Magnetic Shielding Metals and Alloys

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Shielding Alloys
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• Soft magnetic shielding alloys are metals that
  can easily be magnetized. These materials have a
  high magnetic permeability, giving low reluctance
  paths for shifting magnetic fields.
• These properties make soft magnetic shield alloys
  great shields against static and slowly varying
  magnetic fields. Theyre often used to improve
  quality in home theaters and to shield sensitive
  medical and electronic equipment.
• Materials included in the soft magnetic shield
  alloy group include t
• High Perm 49 (alloy 48, 49 50)
• HyMu 80 (alloy 79)

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• By redirecting a magnetic field, magnetic
  shielding metals and alloys minimize that fields
  impact on the item thats being shielded. Used in
  a variety of different settings, these metals
  create a straightforward way for the magnetic
  field to serve its purpose without interfering
  with it. Acting as magnetic field conductors,
  they allow both the field itself and the
  equipment thats operating in it go about their
  business without interfering with one another. In
  healthcare settings, for example, magnetic
  shielding isolates or blocks the magnetic field
  of the MRI magnet in order to eliminate unwanted
  interference from the MRI magnet on nearby
  electronic devices. Radiofrequency shielding, on
  the other hand, prevents the unwanted
  interference of noise or radiofrequencies, often
  in order to avoid image distortion.

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• How Magnetic Shielding Works
• Magnetic shielding is critical when nearby
  devices could potentially be susceptible to
  magnetic interference, such as cardiac
  pacemakers, or other sensitive pieces of
  electronic or medical equipment. Its also used
  when low-frequency external magnetic fields are
  in close proximity and have to be shielded from
  the magnetic or fringe field from the MRI magnet.
• These alloys are also used in research labs that
  rely on ion microscopes and hospitals where EKG
  machines and other equipment must be shielded and
  protected from outside interference. The tests
  that these machines produce must be accurate, and
  any interference could produce anomalies in the
  results.
• Magnetic shielding usually involves using steel
  or copper placed in the walls of the magnet room
  to capture the magnetic field. That shield them
  redirects the magnetic field so that it protects
  the item in question.

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• Materials for Magnetic Shielding
• When selecting metals for applications where
  magnetic shielding is required, consider options
  like HyMu 80, Mu Metal2 47/50 and 48 49
  alloys, all of which have high magnetic
  permeability and can effectively screen
  low-frequency or static magnetic fields.
• Hipernom Alloy is a soft magnetic allow that
  develops extremely high permeabilities with
  minimum hysterersis loss. Its used primarily in
  shielding applications.
• HyMu 80 Mark II is another high-permeability
  alloy that provides the highest permeability in
  exchange for minimum hysteresis loss.
• HyMu 800 is highly-permeable and often used for
  tape-wound toroids and laminations made from
  strips that are 0.006 thick (or less).
• Wear-resistant HyMu 800A is a patented
  nickel-iron-molybdenum soft magnetic allow thats
  been using for recording head laminations. The
  alloy exhibits suitable magnetic characteristics
  for this application plus increased resistance to
  abrasion wear (which results in longer head
  life).
• Other magnetic metals and alloys include Hiperco
  27, Hiperco 50, Hiperco 50A and Hiperco 50B. This
  group of alloys is used across various different
  applications, including aircraft motor and
  generator laminations transformer laminations
  tape toroids and as fine wire in
  telecommunications dry reed switches.

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• Making the Right Choice
• Procurement professionals or engineers that are
  matching up their needs with the right magnetic
  shielding metal or alloy should work from their
  specifications and industry requirements,
  understanding that there are slight nuances among
  the various options. Hyperco 50, for example, has
  three different specifications, but not all of
  them will meet the requirements of the aerospace
  industry (which may require a test, a certain
  level of carbon or some other requirement).
• Key points to consider when selecting magnetic
  shielding metals include
• 1) Exactly what you want to shield2) How much
  outside interference is present or expected3)
  The grade of the magnetic shielding alloy that
  will be used

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• If you dont have a specification for the metal,
  consider whether the material has been used
  before and if any previous test reports are
  available for that material. Also understand that
  because each manufacturer has its own trademark,
  trade name or part number for the metals that
  they make, knowing the material specifications,
  testing and/or past history of usage can help
  ensure that you choose the right product for the
  right application.