1. bimetal product development
      Bimetal main application products: temperature relay, thermal time delay relays, temperature switch, controller temperature, fluorescent starter, bimetal thermometer, thermometer
 2. Description of the bimetal
     Also known as thermal bimetal bimetal due to thermal expansion coefficient of each component layer is different, when the temperature changes, deformation of the active layer is greater than the deformation of the passive layer, so that overall the bimetal will bend to the passive layer side , the curvature of this composite material is deformed so as to change. Wherein, the higher expansion coefficient is called the active layer; a lower coefficient of expansion as the passive layer. However, with the progress of the expansion of the bimetallic applications and integration technology, modern phase has three, four, five bimetallic appear. In fact, those who rely on temperature change and shape change occurs in the composite material, now in the habit is still known as thermal bimetal.
     Production of thermal bimetal material. Thermal bimetal is for relatively simple to achieve automatic control device temperature control. It consists of two layers of different thermal expansion coefficients of metal (or alloy) component. Expansion coefficient of the active layer is a layer of thermal expansion coefficient of the layer known as passive layer. Heat the bimetal, the active layer is greater than the length of the free expansion of the passive layer, but because the two layers firmly together, heat bimetal bent in an arc. On the contrary when cooled. This feature allows the manufacture thermal relay. Commonly used in the motor overload protection.
 


3.Materials Analysis bimetal different layers
       The active layer and the active layer of thermal bimetal certain components, for example; the active layer component Mn75%, Ni15%, Cu10% or Ni20%, Mn6%, the remainder being iron, the thermal expansion coefficient in the 20 ~ 100 ℃ were 27 × 10-6 / ℃ and 20 × 10-6 / ℃; while the passive layer composition of Ni36%, the balance being iron or Ni42%, the balance being iron, the thermal expansion coefficient (1.8 ~ 4.8) × 10-6 / ℃. The method of combining heat bimetal cold-rolled binding, fusion bonding, hot-rolled binding and the like.
Thermal bi-metallic materials can be divided into six kinds.
① Universal: suitable for a variety of uses and a medium temperature range, high sensitivity and strength.
② high temperature: suitable for operation above 300 ℃, has high strength and good oxidation resistance.
③ low temperature: is adapted to operate below 0 ℃.
④ resistance: with the high and low resistivity are available for a variety of small, standardized electrical appliances.
⑤ sensitivity type: high sensitivity, high resistance and other characteristics.
⑥ corrosion resistant: a good corrosion resistance, suitable for the role in the corrosive medium.

Bimetal different grades of technical parameters

Model GB/T4461 -92 Grades Specific bending K Resistivity ρ Bond strength test Reference YB137-69 and Generic brands Nominal value 10-6/℃ (20。-130) Tolerance Nominal value ｕΩ·cm (20+50℃) Allowable deviation I II Linear temperature range℃ Allowed temperature range ℃ Elastic modulus E Mpa not less than density g/cm3 I level II level repeatedly Bent Torsion repeatedly bending bending YDTB20110 5J20110 20.8 ±5% ±7% 113 ±5% Repeated bending to fracture, The fracture must not have a stratification May not be cracking, crack It shall not be less than three times cracking,crack Can not cracks appeared, crack -20~150 -70~200 113000 7.7 5J11 YDTB14140 5J14140 14.5 140 -20~150 -70~200 113000 7.5   YDTB15120 5J15120 15.3 125 -20~200 -70~250 122000 7.6 5J14 YDTB1480 5J1480 14.3 80.0 -30~180 -70~350 147000 8.2 5J18 YDTB1380 5J1380 13.8 80.0 -50~100 -70~350 147000 8.1 5J19 YDTB1580 5J1580 15.0 80.0 -20~180 -70~350 147000 8.1 5J16 YDTB1017 5J1017 10 17.0 ±10% -20~180 -70~400 152000 8.4 5J24 YDTB1070 5J1070 10.8 70.0 -20~350 -70~500 152000 8.0 5J23 YDTB0756 5J0756 7.8 ±8% ±10% 56.0 0~400 -70~500 152000 8.2 5J25 YDTB1306A 5J1306A 13.8 6.0 ±5% -20~150 -70~200 122000 8.3 R6A YDTB1306B 5J1306B 13.5 ±5% ±7% 6.0 -20~150 -70~200 122000 8.3 R6B YDTB1309A 5J1309A 13.9 9.0 ±10% -20~150 -70~200 122000 8.2 R9A YDTB1309B 5J1309B 13.6 9.0 -20~150 -70~200 122000 8.2 R9B YDTB1411A 5J1411A 14.9 11.0 -20~150 -70~200 122000 8.2 R11A YDTB1411B 5J1411B 14.2 11.0 -20~150 -70~200 122000 8.2 R11B YDTB1417A 5J1417A 14.9 17.0 -20~150 -70~200 122000 8.2 R17A YDTB1417B 5J1417B 14.2 17.0 -20~150 -70~200 122000 8.2 R17B5J101 YDTB20110 5J20110 20.8 ±5% ±7% 113 ±5% -20~150 -70~200 113000 7.7 5J11 YDTB14140 5J14140 14.5 140 -20~150 -70~200 113000 7.5   YDTB15120 5J15120 15.3 125 -20~200 -70~250 122000 7.6 5J14 YDTB1478 5J1478 14.3 78.0 -30~180 -70~350 147000 8.2 5J18 YDTB1380 5J1380 13.8 80.0 -50~100 -70~350 147000 8.1 5J19 YDTB1580 5J1580 15.0 80.0 -20~180 -70~350 147000 8.1 5J16 YDTB1017 5J1017 10 17.0 ±10% -20~180 -70~400 152000 8.4 5J24 YDTB1070 5J1070 10.8 70.0 -20~350 -70~500 152000 8.0 5J23 YDTB0756 5J0756 7.8 ±8% ±10% 56.0 0~400 -70~500 152000 8.2 5J25 YDTB1306A 5J1306A 13.8 6.0 ±5% -20~150 -70~200 122000 8.3 R6A YDTB1306B 5J1306B 13.5 ±5% ±7% 6.0 -20~150 -70~200 122000 8.3 R6B YDTB1309A 5J1309A 13.9 9.0 ±10% -20~150 -70~200 122000 8.2 R9A YDTB1309B 5J1309B 13.6 9.0 -20~150 -70~200 122000 8.2 R9B YDTB1411A 5J1411A 14.9 11.0 -20~150 -70~200 122000 8.2 R11A YDTB1411B 5J1411B 14.2 11.0 -20~150 -70~200 122000 8.2 R11B YDTB1417A 5J1417A 14.9 17.0 -20~150 -70~200 122000 8.2 R17A YDTB1417B 5J1417B 14.2 17.0 -20~150 -70~200 122000 8.2 R17B 5J101