Magnetization Process
Magnetizing and Testing Equipment
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- Bu səhifədəki naviqasiya:
- Magnetizing and Testing Equipment Magnetizers
- Magnetization Types N AXIAL S LATERAL
- Hysteresis, Permeameter, BH Curve
- Standards ASTM D 3002 D 3359 DIN EN ISO 2409
- Procedure
- No. Of Cutting Teeths TAR-8601 Cross Hatch Cutter Kit
- Ordering Information Accessories Cat. No. Description Price Blade Spacing
- Replacement Blade
- Standards ASTM D 3359 33 Initial Design Considerations
- Non-Coated, Coated, or Plated: Coating Material: 1 Epoxy 2 Nickel
- Magnetized or Not Magnetized
- Magnetic Properties
- Magnetized
Magnetizing and Testing Equipment Magnetizers: • Capacitive Discharge • Direct Current • Half Cycle • Permanent Magnet Fixtures: • Wire Wound Multipole • Solid Copper Plate • Wire Wound Solenoid s Testing: • Fluxmeter Coil • Gaussmeter • Permeameter Magnetization Types N AXIAL S LATERAL MUTIPOLE RADIAL DIAMETRAL 30
Testing Magnets
A test method or combination of test methods should be based upon the criticality of the requirement, and the cost and ease of performing tests. Ideally, the test results should be able to be directly translated into a functional performance of the magnet. A sampling plan should be specified which inspects the parameters that are critical to the application. Sampling plans can be found in the MMPA 01-100 guidelines.
B-H curves describe the magnetic properties at a specific temperature. B-H curves may be plotted with the use of a Permeameter. In order to plot a B-H curve, a sample of a specific size must be used and then cycled through a magnetization/demagnetization cycle. This test is expensive to perform due to the length of time required to complete. The test is destructive to the sample piece in many cases, and is not practical to perform on a large sample of finished magnets. However, when magnets are machined from a larger block, the supplier may be requested to provide B-H curves for the starting raw stock of magnet material. The B-H test will essentially provide you the demag properties.
Using a test set up consisting of a Helmholtz coil pair connected to a Fluxmeter, total flux measurements can be made to obtain total dipole moments, and interpolated to obtain close estimates of Br, Hc, and BHmax. The inside diameter of the coils should be at least three times the largest dimension of the magnet for accurate results. The angle of orientation of the magnet can also be determined using this method. This is a quick, repeatable and reliable test, and one that is not overly sensitive to magnet placement within the coil.
Flux density measurements are made using a Gaussmeter and an appropriate probe. The probe contains a Hall Effect device whose voltage output is proportional to the flux density. There are two types of probes: Axial, which measures the flux parallel to the probe holder and Transversal, which measures the flux perpendicular to the probe holder. The position of the probe related to the magnet must be exactly the same between each sample. This can be simplified by using a fixing device.
The pull of magnets is proportional to B (flux density) squared. Variations in B occur due to variations in the inherent properties of the magnet itself, as well as environmental effects such as temperature, composition and condition of the material that the magnet is being tested on. Since B decays exponentially from a zero air gap, small inadvertently introduced air gaps between the magnet and the test material can have a large effect on the measured pull. It is therefore recommended that the test is performed with a small air gap. To achieve the best accuracy on the measurements, the test should be made with various air gaps.
31 Cross Cut Test Adhesion
106 Phone 800-343-7721 • Fax 800-394-8215 ISO Class.: 2 / ASTM Class.: 3 B The coating has flaked along the edges and/or at the intersections of the cuts. A cross-cut area significantly greater than 5 %, but not significantly greater than 15 %, is affected. The cross-cut test is a simple and easily practicable method for evaluating the adhesion of single- or multi-coat systems.
– Make a lattice pattern in the film with the appropriate tool, cutting to the substrate – Brush in diagonal direction 5 times each, using a brush pen or tape over the cut and remove with Permacel tape – Examine the grid area using an illuminated magnifier Cross-Cut Results Adhesion is rated in accordance with the scale below. ISO Class.: 0 / ASTM Class.: 5 B The edges of the cuts are completely smooth; none of the squares of the lattice is detached. ISO Class.: 1 / ASTM Class.: 4 B Detachment of small flakes of the coating at the intersections of the cuts. A cross-cut area not significantly greater than 5 % is affected. ISO Class.: 3 / ASTM Class.: 2 B The coating has flaked along the edges of the cuts partly or wholly in large ribbons, and/or it has flaked partly or wholly on different parts of the squares. A cross-cut area significantly greater than 15 %, but not significantly greater than 35 %, is affected. ISO Class.: 4 / ASTM Class.: 1 B The coating has flaked along the edges of the cuts in large ribbons and/or some squares have detached partly or wholly. A cross-cut area significantly greater than 35 %, but not significantly greater than 65 %, is affected. ISO Class.: 5 / ASTM Class.: 0 B Any degree of flaking that cannot even be classified by classification 4.
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Adhesion Parallel Groove Adhesion Test 107
Phone 800-343-7721 • Fax 800-394-8215 Cross Hatch Cutter Kit The Cross Hatch Cutter Kit provides a practical, low cost and widely used method to evaluate adhesion. Measurement of adhesion by tape test Simple and easy to use Each kit comes with a choice of one of three blades: fine blade, medium blade or coarse blade.
Uses the procedure on the previous page 106, and can also be used for pull off adhesion by using the included tape.
$ 208.00
fine 0.04 in (1.0 mm) 11
$ 208.00 medium 0.06 in (1.5 mm) 11 TAR-8603 Cross Hatch Cutter Kit $ 208.00 coarse 0.08 in (2.0 mm) 6 Comes complete with: Blade with holder / handle Hex wrench for changing blades Extra clamp screw Small cleaning brush Lighted magnifier One roll of Permacel 99 Adhesive Tape Plastic case Ordering Information Accessories Cat. No. Description Price Blade Spacing No. Of Teeth TAR-8640 Replacement Blade $ 85.00
fine 0.04 in (1.0 mm) 11
$ 85.00 medium 0.06 in (1.5 mm) 11 TAR-8642 Replacement Blade $ 85.00 coarse 0.08 in (2.0 mm) 6 TAR-8660 Replacement Tape $ 31.00
Permacel 99, 1 in x 72 yds Cross Hatch Cutter Kit Permacel 99 Tape Brush
Wrench Cutter
Magnifier Standards ASTM D 3359 33
Initial Design Considerations Prior to using magnetic modeling software, certain considerations must be given to the selection of the magnet material, the application, environment, and long term consequences. Once these have been considered, the magnet material data for most modeling tools can be imported directly into your software by visiting www.matweb.com and
searching by MAGNETS
OR ALLIANCE LLC
Magnet Environment
Immersed in a fluid – what type
Sealed enclosure Subject to forces – acceleration, shock etc
Subject to radiation – what type, level and duration Temperature extremes in use
Field strength at operating temperature Demagnetization fields
Thermal Properties
Reversible temperature coefficient of residual induction – αBr Reversible temperature coefficient of coercive force – βHc
Reversible temperature coefficient of intrinsic coercive force Curie temperature
Maximum service temperature Selection Based on Required Properties
Coercive force - Hc
Intrinsic coercive force - Hci Maximum Energy Density – (BH)max
Recoil permeability - µrec Hk Value of Hc at 0.9Br
Magnetic flux Φ at required air gap 34 Selection of Magnet Material
Shape and required dimensions
Injection and Compression Bonded or Sintered (fully dense) Orientation (Anisotropic) or non-oriented (Isotropic)
Permanent Magnets Cast Sintered Bonded Other
Alnico Alnico
Ferrite SmCo
NdFeB Calendared Compression Injection Ferrit e
e SmCo
NdFeB Ferrite
SmCo NdFeB
Magnet S l PtCo Cunife
Lodex Vicalloy Remalloy FeCrC
Application and Production Line Factors
Coating Material:
1
2
3
4
5
Method of coating Coating thickness Color or luster
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Magnetized or Not Magnetized:
Working Surface Magnetic Pattern Number of Poles Pole Pitch Magnetized inside or out of assembly Type of Equipment Needed
Specifications That May Be Include In Your Drawing
Tolerances (do they apply before or after coating or plating) Parallelism Squareness Concentricity Surface finish If plated, radiuses on edges Acceptable Chips, Cracks, Burrs
Magnetic Properties (British or SI, ie. Gauss or Tesla) with tolerances
Grade of Selected Magnet (ie. N-35SH for NdFeB)
(ie. Ni, Ni-Cu-Ni, Zn, E-coat)
(drawn as an arrow through the dimension)
(# of poles)
You may find standard recommendations (ex. allowable amount of chipping, magnetic tolerances, etc. ) in the MMPA 0100-00 guide. For a free copy of the publication (courtesy of Int’l Magnetics Assoc), and other design guides, please call 219-548-3799 or visit the Alliance website at
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Additional Items That May or May Not Be Needed
Conform to certain standards like MMPA 0100-00 Humidity testing requirements Conform to European Union directive 2002/95/EC (RoHS) Certificate of Origin Material Certifications Material Safety Data Sheet (MSDS) Testing method for magnetized parts If molded, gate and injector pin locations Packing Specifications
Please let us know if you have any questions or require assistance with any part of this publication
Material properties and other design information can be found on our web site: www.Allianceorg.com
References: Sura Magnets AB- Guide to Magnet Design, Guide to Magnet Materials, information from web site www.suramagnets.com. Sura Magnets is a bonded magnet producer in Soderkoping Sweden MMPA- MMPA 01-100 Guide to Magnetic Properties and the MMPA Design Guide
Information (Material) in this publication is provided solely for the user's information and, while thought to be accurate, is provided strictly "as is" and without warranty of any kind. Alliance LLC, its agents, employees or representatives will not be liable for any damages, direct or indirect, or lost profits arising out of your use of information provided in this publication.
Material in this publication is produced or compiled by Alliance LLC for the purpose of providing general information to our existing or potential customers. Material displayed in this publication is protected by US copyright law and owned by Alliance LLC or the parties identified as having provided the Material. Any copying, posting, or dissemination of this publication, or any part of it, for any purpose whatsoever is strictly prohibited without the express prior written consent of Alliance LLC. To request permission for copying or posting of this publication, or any part of it, please call 219-548-3799 or send a written request to: Alliance LLC, Copyrights and Trademarks, 1150 Eastport Center Drive, Suite G, Valparaiso, Indiana, 46383. 37 Document Outline
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