CN108975902B - Ingredients and manufacturing method of sagger special for high-performance zinc oxide piezoresistor - Google Patents

Abstract

The invention relates to the technical field of manufacturing processes of zinc oxide piezoresistors, and particularly discloses a material and a manufacturing method of a sagger special for a high-performance zinc oxide piezoresistor, wherein the material comprises, by mass, 97 parts of zinc oxide, bismuth oxide, antimony oxide, cobalt oxide, manganese oxide, chromium oxide, nickel oxide and boric acid, wherein the mass ratio of the zinc oxide to the antimony oxide to the cobalt oxide to the zinc oxide to the antimony oxide to the cobalt oxide to. The invention has the beneficial effects that: by adopting a material formula and a manufacturing process which are almost the same as those of the zinc oxide piezoresistor, the sagger special for the zinc oxide piezoresistor is manufactured through mixing grinding, spraying zero granulation, dry pressing forming and binder removal sintering, the sagger is used for loading the zinc oxide piezoresistor blank, even if the sagger is used for loading the zinc oxide piezoresistor blank, the sagger blank is mutually permeated at a high temperature of more than one thousand degrees and is also made of the same material, any pollution is avoided, the problem of long-term winding of the material and atmosphere pollution in high-temperature sintering of the high-quality zinc oxide piezoresistor is solved, and the used materials are common materials, are easy to purchase and lay a foundation for high-end manufacturing.

Description

Ingredients and manufacturing method of sagger special for high-performance zinc oxide piezoresistor

Technical Field

The invention relates to the technical field of manufacturing processes of zinc oxide piezoresistors, in particular to ingredients and a manufacturing method of a sagger special for a high-performance zinc oxide piezoresistor.

Background

China is a large manufacturing country of zinc oxide piezoresistors, the yield accounts for more than 70% of the total world amount, most of the zinc oxide piezoresistors are middle-end and low-end products, and the high-end products occupy a small amount. This phenomenon is mainly caused by the purity of raw materials, manufacturing processes, equipment, and the like.

One reason for this is the loading of the zinc oxide varistor green sheets into the sagger. In the current sintering process, a large amount of saggars made of materials such as alumina, mullite, silicon nitride and the like are still used as blank piece loading carriers, and the zinc oxide piezoresistor blank pieces before sintering are sintered at high temperature of more than one thousand degrees in the sealing environment of the saggars. During the firing process, the sagger body material reacts with the blank sheet at high temperature, and particularly, molecules such as iron, aluminum, silicon, calcium and the like in the sagger body are easy to permeate into the blank sheet to cause pollution, so that the performance indexes of the zinc oxide piezoresistor deviate from the formula design, and the quality is reduced.

Disclosure of Invention

The invention provides a material and a manufacturing method of a sagger special for a high-performance zinc oxide piezoresistor, and solves the technical problems that the existing sagger made of materials such as alumina, mullite, silicon oxide and the like reacts with a blank sheet during firing, so that the pollution of the materials and atmosphere is caused, the performance index of the zinc oxide piezoresistor deviates from the formula design, and the quality is reduced.

In order to solve the technical problems, the invention provides a material of a sagger special for a high-performance zinc oxide piezoresistor, which comprises zinc oxide, bismuth oxide, antimony oxide, cobalt oxide, manganese oxide, chromium oxide, nickel oxide and boric acid in a mass ratio of 97 (0.2-2.5), (0.4-1.5), (0-2.5), (0-1.2), (0-1.3) and (0-1).

As a preferred embodiment, the ingredients of the sagger special for the high-performance piezoresistor provided by the invention comprise zinc oxide, bismuth oxide, antimony oxide, cobalt oxide, manganese oxide, chromium oxide, nickel oxide and boric acid in a mass ratio of 97:0.4:0.4:0.4:0.4:0.4: 0.05.

As another preferred embodiment, the ingredients of the sagger special for the high-performance piezoresistor provided by the invention comprise zinc oxide, bismuth oxide, antimony oxide, cobalt oxide, manganese oxide, chromium oxide, nickel oxide and boric acid in a mass ratio of 97:0.8:1:1:1:1:1: 0.05.

As another preferred embodiment, the ingredients of the sagger special for the high-performance piezoresistor provided by the invention comprise zinc oxide, bismuth oxide, antimony oxide, cobalt oxide, manganese oxide, chromium oxide, nickel oxide and boric acid with the mass ratio of 97:1.3:1.3:2:1.2:1.0:1.0: 0.05.

As another preferred embodiment, the ingredients of the sagger special for the high-performance piezoresistor provided by the invention comprise zinc oxide, bismuth oxide and antimony oxide with the mass ratio of 97:2.5: 0.5.

The sagger made of four different formulas is suitable for the subdivision loading of zinc oxide piezoresistor blank sheets with different voltage gradients and different specifications and varieties, the subdivision loading is to strictly avoid the pollution of materials and atmosphere caused by different formulas, and the method is a measure for obtaining the best quality of all varieties in a whole series.

The invention also provides a manufacturing method for manufacturing the sagger special for the high-performance piezoresistor by adopting the ingredients, which comprises the following steps:

s1, grinding and mixing: grinding and mixing the ingredients, putting the mixture into a ball mill or a stirring mill or a vibration mill, adding pure water, balls and a binder, and grinding and mixing for 2-20 hours;

s2, spray granulation: taking out the ground and mixed slurry, performing spray granulation, and filling the slurry into a charging basket;

s3, dry pressing and forming: after checking that the pressing die is correct, putting the powder in the charging basket into a charging basket of a pressing forming machine, calculating the pressing density, the pressing program and the pressure maintaining time, and pressing into a sagger blank;

s4, binder removal and sintering: and (3) conveying the molded blank body to a glue discharging furnace push plate, conveying the molded blank body and the glue discharging furnace push plate into a glue discharging kiln together, discharging glue at the temperature of 200-650 ℃ for 6-20 hours, conveying the blank body to a firing kiln push plate, conveying the blank body into a furnace together, firing at the temperature of 1100-1650 ℃ for 10-30 hours, and taking out and cooling to obtain the sagger.

Further, in the step S1, the mass ratio of the ingredients, the pure water and the balls is (1-1.2): (0.7-1.1): 0.8-1.2, and the binder is added in a proper amount according to the actual production requirement. The ball mill or the stirring mill or the vibrating mill is key equipment for mixing and grinding materials, and a certain amount of zirconium balls or agate balls are required to be filled in a cylinder body of the ball mill or the stirring mill or the vibrating mill as grinding media during grinding.

Specifically, in step S2, spray granulation is a granulation method in which a mixed and ground slurry or solution is pumped into a vacuum granulation tower through a pressure pump, and the slurry or solution is dried and agglomerated under the action of spraying and hot air flow, thereby obtaining hollow spherical granules.

The checking pressing die has no wrong fingers, whether the pressing die on the forming machine meets the requirements or not is checked before pressing, the pressing die which is not suitable needs to be replaced, repairable damage can be repaired in time, and the matching of the shapes of the pressing dies is ensured without damage.

Further, in the step S3, the sagger blank includes a sagger box blank and a sagger lid blank which are mutually covered; the sagger box body and the sagger lid body become a sagger box body and a sagger lid body (sagger) after the step S4. The overall length of the sagger body is 50-300 mm, the overall width is 40-310 mm, the overall height is 15-180 mm, the thickness of four walls is 3-30 mm, and the inner height of the four walls is 10-170 mm;

the sagger cover body comprises a base wall and an inner convex surface, the length and the width of the base wall are correspondingly equal to the whole length and the whole width of the sagger box body, and the height is 5-30 mm; the height of the inner convex surface is 2-15 mm, the length is 40-280 mm, and the width is 30-290 mm.

In the step S3, the sagger blank needs to consider sintering shrinkage, and all blanks (including the sagger box blank and the sagger cover blank) should have a size 1.12 to 1.22 times that of the finished sagger (including the sagger box body and the sagger cover).

The invention provides a burdening and manufacturing method of a special sagger for a high-performance zinc oxide piezoresistor, which adopts a material formula and a manufacturing process which are almost the same as those of the zinc oxide piezoresistor, prepares the special sagger for the zinc oxide piezoresistor by mixing, grinding, zero-spraying granulation, dry pressing and molding and adhesive-discharging sintering, loads a zinc oxide piezoresistor blank sheet by using the sagger, is the same material even if mutually permeating at a high temperature of more than one thousand degrees, avoids any pollution, solves the problem of long-term winding of material and atmosphere pollution in high-temperature sintering of the zinc oxide piezoresistor, adopts common materials which are extremely easy to purchase, and lays a foundation for high-end manufacturing.

Drawings

FIG. 1 is a process flow chart of a manufacturing method of a sagger special for a high-performance zinc oxide varistor provided by an embodiment of the invention;

FIG. 2 is a schematic diagram of the structure of the sagger box (or sagger box blank) of the embodiment of FIG. 1 provided by the present invention;

FIG. 3 is a schematic view of the structure of the sagger lid (or sagger lid blank) of the embodiment of FIG. 1, according to the present invention.

Detailed Description

The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, which are given solely for the purpose of illustration and are not to be construed as limitations of the invention, including the drawings which are incorporated herein by reference and for illustration only and are not to be construed as limitations of the invention, since many variations thereof are possible without departing from the spirit and scope of the invention.

Example 1

The sagger for the high-performance zinc oxide piezoresistor provided by the embodiment comprises, by mass, 97 (0.2-2.5): 0.4-1.5): 0-2.5): 0-1.2): 0-1.3): 0-1) zinc oxide, bismuth oxide, antimony oxide, cobalt oxide, manganese oxide, chromium oxide, nickel oxide and boric acid.

Preferably, the alloy consists of zinc oxide, bismuth oxide, antimony oxide, cobalt oxide, manganese oxide, chromium oxide, nickel oxide and boric acid in a mass ratio of 97:0.4:0.4:0.4:0.4: 0.05, as shown in table 1.

TABLE 1

On the basis that the formula is known, the sagger needs to be processed, and referring to fig. 1, the following processing technology can be adopted, and the processing technology comprises the following steps:

s1, grinding and mixing: grinding and mixing the ingredients, putting the mixture into a ball mill or a stirring mill or a vibration mill, adding pure water, balls and a binder, and grinding and mixing for 2-20 hours;

s2, spray granulation: taking out the ground and mixed slurry, performing spray granulation, and filling the slurry into a charging basket;

s3, dry pressing and forming: after checking that the pressing die is correct, putting the powder in the charging basket into a charging basket of a pressing forming machine, calculating the pressing density, the pressing program and the pressure maintaining time, and pressing into a sagger blank;

s4, binder removal and sintering: and (3) conveying the molded blank body to a pushing plate of a glue discharging furnace, conveying the molded blank body and the pushing plate of the glue discharging furnace into a glue discharging kiln together, discharging glue at the temperature of 200-650 ℃ for 6-20 hours, conveying the blank body to a firing kiln, firing at the temperature of 1100-1650 ℃ for 10-30 hours, taking out and cooling to obtain the sagger.

It should be noted that, in the step S1, the mass ratio of the ingredients, the pure water and the balls is (1-1.2): (0.7-1.1): 0.8-1.2), such as 1:0.8: 0.8. The adhesive is added in a proper amount according to the actual production requirement. The ball mill or the stirring mill or the vibrating mill is a key device for mixing and grinding materials, and a certain amount of zirconium balls or agate balls are required to be filled in a cylinder body of the ball mill or the stirring mill or the vibrating mill as a grinding medium during grinding.

In step S2, spray granulation is a granulation method in which the mixed and ground slurry or solution is pumped into a vacuum granulation tower through a pressure pump, and the slurry or solution is dried and agglomerated under the action of spraying and hot air flow, thereby obtaining hollow spherical granules.

The checking pressing die has no wrong fingers, whether the pressing die on the forming machine meets the requirements or not is checked before pressing, the pressing die which is not suitable needs to be replaced, repairable damage can be repaired in time, and the matching of the shapes of the pressing dies is ensured without damage.

In the step S3, the sagger blank includes sagger box blanks 1 covering each other₁And a saggar lid blank 2₁(ii) a The sagger box body and the sagger lid body become the sagger box body 1 and the sagger lid body 2 after the step S4. The structure of the sagger body 1 and the sagger cover 2 are respectively shown in fig. 2 and 3, and the size thereof is referred to as table 2 and table 3. The sagger body 1 is 50-300 mm in overall length (L), 40-310 mm in overall width (W), 15-180 mm in overall height (H), 3-30 mm in four-wall thickness (d) and 10-170 mm in four-wall inner height (H); the saggar body 2 comprises a base 21 and an inner convex surface 22, the length (L) of the base¹) And width (W)¹) Is correspondingly equal to the whole length (L) and the whole width (W) of the saggar box body 1 (the ranges are 50-300 mm and 40-310 mm respectively), and the height (H) of the base enclosure 21¹) 5-30 mm; length (l) of said inner convex surface 22¹) 40 to 280mm in width (w)¹) 30 to 290mm in height (h)¹) 2-15 mm.

TABLE 2

TABLE 3

In the step S3, the sagger blank needs to consider sintering shrinkage, and all blanks (including the sagger box blank 1)₁And a saggar lid blank 2₁) The size should be 1.12 to 1.22 times the size of the finished saggar (including the saggar box 1 and the saggar lid 2). The sagger box body 1₁And a saggar lid blank 2₁Refer again to fig. 2 and 3, and the dimensions thereof are shown in tables 4 and 5. The sagger box body 1 is the sagger box body 1 in the step S3 because of shrinkage phenomenon caused by sintering₁The overall length (L) of the wall is 50-360 mm, the overall width (W) is 40-370 mm, the overall height (H) is 15-250 mm, the thickness (d) of the four walls is 3-40 mm, and the inner height (H) of the four walls is 10-230 mm; the sagger lid body 2 is the sagger lid blank 2 in the step S3₁Comprises a base enclosure blank 21₁And an inwardly convex blank 22₁Said base-surrounding blank 21₁Length (L) of¹) And width (W)¹) With the sagger box blank 1₁The whole length (L) and the whole width (W) are correspondingly equal (the ranges are respectively 50-360 mm and 40-370 mm), and the base enclosure blank body 21₁Height (H) of¹) 5-40 mm; said inner convex blank 22₁Length (l) of¹) 40-340 mm, width (w)¹) 30 to 350mm in height (h)¹) 2-20 mm.

TABLE 4

TABLE 5

Example 2

The difference between this embodiment and embodiment 1 is that the sagger dedicated for the high performance zinc oxide varistor has different ingredients, and is suitable for the subdivided loading of zinc oxide varistor green sheets with different voltage gradients and different specifications and varieties, and the subdivided loading is to strictly avoid the pollution of materials and atmosphere caused by different formulations, and is a measure for obtaining the best quality of all kinds of full series. The material formula and the manufacturing process almost the same as those of the zinc oxide piezoresistor are adopted as much as possible.

The ingredients of the sagger special for the high-performance zinc oxide piezoresistor provided by the embodiment are composed of zinc oxide, bismuth oxide, antimony oxide, cobalt oxide, manganese oxide, chromium oxide, nickel oxide and boric acid in a mass ratio of 97:0.8:1:1:1:1:1:0.05 as shown in table 4.

TABLE 6

Name of Material	Mass ratio%
		Zinc oxide	97.0
Bismuth oxide	0.8
		Antimony oxide	1.0
Cobalt oxide	1.0
		Manganese oxide	1.0
Chromium oxide	1.0
		Nickel oxide	1.0
Boric acid	0.05

Example 3

The difference between the present example and examples 1 and 2 is that the high performance zinc oxide varistor specialized sagger has different ingredients. The ingredients of the sagger special for the high-performance zinc oxide piezoresistor provided by the embodiment are composed of zinc oxide, bismuth oxide, antimony oxide, cobalt oxide, manganese oxide, chromium oxide, nickel oxide and boric acid in a mass ratio of 97:1.3:1.3:2:1.2:1.0:1.0:0.05 as shown in table 7.

TABLE 7

Name of Material	Mass ratio%
		Zinc oxide	97.0
Bismuth oxide	1.3
		Antimony oxide	1.3
Cobalt oxide	2.0
		Manganese oxide	1.2
Chromium oxide	1.0
		Nickel oxide	1.0
Boric acid	0.05

Example 4

The difference between the present example and examples 1, 2 and 3 is that the high performance zinc oxide varistor specialized sagger has different ingredients. As shown in table 8, the alloy consisted of zinc oxide, bismuth oxide, and antimony oxide in a mass ratio of 97:2.5: 0.5.

TABLE 8

Name of Material	Mass ratio%
		Zinc oxide	97.0
Bismuth oxide	2.5
		Antimony oxide	0.5

In summary, the invention provides a burdening and manufacturing method of a special sagger for a high-performance zinc oxide piezoresistor, which adopts a material formula and a manufacturing process almost the same as those of the zinc oxide piezoresistor, prepares the special sagger for the zinc oxide piezoresistor by mixing, grinding, zero-spraying granulation, dry pressing and molding, and binder removal sintering, loads a zinc oxide piezoresistor blank sheet by using the sagger, is the same material even if mutually permeating at a high temperature of more than one thousand degrees, avoids any pollution, solves the problem of long-term winding of the material and the pollution in the high-temperature sintering of the zinc oxide piezoresistor, and adopts common materials which are extremely easy to purchase, and lays a foundation for high-end manufacturing.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.

Claims (9)

1. A material for a special sagger of a high-performance piezoresistor is characterized by comprising, by mass, 97 (0.2-2.5): 0.4-1.5): 0-2.5): 0-1.2): 0-1.3): 0-1.1 zinc oxide, bismuth oxide, antimony oxide, cobalt oxide, manganese oxide, chromium oxide, nickel oxide and boric acid.

2. The formulation for a high performance varistor specialized sagger of claim 1, wherein: the paint consists of zinc oxide, bismuth oxide, antimony oxide, cobalt oxide, manganese oxide, chromium oxide, nickel oxide and boric acid in a mass ratio of 97:0.4:0.4:0.4:0.4:0.4: 0.05.

3. The formulation for a high performance varistor specialized sagger of claim 1, wherein: the paint consists of zinc oxide, bismuth oxide, antimony oxide, cobalt oxide, manganese oxide, chromium oxide, nickel oxide and boric acid in a mass ratio of 97:0.8:1:1:1:1: 0.05.

4. The formulation for a high performance varistor specialized sagger of claim 1, wherein: the paint consists of zinc oxide, bismuth oxide, antimony oxide, cobalt oxide, manganese oxide, chromium oxide, nickel oxide and boric acid with the mass ratio of 97:1.3:1.3:2:1.2:1.0:1.0: 0.05.

5. The formulation for a high performance varistor specialized sagger of claim 1, wherein: consists of zinc oxide, bismuth oxide and antimony oxide with the mass ratio of 97:2.5: 0.5.

6. A manufacturing method of a sagger special for a high-performance piezoresistor is characterized by comprising the following steps:

s1, grinding and mixing: grinding and mixing the ingredients of any one of claims 1 to 4, putting the mixture into a ball mill, a stirring mill or a vibrating mill, adding pure water, balls and a binder, and grinding and mixing for 2 to 20 hours;

s2, spray granulation: taking out the ground and mixed slurry, performing spray granulation, and filling the slurry into a charging basket;

s3, dry pressing and forming: after checking that the pressing die is correct, putting the powder in the charging basket into a charging basket of a pressing forming machine, and pressing into a sagger blank;

s4, binder removal and sintering: and (3) conveying the molded blank body to a glue discharging kiln, discharging glue at the temperature of 200-650 ℃ for 6-20 hours, conveying to a firing kiln, firing at the temperature of 1100-1650 ℃ for 10-30 hours, taking out, and cooling to obtain the sagger.

7. The manufacturing method of the sagger special for the high-performance piezoresistor as claimed in claim 6, characterized in that: in the step S1, the mass ratio of the ingredients, the pure water and the balls is (1-1.2): (0.7-1.1): 0.8-1.2.

8. The manufacturing method of the sagger special for the high-performance piezoresistor as claimed in claim 6, characterized in that: in the step S3, the sagger blank includes a sagger box blank and a sagger lid blank that are mutually covered; the sagger box body and the sagger lid body become the sagger box body and the sagger lid body after the step S4.

9. The manufacturing method of the sagger special for the high-performance piezoresistor as claimed in claim 8, characterized in that: the overall length of the sagger body is 50-300 mm, the overall width is 40-310 mm, the overall height is 15-180 mm, the thickness of four walls is 3-30 mm, and the inner height of the four walls is 10-170 mm;

the sagger cover body comprises a base wall and an inner convex surface, the length and the width of the base wall are correspondingly equal to the whole length and the whole width of the sagger box body, and the height is 5-30 mm; the height of the inner convex surface is 2-15 mm, the length is 40-280 mm, and the width is 30-290 mm.

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