3150, Tampa, FL 33602, USA; phone: +1 813 3140280; e-mail: otis.buchanan@liquidmetal.com; Internet:
www.liquidmetal.com.
Zachary Turke
Copyright ©2003 European Medical Device Manufacturer
