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 Posted: Sun 2:00, 16 Jan 2011 Post subject: moncler daunenjacke MgB2FeCu with the critical cur |
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MgB2/Fe/Cu with the critical current anisotropy and hysteresis
Will use this MgB2/Cu complex processing into both sides of the biaxial rolling method was 0.96mm and 0.83mm wide and square lines. Another specification 0.96mmx0.96mm the square lines for further processing: 1) processed into 0.36mmx2.72mm biaxial rolling band method; 2) rotary forging and stretching method processed into OD 0 .8 mm line. Finally, with a 4cm long in calm under pressure 0.7GPa and 1.5GPa pressure 10min. Mga2/Fe/Cu in the production of single line, using the OD / ID: 8.0/6.0 brass, and the outer diameter. 0/4.2 of the iron pipe. Copper shell and the Fe / Cu shell line fill factor (Mga2 and the metal shell ratio) were 46% and 25%. Measurements showed that the MgB2 powder bought a wide range of grain size distribution, in the 0.1gm,, ~ 601. tm between the powder in the presence of up to 5wt% MgO the second phase. Experimental results show that even with further pressure, nor can textured MgB2 powder. On with the original powder were pressed into the small temperature measurements show that the resistance, a Rr) curves are two changes reflect the changes in MgB2 grain quality, this change may be due to stoichiometric or strain caused by the different . Mga2/Cu, MgB2/Fe/Cu composite cable (with) in the grain products used in the connection properties and deformation and final shape of a great relationship. And rotary forging and tensile samples obtained compared to the sample with the highest rolling axis critical current density, Mga2 grain core also has the best connectivity features. Measured biaxial rolling Mga2/Cu, Mga / Fe / Cu samples the highest single line of the critical current density were 8700A/cm, and 55830A/cm. Although the appropriate HIP to improve the grain connection, but adversely affect the pinning. Fill factor, additional pressure, and complex geometry can also affect the compressive strain state of MgB2 core, thus affecting the pinning force. In general, the increased pressure to improve the connection between the product particles, but also reduce the high density Mga2 (biaxial rolling) the pinning force,[link widoczny dla zalogowanych], the impact of low-density line of stretch forming is not the case . Mga2 the quality of the original powder (the degree of grain refinement, grain uniformity, MgO content) is the first place (ex-situ) production of powder loaded tube MgB2 single line of high-quality and multi-core wire an important factor. MgB2/Fe/Cu with the critical current anisotropy and hysteresis due to the anisotropy of superconductors pinning force and critical current have a great impact, so the practical applications of anisotropy is an important factor to consider. According to reports, the crystal has a preferred orientation of the superconducting critical field H. 2 (T) anisotropy (H. B / H) is generally between 1.1 to 1.7,[link widoczny dla zalogowanych], while the thin single-crystal epitaxial superconductors and superconductors is the anisotropy ratio will be higher. Slovak Institute of Electrical Engineering with the first bit method (ex.situ) fl ~ lJ MgB2/Fe/Cu superconducting tape prepared and studied with the transmission of such superconducting current anisotropy, and hysteresis. Mga2/Fe/Cu complex for the production, the use of the outer diameter = 8.0/6.0 brass and OD / ID = 6.0/4.2 iron pipe. From 阿尔法阿耶萨 (AIraAesar) company bought Mga2 powder and loaded into the iron tube, hand-fitted solid,[link widoczny dla zalogowanych], and then into the brass, assembled into complexes. This MgB2/Fe/Cu complex will be processed into swaging 0.7mm diameter wire. Then with the axis of rolling method (TAR) ~ I as 0.34mmx2.76mm band, fill factor (Mga2 and the metal shell ratio) was 25%. In the temperature range 4.2K-15K and 0T ~ 5.5T magnetic field (up field and down field), the well strip in parallel and perpendicular plane case,[link widoczny dla zalogowanych], the measured sample V. I curve to evaluate the critical current criterion for the lgvcm one. The results showed that the vertical field in the direction of the samples have high critical current,[link widoczny dla zalogowanych], this Mga2/Fe/Cu sample critical current anisotropy only in the low field (0T-2.ST) appears under. The magnetic properties and iron shell related. Because the powder with the same technology to produce the Mga2/Cu tubing samples no such anisotropy exists. In MgB2 composite wire, the barrier layer will affect the existence of ferromagnetic critical current Ic (B) characteristics of communication applications in the future could lead to a high hysteresis loss. Metal Express 2002 ll of 7
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