ASTM TM2 Thermostatic Bimetal strip
Bimetallic TB208/110 holds very high thermal sensitivity and higher
resistivity,but the modulus of elasticity and allowable stress is
lower,it can improve the sensitivity of the instrument,decrease the
size and increase the force.
Thermal bimetal strip is by the different expansion coefficient of
two or more than two layers of metal or metal solid combination,
and along the entire interface varies with temperature and the
thermal function of shape changes in composite materials.One of
high expansion coefficient become active layer, low expansion
coefficient becomes passive.When requirements with high
resistivity, but heat sensitive resistance performance is
essentially the same type of thermal bimetal series, can be added
between the two layers of different thickness of middle layer as a
shunt layer, is to achieve the purpose of control different
resistivity.
The basic characteristic of the thermal bimetal is changing with
temperature and temperature deformation, resulting in a certain
moment.Many devices use this feature to convert heat energy into
mechanical work to achieve automatic control.Thermal bimetal used
for control system and temperature sensor in the measuring
instrument.
Composition
| Grade | ASTM TM2 |
| High expansion layer | Mn75Ni15Cu10 |
| Low expansion layer | Ni36 |
Chemical composition(%)
| Grade | C | Si | Mn | P | S | Ni | Cr | Cu | Fe |
| Ni36 | ≤0.05 | ≤0.3 | ≤0.6 | ≤0.02 | ≤0.02 | 35~37 | - | - | Bal. |
| Grade | C | Si | Mn | P | S | Ni | Cr | Cu | Fe |
| Mn75Ni15Cu10 | ≤0.05 | ≤0.5 | Bal. | ≤0.02 | ≤0.02 | 14~16 | - | 9~11 | ≤0.8 |
Typical Physical properties
| Density (g/cm3) | 7.7 |
| Electrical resistivity at 20ºC(ohm mm2/m) | 1.13 ±5% |
| Thermal conductivity, λ/ W/(m*ºC) | 6 |
| Elastic Modulus, E/ Gpa | 113~142 |
| Bending K / 10-6 ºC-1(20~135ºC) | 20.8 |
| Temperature bending rate F/(20~130ºC)10-6ºC-1 | 39.0%±5% |
| Allowable temperature (ºC) | -70~ 200 |
| Linear temperature (ºC) | -20~ 150 |
Application: The material is mainly used as Non magnetic non matching ceramic
sealing material in Gyro and other electric vacuum devices.
