Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Materials Science: metals with diamonds

28.05.2009
An Inter-Faculty research team at the Vienna University of Technology is examining dimensionally stable and thermoconducting material combinations for nuclear fusion.

Material scientists are developing composites which are made of dissimilar materials in order to be able to offer new customised application profiles. Researchers at the Vienna University of Technology (TU) have examined promising metal-matrix composites, which are very good conductors of heat and are able to withstand mechanical loads at elevated temperatures of up to 550 degrees and expand only very little with increasing temperature.

These material combinations may be used in the ITER nuclear reactor, which is currently being constructed at Cadarache, France, and where they are intended to be used in cooling the first wall of the experimental reactor. Enhanced heat removal is playing an increasingly important role in the field of power electronics for engines and computers. Unless excess heat can be dissipated, the power of computers can no longer be increased. Last but not least, metal matrix composites can be used as cooling materials in rocket engines.

Four TU institutes are working on material combinations as part of an EU project of the 6th Framework Programme called ExtreMat (http://www.extremat.org/), which stands for "New Materials for Extreme Environments". "We examined some metal matrix composites and their interfacial bonding which are promising for use in nuclear reactor heat sinks, rocket engines or in power electronics. The characterisation of these heterogeneous materials falls within our area of competency", says Professor H. Peter Degischer, Head of the Institute of Materials Science and Material Technology at the TU Vienna. Copper and silver are efficient conductors, but due to their relatively high coefficient of thermal expansion, do not provide enough inherent strength when changes in temperature occur. In addition, their mechanical strength is sharply reduced at elevated temperatures. Copper deforms like butter from 300 degrees onwards". Strengthening with silicon carbide or tungsten fibres with some 0.1 millimetres or carbon fibres with less than 1/100 millimetres diameter increases the strength and the form stability without reducing conductivity. Degischer believes that a combination of silver with diamond particles of approx. 0.1 millimetres of diameter which are connected by means of thin silicon bridges holds the most promise for power electronics.

By using simulation calculations, both the internal stresses and the thermal conductivity were predicted for given internal arrangements of composites. The Austrian company PLANSEE could set up industrial production for these new materials. "During our investigations with a synchrotron, a particularly brilliant X-ray source, in Grenoble we were able to see how the composites? components, which are arranged three-dimensionally, deformed in different ways upon being repeatedly heated up and cooled down. Furthermore, we were able to ascertain the point at which debonds on the interface between metal matrix and diamond particles become visible in micro-tomography. These debonds are a consequence of local tensile stresses during changes in temperature. The conducting bond to the cooling plate was produced using a new coating procedure", says Degischer.

Chemists (Ass. Prof. C. Edtmaier), physicists (Prof. C. Eisenmenger-Sittner), micro-mechanicists (Prof. H. Böhm) and material scientists from the TU collaborated with two Austrian partners and 35 other European research institutes and companies on the research project "ExtreMat". Four doctoral students successfully carried out the scientific work for the project part on behalf of the TU. Almost 1 million euro has been spent on the project over the past 4 years, 50 percent of which was financed by the European Commission.

Photo download: https://www.tuwien.ac.at/index.php?id=8822

Video: http://www.tuwien.ac.at/flash_video/090507metall_mit_diamanten/

Please direct queries to:
Prof. H. Peter Degischer
Institute of Material Science and
Material Technology
Vienna University of Technology
Karlsplatz 13, 1040 Vienna
T +43/1/58801 - 30801
F +43/1/58801 - 30899
E hpdegi@pop.tuwien.ac.at
Released by:
Daniela Hallegger, M.A.
TU Vienna - PR and Communication
Operngasse 11/E011, A-1040 Vienna
T +43-1-58801-41027
F +43-1-58801-41093
E daniela.hallegger@tuwien.ac.at

Werner Sommer | idw
Further information:
http://www.tuwien.ac.at/pr

More articles from Materials Sciences:

nachricht Pressure tuned magnetism paves the way for novel electronic devices
18.12.2018 | Bar-Ilan University

nachricht Researchers observe charge-stripe crystal phase in an insulating cuprate
18.12.2018 | Boston College

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Data storage using individual molecules

Researchers from the University of Basel have reported a new method that allows the physical state of just a few atoms or molecules within a network to be controlled. It is based on the spontaneous self-organization of molecules into extensive networks with pores about one nanometer in size. In the journal ‘small’, the physicists reported on their investigations, which could be of particular importance for the development of new storage devices.

Around the world, researchers are attempting to shrink data storage devices to achieve as large a storage capacity in as small a space as possible. In almost...

Im Focus: Data use draining your battery? Tiny device to speed up memory while also saving power

The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.

Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...

Im Focus: An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes

Personal patches could reduce energy waste in buildings, Rutgers-led study says

What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

Pressure tuned magnetism paves the way for novel electronic devices

18.12.2018 | Materials Sciences

New type of low-energy nanolaser that shines in all directions

18.12.2018 | Physics and Astronomy

NASA research reveals Saturn is losing its rings at 'worst-case-scenario' rate

18.12.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>