93 research outputs found
Studying microstructure of sintered magnets Co-25% Sm
Metallographic study of sintered rare-earth Co- 25% Sm magnets microstructure of KS-25 brand was carried out by scanning electron force microscopy (EDS-analysis). A dendritic structure with three phases was found: branches of dendrites are SmCo5; interdendritic space is a mixture of two phases SmCo5 and Sm2Co17. Crystals of 1-5 ΞΌm of Zr5Co3FeSm compound and inclusions of Sm2O3 samarium of a globular form of 2-10 ΞΌm in size were founded also in the microstructure. Study of the domain structure on surfaces perpendicular to magnetization axis by magnetic force microscopy (MFM) showed presence of strong magnetocrystalline anisotropy. Comparison of magnetic images with electron microscopic images of surface made it possible to conclude that SmCo5 dendrites correspond to large domains βΌ 30-50 ΞΌm in size and the interdendritic space consisting of a mixture of two phases SmCo5 and Sm2Co17 correspond to a domain structure in labyrinth form with a size of βΌ 3-5 ΞΌm. Β© 2019 Published under licence by IOP Publishing Ltd.Government Council on Grants, Russian Federation: β 02.Authors are grateful for the support of experimental works by Act 211 Government Russian Federation, contract β 02.A03.21.0006
ΠΠ°Π³Π½ΠΈΡΠ½Π°Ρ ΡΡΡΡΠΊΡΡΡΠ° ΡΠΏΠ΅ΡΠ΅Π½Π½ΡΡ ΠΌΠ°Π³Π½ΠΈΡΠΎΠ² Π‘ΠΎβ25%Sm ΠΏΠΎΡΠ»Π΅ ΡΠ»Π΅ΠΊΡΡΠΎΡΡΠΎΠ·ΠΈΠΎΠ½Π½ΠΎΠΉ ΠΎΠ±ΡΠ°Π±ΠΎΡΠΊΠΈ
Scanning electron microscopy and magnetic force microscopy were used to conduct the metallographic study of the surface microstructure of KS25 grade Coβ25%Sm sintered rare-earth magnets after Electrical Discharge Machining (EDM). The chemical composition of the studied samples: Sm β 25 wt.%; Fe β 18 wt.%; Cu β 5 wt.%; Zr β 3 wt.%; Co β the rest. One of the sample surfaces was subjected to EDM in various ways with changes in such EDM parameters as the straight-line processing speed and offset. The microstructure of magnets contains four coexisting phases: SmCo5, Sm2Co17, Zr5Co3FeSm and Sm2O3. The grain size is 10β50 ΞΌm. Crystals of the Zr5Co3FeSm intermetallic compound are 1β5 ΞΌm in size, and globular inclusions of Sm2O3Β samarium oxide are 2β10 ΞΌm. EDM affected the thickness and chemical composition of the defective layer. In general, the chemical composition varies slightly in the direction from the defective layer inward the sample: the content of Sm, Cu, O, and Zr decreases; the content of Fe and Co increases. At a distance of 500 ΞΌm from the defective layer inwards the sample, the grain size increases by 40β50 %, while the porosity decreases. At the same time, the size of Sm2O3Β oxides slightly increases. The study of the magnetic structure on surfaces perpendicular to the axis of magnetization by means of magnetic force microscopy revealed the presence of a complex domain structure of grains in the form of a labyrinth with a domain size of ~3Γ·5 ΞΌm. Separate singledomain grains ~30Γ·50 ΞΌm in size were also found. Due to the material heating and oxidation, EDM promotes the domain structure of grains appearing in the form of a labyrinth instead of single-domain grains, and the SmCo5Β βΒ Sm2Co17Β phase transition, which causes a decrease in coercive force.Π‘ΡΠ΅Π΄ΡΡΠ²Π°ΠΌΠΈ ΡΠΊΠ°Π½ΠΈΡΡΡΡΠ΅ΠΉ ΡΠ»Π΅ΠΊΡΡΠΎΠ½Π½ΠΎΠΉ ΠΌΠΈΠΊΡΠΎΡΠΊΠΎΠΏΠΈΠΈ ΠΈ ΠΌΠ°Π³Π½ΠΈΡΠ½ΠΎΠΉ ΡΠΈΠ»ΠΎΠ²ΠΎΠΉ ΠΌΠΈΠΊΡΠΎΡΠΊΠΎΠΏΠΈΠΈ ΠΏΡΠΎΠ²Π΅Π΄Π΅Π½ΠΎ ΠΌΠ΅ΡΠ°Π»Π»ΠΎΠ³ΡΠ°ΡΠΈΡΠ΅ΡΠΊΠΎΠ΅ ΠΈΠ·ΡΡΠ΅Π½ΠΈΠ΅ ΠΌΠΈΠΊΡΠΎΡΡΡΡΠΊΡΡΡΡ ΠΏΠΎΠ²Π΅ΡΡ
Π½ΠΎΡΡΠΈ ΡΠΏΠ΅ΡΠ΅Π½Π½ΡΡ
ΡΠ΅Π΄ΠΊΠΎΠ·Π΅ΠΌΠ΅Π»ΡΠ½ΡΡ
ΠΌΠ°Π³Π½ΠΈΡΠΎΠ² Π‘ΠΎβ25%Sm ΠΌΠ°ΡΠΊΠΈ ΠΠ‘25 ΠΏΠΎΡΠ»Π΅ ΡΠ»Π΅ΠΊΡΡΠΎΡΡΠΎΠ·ΠΈΠΎΠ½Π½ΠΎΠΉ ΠΎΠ±ΡΠ°Π±ΠΎΡΠΊΠΈ (ΠΠΠ). Π₯ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΈΠΉ ΡΠΎΡΡΠ°Π² ΠΈΡΡΠ»Π΅Π΄ΡΠ΅ΠΌΡΡ
ΠΎΠ±ΡΠ°Π·ΡΠΎΠ², ΠΌΠ°Ρ.%: Sm β 25, Fe β 18, Cu β 5, Zr β 3, Co β ΠΎΡΡΠ°Π»ΡΠ½ΠΎΠ΅. ΠΠ΄Π½Π° ΠΈΠ· ΠΏΠΎΠ²Π΅ΡΡ
Π½ΠΎΡΡΠ΅ΠΉ ΠΎΠ±ΡΠ°Π·ΡΠ° Π±ΡΠ»Π° ΠΏΠΎΠ΄Π²Π΅ΡΠ³Π½ΡΡΠ° ΡΠ»Π΅ΠΊΡΡΠΎΡΡΠΎΠ·ΠΈΠΎΠ½Π½ΠΎΠΉ ΠΎΠ±ΡΠ°Π±ΠΎΡΠΊΠ΅ ΡΠ°Π·Π»ΠΈΡΠ½ΡΠΌΠΈ ΡΠΏΠΎΡΠΎΠ±Π°ΠΌΠΈ ΠΏΡΠΈ ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΠΈ ΡΠ°ΠΊΠΈΡ
ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΠΎΠ² ΠΠΠ, ΠΊΠ°ΠΊ ΡΠΊΠΎΡΠΎΡΡΡ ΠΎΠ±ΡΠ°Π±ΠΎΡΠΊΠΈ ΠΏΠΎ ΠΏΡΡΠΌΠΎΠΉ Π»ΠΈΠ½ΠΈΠΈ ΠΈ ΠΎΡΡΠ΅Ρ. Π ΠΌΠΈΠΊΡΠΎΡΡΡΡΠΊΡΡΡΠ΅ ΠΌΠ°Π³Π½ΠΈΡΠΎΠ² ΠΏΡΠ΅Π΄ΡΡΠ°Π²Π»Π΅Π½Ρ 4 ΡΠΎΡΡΡΠ΅ΡΡΠ²ΡΡΡΠΈΠ΅ ΡΠ°Π·Ρ: SmCo5, Sm2Co17, Zr5Co3FeSm ΠΈ Sm2O3. Π Π°Π·ΠΌΠ΅Ρ Π·Π΅ΡΠ½Π° ΡΠΎΡΡΠ°Π²Π»ΡΠ΅Ρ 10β50 ΠΌΠΊΠΌ. ΠΡΠΈΡΡΠ°Π»Π»Ρ ΠΈΠ½ΡΠ΅ΡΠΌΠ΅ΡΠ°Π»Π»ΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΡΠΎΠ΅Π΄ΠΈΠ½Π΅Π½ΠΈΡ Zr5Co3FeSm ΠΈΠΌΠ΅ΡΡ ΡΠ°Π·ΠΌΠ΅Ρ 1β5 ΠΌΠΊΠΌ, Π²ΠΊΠ»ΡΡΠ΅Π½ΠΈΡ ΠΎΠΊΡΠΈΠ΄Π° ΡΠ°ΠΌΠ°ΡΠΈΡ Sm2O3Β Π³Π»ΠΎΠ±ΡΠ»ΡΡΠ½ΠΎΠΉ ΡΠΎΡΠΌΡ Π±ΡΠ»ΠΈ Π²Π΅Π»ΠΈΡΠΈΠ½ΠΎΠΉ 2β10 ΠΌΠΊΠΌ. Π‘ΠΏΠΎΡΠΎΠ± ΠΠΠ ΠΎΠΊΠ°Π·Π°Π» Π²Π»ΠΈΡΠ½ΠΈΠ΅ Π½Π° ΡΠΎΠ»ΡΠΈΠ½Ρ ΠΈ Ρ
ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΈΠΉ ΡΠΎΡΡΠ°Π² Π΄Π΅ΡΠ΅ΠΊΡΠ½ΠΎΠ³ΠΎ ΡΠ»ΠΎΡ. Π ΡΠ΅Π»ΠΎΠΌ Ρ
ΠΈΠΌΠΈΡΠ΅ΡΠΊΠΈΠΉ ΡΠΎΡΡΠ°Π² ΠΏΡΠΈ ΡΠ΄Π°Π»Π΅Π½ΠΈΠΈ ΠΎΡ Π΄Π΅ΡΠ΅ΠΊΡΠ½ΠΎΠ³ΠΎ ΡΠ»ΠΎΡ Π² Π³Π»ΡΠ±Ρ ΠΎΠ±ΡΠ°Π·ΡΠ° ΠΈΠ·ΠΌΠ΅Π½ΡΠ΅ΡΡΡ Π½Π΅Π·Π½Π°ΡΠΈΡΠ΅Π»ΡΠ½ΠΎ: ΡΠΎΠ΄Π΅ΡΠΆΠ°Π½ΠΈΠ΅ Sm, Cu, Π ΠΈ Zr ΡΠ½ΠΈΠΆΠ°Π΅ΡΡΡ, Π° Fe ΠΈ Π‘ΠΎ β ΠΏΠΎΠ²ΡΡΠ°Π΅ΡΡΡ. Π Π°Π·ΠΌΠ΅Ρ Π·Π΅ΡΠ½Π° Π½Π° Π³Π»ΡΠ±ΠΈΠ½Π΅ 500 ΠΌΠΊΠΌ ΠΎΡ Π΄Π΅ΡΠ΅ΠΊΡΠ½ΠΎΠ³ΠΎ ΡΠ»ΠΎΡ ΡΠ²Π΅Π»ΠΈΡΠΈΠ²Π°Π΅ΡΡΡ Π½Π° 40β50 %, Π° ΠΏΠΎΡΠΈΡΡΠΎΡΡΡ, Π½Π°ΠΎΠ±ΠΎΡΠΎΡ, ΡΠΌΠ΅Π½ΡΡΠ°Π΅ΡΡΡ; ΡΠ°Π·ΠΌΠ΅Ρ ΠΎΠΊΡΠΈΠ΄ΠΎΠ² Sm2O3Β ΠΏΡΠΈ ΡΡΠΎΠΌ Π½Π΅Π·Π½Π°ΡΠΈΡΠ΅Π»ΡΠ½ΠΎ Π²ΠΎΠ·ΡΠ°ΡΡΠ°Π΅Ρ. ΠΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠ΅ ΡΡΠ΅Π΄ΡΡΠ²Π°ΠΌΠΈ ΠΌΠ°Π³Π½ΠΈΡΠ½ΠΎΠΉ ΡΠΈΠ»ΠΎΠ²ΠΎΠΉ ΠΌΠΈΠΊΡΠΎΡΠΊΠΎΠΏΠΈΠΈ ΠΌΠ°Π³Π½ΠΈΡΠ½ΠΎΠΉ ΡΡΡΡΠΊΡΡΡΡ Π½Π° ΠΏΠΎΠ²Π΅ΡΡ
Π½ΠΎΡΡΡΡ
, ΠΏΠ΅ΡΠΏΠ΅Π½Π΄ΠΈΠΊΡΠ»ΡΡΠ½ΡΡ
ΠΎΡΠΈ Π½Π°ΠΌΠ°Π³Π½ΠΈΡΠΈΠ²Π°Π½ΠΈΡ, ΠΏΠΎΠΊΠ°Π·Π°Π»ΠΎ Π½Π°Π»ΠΈΡΠΈΠ΅ ΡΠ»ΠΎΠΆΠ½ΠΎΠΉ Π΄ΠΎΠΌΠ΅Π½Π½ΠΎΠΉ ΡΡΡΡΠΊΡΡΡΡ Π·Π΅ΡΠ΅Π½ Π² Π²ΠΈΠ΄Π΅ Π»Π°Π±ΠΈΡΠΈΠ½ΡΠ° Ρ ΡΠ°Π·ΠΌΠ΅ΡΠΎΠΌ Π΄ΠΎΠΌΠ΅Π½Π° ~3Γ·5 ΠΌΠΊΠΌ. ΠΠ±Π½Π°ΡΡΠΆΠ΅Π½Ρ ΡΠ°ΠΊΠΆΠ΅ ΠΎΡΠ΄Π΅Π»ΡΠ½ΡΠ΅ ΠΎΠ΄Π½ΠΎΠ΄ΠΎΠΌΠ΅Π½Π½ΡΠ΅ Π·Π΅ΡΠ½Π° ΡΠ°Π·ΠΌΠ΅ΡΠΎΠΌ ~30Γ·50 ΠΌΠΊΠΌ. ΠΠ»Π΅ΠΊΡΡΠΎΡΡΠΎΠ·ΠΈΠΎΠ½Π½Π°Ρ ΠΎΠ±ΡΠ°Π±ΠΎΡΠΊΠ° ΠΈΠ·-Π·Π° Π½Π°Π³ΡΠ΅Π²Π° ΠΈ ΠΎΠΊΠΈΡΠ»Π΅Π½ΠΈΡ ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»Π° ΡΠΏΠΎΡΠΎΠ±ΡΡΠ²ΡΠ΅Ρ Π²ΠΎΠ·Π½ΠΈΠΊΠ½ΠΎΠ²Π΅Π½ΠΈΡ Π΄ΠΎΠΌΠ΅Π½Π½ΠΎΠΉ ΡΡΡΡΠΊΡΡΡΡ Π·Π΅ΡΠ΅Π½ Π² Π²ΠΈΠ΄Π΅ Π»Π°Π±ΠΈΡΠΈΠ½ΡΠ° Π²ΠΌΠ΅ΡΡΠΎ ΠΎΠ΄Π½ΠΎΠ΄ΠΎΠΌΠ΅Π½Π½ΡΡ
Π·Π΅ΡΠ΅Π½, Π° ΡΠ°ΠΊΠΆΠ΅ ΡΠ°Π·ΠΎΠ²ΠΎΠΌΡ ΠΏΠ΅ΡΠ΅Ρ
ΠΎΠ΄Ρ SmCo5Β βΒ Sm2Co17, ΡΡΠΎ Π²ΡΠ·ΡΠ²Π°Π΅Ρ ΡΠΌΠ΅Π½ΡΡΠ΅Π½ΠΈΠ΅ ΠΊΠΎΡΡΡΠΈΡΠΈΠ²Π½ΠΎΠΉ ΡΠΈΠ»Ρ
Site-Specifically Labeled Immunoconjugates for Molecular ImagingβPart 1: Cysteine Residues and Glycans
Combined study of processes of formation of oxide and metal-oxide catalysts and the nature of their active surface
Einfluss des pH beim FΓ€llen von Calcium-nickel-phosphaten auf deren katalytische DehydrierungsaktivitΓ€t
- β¦