A kind of piezoresistive material and preparation method thereof
Technical field
A kind of (Ba is provided
xca
1-x) (Ti
ym
1-y) O
3-zBiFeO
3system pressure-sensitive ceramic resistor material, also relates to three kinds of methods of this pressure-sensitive ceramic resistor material of preparation, belongs to pressure-sensitive ceramic resistor material field.
Background technology
Pressure-sensitive semiconductor pottery refers to that resistance value becomes the semiconductive ceramic of remarkable nonlinear relationship with impressed voltage, and encapsulating after adding top electrode during use becomes piezoresistor.Full Name in English is Variable Resistor, is called for short Variable, therefore is also called varistor.The electrical nonlinearity excellent because of it and good surge absoption ability, be widely used in power electronic system as voltage stabilizing element and over-voltage protection element.At electric lightning, motor, wire telephony exchange board, silicon rectifier, colour television set, its absorption abnormal voltage used for relay protection, its absorption of noise of micromotor.
The semiconductor ceramic material manufacturing piezoresistor has SiC, ZnO, BaTiO
3, Fe
2o
3, SnO
2, SrTiO
3deng.Wherein BaTiO
3, Fe
2o
3what utilize is the non-ohmic behavior at electrode and sintered compact interface, and SiC, ZnO, SrTiO
3what utilize is crystal boundary non-ohmic behavior.Most widely used, performance is it is preferred that ZnO pressure-sensitive semiconductor is ceramic at present.
In recent years; along with the development of light, thin, short, the little and multifunction of electronic machine and device; the requirement of ceramic varistor device as protection element in the computer, electronic machine of large-scale integrated circuit (LSI) and super large-scale integration (SLSI) is more and more higher; current resistor can not meet the needs of development; the jumbo resistor of novel high-performance and resistive material are paid close attention to widely, and piezoresistive material and voltage dependent resistor are one of them important research directions.
Summary of the invention
The invention provides a kind of pressure-sensitive ceramic resistor material, its composition is expressed by the following formula: (Ba
xca
1-x) (Ti
ym
1-y) O
3-zBiFeO
3, in general formula, M is the one in Zr and Sn element, and the value of x is 0≤x≤1, and the value of y is 0≤y≤1, and the value of z is 0.1≤z≤1.Piezoceramic material of the present invention, when M is selected from Zr, x is preferably 0.75-0.85, and y is preferably 0.9-0.95, and z is preferably 0.1-0.2.When M is selected from Sn, x preferably from 0.7-1, y preferably from 0.8-0.9, z preferably from 0.3-0.6.
The object of the present invention is to provide one (Ba
xca
1-x) (Ti
ym
1-y) O
3-zBiFeO
3system pressure-sensitive ceramic resistor material, preparation method is solid-phase synthesis, hydrothermal method, liquid-phase mixing and solid state sintering combined techniques.Preparation technology of the present invention is simple, and prepared pressure-sensitive ceramic resistor material has good voltage-dependent characteristic and energy density is large, and nonlinear factor is high, environmental protection.
The invention provides above-mentioned (Ba
xca
1-x) (Ti
ym
1-y) O
3-zBiFeO
3the preparation method of system pressure-sensitive ceramic resistor material,
Method one: solid-phase synthesis, comprises the following steps:
Step one: according to general formula (Ba
xca
1-x) (Ti
ym
1-y) O
3-zBiFeO
3in stoichiometric ratio accurately take raw material BaCO
3, CaCO
3, TiO
2, MO
2, Bi
2o
3and Fe
2o
3, put into ball grinder, add dehydrated alcohol, mixing is ball milling also.
Step 2: carry out first time pre-burning after being dried by the compound after ball milling.
Step 3: the powder after first time pre-burning is added dehydrated alcohol and carries out ball milling.
Step 4: carry out second time pre-burning after being dried by the compound after ball milling.
Step 5: the powder after second time pre-burning is added dehydrated alcohol and carries out ball milling, sieves after then being dried by the compound obtained; Add binding agent in compound after sizing again to grind, after making the two sufficient Homogeneous phase mixing, carry out second time and sieve.
Step 6: the compound after having sieved is carried out ripening more than 12 hours, allows binding agent fully mix with powder, be pressed into ceramic green sheet, and carry out plastic removal process.
Step 7: the ceramic green sheet after plastic removal process is calcined, is cooled to room temperature subsequently.
Step 8: cooled ceramic green sheet is carried out polishing both surfaces, drapes over one's shoulders silver electrode, obtains pressure-sensitive ceramic resistor material.
Method two: hydrothermal method, comprises the following steps:
Step one: according to general formula (Ba
xca
1-x) (Ti
ym
1-y) O
3-zBiFeO
3in stoichiometric ratio accurately take raw material, by BaCl
2, CaCl
2, ZrOCl
2(SnCl
4), Bi (NO
3)
3with Fe (NO
3)
3soluble in water to dissolving completely respectively, then mix, stir and keep it to clarify; TiCl is added successively in settled solution
4and NaOH, obtain presoma.
Step 2: presoma is carried out hydro-thermal reaction, obtains (Ba after cooling
xca
1-x) (Ti
ym
1-y) O
3-zBiFeO
3mixed powder.
Step 3: mixed powder is sieved through washing, precipitation post-drying; Add binding agent in compound after sizing again to grind, after making the two sufficient Homogeneous phase mixing, carry out second time and sieve.
Step 4: the compound after having sieved is carried out ripening more than 12 hours, allows binding agent fully mix with powder, be pressed into ceramic green sheet, and carry out plastic removal process.
Step 5: the ceramic green sheet after plastic removal process is calcined, is cooled to room temperature subsequently.
Step 6: cooled ceramic green sheet is carried out polishing both surfaces, drapes over one's shoulders silver electrode, obtains pressure-sensitive ceramic resistor material.
Method three: liquid-phase mixing and solid state sintering combined techniques, comprise the following steps:
Step one: according to general formula (Ba
xca
1-x) (Ti
ym
1-y) O
3-zBiFeO
3in stoichiometric ratio accurately take raw material.
Step 2: by load weighted Ba (CH
3cOO)
2and Ca (CH
3cOO)
2in beaker, be formulated as settled solution respectively then mix, stir and keep its clarification; TiO is added successively in settled solution
2, MO
2, Bi (NO
3)
3and Fe
2o
3, monohydrate potassium.
Step 3: mixed solution is placed in heated and stirred on magnetic agitation platform until evaporating water, is then positioned over heating, drying in baking oven, the partially carbonized variable color of compound; From baking oven, compound carefully scrapes by the rear spoon of taking-up and brush from beaker, grinds levigate in mortar.
Step 4: compound is placed in alumina crucible, remaining organism is removed in thermal treatment.
Step 5: taken out from crucible by the compound after thermal treatment and be placed in mortar porphyrize, and then put in crucible, starts first time pre-burning.
Step 6: the powder after first time pre-burning is added dehydrated alcohol and carries out ball milling.
Step 7: carry out second time pre-burning after being dried by the compound after ball milling.
Step 8: the powder after second time pre-burning is added dehydrated alcohol and carries out ball milling, sieves after then being dried by the compound obtained; Add binding agent in compound after sizing again to grind, after making the two sufficient Homogeneous phase mixing, carry out second time and sieve.
Step 9: the compound after having sieved is carried out ripening more than 12 hours, allows binding agent fully mix with powder, be pressed into ceramic green sheet, and carry out plastic removal process.
Step 10: the ceramic green sheet after plastic removal process is calcined, is cooled to room temperature subsequently.
Step 11: cooled ceramic green sheet is carried out polishing both surfaces, drapes over one's shoulders silver electrode, obtains pressure-sensitive ceramic resistor material.
Embodiment
For making the object, technical solutions and advantages of the present invention clearly, below in conjunction with specific embodiment, technical scheme of the present invention and effect are described.
Embodiment 1
This example provides one (Ba
xca
1-x) (Ti
ym
1-y) O
3-zBiFeO
3system pressure-sensitive ceramic resistor material, its formula composed as follows represents: (Ba
0.85ca
0.15) (Ti
0.9zr
0.1) O
3-0.1BiFeO
3, wherein the value of M to be the value of Zr, x be 0.85, y is the value of 0.90, z is 0.1.
(Ba in the present embodiment
0.85ca
0.15) (Ti
0.9zr
0.1) O
3-0.1BiFeO
3the preparation method of system pressure-sensitive ceramic resistor material, concrete steps are as follows:
Step one: according to general formula (Ba
0.85ca
0.15) (Ti
0.9zr
0.1) O
3-0.1BiFeO
3stoichiometric ratio accurate calculation and precise BaCO
3, CaCO
3, TiO
2, ZrO
2, Bi
2o
3and Fe
2o
3, put into ball grinder, add dehydrated alcohol, ball milling 10 hours under ball milling speed is 400r/min.
Step 2: the compound after ball milling is placed in baking oven in temperature 80 DEG C oven dry, then rises to 1100 DEG C with the temperature rise rate of 3 DEG C/min, keep this temperature calcination after 8 hours, with stove Temperature fall to room temperature.
Step 3: the powder after first time pre-burning is added dehydrated alcohol, ball milling 10 hours under ball milling speed is 400r/min.
Step 4: the compound after ball milling is placed in baking oven in temperature 80 DEG C oven dry, then rises to 1100 DEG C with the temperature rise rate of 3 DEG C/min, keep this temperature calcination after 8 hours, with stove Temperature fall to room temperature.
Step 5: the powder after second time pre-burning is added dehydrated alcohol, ball milling 10 hours under ball milling speed is 400r/min, crosses 300 order dusting covers after then being dried at 80 DEG C by the compound obtained; Add appropriate binding agent in compound after sizing again to grind, after making the two sufficient Homogeneous phase mixing, after 200 mesh sieves.Wherein, binding agent to be weight percentage be 5% polyvinyl alcohol water solution, its consumption is 7% of mixed powder gross weight.
Step 6: the compound after having sieved is carried out ripening more than 12 hours, binding agent is allowed fully to mix with powder, under pressure 8Mpa, be pressed into ceramic green sheet, and rise to 750 DEG C with the temperature rise rate of 3C/min, soaking time is carry out plastic removal process in 5 hours.
Step 7: the ceramic green sheet after plastic removal process is risen to 1300 DEG C with the temperature rise rate of 5 DEG C/min, keeps this temperature calcination after 2 hours, is cooled to room temperature.
Step 8: cooled ceramic green sheet is carried out polishing both surfaces, drapes over one's shoulders silver electrode, obtains pressure-sensitive ceramic resistor material.
Learn after tested: the pressure-sensitive ceramic resistor material that the present embodiment prepares performance perameter is at room temperature as follows: voltage gradient=26.5V/mm, 2ms energy tolerance=524J/cm
3, α=196, leakage current=3.42 μ A.
Embodiment 2
This example provides one (Ba
xca
1-x) (Ti
ym
1-y) O
3-zBiFeO
3system pressure-sensitive ceramic resistor material, its formula composed as follows represents: BaTi
0.9sn
0.1o
3-0.6BiFeO
3, wherein the value of M to be the value of Sn, x be 1, y is the value of 0.90, z is 0.6.
BaTi in the present embodiment
0.9sn
0.1o
3-0.6BiFeO
3the preparation method of system pressure-sensitive ceramic resistor material, concrete steps are as follows:
Step one: according to Formula B aTi
0.9sn
0.1o
3-0.6BiFeO
3stoichiometric ratio accurate calculation and precise BaCO
3, TiO
2, SnO
2, Bi
2o
3and Fe
2o
3, put into ball grinder, add dehydrated alcohol, ball milling 12 hours under ball milling speed is 400r/min.
Step 2: the compound after ball milling is placed in baking oven in temperature 80 DEG C oven dry, then rises to 1000 DEG C with the temperature rise rate of 3 DEG C/min, keep this temperature calcination after 8 hours, with stove Temperature fall to room temperature.
Step 3: the powder after first time pre-burning is added dehydrated alcohol, ball milling 12 hours under ball milling speed is 400r/min.
Step 4: the compound after ball milling is placed in baking oven in temperature 80 DEG C oven dry, then rises to 1050 DEG C with the temperature rise rate of 3 DEG C/min, keep this temperature calcination after 8 hours, with stove Temperature fall to room temperature.
Step 5: the powder after second time pre-burning is added dehydrated alcohol, ball milling 10 hours under ball milling speed is 400r/min, crosses 300 order dusting covers after then being dried at 80 DEG C by the compound obtained; Add appropriate binding agent in compound after sizing again to grind, after making the two sufficient Homogeneous phase mixing, after 300 mesh sieves.Wherein, binding agent to be weight percentage be 5% polyvinyl alcohol water solution, its consumption is 7% of mixed powder gross weight.
Step 6: the compound after having sieved is carried out ripening more than 12 hours, binding agent is allowed fully to mix with powder, under pressure 8Mpa, be pressed into ceramic green sheet, and rise to 750 DEG C with the temperature rise rate of 3C/min, soaking time is carry out plastic removal process in 5 hours.
Step 7: the ceramic green sheet after plastic removal process is risen to 1300 DEG C with the temperature rise rate of 5 DEG C/min, keeps this temperature calcination after 2 hours, is cooled to room temperature.
Step 8: cooled ceramic green sheet is carried out polishing both surfaces, drapes over one's shoulders silver electrode, obtains pressure-sensitive ceramic resistor material.
Learn after tested: the pressure-sensitive ceramic resistor material that the present embodiment prepares performance perameter is at room temperature as follows: voltage gradient=26.2V/mm, 2ms energy tolerance=430J/cm
3, α=185, leakage current=3.94 μ A.
Embodiment 3
This example provides one (Ba
xca
1-x) (Ti
ym
1-y) O
3-zBiFeO
3system pressure-sensitive ceramic resistor material, its formula composed as follows represents: Ba
0.8ca
0.2ti
0.95zr
0.05o
3-0.2BiFeO
3, wherein the value of M to be the value of Zr, x be 0.8, y is the value of 0.95, z is 0.2.
Ba in the present embodiment
0.8ca
0.2ti
0.95zr
0.05o
3-0.2BiFeO
3the preparation method of system pressure-sensitive ceramic resistor material, concrete steps are as follows:
Step one: according to Formula B a
0.8ca
0.2ti
0.95zr
0.05o
3-0.2BiFeO
3in stoichiometric ratio accurately take raw material, by BaCl
2, CaCl
2, ZrOCl
2, Bi (NO
3)
3with Fe (NO
3)
3soluble in water to dissolving completely respectively, then mix, stir and keep it to clarify; TiCl is added successively in settled solution
4and NaOH, obtain presoma.
Step 2: presoma is put into reactor, is carry out hydro-thermal reaction in 10-14 hour 160-200 DEG C of soaking time, obtains Ba after cooling
0.8ca
0.2ti
0.95zr
0.05o
3-0.2BiFeO
3mixed powder.
Step 3: by mixed powder through washing, precipitation, crosses 300 order dusting covers after drying at 80 DEG C; Add appropriate binding agent in compound after sizing again to grind, after making the two sufficient Homogeneous phase mixing, after 300 mesh sieves.Wherein, binding agent to be weight percentage be 5% polyvinyl alcohol water solution, its consumption is 7% of mixed powder gross weight.
Step 4: the compound after having sieved is carried out ripening more than 12 hours, binding agent is allowed fully to mix with powder, under pressure 8Mpa, be pressed into ceramic green sheet, and rise to 750 DEG C with the temperature rise rate of 3C/min, soaking time is carry out plastic removal process in 5 hours.
Step 5: the ceramic green sheet after plastic removal process is risen to 1300 DEG C with the temperature rise rate of 5 DEG C/min, keeps this temperature calcination after 2 hours, is cooled to room temperature.
Step 6: cooled ceramic green sheet is carried out polishing both surfaces, drapes over one's shoulders silver electrode, obtains pressure-sensitive ceramic resistor material.
Learn after tested: the pressure-sensitive ceramic resistor material that the present embodiment prepares performance perameter is at room temperature as follows: voltage gradient=28.4V/mm, 2ms energy tolerance=392J/cm
3, α=198, leakage current=3.28 μ A.
Embodiment 4
This example provides one (Ba
xca
1-x) (Ti
ym
1-y) O
3-zBiFeO
3system pressure-sensitive ceramic resistor material, its formula composed as follows represents: Ba
0.84ca
0.16ti
0.9sn
0.1o
3-0.4BiFeO
3, wherein the value of M to be the value of Sn, x be 0.84, y is the value of 0.9, z is 0.4.
Ba in the present embodiment
0.84ca
0.16ti
0.9sn
0.1o
3-0.4BiFeO
3the preparation method of system pressure-sensitive ceramic resistor material, concrete steps are as follows:
Step one: according to Formula B a
0.84ca
0.16ti
0.9sn
0.1o
3-0.4BiFeO
3in stoichiometric ratio accurately take raw material, by BaCl
2, CaCl
2, SnCl
4, Bi (NO
3)
3with Fe (NO
3)
3soluble in water to dissolving completely respectively, then mix, stir and keep it to clarify; TiCl is added successively in settled solution
4and NaOH, obtain presoma.
Step 2: presoma is put into reactor, is carry out hydro-thermal reaction in 10-14 hour 160-200 DEG C of soaking time, obtains Ba after cooling
0.84ca
0.16ti
0.9sn
0.1o
3-0.4BiFeO
3mixed powder.
Step 3: by mixed powder through washing, precipitation, crosses 300 order dusting covers after drying at 80 DEG C; Add appropriate binding agent in compound after sizing again to grind, after making the two sufficient Homogeneous phase mixing, after 300 mesh sieves.Wherein, binding agent to be weight percentage be 5% polyvinyl alcohol water solution, its consumption is 7% of mixed powder gross weight.
Step 4: the compound after having sieved is carried out ripening more than 12 hours, binding agent is allowed fully to mix with powder, under pressure 8Mpa, be pressed into ceramic green sheet, and rise to 750 DEG C with the temperature rise rate of 3C/min, soaking time is carry out plastic removal process in 5 hours.
Step 5: the ceramic green sheet after plastic removal process is risen to 1300 DEG C with the temperature rise rate of 5 DEG C/min, keeps this temperature calcination after 2 hours, is cooled to room temperature.
Step 6: cooled ceramic green sheet is carried out polishing both surfaces, drapes over one's shoulders silver electrode, obtains pressure-sensitive ceramic resistor material.
Learn after tested: the pressure-sensitive ceramic resistor material that the present embodiment prepares performance perameter is at room temperature as follows: voltage gradient=27.1V/mm, 2ms energy tolerance=443J/cm
3, α=207, leakage current=3.46 μ A.
Embodiment 5
This example provides one (Ba
xca
1-x) (Ti
ym
1-y) O
3-zBiFeO
3system pressure-sensitive ceramic resistor material, its formula composed as follows represents: Ba
0.75ca
0.25ti
0.9zr
0.1o
3-0.2BiFeO
3, wherein the value of M to be the value of Zr, x be 0.75, y is the value of 0.90, z is 0.2.
Ba in the present embodiment
0.75ca
0.25ti
0.9zr
0.1o
3-0.2BiFeO
3the preparation method of system pressure-sensitive ceramic resistor material, concrete steps are as follows:
Step one: according to Formula B a
0.75ca
0.25ti
0.9zr
0.1o
3-0.2BiFeO
3stoichiometric ratio accurate calculation and precise raw material.
Step 2: by load weighted Ba (CH
3cOO)
2and Ca (CH
3cOO)
2in beaker, be formulated as settled solution respectively then mix, stir and keep its clarification; TiO is added successively in settled solution
2, ZrO
2, Bi (NO
3)
3and Fe
2o
3, monohydrate potassium.
Step 3: mixed solution to be placed on magnetic agitation platform heated and stirred at temperature 80 DEG C and, until evaporating water, to be then positioned over 250 DEG C of heating, dryings in baking oven, the partially carbonized variable color of compound; From baking oven, compound carefully scrapes by the rear spoon of taking-up and brush from beaker, grinds levigate in mortar.
Step 4: compound is placed in alumina crucible, rises to 750 DEG C with the temperature rise rate of 3 DEG C/min and is incubated 4 hours, removes remaining organism.
Step 5: taken out from crucible by the compound after first time pre-burning and be placed in mortar porphyrize, and then put in crucible, rise to 1000 DEG C with the temperature rise rate of 5 DEG C/min, keeps this temperature calcination after 8 hours, with stove Temperature fall to room temperature.
Step 6: the powder after second time pre-burning is added dehydrated alcohol, ball milling 10 hours under ball milling speed is 400r/min.
Step 7: the compound after ball milling is placed in baking oven in temperature 80 DEG C oven dry, then rises to 1150 DEG C with the temperature rise rate of 5 DEG C/min, keep this temperature calcination after 8 hours, with stove Temperature fall to room temperature.
Step 8: the powder after third time pre-burning is added dehydrated alcohol, ball milling 10 hours under ball milling speed is 400r/min, crosses 300 order dusting covers after then being dried at 80 DEG C by the compound obtained; Add appropriate binding agent in compound after sizing again to grind, after making the two sufficient Homogeneous phase mixing, after 100 mesh sieves.Wherein, binding agent to be weight percentage be 5% polyvinyl alcohol water solution, its consumption is 7% of mixed powder gross weight.
Step 9: the compound after having sieved is carried out ripening more than 12 hours, allows binding agent fully mix with powder, be pressed into ceramic green sheet, and carry out plastic removal process.
Step 10: the ceramic green sheet after plastic removal process is risen to 1350 DEG C with the temperature rise rate of 5 DEG C/min, keeps this temperature calcination 2 hours, is cooled to room temperature subsequently.
Step 11: cooled ceramic green sheet is carried out polishing both surfaces, drapes over one's shoulders silver electrode, obtains pressure-sensitive ceramic resistor material.
Learn after tested: the pressure-sensitive ceramic resistor material that the present embodiment prepares performance perameter is at room temperature as follows: voltage gradient=28.2V/mm, 2ms energy tolerance=459J/cm
3, α=192, leakage current=3.17 μ A.
Embodiment 6
This example provides one (Ba
xca
1-x) (Ti
ym
1-y) O
3-zBiFeO
3system pressure-sensitive ceramic resistor material, its formula composed as follows represents: Ba
0.7ca
0.3ti
0.8sn
0.2o
3-0.3BiFeO
3, wherein the value of M to be the value of Sn, x be 0.7, y is the value of 0.8, z is 0.3.
Ba in the present embodiment
0.7ca
0.3ti
0.8sn
0.2o
3-0.3BiFeO
3the preparation method of system pressure-sensitive ceramic resistor material, concrete steps are as follows:
Step one: according to Formula B a
0.7ca
0.3ti
0.8sn
0.2o
3-0.3BiFeO
3stoichiometric ratio accurate calculation and precise raw material.
Step 2: by load weighted Ba (CH
3cOO)
2and Ca (CH
3cOO)
2in beaker, be formulated as settled solution respectively then mix, stir and keep its clarification; TiO is added successively in settled solution
2, SnO
2, Bi (NO
3)
3and Fe
2o
3, monohydrate potassium.
Step 3: mixed solution to be placed on magnetic agitation platform heated and stirred at temperature 80 DEG C and, until evaporating water, to be then positioned over 250 DEG C of heating, dryings in baking oven, the partially carbonized variable color of compound; From baking oven, compound carefully scrapes by the rear spoon of taking-up and brush from beaker, grinds levigate in mortar.
Step 4: compound is placed in alumina crucible, rises to 750 DEG C with the temperature rise rate of 3 DEG C/min and is incubated 4 hours, removes remaining organism.
Step 5: taken out from crucible by the compound after first time pre-burning and be placed in mortar porphyrize, and then put in crucible, rise to 1000 DEG C with the temperature rise rate of 5 DEG C/min, keeps this temperature calcination after 8 hours, with stove Temperature fall to room temperature.
Step 6: the powder after second time pre-burning is added dehydrated alcohol, ball milling 10 hours under ball milling speed is 400r/min.
Step 7: the compound after ball milling is placed in baking oven in temperature 80 DEG C oven dry, then rises to 1150 DEG C with the temperature rise rate of 5 DEG C/min, keep this temperature calcination after 8 hours, with stove Temperature fall to room temperature.
Step 8: the powder after third time pre-burning is added dehydrated alcohol, ball milling 10 hours under ball milling speed is 400r/min, crosses 300 order dusting covers after then being dried at 80 DEG C by the compound obtained; Add appropriate binding agent in compound after sizing again to grind, after making the two sufficient Homogeneous phase mixing, after 100 mesh sieves.Wherein, binding agent to be weight percentage be 5% polyvinyl alcohol water solution, its consumption is 7% of mixed powder gross weight.
Step 9: the compound after having sieved is carried out ripening more than 12 hours, allows binding agent fully mix with powder, be pressed into ceramic green sheet, and carry out plastic removal process.
Step 10: the ceramic green sheet after plastic removal process is risen to 1350 DEG C with the temperature rise rate of 5 DEG C/min, keeps this temperature calcination 2 hours, is cooled to room temperature subsequently.
Step 11: cooled ceramic green sheet is carried out polishing both surfaces, drapes over one's shoulders silver electrode, obtains pressure-sensitive ceramic resistor material.
Learn after tested: the pressure-sensitive ceramic resistor material that the present embodiment prepares performance perameter is at room temperature as follows: voltage gradient=28.9V/mm, 2ms energy tolerance=262J/cm
3, α=176, leakage current=3.37 μ A.