To make super-durable and strong details it is necessary to use so-called diamond composites, i.e. materials (matrixes) with incorporated tiny diamonds. The matrix is to be durable, strong, wear-proof as well as monolithic by structure ensuring chemical interaction with diamonds. To avoid internal tension this matrix must have physical characteristics close to diamond ones. In other case the detail will collapse under load.
Carbide materials fit all these requirements because they are strong, wear-proof, thermostable and with high thermal conductivity. High thermal conductivity prevents the detail cracking at a temperature drop (as a glass can crack when filling with boiling water). It is impossible to make such materials by sintering diamonds with silicon carbide, because the required temperatures are so high that diamond just will turn into graphite. The sintering diamond grains with carbide at lower temperature and high pressure (about 8.5 GPa) is a rather expensive process and it can be applied only for manufacturing small details of a simple shape.
The scientists from the Saint-Petersburg-based Central Research Institute of Materials and their colleagues from the Royal Institute of Technology (Stockholm) have invented a new method. They have proposed to press half-finished details (blanks) from the powder made of micron-sized diamonds. Then they heated the details in a vacuum oven and saturated them with liquid silicon. During this procedure the diamond surface turns into graphite-like carbon which interacts with liquid silicon. As a result the finished detail represents a monolith of the required shape which consists from small diamonds soldered one with another by silicon carbide, and silicon itself.
Olga Maksimenko | Informnauka
Decoding cement's shape promises greener concrete
08.12.2016 | Rice University
Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D
08.12.2016 | DOE/Brookhaven National Laboratory
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine