Klas[edite]
Leman Neyodim yo klase dapre pwodwi enèji maksimòm yo, ki gen rapò ak pwodiksyon flux mayetik pou chak volim inite. Valè ki pi wo yo endike leman pi fò. Pou leman NdFeB sintered, gen yon klasifikasyon entènasyonal lajman rekonèt. Valè yo varye ant 28 jiska 52. Premye lèt N anvan valè yo kout pou neyodim, sa vle di leman NdFeB sintered. Lèt ki swiv valè yo endike koersivite intrinsèque ak tanperati maksimòm opere (ki gen rapò pozitivman ak tanperati Curie), ki varye ant default (jiska 80 degre oswa 176 degre F) jiska TH (230 degre oswa 446 degre F).
Klas leman NdFeB sintered:
N30 – N55
N30M – N50M
N30H – N50H
N30SH – N48SH
N30UH – N42UH
N28EH – N40EH
N28TH – N35TH
Pwopriyete mayetik[edite]
Kèk pwopriyete enpòtan yo itilize pou konpare leman pèmanan yo se:
Remanans (Br), ki mezire fòs chan mayetik la.
Koersivite (Hci), rezistans materyèl la pou vin demagnetized.
Maksimòm pwodwi enèji (BHmax), dansite enèji mayetik,[18]karakterize pa valè maksimòm mayetik flux dansite (B) fwa mayetik jaden fòs (H).
Tanperati Curie (TC), tanperati a nan ki materyèl la pèdi mayetis li yo.
Leman Neyodim gen pi wo remanans, pi wo coercivity ak pwodwi enèji, men souvan pi ba tanperati Curie pase lòt kalite leman. Espesyal Neyodim Eman alyaj ki gen ladan tèrbyòm ak disprosyòm yo te devlope ki gen pi wo tanperati Curie, ki pèmèt yo tolere pi wo tanperati.[19]Tablo ki anba a konpare pèfòmans mayetik leman neyodim ak lòt kalite leman pèmanan.
| Eman | Br (T) |
Hci (kA/m) |
BHmax (kJ/m3) |
TC | |
|---|---|---|---|---|---|
| (degre) | (degre F) | ||||
| Nd2Fe14B, sintered | 1.0–1.4 | 750–2000 | 200–440 | 310–400 | 590–752 |
| Nd2Fe14B, estokaj | 0.6–0.7 | 600–1200 | 60–100 | 310–400 | 590–752 |
| SmCo5, sintered | 0.8–1.1 | 600–2000 | 120–200 | 720 | 1328 |
| Sm (Ko, Fe, Cu, Zr)7, 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-ferit, sintered | 0.2–0.78 | 100–300 | 10–40 | 450 | 842 |
Pwopriyete fizik ak mekanik[edite]
Fotomikrograf NdFeB. Rejyon dente yo se kristal metal yo, ak bann ki andedan yo se domèn mayetik yo.
| Pwopriyete | Neyodim | Sm-Co |
|---|---|---|
| Remanans (T) | 1–1.5 | 0.8–1.16 |
| Koersivite (MA/m) | 0.875–2.79 | 0.493–2.79 |
| Pèmeyabilite rkul | 1.05 | 1.05–1.1 |
| Tanperati koyefisyan remanans (%/K) | −(0.12–0.09) | −(0.05–0.03) |
| Koyefisyan tanperati nan coercivity (% / K) | −(0.65–0.40) | −(0.30–0.15) |
| Tanperati Curie (degre) | 310–370 | 700–850 |
| Dansite (g/cm3) | 7.3–7.7 | 8.2–8.5 |
| Koyefisyan ekspansyon tèmik, paralèl ak mayetizasyon (1/K) | (3–4)×10−6 | (5–9)×10−6 |
| Koyefisyan ekspansyon tèmik, pèpandikilè ak mayetizasyon (1/K) | (1–3)×10−6 | (10–13)×10−6 |
| Fòs flexural (N/mm2) | 200–400 | 150–180 |
| Fòs konpresyon (N/mm2) | 1000–1100 | 800–1000 |
| Fòs rupture (N/mm2) | 80–90 | 35–40 |
| Vickers dite (HV) | 500–650 | 400–650 |
| Rezistans elektrik (Ω·cm) | (110–170)×10−6 | (50–90)×10−6 |
