Razlika između inačica stranice »Magnetska vodljivost«
Izvor: Hrvatska internetska enciklopedija
m (Bot: Automatska zamjena teksta (-{{cite web +{{Citiraj web)) |
m (Bot: Automatska zamjena teksta (-{{Citiraj web +{{Citiranje weba)) |
||
| Redak 31: | Redak 31: | ||
| | | | ||
| 1.26 · 10<sup>0</sup> | | 1.26 · 10<sup>0</sup> | ||
| 1 000 000 <ref>{{ | | 1 000 000 <ref>{{Citiranje weba|url=http://www.metglas.com/products/page5_1_2_6.htm |title="Metglas Magnetic Alloy 2714A", ''Metglas'' |publisher=Metglas.com |date= |accessdate=2011-11-08}}</ref> | ||
| kod 0.5 [[Tesla|T]] | | kod 0.5 [[Tesla|T]] | ||
| 100 kHz | | 100 kHz | ||
| Redak 38: | Redak 38: | ||
| | | | ||
| 2.5 · 10<sup>-1</sup> | | 2.5 · 10<sup>-1</sup> | ||
| 200 000 <ref name="Iron">{{ | | 200 000 <ref name="Iron">{{Citiranje weba|url=http://hyperphysics.phy-astr.gsu.edu/hbase/tables/magprop.html#c2 |title="Magnetic Properties of Ferromagnetic Materials", ''Iron'' |publisher=C.R Nave Georgia State University |date= |accessdate=2013-12-01}}</ref> | ||
| | | | ||
| | | | ||
| Redak 45: | Redak 45: | ||
| | | | ||
| 1.0 · 10<sup>-1</sup> | | 1.0 · 10<sup>-1</sup> | ||
| 80 000 <ref name="Nanoperm">{{ | | 80 000 <ref name="Nanoperm">{{Citiranje weba|url=http://www.magnetec.de/eng/pdf/werkstoffkennlinien_nano_e.pdf |title="Typical material properties of NANOPERM", ''Magnetec'' |format=PDF |date= |accessdate=2011-11-08}}</ref> | ||
| kod 0.5 T | | kod 0.5 T | ||
| 10 kHz | | 10 kHz | ||
| Redak 52: | Redak 52: | ||
| | | | ||
| 2.5 · 10<sup>-2</sup> | | 2.5 · 10<sup>-2</sup> | ||
| 20 000 <ref name="hyper">{{ | | 20 000 <ref name="hyper">{{Citiranje weba|url=http://hyperphysics.phy-astr.gsu.edu/hbase/solids/ferro.html |title="Relative Permeability", ''Hyperphysics'' |publisher=Hyperphysics.phy-astr.gsu.edu |date= |accessdate=2011-11-08}}</ref> | ||
| kod 0.002 T | | kod 0.002 T | ||
| | | | ||
| Redak 59: | Redak 59: | ||
| | | | ||
| 6.3 · 10<sup>-2</sup> | | 6.3 · 10<sup>-2</sup> | ||
| 50 000 <ref name="nickal">{{ | | 50 000 <ref name="nickal">{{Citiranje weba|url=http://www.nickel-alloys.net/nickelalloys.html |title=Nickel Alloys-Stainless Steels, Nickel Copper Alloys, Nickel Chromium Alloys, Low Expansion Alloys |publisher=Nickel-alloys.net |date= |accessdate=2011-11-08}}</ref> | ||
| | | | ||
| | | | ||
| Redak 66: | Redak 66: | ||
| | | | ||
| 2.3 · 10<sup>-2</sup> | | 2.3 · 10<sup>-2</sup> | ||
| 18 000 <ref name="vacuumschmeltze">{{ | | 18 000 <ref name="vacuumschmeltze">{{Citiranje weba|url=http://www.vacuumschmelze.com/fileadmin/Medienbiliothek_2010/Downloads/HT/2013-03-27_Soft_Magnetic_Cobalt-_Iron_Alloys_final_version.pdf |title="Soft Magnetic Cobalt-Iron Alloys", ''Vacuumschmeltze'' |publisher=www.vacuumschmeltze.com |date= |accessdate=2013-08-03}}</ref> | ||
| | | | ||
| | | | ||
| Redak 94: | Redak 94: | ||
| | | | ||
| 1.26 · 10<sup>-3</sup> - 2.26 · 10<sup>-3</sup> | | 1.26 · 10<sup>-3</sup> - 2.26 · 10<sup>-3</sup> | ||
| 1 000 – 1 800<ref name="Carpenter">{{ | | 1 000 – 1 800<ref name="Carpenter">{{Citiranje weba|url=http://www.cartech.com/techarticles.aspx?id=1476|title=Magnetic Properties of Stainless Steels|author=Carpenter Technology Corporation|publisher=Carpenter Technology Corporation|year=2013}}</ref> | ||
| | | | ||
| | | | ||
| Redak 143: | Redak 143: | ||
| | | | ||
| 1.26 · 10<sup>-6</sup> - 8.8 · 10<sup>-6</sup> | | 1.26 · 10<sup>-6</sup> - 8.8 · 10<sup>-6</sup> | ||
| 1.003–7 <ref name="SSAS">{{ | | 1.003–7 <ref name="SSAS">{{Citiranje weba|url=http://www.bssa.org.uk/cms/File/SSAS2.81-Magnetic%20Properties.pdf|title=Magnetic Properties of Stainless Steel|author=British Stainless Steel Association|publisher=Stainless Steel Advisory Service|year=2000}}</ref> | ||
| | | | ||
| | | | ||
| Redak 163: | Redak 163: | ||
|- | |- | ||
|[[Aluminij]] | |[[Aluminij]] | ||
| 2.22 · 10<sup>-5</sup> <ref name="clarke">{{ | | 2.22 · 10<sup>-5</sup> <ref name="clarke">{{Citiranje weba|author=Richard A. Clarke |url=http://www.ee.surrey.ac.uk/Workshop/advice/coils/mu/ |title=Clarke, R. ''Magnetic properties of materials'', surrey.ac.uk |publisher=Ee.surrey.ac.uk |date= |accessdate=2011-11-08}}</ref> | ||
| 1.256665 · 10<sup>-6</sup> | | 1.256665 · 10<sup>-6</sup> | ||
| 1.000022 | | 1.000022 | ||
| Redak 186: | Redak 186: | ||
| | | | ||
| | | | ||
| 1 <ref>{{ | | 1 <ref>{{Citiranje weba|author=NDT.net |url=http://www.ndt.net/article/ndtce03/papers/v078/v078.htm |title=Determination of dielectric properties of insitu concrete at radar frequencies |publisher=Ndt.net |date= |accessdate=2011-11-08}}</ref> | ||
| | | | ||
| | | | ||
Trenutačna izmjena od 08:19, 1. prosinca 2021.
Pojednostavljeni usporedni pregled magnetske permeabilnosti: feromagnetika (μf), paramagnetika(μp), vakuuma (μ0) i dijamagnetika (μd).
Magnetska vodljivost (oznaka Λ) šipke ili žice, ploštine poprječnoga presjeka S i duljine l, dana je izrazom:
- [math]\displaystyle{ \Lambda=\mu \cdot \frac{S}{l} }[/math]
gdje je: μ - magnetska permeabilnost; recipročna je vrijednost reluktancije (magnetskoga otpora) magnetskoga kruga; mjerna je jedinica henri (H). [1]
Magnetska permeabilnost
Podrobniji članak o temi: Magnetska permeabilnostMagnetska permeabilnost je elektromagnetna osobina materijala koja pokazuje intenzitet magnetizacije tijela kada su ona izložena vanjskim magnetnom polju. Magnetska permeabilnost se označava grčkim slovom mi (μ). Pojam magnetska permeabilnost osmislio je Oliver Heaviside 1885. U jedinicama SI sustava, permeabilnost se izražava u Henrijima po metru (H/m), ili u Newtonima po Amperu na kvadrat (N/A2) ili Volt · sekunda na Amper · metar {Vs/Am}.
Magnetska permeabilnost vakuuma ili univerzalna magnetska konstanta (znak [math]\displaystyle{ \mu_0 }[/math]) je prirodna konstanta magnetske permeabilnosti za vakuum, koja iznosi: [math]\displaystyle{ \mu_0 }[/math]= 4π · 10–7 H/m [2] ili [math]\displaystyle{ \mu_0 }[/math] = 12.566370614 · 10–7 N/A². Jednaka je recipročnoj vrijednosti umnoška dielektrične permitivnosti vakuuma ε0 i kvadrata brzine svjetlosti c u vakuumu: μ0 = 1/(ε0c2). [3]
Vrijednosti za neke materijale
| Materijal | Susceptibilnost χm (volumetrijski SI) |
Permeabilnost μ [H/m] | Relativna permeabilnost μ/μ0 | Magnetsko polje | Frekvencija (max.) |
|---|---|---|---|---|---|
| Metglas | 1.26 · 100 | 1 000 000 [4] | kod 0.5 T | 100 kHz | |
| Željezo (99.95% čisto Fe normalizirano u H) | 2.5 · 10-1 | 200 000 [5] | |||
| Nanoperm | 1.0 · 10-1 | 80 000 [6] | kod 0.5 T | 10 kHz | |
| Mu-metal | 2.5 · 10-2 | 20 000 [7] | kod 0.002 T | ||
| Mu-metal | 6.3 · 10-2 | 50 000 [8] | |||
| Kobalt-željezo (trake visoke permeabilnosti) | 2.3 · 10-2 | 18 000 [9] | |||
| Permalloy | 8 000 | 1.0 · 10-2 | 8 000 | kod 0.002 T | |
| Željezo (99.8% čisto) | 6.3 · 10-3 | 5 000 | |||
| Električarski čelik | 5.0 · 10-3 | 4 000 | kod 0.002 T | ||
| Feritični nehrđajući čelik (normaliziran) | 1.26 · 10-3 - 2.26 · 10-3 | 1 000 – 1 800[10] | |||
| Martenzitni nehrđajući čelik (normaliziran) | 9.42 · 10-4 - 1.19 · 10-3 | 750 – 950 | |||
| Ferit (manganski cink) | > 8.0 · 10-4 | 640 (ili više) | 100 kHz ~ 1 MHz | ||
| Ferit (niklov cink) | 2.0 · 10-5 - 8.0 · 10-4 | 16 – 640 | 100 kHz ~ 1 MHz | ||
| Ugljični čelik | 1.26 · 10-4 | 100 | kod 0.002 T | ||
| Nikal | 1.26 · 10-4 - 7.54 · 10-4 | 100 – 600 | kod 0.002 T | ||
| Martenzitni nehrđajući čelik (kaljen) | 5.0 · 10-5 - 1.2 · 10-4 | 40 – 95 | |||
| Austenitni nehrđajući čelik | 1.26 · 10-6 - 8.8 · 10-6 | 1.003–7 [11] | |||
| Neodimijev magnet | 1.32 · 10-6 | 1.05 [12] | |||
| Platina | 1.25697 · 10-6 | 1.000265 | |||
| Aluminij | 2.22 · 10-5 [13] | 1.256665 · 10-6 | 1.000022 | ||
| Drvo | 1.25663760 · 10-6 | 1.00000043 | |||
| Zrak | 1.25663753 · 10-6 | 1.00000037 [14] | |||
| Beton (suhi) | 1 [15] | ||||
| Vakuum | 0 | 4π × 10−7 (μ0) | 1 (točno, po definiciji) | ||
| Vodik | -2.2 · 10-9 [13] | 1.2566371 · 10-6 | 1.0000000 | ||
| Teflon | 1.2567 · 10-6 [7] | 1.0000 | |||
| Safir | -2.1 · 10-7 | 1.2566368 · 10-6 | 0.99999976 | ||
| Bakar | -6.4 · 10-6 ili -9.2 · 10-6 [13] | 1.256629 · 10-6 | 0.999994 | ||
| Voda | -8.0 · 10-6 | 1.256627 · 10-6 | 0.999992 | ||
| Bizmut | -1.66 · 10-4 | 1.25643 · 10-6 | 0.999834 | ||
| Supravodič | −1 | 0 | 0 |
Izvori
- ↑ vodljivost, [1] "Hrvatska enciklopedija", Leksikografski zavod Miroslav Krleža, www.enciklopedija.hr, 2014.
- ↑ The NIST reference on fundamental physical constants
- ↑ magnetska permeabilnost vakuuma, [2] "Hrvatska enciklopedija", Leksikografski zavod Miroslav Krleža, www.enciklopedija.hr, 2014.
- ↑ ""Metglas Magnetic Alloy 2714A", ''Metglas''". Metglas.com. http://www.metglas.com/products/page5_1_2_6.htm Pristupljeno 8. studenoga 2011.
- ↑ ""Magnetic Properties of Ferromagnetic Materials", ''Iron''". C.R Nave Georgia State University. http://hyperphysics.phy-astr.gsu.edu/hbase/tables/magprop.html#c2 Pristupljeno 1. prosinca 2013.
- ↑ ""Typical material properties of NANOPERM", ''Magnetec''" (PDF). http://www.magnetec.de/eng/pdf/werkstoffkennlinien_nano_e.pdf Pristupljeno 8. studenoga 2011.
- ↑ 7,0 7,1 ""Relative Permeability", ''Hyperphysics''". Hyperphysics.phy-astr.gsu.edu. http://hyperphysics.phy-astr.gsu.edu/hbase/solids/ferro.html Pristupljeno 8. studenoga 2011.
- ↑ "Nickel Alloys-Stainless Steels, Nickel Copper Alloys, Nickel Chromium Alloys, Low Expansion Alloys". Nickel-alloys.net. http://www.nickel-alloys.net/nickelalloys.html Pristupljeno 8. studenoga 2011.
- ↑ ""Soft Magnetic Cobalt-Iron Alloys", ''Vacuumschmeltze''". www.vacuumschmeltze.com. http://www.vacuumschmelze.com/fileadmin/Medienbiliothek_2010/Downloads/HT/2013-03-27_Soft_Magnetic_Cobalt-_Iron_Alloys_final_version.pdf Pristupljeno 3. kolovoza 2013.
- ↑ Carpenter Technology Corporation (2013). "Magnetic Properties of Stainless Steels". Carpenter Technology Corporation. http://www.cartech.com/techarticles.aspx?id=1476
- ↑ British Stainless Steel Association (2000). "Magnetic Properties of Stainless Steel". Stainless Steel Advisory Service. http://www.bssa.org.uk/cms/File/SSAS2.81-Magnetic%20Properties.pdf
- ↑ Juha Pyrhönen, Tapani Jokinen, Valéria Hrabovcová (2009). Design of Rotating Electrical Machines. John Wiley and Sons. str. 232. ISBN 0-470-69516-1. http://books.google.com/?id=_y3LSh1XTJYC&pg=PT232
- ↑ 13,0 13,1 13,2 Richard A. Clarke. "Clarke, R. ''Magnetic properties of materials'', surrey.ac.uk". Ee.surrey.ac.uk. http://www.ee.surrey.ac.uk/Workshop/advice/coils/mu/ Pristupljeno 8. studenoga 2011.
- ↑ B. D. Cullity and C. D. Graham (2008), Introduction to Magnetic Materials, 2nd edition, 568 pp., p.16
- ↑ NDT.net. "Determination of dielectric properties of insitu concrete at radar frequencies". Ndt.net. http://www.ndt.net/article/ndtce03/papers/v078/v078.htm Pristupljeno 8. studenoga 2011.