Qib [edit]
Neodymium hlau nplaum raug muab qhab nia raws li lawv cov khoom siv hluav taws xob siab tshaj plaws, uas cuam tshuam nrog cov khoom sib nqus flux tso tawm ib chav tsev ntim. Cov nqi siab dua qhia cov hlau nplaum muaj zog. Rau sintered NdFeB hlau nplaum, muaj kev lees paub thoob ntiaj teb kev faib tawm. Lawv qhov tseem ceeb ntawm 28 mus txog 52. Thawj tsab ntawv N ua ntej qhov tseem ceeb yog luv rau neodymium, lub ntsiab lus sintered NdFeB hlau nplaum. Cov ntawv tom qab qhov tseem ceeb qhia txog kev sib koom ua ke thiab qhov siab tshaj plaws ntawm kev ua haujlwm kub (zoo cuam tshuam nrog Curie kub), uas nyob ntawm lub neej ntawd (txog 80 degree lossis 176 degree F) rau TH (230 degree lossis 446 degree F).
Qib ntawm sintered NdFeB hlau nplaum:
N30 – N55
N30M – N50M
N30H – N50H
N30SH - N48SH
N30UH – N42UH
N28EH - N40EH
N28TH – N35TH
Magnetic properties[edit]
Qee cov khoom tseem ceeb siv los sib piv cov hlau nplaum ruaj khov yog:
Remanence (Br), uas ntsuas lub zog ntawm magnetic teb.
Kev coercivity (Hci), cov khoom tiv thaiv los ua demagnetized.
Cov khoom siv hluav taws xob siab tshaj plaws (BHmax), qhov ceev ntawm magnetic zog,[18]tus cwj pwm los ntawm tus nqi siab tshaj plaws ntawm magnetic flux ceev (B) lub sij hawm sib nqus teb zog (H).
Curie kub (TC), qhov kub ntawm cov khoom poob nws cov hlau nplaum.
Neodymium hlau nplaum muaj ntau dua remanence, ntau dua coercivity thiab zog khoom, tab sis feem ntau qis Curie kub dua lwm hom hlau nplaum. Cov hlau nplaum tshwj xeeb neodymium hlau nplaum uas suav nrog terbium thiab dysprosium tau tsim muaj qhov kub siab Curie, tso cai rau lawv ua kom sov siab dua.[19]Cov lus hauv qab no sib piv cov kev sib nqus ntawm cov hlau nplaum neodymium nrog rau lwm hom hlau nplaum ruaj khov.
| Magnet | Br (T) |
Hci (kA / m) |
BHmax (kJ/m3) |
TC | |
|---|---|---|---|---|---|
| (degree) | ( degree F) | ||||
| Nd2Fe14B, ua sintered | 1.0–1.4 | 750–2000 | 200–440 | 310–400 | 590–752 |
| Nd2Fe14B, sib | 0.6–0.7 | 600–1200 | 60–100 | 310–400 | 590–752 |
| SmCo5, ua sintered | 0.8–1.1 | 600–2000 | 120–200 | 720 | 1328 |
| Sm(Co, Fe, Cu, Zr)7, ua sintered | 0.9–1.15 | 450–1300 | 150–240 | 800 | 1472 |
| Alnico, sintered | 0.6–1.4 | 275 | 10–88 | 700–860 | 1292–1580 |
| Sr-ferrite, sintered | 0.2–0.78 | 100–300 | 10–40 | 450 | 842 |
Lub cev thiab mechanical zog [hloov kho]
Photomicrograph ntawm NdFeB. Cov cheeb tsam jagged edged yog cov hlau siv lead ua, thiab cov kab txaij hauv yog cov sib nqus sib nqus.
| Khoom | Neodymium | Sm Co |
|---|---|---|
| Remanence (T) | 1–1.5 | 0.8–1.16 |
| Kev ua haujlwm siab (MA / m) | 0.875–2.79 | 0.493–2.79 |
| Recoil permeability | 1.05 | 1.05–1.1 |
| Kub coefficient ntawm remanence (% / K) | −(0.12–0.09) | −(0.05–0.03) |
| Kub coefficient ntawm coercivity (% / K) | −(0.65–0.40) | −(0.30–0.15) |
| Curie kub (degree) | 310–370 | 700–850 |
| Qhov ceev (g / cm3) | 7.3–7.7 | 8.2–8.5 |
| Thermal expansion coefficient, parallel rau magnetization (1 / K) | (3–4)×10−6 | (5–9)×10−6 |
| Thermal expansion coefficient, perpendicular rau magnetization (1 / K) | (1–3)×10−6 | (10–13)×10−6 |
| Flexural zog (N / mm2) | 200–400 | 150–180 |
| Compressive zog (N / mm2) | 1000–1100 | 800–1000 |
| Tensile zog (N / mm2) | 80–90 | 35–40 |
| Vickers hardness (HV) | 500–650 | 400–650 |
| Hluav taws xob tiv taus (Ω·cm) | (110–170)×10−6 | (50–90)×10−6 |
