High-quality nanopowders made of refractory ceramics are a rare and very expensive material. All known methods of their manufacturing face the same problems - scanty quantities, extensive variety of particle sizes and expensive production. Researchers from the town of Tomsk have invented and manufactured a device to produce a choice selection of particles - all particles are equal to the required size and inexpensive. The project has been funded by two foundations - the Russian Foundation for Basic Research and the Foundation for Promotion of Small-Scale Enterprises Development in Scientific and Technological Area.
Researchers of the Tomsk State University jointly with their colleagues from the MIPOR research-and-production association have designed a device and manufactured with its help pilot lots of some nanopowders, including the silicon powder and the silicium nitride and silicon carbide powders. The project has been funded by two foundations ? the Russian Foundation for Basic Research and the Foundation for Promotion of Small-Scale Enterprises Development in Scientific and Technological Area.
The action of a new device is based on the method the researchers called ?self-abrasion?. In the device, the fluid jet captures the particles and brings them upwards to the separation zone at the velocity close to the transsonic speed. The centrifugal separator separates off the thin fraction, i.e. the smallest particles. Heavy and large particles fall back to the pounding zone. The streams meet each other, but their velocities are different: they fly up at a high speed and fall down rather slowly, along with that the layer contains the non-ground material, which is constantly poured into the device. Microwhirlwinds originate at the ?stream/non-ground material? border due to significant difference of velocities, the relative velocities of particles inside the microwhirlwinds reach 100 to 300 meters per second. The particles break to pieces blowing each other, friction polishing the particles.
First, the researchers guided by Yuri Birukov investigated the entire process with the help of the mathematical model. The researchers determined how many times each particle is to collide with others to get broken into pieces and then to get ground through to the required size and shape, what should be the device parameters and the gas velocity to get the nanopowder with predetermined characteristics at the output. Besides, in order to exclude milling of admixtures, the particles should not touch the walls of the device in the course of circulation.
Sergey Komarov | alfa
Siberian scientists suggested a new method for synthesizing a promising magnetic material
23.01.2018 | Siberian Federal University
Complex tessellations, extraordinary materials
23.01.2018 | Technische Universität München
Physicists have developed a technique based on optical microscopy that can be used to create images of atoms on the nanoscale. In particular, the new method allows the imaging of quantum dots in a semiconductor chip. Together with colleagues from the University of Bochum, scientists from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute reported the findings in the journal Nature Photonics.
Microscopes allow us to see structures that are otherwise invisible to the human eye. However, conventional optical microscopes cannot be used to image...
On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.
We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
23.01.2018 | Life Sciences
23.01.2018 | Earth Sciences
23.01.2018 | Physics and Astronomy