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- the simple semiconductors incorporating one element.,
- the difficult semiconductors being chemical compounds and alloys.
Magnetic steel and alloys characterize magnetic permeability, coercive force
and a residual induction. Depending on values of these sizes magnetic materials
divide on:
- magnetic and soft materials (ferromagnetic), having small coercive force and
big magnetic permeability. They are electro-technical iron and steel, iron-nickel
alloys (permalloy).,
- magnetic and firm steel and alloys having big coercive force. These are high-
carbonaceous and alloyed became, special alloys.
Alloys with high electric resistance are applied to manufacturing of electro-
heaters and elements of resistance (resistors) and rheostats.
In the industry wide application was received by the materials possessing high
a limit of elasticity and a limit of endurance. These properties of materials are
provided with their thermal processing - training and the subsequent water-
tempering. Medium-carbon steel with elastic properties apply to manufacturing
of springs, springs of general purpose. To manufacturing of elastic elements in
instrumentation apply alloys with special elastic characteristics. Springs,
membranes, bellows-produce from alloys 42НХТЮ, 17ХНГТ, 68НХВКТЮ,
etc. These alloys in the tempered condition are rather technological in
processing, and after aging gain high elasticity and durability.
Alloys with set by factor of thermal expansion contain a large amount of
nickel. The alloy 36Н-an invar, doesn't extend almost at temperatures from a
minus 60 to +100?С, possesses good office characteristics, is technological and
corrosion-resistant. Invar alloying cobalt receives a super invar. These alloys
apply to manufacturing of details of the devices demanding the constant sizes in
the range of climatic changes of temperatures.
For connection of metal details of devices with the glass apply the alloys of
Fe-Ni alloyed by cobalt or copper. To connections with heat-resistant glass
apply an alloy 29НК (29 % of nickel and 18 % of cobalt) - cover. To not heat-
resistant glasses apply an alloy 48Н-platynite.
In instrumentation widely use the materials consisting of two layers of
materials with various temperature factors of foundry expansion – thermo
bimetals. Thermo bimetals apply to manufacturing of thermal relays, condensers
and alarm fire devices.
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