permanent magnet materials - goyeneche bernal riano

7/27/2019 Permanent Magnet Materials - Goyeneche Bernal Riano

1/35

Carlos Chvez Goyeneche

Daniel Parra BernalJohan Sandoval Riao


2/35

Permanent Magnet Material: designated as amagnetically hard material, has a coercive

force generally greater than 120 Oe.

Individual Magnet: The term individualmagnet denotes a magnet purchased in a size

and shape to be ready for directincorporation into a magnetic circuit.


3/35

Demagnetized Magnet: For the purposes ofthis standard, a magnet shall be considereddemagnetized if, when any of its poles is

dipped in soft iron powder (of 5 - 10 mesh),not more than 3 particles of powder adhereto it anywhere upon withdrawal.

Magnetism: Magnetism is a property of

materials that respond to anapplied magnetic field. Permanentmagnets have persistent magnetic fieldscaused by ferromagnetism.


4/35

Alnico

CeramicRare-Earth

Iron-Chromium-Cobalt


5/35


6/35


7/35

LackDuctility InherentlyBrittle Hardness TensileStrength


8/35

Dimensions and tolerances shall be asspecified on the magnet drawing

Normally the magnet user furnishes a

drawing to the manufacturer showingall dimensions and tolerances

The standard for drawing, drawing

notation and tolerancing is thatestablished in ANSI Y 14.5.


9/35

Most manufacturers use statistical process

control to monitor key parameters at eachprocess step.


10/35


11/35

Tolerances

5%Residual

FluxDensity

8%Coercive

Force


12/35


13/35

Alnico magnets are made from an alloyof Aluminum, Nickel and Cobalt, hencethe name. In addition to the above

three, there can also be other metalsadded to the composition at times likeTitanium and Copper. By varying the

composition it is possible to tailor themagnetic properties to meet the needsof a wide variety of user endedapplications.


14/35

Alnico magnets are manufactured by usingprimarily two processes:

Cast alnico magnets that are made by pouringmelted alnico into a mold. The solidifiedmaterial is rough ground and then heat treatedand cooled. The material is either anisotropic(treated in a magnetic field) or isotropic(treated outside a magnetic field). After

treatment the material is ground to specifictolerances and magnetized.


15/35

Sintered alnico magnets are made from apowdered mixture of ingredients that arepressed into a die under tons ofpressure. They are then sintered in ahydrogen atmosphere and cooled in ananisotropic or isotropic environment.


16/35

Alnico magnets have several attributes thatmake them highly desirable materials forindustrial use. Developed in the 1940s, theAlnico magnets continue to be the desiredchoice of material for manyapplications. The exceptional lineartemperature characteristics exhibited byalnico magnets along with high magnetic fluxdensity and good corrosion resistance areideally suited for use in products of all sizesand shapes. Alnico magnets display thefollowing unique properties:


17/35

They exhibit small changes in magnetic

properties to temperature effects.Maximum working temperatures can be as

high as 450-5500 C.

Have low coercive force.

Strong corrosion resistance.

No coating needed for surface protection.


18/35

Alnico magnets are commonly used inapplications such as instruments and metersthat require very stable temperatureproperties. Electronic ignition systems,generators, vending machines, hand tools,magnetic reed switches, volt-amp metersand medical instruments are some of thecommonly used applications of alnicomagnets.


19/35

Other applications include: Sintered alnico magnets are used in the buzzers

of mobile phones, hearing aids and mini

speakers. In the automotive industry, alnico magnets are

used in the lighters and odometers ofautomobiles and motorcycles.

Alnico magnets are also widely applied in high

stability fields like aviation, military technologyand space flights. They are important components of inner

magnetic voltmeter / ammeter, electronic typepower energy measuring instrument, avometers

and flow meters. Alnico magnets are also used in a wide range of

magnetic sensors, polarized relays, andtemperature and pressure controllers.


20/35

The generalformula MO56Fe2O3describes thechemical

composition offerrite (ceramic)permanentmagnets, where M

generallyrepresents bariumor strontium or anycombination of thetwo.

http://www.centromagnetico.com/catalogo/imanes/ceramica.html
http://www.centromagnetico.com/catalogo/imanes/ceramica.htmlhttp://www.centromagnetico.com/catalogo/imanes/ceramica.htmlhttp://www.centromagnetico.com/catalogo/imanes/ceramica.htmlhttp://www.centromagnetico.com/catalogo/imanes/ceramica.htmlhttp://www.centromagnetico.com/catalogo/imanes/ceramica.htmlhttp://www.centromagnetico.com/catalogo/imanes/ceramica.htmlhttp://www.centromagnetico.com/catalogo/imanes/ceramica.htmlhttp://www.centromagnetico.com/catalogo/imanes/ceramica.htmlhttp://www.centromagnetico.com/catalogo/imanes/ceramica.htmlhttp://www.centromagnetico.com/catalogo/imanes/ceramica.htmlhttp://www.centromagnetico.com/catalogo/imanes/ceramica.htmlhttp://www.centromagnetico.com/catalogo/imanes/ceramica.html


21/35

Ceramic magnets aregenerally formed by acompression orextrusion molding.Magnetic performancecan be increased in apreferred direction byapplying a magneticfield in that directionduring the moldingprocess.


22/35

Ceramic magnets areused for their magneticcapability, not for theirmechanical properties. Itis recommended thatthey not be used forstructural purposes sincethey are low in tensileand flexural strength.

http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232
http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232http://ciudaddepuebla.olx.com.mx/perfil-de-aluminio-estructural-ranurado-moas-compatible-con-ips-item-mk-iid-98398232


23/35

Imperfections such as cracks, porosity, voids,

surface finish, etc., all of the type commonlyfound in sintered ceramic magnets. shall notconstitute reason for rejection


24/35


25/35


26/35


27/35

CHEMICAL COMPOSITION

These alloys are usually binary or ternaryalloys with the approximate atomic ratio ofone rare earth atom to five cobalt atoms

Rare-EarthCobalt 5

These alloys are an age hardening type witha composition ratio of 2 rare earth atoms to13-17 atoms of transition metals

Rare-Earth 2Transition

Element 17

These alloys have a composition of two rareearth atoms to 14 iron atoms with one boronatom

Rare EarthIron Alloys


28/35

MANUFACTURING METHODS

The rare earth magnet alloys are usuallyformed by powder metallurgical processes

The magnetic performance of all grades isoptimized by applying a magnetic field


29/35


30/35


31/35

These alloys are primarily of the Iron-Chromium-Cobalt composition. Somegrades may also contain additions of

vanadium, silicon, titanium,zirconium, manganese, molybdenumor aluminum.


32/35

The Iron-Chromium-Cobalt alloys are formedeither by casting to size or by casting in theform of an ingot which is then rolled and/ordrawn either to final shape or to form which

can then be cut. Heat treatment is essential todevelop the magnetic properties. Themagnetic properties can be increased in apreferred direction by applying a magneticfield during heat treatment. Although this alloyis hard and brittle in its fully heat treatedcondition, it is sufficiently ductile to be rolled,drawn, machined, turned or threaded prior toits final heat treatment.


33/35

Iron chromium Cobalt (FeCrCo) magnets aresimilar to Alnico magnets in magnetic property,but they have better mechanical property.FeCrCo alloys can be easily hot deformed andmachined. There are practically no limitationsof their shapes and sizes. They can be made toblock, square rods, round rods, tube, strips,wire. FeCrCo magnets are beneficialcombination of magnets and mechanicalproperties. Their maximum workingtrmperature can be as high as 400C.


34/35

FeCrCo magnets are widely used in aviation,automobile instrument, compass, oilexploration, hydraulic gauge, computer-embroidering machine, signal generator,counter, hearing aid, medical machine, guardagainst theft, alarm system, etc.


35/35

http://www.smma.org/PDFs/0100-00.pdf

http://rdu.unc.edu.ar/bitstream/handle/UNC/49/15842.pdf?sequence=1
http://www.smma.org/PDFs/0100-00.pdfhttp://rdu.unc.edu.ar/bitstream/handle/UNC/49/15842.pdf?sequence=1http://rdu.unc.edu.ar/bitstream/handle/UNC/49/15842.pdf?sequence=1http://rdu.unc.edu.ar/bitstream/handle/UNC/49/15842.pdf?sequence=1http://rdu.unc.edu.ar/bitstream/handle/UNC/49/15842.pdf?sequence=1http://www.smma.org/PDFs/0100-00.pdfhttp://www.smma.org/PDFs/0100-00.pdfhttp://www.smma.org/PDFs/0100-00.pdf

permanent magnet materials - goyeneche bernal riano

Documents