Projects / Programmes source: ARIS

Protected Permanent Magnets for Advanced High-Temperature Applications

Research activity

Code Science Field Subfield
2.04.02  Engineering sciences and technologies  Materials science and technology  Metallic materials 

Code Science Field
P260  Natural sciences and mathematics  Condensed matter: electronic structure, electrical, magnetic and optical properties, supraconductors, magnetic resonance, relaxation, spectroscopy 

Code Science Field
2.05  Engineering and Technology  Materials engineering 
magnet, rare earth, corrosion, coating, high temperature
Evaluation (rules)
source: COBISS
Researchers (9)
no. Code Name and surname Research area Role Period No. of publicationsNo. of publications
1.  18271  PhD Miha Čekada  Materials science and technology  Researcher  2011 - 2014  445 
2.  04355  PhD Spomenka Kobe  Materials science and technology  Researcher  2011 - 2014  767 
3.  15654  PhD Matej Andrej Komelj  Materials science and technology  Researcher  2011 - 2014  176 
4.  18594  PhD Paul John Mc Guiness  Materials science and technology  Head  2011 - 2014  338 
5.  21523  PhD Iztok Naglič  Materials science and technology  Researcher  2011 - 2014  179 
6.  24381  PhD Aleš Nagode  Materials science and technology  Researcher  2011 - 2014  407 
7.  28208  PhD Mitja Petrič  Materials science and technology  Researcher  2011 - 2014  328 
8.  15604  Tomaž Sirnik    Technical associate  2011 - 2014 
9.  18824  PhD Kristina Žužek  Materials science and technology  Researcher  2011 - 2014  365 
Organisations (2)
no. Code Research organisation City Registration number No. of publicationsNo. of publications
1.  0106  Jožef Stefan Institute  Ljubljana  5051606000  91,921 
2.  1555  University of Ljubljana, Faculty of Natural Sciences and Engeneering  Ljubljana  1627074  19,939 
Abstract A recent overview of the market for rare-earth transition-metal (RE-TM) permanent magnets has suggested that there is a market of 2–5 tonnes per year in the period 2012–2017 for magnets capable of operating in the range 400–500°C. The applications for these highly specialised materials include TWTs, accelerometers, aeronautic gyroscopes and aircraft-engine micro-motors and micro-generators. This market is relatively small for the major European manufacturers, but represents an ideal size for Magneti Ljubjana, d. d., who would aim to capture a 25–50% share if they can produce magnets with a) the required high-temperature magnetic properties, and b) an effective coating to prevent oxidation and evaporation at these very high temperatures. First, developing the high-temperature magnetic properties. Sm2Co17-type magnets have a high Curie temperature, but the negative temperature dependence of their magnetisation is also relatively high, meaning the magnets lose a lot of remanence as things get hot: about 20% for every 100°C. Our aim is to substitute some of the Sm with RE elements like Dy, Ho, Er, but principally Gd, in order to reduce the temperature dependence – theoretical studies have shown that substituting 55% of the Sm with Gd could reduce the temperature dependence to zero – and combine this with our experience of developing specialised magnets for advanced applications, e.g., micro-electro-mechanical systems [see, as an example, our paper on ultra-thin sintered magnets for MEMS in Research Achievements, 1.] and working with permanent magnets on the nanoscale [Research Achievements, 2.] and Sm-based magnets in high-temperature gaseous atmospheres [Research Achievements, 3.] to be able to design a magnet that can operate at 400–500°C and, very importantly, can be fabricated using the facilities available at Magneti. Second, developing a coating to prevent both oxidation and evaporation. Under the normal operating conditions for permanent magnets, i.e., room temperature to 180°C, the main problem associated with the long-term stability of magnets can be described as corrosion. However, above 400°C the problem is oxidation, and to a lesser extent, but still concerning, the evaporation of Sm. For this reason we cannot rely on conventional magnet coatings like Al, Cu, Ni or Cr, of which we have considerable experience, e.g., see our very recent paper on corrosion protection [Research Achievements, 4.] carried in cooperation with bilateral project partners in China. However, our work on protective coatings as coordinator of the multi-partner EU 6FP project Hy-nano-IM [Socio-economic Achievements, 2] suggests that nanostructured coatings based on TiAlN could provide an exciting and innovative solution to this challenging problem. The main advantages of such coatings are that i) they offer excellent protection, ii) they are potentially easy to apply in a uniform, 100% coating layer, and – which is particularly important for the magnetic properties – iii) they are thin (~5 microns), and so have a minimal diluting effect on the magnetic properties of the material. Of course, TiAlN represents only a very promising starting point; the specific properties of Sm2Co17-based magnets will require the full development of a case-specific coating.
Significance for science
The group at the JSI has made many important contributions with SmCo, NdFeB and SmFeN magnets and is one of the lead research departments in the field of permanent magnets in the world. This it has proven by getting four European projects in the thematic of permanent magnets in the last three years. In addition, Magneti has for more than 20 years been one of Europe’s most successful small/medium magnet producers. These two partners have together with the University of Ljubljana used all their knowledge and experience to push forward a new type of product that will open up a new, relatively small (in the global sense) but highly profitable market for the company. The project achieved some important scientific breakthroughs for the research team as a whole. We have successfully development of a permanent-magnet material that can operate at 400-500 oC, as compared to a current limit of 350oC, for applications such as TWTs, accelerometers, aeronautic gyroscopes and aircraft-engine micro-motors and micro-generators. We also development of a new, thin coating to prevent oxidation and rare-earth evaporation at 400-500oC, which represents a major obstacle to the successful implementation of ultra-high-temperature permanent magnets. There are four papers being written at the moment, which will be published in prestigious scientific and technology journals. There is also a patent in preparation that will benefit all of the members of the research team. The results will lead to successful application for future scientific funds for related projects that will benefit Slovenian scientists working in this field at all levels. The research team will also be open to the potential of licensing technological developments patented in the course of the project to companies in Slovenia, Europe and throughout the world.
Significance for the country
The researched magnetic material will be directly applicable in aerospace applications within the next 2-7 years, and in electric vehicles over the next 5-15 years. Success in achieving 25-50% of the ultra-high-temperature market for magnets operating at 400-500oC will have the following direct economic effects: a growth in sales for Magneti of 15-30% in the next 5 years ; a significant contribution to the Slovenian national economy, related to the economic success of the project; a market share of up to 50% for EU producers, in relation to the other world producers, over the next 10 years as a result of sales from Magneti and company partnerships with other Slovenian and EU producers. The expected economic success will also be reflected in increased employment at Magneti: an estimated 20-50 more people will be employed over the next 5 years. Additionally 7 Slovenian companies will indirectly benefit the increased production of Magneti, with approximately 15 additional jobs being created through related activities in electronic components, process engineering, distribution and supply. The technology which was developed is at a much higher level than many of the conventional magnet production methods because of the need to work in carefully controlled inert atmospheres and with very tight tolerances being applied to many of the processing steps. This created higher-skilled, and higher-paid jobs through the production of higher-value devices. It is important to maintain a technological edge to prevent job losses through competitive permanent-magnet production in relatively low-wage economies, like China. This is a real risk for many European magnet manufacturers, especially small/medium companies like Magneti. The produced magnets will be also ecologically friendlier, because it will partially replace the “dirty” processes of producing ferrites and AlNiCos and these magnets will also enable cleaner, more-energy-efficient technologies. This applies most particularly to the applications in transport.
Most important scientific results Annual report 2011, 2012, 2013, final report, complete report on dLib.si
Most important socioeconomically and culturally relevant results Annual report 2011, 2012, 2013, final report, complete report on dLib.si
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