Half diamond, half cubic boron, all cutting business

September 08, 2015

WASHINGTON, D.C., September 8, 2015 -- Diamonds are forever, except when they oxidize while cutting through iron, cobalt, nickel, chromium, or vanadium at high temperatures. Conversely, cubic boron nitride possesses superior chemical inertness but only about half of the hardness of diamonds. In an attempt to create a superhard material better suited for a wide variety of materials on an industrial scale, researchers at Sichuan University in Chengdu, China, have created an alloy composed of diamonds and cubic boron nitride (cBN) that boasts the benefits of both.

"Diamond and cubic boron nitride could readily form alloys that can potentially fill the performance gap because of their affinity in structure lattices and covalent bonding character," said Duanwei He, a professor at Sichauan University's Institute of Atomic and Molecular Physics. "However, the idea has never been demonstrated because samples obtained in previous studies are too small to test their practical performance."

He and his colleagues at the University of Nevada and the Chinese Academy of Sciences detail their procedure this week in Applied Physics Letters, from AIP Publishing.

To synthesize diamond-cBN alloys, the researchers subjected a homogenous mixture of diamond and cubic boron nitride powder to a vacuum furnace at 1300 K for two hours, then pressed the material into 3.5 millimeter pellets under pressure greater than 15 gigapascals and temperatures above 2000 K. The pellets were then polished and sharpened into cutting implements.

The researchers tested the cutting performances of their alloy on hardened steel and granite bars on a computer numerical controlled lathe. They found that the diamond-cBN alloy rivaled polycrystalline cubic boron nitride's wear and tool life on the steel samples, and exhibited significantly less wear when cutting through granite. The alloy also demonstrated a more preferable high-speed cutting performance than either polycrystalline CBN or commercial polycrystalline diamonds.

Future work for He and his colleagues involves developing synthesis technology for centimeter-sized diamond-cBN alloy bulks to bring the process up to industrial-scale production.
-end-
The article, "Diamond-cBN Alloy: a Universal Cutting Method" is authored by Pei Wang, Duanwei He, Liping Wang, Zili Kou, Yong Li, Lun Xiong, Qiwei Hu, Chao Xu, Li Lei, Qiming Wang, Jing Liu, and Yusheng Zhao. It will appear in the journal Applied Physics Letters on September 8, 2015 (DOI: 10.1063/1.4929728). After that date, it can be accessed at: http://scitation.aip.org/content/aip/journal/apl/107/10/10.1063/1.4929728

ABOUT THE JOURNAL

Applied Physics Letters features concise, rapid reports on significant new findings in applied physics. The journal covers new experimental and theoretical research on applications of physics phenomena related to all branches of science, engineering, and modern technology. http://apl.aip.org

American Institute of Physics

Related Diamond Articles from Brightsurf:

Getting single-crystal diamond ready for electronics
Researchers from Osaka University and collaborating partners polished single-crystal diamond to near-atomic smoothness without damaging it.

Turning diamond into metal
Researchers have discovered a way to tweak tiny needles of diamond in a controlled way to transform their electronic properties, dialing them from insulating, through semiconducting, all the way to highly conductive, or metallic.

Building a harder diamond
Scientists at the University of Tsukuba create a theoretical carbon-based material that would be even harder than diamond.

Quantum diamond sensing
Researchers from the University of Maryland and colleagues report a new quantum sensing technique that allows high-resolution nuclear magnetic resonance spectroscopy on small molecules in dilute solution in a 10 picoliter sample volume -- roughly equivalent to a single cell.

Shining like a diamond: A new species of diamond frog from northern Madagascar
Despite the active ongoing taxonomic progress on the Madagascar frogs, the amphibian inventory of this hyper-diverse island is still very far from being complete.

The IKBFU scientists created the first diamond x-ray micro lens
A diamond is a unique and expensive material. But it is almost indestructible which makes the lens made of it more economically profitable than metallic or polymeric ones in the long run.

Stanford research maps a faster, easier way to build diamond
With the right amount of pressure and surprisingly little heat, a substance found in fossil fuels can transform into pure diamond.

Bending diamond at the nanoscale
A team of Australian scientists has discovered diamond can be bent and deformed, at the nanoscale at least.

A tech jewel: Converting graphene into diamond film
Can two layers of the ''king of the wonder materials,'' i.e. graphene, be linked and converted to the thinnest diamond-like material, the ''king of the crystals''?

Researchers teleport information within a diamond
Researchers from the Yokohama National University have teleported quantum information securely within the confines of a diamond.

Read More: Diamond News and Diamond Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.