IDEA #9BD4LD Surerconducting Nanommaterials For Cryogenic Electrical Machines

NEW(cid:3)MATERIALS(cid:3)AND(cid:3)NANOTECHNOLOGY SURERCONDUCTING NANOMMATERIALS FOR CRYOGENIC ELECTRICAL MACHINES Description The aim of presented project is formation of magnesium diboride based superconducting nanostructural materials with high level of critical current density, jc, field of irre$ versibility, Hirr, trapped magnetic field, B, microhardness, Hv, fracture toughness, k1c, Young modulus, E, and density close to the theoretical one. Such materials will be effective for application in the cryogenic electrical machines (electric motors, pumps) working at the liquid hydrogen temperature (20 K). The increase of jc and B we plan to reach using high pressure$high temperature synthesis and alloying. In the frame of the project an electromotor will be constructed based on the best of developed materials and its efficiency will be estimated. The magnesium diboride based supercon$ ductive blocks for the elements of the electromotor rotor will be produced by high pressure$high temperature synthesis. Modern technological progress is aimed at substitution of fuel for aircrafts and combustion engines of autotransport and watertransport (submarines) by hydrogen, at the develop$ ment of electrical power networks (first of all on the territory of the USA) by which the electrical power should be trans$ mitted to big distances through the superconductive cables at the liquid hydrogen temperature and using liquid hydrogen as cooling agent. These directions caused great interest to electric machines working at the liquid hydrogen temperature. Superconductive electromotors and pumps for liquid hydro$ gen pumping will be in great demand when new technologies utilizing liquid hydrogen are introduced: they are more effec$ tive than traditional ones due to essentially smaller weight, considerably higher speed of operation in the reversion regime and higher specific output power on the rotor surface. Innovative Aspect and Main Advantages Scientific and technological approach to development of bulk materials using magnesium diboride is based on syn$ thesis in high pressure conditions. Improved magnetic properties are to be obtained due to high material density, nano$dimensional defects and chemical doping. Special attention will be paid to technological basis of synthesis of bulk blocks with typical dimensions up to 50 mm and fur$ ther selection of samples with equal parameters by frozen magnetic field estimation and measuring of the levitation force. Developed magnesium diboride based superconduc$ ting nanostructural materials should have high level of critical current density at 20 Kjc ≥ 1000–100 kА/сm2 in the fields 3–4 Т, field of irreversibility, Hirr ≥ 8 Т, trapped mag$ netic field, В ≥ 2 Т for the samples 30–50 mm in diameter, microhardness, Нv ≥ 15 GPa at P = 4,9 N, fracture tough$ ness, к1с ≥ 7 МPа×m1/2, Young modulus, Е ≥ 220 GPа and density close to the theoretical one. One of the advantages of superconductive motors, gen$ erators and pumps is high power density due to a small size of rotor that allows an essential decrease in size (by 5–8 times) and weight, as well as achieving of high dynam$ ics: a high angle acceleration which is especially important when a device operates under the conditions of high reverse frequency. The use of superconductive electrical machines 48 Fig. 1. Superconducting nanostructural magnesiumMdiborideM based material for cryogenic electrical machines saves energy resources. Advancement in applications of the second$type superconductors in electrical machines is close$ ly related to materials improvement, because in operation they should provide high currents in magnetic field and should withstand stresses induced by magnetic fields and temperature variations during heating$cooling processes. Areas of Application Electroengineering (electromotors, generators and pumps for liquid gases pumping, fault current limiters), magnetic transport (MAGLEV), fly$wheel energy storage systems Stage of Development National patents, know$how Development phase $ labora$ tory tested Contact Details Institute for Superhard Materials of the National Academy of Sciences of Ukraine Tatiana Alexeevna Prikhna 2, Avtozavodskaya Str., Kiev 04074, Ukraine Tel.: +380$44$430$11$26 Fax: +380$44$430$11$26 EMmail: prikhna@iptelecom.net.ua, prikhna@mail.ru,www. ism.kiev.ua SCIENCE AND INNOVATION. № 4, 2006