Iron-based ferrite material and preparation method and application thereof
阅读说明：本技术 一种铁基-铁氧体材料及其制备方法与用途 (Iron-based ferrite material and preparation method and application thereof ) 是由 林文言 于 2020-12-08 设计创作，主要内容包括：本发明提供了一种铁基-铁氧体材料及其制备方法,由铁粉和铁氧体组成；并提供了上述铁基-铁氧体材料在制备粉末冶金摩擦材料和制备汽车刹车片中的用途,同时提供了制备上述铁基-铁氧体材料刹车片的方法。本发明提供的铁基-铁氧体材料打破了铁氧体材料通常用于制备磁性材料的常规,创造性的将其与铁粉复合,制备出粉末冶金摩擦材料和汽车刹车片,不但降低了有机物对环境的危害,同时降低了空气中粉尘含量。(The invention provides an iron-based ferrite material and a preparation method thereof, wherein the iron-based ferrite material consists of iron powder and ferrite; the application of the iron-based ferrite material in preparing powder metallurgy friction materials and automobile brake pads is provided, and the method for preparing the iron-based ferrite material brake pads is also provided. The iron-based ferrite material breaks through the conventional process that the ferrite material is usually used for preparing magnetic materials, and is creatively compounded with iron powder to prepare the powder metallurgy friction material and the automobile brake pad, so that the harm of organic matters to the environment is reduced, and the dust content in the air is reduced.)
1. An iron-based ferrite material is characterized by comprising the following raw materials in percentage by weight: 40-60% of iron powder and the balance of ferrite.
2. The iron-based-ferrite material of claim 1, wherein the iron powder is a pure iron powder having a particle size of 120 mesh.
3. The iron-based ferrite material of claim 1, wherein the ferrite is strontium ferrite having a grain size of 40 microns.
4. The method of preparing an iron-based-ferrite material as claimed in claim 1, comprising the steps of: and uniformly mixing the iron powder and the ferrite to obtain the ferrite.
5. Use of an iron-based-ferrite material according to claim 1 in the preparation of powder metallurgy friction materials.
6. Use of an iron-based ferrite material according to claim 1 in the manufacture of an automotive brake pad.
7. The preparation method of the iron-based ferrite friction plate is characterized by comprising the following steps of:
(1) adding a lubricant into an iron-based ferrite material, and uniformly mixing to obtain powder;
(2) pressing the powder into a pressed compact, and then sintering;
(3) and after sintering, obtaining the iron-based ferrite friction plate.
8. The method for preparing an iron-based ferrite friction plate as claimed in claim 7, wherein the friction plate can be sequentially combined with a heat insulation layer and a back plate to prepare a brake pad; the method also comprises surface treatment of the friction plate.
9. The method for preparing an iron-based-ferrite friction plate according to claim 7, wherein the lubricant is zinc stearate or polyvinyl alcohol aqueous solution, and the amount of the lubricant added is 1-2% by mass of the powder.
10. The method of claim 7, wherein the pressing pressure is 4-5 ton/cm2(ii) a The sintering temperature is 1100 ℃, the sintering time is 3-4h, and N is introduced in the sintering process2And protecting, wherein the heating rate in the sintering process is 50-100 ℃/h.
Technical Field
The invention belongs to the field of materials, and particularly relates to an iron-based ferrite material, and a preparation method and application thereof.
Background
The friction material of the existing automobile brake pad is made of thermosetting high polymer material similar to phenolic resin, and is formed by mixing ceramic particles formed by thermally bonding various combinations of silicide, carbide, nitride, oxide and the like. Although the brake pad completely meets the service performance requirements in the aspect of automobile braking, phenol, formaldehyde and derivatives thereof are released in the braking process due to thermal oxidation degradation, and toxic substances are emitted in the living environment of human beings. More seriously, the ceramic substance in the brake pad is abraded to form PM2.5 dust which is discharged into the air, and the dust, like asbestos, has great harm to the health of people. After the micro-dust enters the body, the 'micro-acid' and 'micro-base' substances in the human body can not change the properties and the forms of the substances, and the substances can be deposited in organs such as lung cells, blood vessels, hearts and the like of the human body to form spots and blocks, so that the organs of the human body are diseased. This should be the main reason for the recent development of pulmonary, tracheal, cardiovascular and cerebrovascular diseases.
Meanwhile, the research and development group carries out replacement research and development on the friction material of the brake pad, and the pure iron oxide material cannot become the friction material of the brake pad in the replacement process, so that the friction material is fragile and easy to crack, and the performance cannot reach the standard. Based on the above, the research and development group further improves on the basis of iron oxide, and proposes that the iron-based ferrite replaces the existing ceramic brake pad, so that the emission of toxic gases such as phenol and formaldehyde is avoided, and the emission of ceramic PM2.5 dust is also avoided. Although the iron-based ferrite brake pad can also generate a certain amount of PM2.5 dust, the chemical component of the iron-based ferrite brake pad is ferric oxide which can be changed by weak acid and weak alkaline substances in a human body; on the other hand, because of the high specific gravity of the iron oxide, the iron oxide is not easy to diffuse and float in the air, and because of the strong water absorption, the dust is gathered and falls to the ground. Compared with the prior art, the pollution degree of the air conditioner to the air is obviously better. Accordingly, the present invention is particularly set forth.
Disclosure of Invention
The technical problem to be solved by the invention is to overcome the defects and shortcomings in the background art and provide an iron-based ferrite material which is safe and nontoxic to use and has excellent comprehensive performance, and a preparation method and application thereof.
In order to solve the above technical problems, the present invention provides the following technical solutions.
An iron-based ferrite material comprises the following raw materials in percentage by weight: 40-60% of iron powder and the balance of ferrite.
The iron powder is pure iron powder with the granularity of 120 meshes.
The ferrite is strontium ferrite and has the granularity of 40 microns.
Preferably, the iron-based ferrite material consists of the following raw materials in percentage by weight: 40% of iron powder and 60% of ferrite.
Preferably, the iron-based ferrite material consists of the following raw materials in percentage by weight: 43% of iron powder and 57% of ferrite.
Preferably, the iron-based ferrite material consists of the following raw materials in percentage by weight: 45% of iron powder and 55% of ferrite.
Preferably, the iron-based ferrite material consists of the following raw materials in percentage by weight: 53% of iron powder and 47% of ferrite.
Preferably, the iron-based ferrite material consists of the following raw materials in percentage by weight: 55% of iron powder and 45% of ferrite.
Preferably, the iron-based ferrite material consists of the following raw materials in percentage by weight: 58% of iron powder and 42% of ferrite.
Preferably, the iron-based ferrite material consists of the following raw materials in percentage by weight: 60% of iron powder and 40% of ferrite.
A preparation method of an iron-based ferrite material comprises the following steps: and uniformly mixing the iron powder and the ferrite to obtain the ferrite.
The application of the iron-based ferrite material in preparing powder metallurgy friction materials.
The iron-based ferrite material is used for preparing the automobile brake pad.
A preparation method of an iron-based ferrite friction plate comprises the following steps.
(1) Adding the lubricant into the iron-based ferrite material, and uniformly mixing to obtain powder.
(2) Pressing the powder into a compact, and then sintering.
(3) And after sintering, obtaining the iron-based ferrite friction plate.
The friction plate can be sequentially combined with the heat insulation layer and the back plate into a whole to prepare the brake pad.
The lubricant is zinc stearate or polyvinyl alcohol aqueous solution; the addition amount of the lubricant is 1-2% of the mass of the powder.
In the pressing process, the pressure is 4-5 tons of force/cm2。
The sintering temperature is 1100-1130 ℃.
The sintering time is 3-4 h; introducing N in the sintering process2And (4) protecting.
The heating rate in the sintering process is 50-100 ℃/h.
Further, the preparation method of the iron-based-ferrite friction plate can also comprise the step of carrying out surface treatment on the friction plate.
Compared with the prior art, the invention has the following beneficial effects.
(1) The invention provides the application of the iron-based ferrite material in preparing powder metallurgy friction materials and automobile brake pads, can replace the brake pads which are commonly used at present and are made of ceramic materials, and reduces the toxic substances such as phenol and formaldehyde discharged in the environment and ceramic PM2.5 dust which can not be decomposed by human bodies.
(2) Although iron-based ferrite brake pads can generate certain dust in the using process, the chemical components of the iron-based ferrite brake pads are mainly iron oxide dust which can be changed by weak acid and weak base substances in a human body and is harmless to the human body; meanwhile, the iron oxide has a large specific gravity, is not easy to diffuse and float in the air, has strong water absorption, and can quickly fall to the ground even if micro powder is formed; compared with the pollution degree to the air.
(3) The invention disperses pure iron powder in ferrite to make iron powder particles reach metal bonding and Fe2O3To Fe3O4And maintains its FeO (Fe)2O3) Spinel-type crystal system (or trans-spinel structure); the key to ensuring this condition is the raw material ratio of iron powder to ferrite and the sintering temperature, since the surface area of the added Fe powder particles determines the amount of FeO and the remaining iron powder (as matrix), and the sintering temperature 1100-1130 ℃ determines the "Fe-3O4The structure of "does not change.
Drawings
FIG. 1 is a schematic view of the friction plate of the present invention combined with a heat insulation layer and a back plate in sequence.
FIG. 2 is a process flow for manufacturing a friction plate according to the present invention. Wherein: 1-friction plate, 2-heat insulation layer and 3-back plate.
Detailed Description
In order to facilitate an understanding of the invention, the invention will be described more fully and in detail below with reference to the accompanying drawings and preferred embodiments, but the scope of the invention is not limited to the specific embodiments below. Unless otherwise defined, all terms of art used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention. Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment and the like used in the present invention are commercially available or can be prepared by existing methods.
Example 1.
A preparation method of an iron-based ferrite friction plate comprises the following steps.
(1) Adding 1% zinc stearate of the iron-based ferrite material into the iron-based ferrite material, and uniformly mixing to obtain powder.
(2) Loading the powder into a steel die for press forming at 4-5 ton/cm2Pressing under pressure, and demolding to obtain green compact; putting the qualified pressed compact into a continuous sintering furnace for sintering at the heating rate of 50-100 ℃/h and the sintering temperature of 1100 ℃ for 3h, and introducing N in the process2And (6) protecting.
(3) And after sintering, obtaining the iron-based ferrite friction plate.
The iron-based ferrite material consists of 40% of pure iron powder and 60% of strontium ferrite.
Example 2.
A preparation method of an iron-based ferrite friction plate comprises the following steps.
(1) Adding 1% of polyvinyl alcohol of the iron-based ferrite material into the iron-based ferrite material, and uniformly mixing to obtain powder.
(2) Loading the powder into a steel die for press forming at 4-5 ton/cm2Pressing under pressure, and demolding to obtain green compact; putting the qualified pressed compact into a continuous sintering furnace for sintering, wherein the heating rate is 50-100 ℃/h, the sintering temperature is 1130 ℃, the temperature is kept for 4h, and N is introduced in the process2And (6) protecting.
(3) And after sintering, obtaining the iron-based ferrite friction plate.
The iron-based ferrite material consists of 43% of pure iron powder and 57% of strontium ferrite.
Example 3.
A preparation method of an iron-based ferrite friction plate comprises the following steps.
(1) Adding 1% of polyvinyl alcohol of the iron-based ferrite material into the iron-based ferrite material, and uniformly mixing to obtain powder.
(2) Loading the powder into a steel die for press forming at 4-5 ton/cm2Pressing under pressure, and demolding to obtain green compact; putting the qualified pressed compact into a continuous sintering furnace for sintering, wherein the heating rate is 50-100 ℃/h, the sintering temperature is 1130 ℃, the temperature is kept for 4h, and N is introduced in the process2And (6) protecting.
(3) And after sintering, obtaining the iron-based ferrite friction plate.
The iron-based ferrite material consists of 45% of pure iron powder and 55% of strontium ferrite.
Example 4.
A preparation method of an iron-based ferrite friction plate comprises the following steps.
(1) Adding 1% of polyvinyl alcohol of the iron-based ferrite material into the iron-based ferrite material, and uniformly mixing to obtain powder.
(2) Loading the powder into a steel die for press forming at 4-5 ton/cm2Pressing under pressure, and demolding to obtain green compact; putting the qualified pressed compact into a continuous sintering furnace for sintering, wherein the heating rate is 50-100 ℃/h, the sintering temperature is 1130 ℃, the temperature is kept for 4h, and N is introduced in the process2And (6) protecting.
(3) And after sintering, obtaining the iron-based ferrite friction plate.
The iron-based ferrite material consists of 53% of pure iron powder and 47% of strontium ferrite.
Example 5.
A preparation method of an iron-based ferrite friction plate comprises the following steps.
(1) Adding 1% of polyvinyl alcohol of the iron-based ferrite material into the iron-based ferrite material, and uniformly mixing to obtain powder.
(2) Loading the powder into a steel die for press forming at 4-5 ton/cm2Pressing under pressure, and demolding to obtain green compact; putting the qualified pressed compact into a continuous sintering furnace for sintering, wherein the heating rate is 50-100 ℃/h, the sintering temperature is 1130 ℃, the temperature is kept for 4h, and N is introduced in the process2And (6) protecting.
(3) And after sintering, obtaining the iron-based ferrite friction plate.
The iron-based ferrite material consists of 55% of pure iron powder and 45% of strontium ferrite.
Example 6.
A preparation method of an iron-based ferrite friction plate comprises the following steps.
(1) Adding 1% of polyvinyl alcohol of the iron-based ferrite material into the iron-based ferrite material, and uniformly mixing to obtain powder.
(2) Loading the powder into a steel die for press forming at 4-5 ton/cm2Pressing under pressure, and demolding to obtain green compact; putting the qualified pressed compact into a continuous sintering furnace for sintering, wherein the heating rate is 50-100 ℃/h, the sintering temperature is 1130 ℃, the temperature is kept for 4h, and N is introduced in the process2And (6) protecting.
(3) And after sintering, obtaining the iron-based ferrite friction plate.
The iron-based ferrite material consists of 58% of pure iron powder and 42% of strontium ferrite.
Example 7.
A preparation method of an iron-based ferrite friction plate comprises the following steps.
(1) Adding 1% of polyvinyl alcohol of the iron-based ferrite material into the iron-based ferrite material, and uniformly mixing to obtain powder.
(2) Loading the powder into a steel die for press forming at 4-5 ton/cm2Pressing under pressure, and demolding to obtain green compact; putting the qualified pressed compact into a continuous sintering furnace for sintering, wherein the heating rate is 50-100 ℃/h, the sintering temperature is 1130 ℃, the temperature is kept for 4h, and N is introduced in the process2And (6) protecting.
(3) And after sintering, obtaining the iron-based ferrite friction plate.
The iron-based ferrite material consists of 60% of pure iron powder and 40% of strontium ferrite.
Example 8.
A preparation method of an iron-based ferrite friction plate comprises the following steps.
(1) Adding 1% of polyvinyl alcohol of the iron-based ferrite material into the iron-based ferrite material, and uniformly mixing to obtain powder.
(2) Loading the powder into a steel die for press forming at 4-5 ton/cm2Pressing under pressure, and demolding to obtain green compact; putting the qualified pressed compact into a continuous sintering furnace for sintering, wherein the heating rate is 50-100 ℃/h, the sintering temperature is 1130 ℃, the temperature is kept for 4h, and N is introduced in the process2And (6) protecting.
(3) And after sintering, obtaining the iron-based ferrite friction plate.
The iron-based ferrite material consists of 35% of pure iron powder and 65% of strontium ferrite.
Example 9.
A preparation method of an iron-based ferrite friction plate comprises the following steps.
(1) Adding 1% of polyvinyl alcohol of the iron-based ferrite material into the iron-based ferrite material, and uniformly mixing to obtain powder.
(2) Loading the powder into a steel die for press forming at 4-5 ton/cm2Pressing under pressure, and demolding to obtain green compact; putting the qualified pressed compact into a continuous sintering furnace for sintering, wherein the heating rate is 50-100 ℃/h, the sintering temperature is 1130 ℃, the temperature is kept for 4h, and N is introduced in the process2And (6) protecting.
(3) And after sintering, obtaining the iron-based ferrite friction plate.
The iron-based ferrite material consists of 65% of pure iron powder and 35% of strontium ferrite.
The iron-based ferrite friction plate prepared in the examples 1 to 9 can be combined with a heat insulation layer and a back plate into a whole in sequence, and the performance test results of the prepared brake pad are shown in table 1. The friction coefficients of the brake pads prepared in the embodiments 1 to 7 are stable and are all 0.35 to 0.39, and the wear resistance meets the use requirement.
Table 1. iron-based-ferrite brake pad performance test results.
Coefficient of friction
Example 1
0.39
Example 2
0.37
Example 3
0.38
Example 4
0.35
Example 5
0.37
Example 6
0.36
Example 7
0.35
Example 8
0.31
Example 9
0.30