Synthesizing High-Quality Calcium Boride at Nanoscale
With numerous attractive properties, calcium hexaboride offers great promise for many industrial uses, particularly in PEM fuel cells for electric cars. While previous commercial attempts to synthesize the compound have been unsuccessful, scientists at Argonne National Laboratory and Southern Illinois University (SIU) have devised innovative methods for synthesizing high-quality calcium boride nanoparticles.Description
Calcium hexaboride, also known as calcium boride (CaB6), is a chemically inert powder known for its stability, exquisite hardness, high melting point and high electrical conductivity. Interestingly, although neither of the two elements that comprise calcium boride is magnetic, as a compound, calcium boride is highly magnetic. All of these properties make calcium boride a highly attractive candidate for use in numerous industries, including electronics, aerospace and energy.
Currently, no other commercial attempts to synthesize calcium boride have been successful, owing to high cost, low purity of outcomes or particles that ranged widely in size. However, Argonne and SIU researchers have succeeded in synthesizing compositionally pure calcium boride at the laboratory scale using two different precursors. In one process, calcium carbonate powder was coated with carbon by cracking propylene (C3H6) at 550° C. Carbon deficiency was compensated for by adding additional carbon black powder. This was then mechanically mixed with B4C. In another process, the precursor was prepared by mechanically mixing boric acid, calcium carbonate and carbon black. In both cases, the precursor material was treated at 1600° C for four hours under flowing argon.Benefits
Calcium boride is prized for its unique properties—stability, hardness, high melting point and conductivity. Innovative processes for synthesizing calcium boride make it readily available for manufacturing processes in many industries.Applications and Industries
- Manufacture of boron-alloyed steel
- Deoxidation agent in the production of oxygen-free copper (which has higher conductivity than conventionally produced copper)
- Surface protection, abrasives, tools and wear-resistant materials
- N-type thermoelectric materials
Process has been reduced to practice; the next step is scale-up to commercial production.Patents and Patent Applications
|Title and Abstract||
SYNTHESIS OF METAL BORIDES
Methods for the synthesis of metal borides. Metal boride compounds synthesized by those methods are also disclosed.
|Technology ID||Development Stage||Availability||Published||Last Updated|
|ANL –IN- 10-044||Prototype||Available||07/16/2013||07/16/2013|