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MAGNETS INFORMATION

  • Kasaysayan ug Kasaysayan
  • Design
  • Pagpili sa Magnet
  • Pagtambal sa Ibabaw
  • Pag-magnet
  • Laki sa Dimensyon, Laki ug pagtugot
  • Prinsipyo sa kaluwasan alang sa operasyon nga manwal

Kasaysayan ug Kasaysayan

Permanent magnets are a vital part of modern life. They are found in or used to produce almost every modern convenience today. The first permanent magnets were produced from naturally occurring rocks called lodestones. These stones were first studied over 2500 years ago by the Chinese and subsequently by the Greeks, who obtained the stone from the province of Magnetes, from which the material got its name. Since then, the properties of magnetic materials have been profoundly improved and todays permanent magnet materials are many hundreds of times stronger than the magnets of antiquity. The term permanent magnet comes from the ability of the magnet to hold an induced magnetic charge after it is removed from the magnetizing device. Such devices may be other strongly magnetized permanent magnets, electro-magnets or coils of wire that are briefly charged with electricity. Their ability to hold a magnetic charge makes them useful for holding objects in place, converting electricity to motive power and vice versa (motors and generators), or affecting other objects brought near them.


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Design

Ang superyor nga magnetic performance usa ka function sa mas maayo nga magnetic engineering. Alang sa mga kustomer nga nanginahanglan tabang sa disenyo o komplikado nga mga laraw sa sirkito, Mga QM team of experienced application engineers and knowledgeable field sales engineers is at your service. QM engineers work with customers to improve or validate existing designs as well as develop novel designs that produce special magnetic effects. QM has developed patented magnetic designs that deliver extremely strong, uniform or specially shaped magnetic fields that often replace bulky and inefficient electro-magnet and permanent magnet designs. Customers are confident when hey bring a complex concept or new idea that QM makasugat niana nga hagit pinaagi sa pagdrowing gikan sa 10 ka tuig nga napamatud-an nga magnetic expertise. QM has the people, products and technology that put magnets to work.


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Pagpili sa Magnet

Ang pagpili sa magnet alang sa tanan nga mga aplikasyon kinahanglan nga tagdon ang tibuuk nga magnetic circuit ug ang palibot. Kung diin ang Alnico angay, ang gidak-on sa magnet mahimong maminusan kung mahimo kini mag-magnetize pagkahuman sa pag-assemble sa magnetic circuit. Kung gigamit nga independente sa ubang mga sangkap sa sirkito, sama sa mga aplikasyon sa seguridad, ang epektibo nga gitas-on sa ratio sa diametro (may kalabutan sa permeance coefficient) kinahanglan nga igo nga igo aron mahimo ang magnet nga molihok labaw sa tuhod sa ikaduha nga quadrant demagnetization curve niini. Para sa mga kritikal nga aplikasyon, ang Alnico magnets mahimong ma-calibrate sa usa ka establisado nga reference flux density value.

A by-product of low coercivity is sensitivity to demagnetizing effects due to external magnetic fields, shock, and application temperatures. For critical applications, Alnico magnets can be temperature stabilized to minimize these effects  There are four classes of modern commercialized magnets, each based on their material composition. Within each class is a family of grades with their own magnetic properties. These general classes are:

  • Neodymium Iron Boron
  • Samarium Cobalt
  • seramiko
  • Alnico

NdFeB and SmCo are collectively known as Rare Earth magnets because they are both composed of materials from the Rare Earth group of elements. Neodymium Iron Boron (general composition Nd2Fe14B, often abbreviated to NdFeB) is the most recent commercial addition to the family of modern magnet materials. At room temperatures, NdFeB magnets exhibit the highest properties of all magnet materials. Samarium Cobalt is manufactured in two compositions: Sm1Co5 and Sm2Co17 - often referred to as the SmCo 1:5 or SmCo 2:17 types. 2:17 types, with higher Hci values, offer greater inherent stability than the 1:5 types. Ceramic, also known as Ferrite, magnets (general composition BaFe2O3 or SrFe2O3) have been commercialized since the 1950s and continue to be extensively used today due to their low cost. A special form of Ceramic magnet is "Flexible" material, made by bonding Ceramic powder in a flexible binder. Alnico magnets (general composition Al-Ni-Co) were commercialized in the 1930s and are still extensively used today.

These materials span a range of properties that accommodate a wide variety of application requirements. The following is intended to give a broad but practical overview of factors that must be considered in selecting the proper material, grade, shape, and size of magnet for a specific application. The chart below shows typical values of the key characteristics for selected grades of various materials for comparison. These values will be discussed in detail in the following sections.

Magnet Materyal nga Pagtandi

Materyal nga
Grade
Br
Hc
Hci
BH max
T max(Deg c)*
NdFeB
39H
12,800
12,300
21,000
40
150
SmCo
26
10,500
9,200
10,000
26
300
NdFeB
B10N
6,800
5,780
10,300
10
150
Alnico
5
12,500
640
640
5.5
540
seramiko
8
3,900
3,200
3,250
3.5
300
flexible
1
1,500
1,380
1,380
0.6
100

* T max (maximum practical operating temperature) is for reference only. The maximum practical operating temperature of any magnet is dependent on the circuit the magnet is operating in.


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Pagtambal sa Ibabaw

Magnets may need to be coated depending on the application for which they are intended. Coating magnets improves appearance, corrosion resistance, protection from wear and may be appropriate for applications in clean room conditions.
Samarium Cobalt, Alnico materials are corrosion resistant, and do not require to be coated against corrosion. Alnico is easily plated for cosmetic qualities.
NdFeB magnets are particularly susceptible to corrosion and are often protected in this way. There are a variety of coatings suitable for permanent magnets, Not all types of coating will be suitable for every material or magnet geometry, and the final choice will depend on the application and environment. An additional option is to house the magnet in an external casing to prevent corrosion and damage.

Available Coatings

Su rface

Taklap, sapaw

Gibag-on (Microns)

Kolor

-ato

Pagpalabay


1

Bulak nga Grey

Temporaryo nga Proteksyon

Nikel

Ni+Ni

10-20

Hayag nga Silver

Maayo kaayo batok sa Humidity

Ni+Cu+Ni

zinc

Zn

8-20

Bright Blue

Good Against Salt Spray

C-Zn

Shinny Color

Excellent Against Salt Spray

Tin

Ni+Cu+Sn

15-20

Silver

Superior  Against Humidity

sa bulawan

Ni+Cu+Au

10-20

sa bulawan

Superior  Against Humidity

tumbaga

Ni+Cu

10-20

sa bulawan

Temporaryo nga Proteksyon

Epoxy

Epoxy

15-25

Itom, Pula, Gray

Maayo Batok sa Humidity
Salt Spray

Ni+Cu+Epoxy

Zn+Epoxy

Kemikal nga

Ni

10-20

Bulak nga Grey

Maayo Batok sa Humidity

Parylene

Parylene

5-20

Grey

Excellent Against Humidity, Salt Spray. Superior Against Solvents, Gases, Fungi and Bacteria.
 FDA Approved.


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Pag-magnet

Permanent magnet supplied under two conditions, Magnetized or no magnetized, is usually not marked its polarity. If the user require, we could mark the polarity by the means agreed on. When pacing the order, the user should inform the supply condition and if the mark of the polarity is necessary.

Ang magnetization field sa permanente nga magnet may kalabutan sa permanente nga magnetic material type ug ang intrinsic coercive force niini. Kung ang magnet kinahanglan nga magnetization ug demagnetization, palihug kontaka kami ug pangayo alang sa suporta sa teknik.

There are two methods to magnetize the magnet: DC field and pulse magnetic field.

There are three methods to demagnetize the magnet: demagnetization by heat is a special process technique. demagnetization in AC field. Demagnetization in DC field. This asks for very strong magnetic field and high demagnetization skill.

Geometry porma ug magnetization direksyon sa permanenteng magnet: sa prinsipyo, kita og permanente nga magnet sa lain-laing mga porma. Kasagaran, kini naglakip sa block, disc, singsing, bahin ug uban pa. Ang detalyado nga paghulagway sa direksyon sa magnetization anaa sa ubos:

Directions of Magnetization
(Diagrams Indicating Typical Directions Of Manetization)

oriented pinaagi sa gibag-on

axially oriented

axially oriented in segments

oriented lateral multipole sa usa ka nawong

multipole oriented sa mga bahin sa gawas nga diametro *

multipole oriented in segments on one face

radially oriented *

oriented through diameter *

multipole oriented in segments on inside diameter*

ang tanan anaa ingon nga isotropic o anisotropic nga materyal

*mabatonan lamang sa isotropic ug pipila ka materyal nga anisotropic lamang


radially oriented

diametrical nga oriented


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Laki sa Dimensyon, Laki ug pagtugot

Except for the dimension in the direction of magnetization, the maximum dimension of the permanent magnet is not exceed 50mm, which is limited by the orientation field and sintering equipment. The dimension in the unmagnetization direction is up to 100mm.

Ang pagkamatugtanon kasagaran +/- 0.05 -- +/- 0.10mm.

Remark: Other shapes can be manufactured according to customer's sample or blue print

Singsing
Outer Diameter
Inner Diameter
gibag-on
maximum
100.00mm
95.00m
50.00mm
minimum
3.80mm
1.20mm
0.50mm
disc
diametro
gibag-on
maximum
100.00mm
50.00mm
minimum
1.20mm
0.50mm
block
gitas-on
gilapdon
gibag-on
maximum 100.00mm
95.00mm
50.00mm
minimum 3.80mm
1.20mm
0.50mm
Arc-segment
Panggawas nga Radius
Sulod nga Radius
gibag-on
maximum 75mm
65mm
50mm
minimum 1.9mm
0.6mm
0.5mm



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Prinsipyo sa kaluwasan alang sa operasyon nga manwal

1. The magnetized permanent magnets with strong magnetic field attract the iron and other magnetic matters around them greatly. Under common condition, the manual operator should be very careful to avoid any damage. Due to the strong magnetic force, the big magnet close to them takes the risk of damage. People always process these magnets separately or by clamps. In this case, we should ware the protection gloves in operation.

2. In this circumstance of strong magnetic field, any sensible electronic component and test meter may be altered or damaged. Please see to it that the computer, display and magnetic media , for example the magnetic disc ,magnetic cassette tape and video record tape etc., are far from the magnetized components, say farther than 2m.

3. Ang pagbangga sa mga puwersa sa pagdani tali sa duha ka permanente nga magnet magdala ug dagkong mga kidlat. Busa, ang mga butang nga masunog o mobuto kinahanglan dili ibutang sa ilang palibot.

4. When the magnet is exposed to hydrogen, it is prohibited to use permanent magnets without protection coating. The reason is that the sorption of hydrogen will destroy the microstructure of the magnet and lead to the deconstruction of the magnetic properties. The only way to protect the magnet effectively is to enclose the magnet in a case and seal it.


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