Open Competition 2 - Chemistry and Materials

Triboelectric Separation of Ceramic Impurities from Powder Metallurgy Alloys

Sponsor: Tribo Flow Separations, LLC

• Project Performance Period: 10/1/2001 - 9/30/2004
• Total project (est.): $2,141,203.00
• Requested ATP funds: $1,823,425.00

Specialty metal alloys made from powder metallurgical techniques are advantageous for critical applications like high-speed machine tools and medical implants. Fabricated parts from metal powders have a more uniform microstructure, and significantly improved mechanical and thermal properties relative to conventional cast- or wrought-metal parts. Because of these advantages, the market for powder metallurgy special alloys is growing at a rate of 5 percent annually to 20 percent. This growth could be even greater, but is limited by the higher costs of powder metallurgical alloys in comparison with conventional cast or wrought materials. Currently, a key issue driving up costs is the need to remove ceramic impurities from the powders by sieving techniques. Sieving also causes up to 15 to 25 percent in yield loss of the metal powder. To achieve greater productivity and purity in metal powders, Tribo Flow Separations, LLC (Lexington, Ky.) and its subcontractor Carpenter Powder Products (Bridgeville, Penn.) propose a 2-year project to develop a prototype-scale (50 kg/hr) triboelectric separation system. This technology, based on a process developed at the University of Kentucky, uses controlled, turbulent flow and an electric field to selectively separate powdered metal particles from impurity particles. The technology has very high throughput and is capable of generating products with impurity concentrations as low as one part per billion when starting with impurity levels of parts per million. The goal of the project is to create previously unattainable, hyper-pure metal powders at up to a 50 percent increase in productivity over current industrial practices. Triboelectric purification technology also would reduce by 50 percent the amount of energy and specialty gases used to produce powder metals. Successful development of triboelectric purification technology would increase the present 20 percent share of metal-powder alloys used in the $5 billion worldwide market for high-speed cutting tools. In addition, the use of more highly purified powders in alloys for prosthetic implants (such as for hip replacement) could reduce the $650 million annual replacement cost associated with correcting implant imperfections.

For project information:

Melissa P. Ochsenbein, (859) 552-6229
melissa@triboflow.com

ATP Project Manager

Jean-Louis Staudenmann, (301) 975-4866
jstaudenmann@nist.gov