Temp.
Coeff.of Br:
Density:
Vickers
Hardness:
Tensile Strength:
Specific Heat
Young’s.
Modulus:
Poisson’s.Ratio
Curie Temperature: |
-0.11%/℃
7.3 –7.5g/cm3
600Hv
8.0kg/mm2
0.12 kCal/(kg,℃
1.6×10(11)N/m2
0.24
310-340℃ |
Temp.Coeff.of
Hc:
Electrical
Resistivity:
Flexural
Strength:
Coeff. Of Thermal Expansion:
Thermal Conductivity:
Rigidity:
Compressibility |
-0.60
% /℃
114μΩ..cm
25kg/mm
4×10 -6/℃
7.7kcal/(m.h. ℃)
0.64N/m2
9.8×10-12 m2/N
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Types
of Coatings
The
coatigns can be divided into two basic groups: metallic and organic.
to meet special requirements and on request, double coatings of metal/metal,
metal/varnish
and
a number
of special coatings are available.
Metallic
coatings
Usually, galvanic processes are used for metallic coating.we have
…Zinc
coatings (blue passivated or yellow passivated )
…Nickel
+ Nickel coating
…Nickel
+ Tin coating
…Nickel
+ Copper + Nickel coating (available starting from June,1998)
Organic coatings
…Nickel
+ Epoxy coating
…Epoxy
coating
Temporary
corrosion protection /Surface Passivation
To protect uncoated magnets temporarily, e. g., during transport or
storage,
Passivation can be made. This protects NdFeB magnets sufficiently
against temporary environmental influences, such as a rise in humidity.
With this special treatment, magnets can be stored under normal ambient
conditions.
Passivated magnets is not suitable to be installed into system without
further treament .
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