CN112517837A - Aluminum bronze lost foam casting environment-friendly coating and preparation method thereof - Google Patents
Aluminum bronze lost foam casting environment-friendly coating and preparation method thereof Download PDFInfo
- Publication number
- CN112517837A CN112517837A CN202011419597.5A CN202011419597A CN112517837A CN 112517837 A CN112517837 A CN 112517837A CN 202011419597 A CN202011419597 A CN 202011419597A CN 112517837 A CN112517837 A CN 112517837A
- Authority
- CN
- China
- Prior art keywords
- coating
- weight
- parts
- base material
- lost foam
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C3/00—Selection of compositions for coating the surfaces of moulds, cores, or patterns
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C7/00—Patterns; Manufacture thereof so far as not provided for in other classes
- B22C7/02—Lost patterns
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Mold Materials And Core Materials (AREA)
- Compositions Of Oxide Ceramics (AREA)
Abstract
The invention discloses an aluminum bronze lost foam casting environment-friendly coating and a preparation method thereof, and the coating comprises 100 parts by weight of a refractory base material, 2-3 parts by weight of sodium bentonite, 0.3 part by weight of CMC, 3-5 parts by weight of silica sol, 0.05 part by weight of PAM, 50-80 parts by weight of water, 0.4-1.5 parts by weight of JFC, 1-3 parts by weight of n-butyl alcohol, 0.1-0.5 part by weight of formalin and 20-40 parts by weight of pore-forming agent, wherein the refractory base material contains a sintering aid. The mechanical strength of the coating is better, both after drying and after sintering.
Description
Technical Field
The invention relates to the field of casting coatings, and particularly relates to an aluminum bronze lost foam casting environment-friendly coating and a preparation method thereof.
Background
The basic principle of the lost foam casting is as follows: after a fireproof coating layer is coated on a foaming plastic mould with a similar casting shape, the mould is placed in a sand box, dry sand is filled around the mould, the mould is compacted and modeled through vibration, then molten metal is poured, and the foamed plastic is pyrolyzed and disappears under the heat action of the high-temperature molten metal, so that the molten metal is filled in a space where the foamed plastic film disappears, and the model filling is completed. As a novel casting method, the lost foam casting has the characteristics of being better than other casting methods: (1) the casting precision is high, and the surface roughness is low. (2) The degree of freedom of design is large. (3) The process is comparatively simple, and work efficiency is high (4) production environment is clean, clean. (5) The production cost is low.
Because the key technology of the lost foam casting forming is coating technology, the good and bad of the coating has the crucial influence on the quality of the lost foam casting. For a long time, most of the coatings for aluminum bronze castings in China are consistent with iron castings. Although the melting point of the aluminum bronze is lower than that of steel, in order to ensure that the lost foam is quickly and sufficiently gasified and disappears in the casting process, the casting temperature needs to be 1100-1300 ℃, so that the coating needs to have good fire resistance and air permeability and simultaneously has sintering property so as to improve the surface quality of a casting and the stability of a cavity in the casting process. In order to keep the lost foam not deformed and damaged when being buried in a sand mold, the lost foam coating also needs to have certain mechanical strength after being dried and solidified, and meanwhile, the aluminum bronze contains certain aluminum and is easy to oxidize and absorb hydrogen, so that the selected material is not easy to react with copper, aluminum and oxides.
It is believed that the process of forming one or more solid (metal, oxide, nitride, clay) powders, which begin to shrink after heating to a certain temperature and become a dense, hard sintered body below the melting point temperature is called sintering, based on the macroscopic changes that occur in the sintered powder body. Sintering is an important link for preparing powder metallurgy, refractory materials and ultrahigh temperature materials. The purpose of sintering is to transform the refractory mass from a powder form to a compact body. The dense body is a polycrystalline material, the microstructure of which consists of crystals, glass bodies and pores. The sintering process directly affects the size and distribution of the crystals of the dense body, and the distribution of the pores is also determined by the sintering process. Sintering is macroscopically manifested by volume shrinkage, densification and increased strength.
The refractory aggregate selected may react with the metal oxide. The refractory aggregate comprises zircon powder, high alumina bauxite powder, talcum powder, mica powder and the like. The surface of the silicate is finely groundThe product becomes large, broken bonds are generated, and the broken bonds are broken at high temperature to generate amorphous SiO2Amorphous SiO2Can react with ferrous iron oxide to generate low-melting-point substances. This allows the refractory aggregate to be sintered at 1200 to 1300 ℃. This gives the refractory aggregate the characteristics of high refractoriness and low sintering point, since the reaction takes place on the surface of the particles.
Strategies for lowering the sintering temperature are: the added sintering aid and the binder can decompose amorphous silicon dioxide or aluminum trioxide. Common additives mainly comprise clay, silica sol, bentonite, alumina silicate, water glass and the like. They mainly act as binders at low temperatures, can be decomposed by heating during casting to produce amorphous silica and alumina, and react with ferrous oxide to produce low-melting-point substances, which act as sintering aids at high temperatures. The high refractoriness aggregate is added with a low refractoriness material with similar composition. For example, alunite powder or kaolin powder is added into corundum powder; feldspar, talcum powder and mica powder are added into the quartz powder aggregate; to the flake graphite, soil-like graphite or the like is added. After the low-refractoriness material is dissolved, the surface of the high-refractoriness material is corroded, and the sintering aid effect is achieved. Or mixing the refractory aggregate and the additive to make the oxide component be low-melting compound or low-melting eutectic substance. Substances such as a flux and a flux-resistant agent for adjusting the sinterability may be added to improve the sinterability of the coating. Such as fluorides, alkali metals, alkali metal oxides, and the like.
Quartz powder and bauxite are widely used as cheap and easily available refractory aggregates on lost foam coatings, but the sinterability of the quartz powder and the bauxite is poor. When used as a refractory aggregate, the coating often causes defects such as sand burning of a casting, poor coating stripping property and the like. The principle of the lost foam coating at the beginning of design is that the refractory aggregate needs to be sintered and stripped, and if the sintering property of the refractory aggregate is poor at the pouring temperature. A dense sintered layer having sufficient strength cannot be formed and cannot withstand the erosion action of the molten metal during casting. The molten metal penetrates through the coating to corrode the casting mould, so that the casting has the sand sticking defect, and the coating is easy to stick on the surface of the casting and is not easy to peel off even if the sand sticking is not caused.
The sintering aid has the main function of promoting the sintering of the coating, so that a glass phase is formed in the sintered coating, and the stripping property of the coating is improved. Meanwhile, the compactness of the refractory aggregate is improved, and the rigidity and the strength of the coating are also improved. However, the addition of the sintering aid has a great influence on the air permeability of the coating, because the increase in density after sintering is likely to result in a great reduction in the air permeability of the coating.
Disclosure of Invention
The technical problems to be solved by the invention are as follows: the existing coating has poor air permeability, and the strength of the coating after coating and sintering is influenced after the porous material is added.
In order to solve the technical problems, the invention provides the following technical scheme:
the aluminum bronze lost foam casting environment-friendly coating is prepared from the following components in parts by weight: 100 parts of a refractory base material, 2-3 parts of sodium bentonite, 0.3 part of CMC, 3-5 parts of silica sol, 0.05 part of PAM, 50-80 parts of water, 0.4-1.5 parts of JFC, 1-3 parts of n-butyl alcohol, 0.1-0.5 part of formalin and 20-40 parts of a pore-forming agent, wherein the pore-forming agent is self-assembled into an ordered structure after the coating is dried and solidified, and is carbonized into a porous ordered structure at the temperature of 700-1300 ℃; the fireproof base material comprises 5-10 wt% of a sintering aid, 5-10 wt% of mica, 20-30 wt% of diatomite and 50-70 wt% of bauxite, wherein the sintering aid comprises LiF and SrCO3、ZnO、B2O3The sintering aid reduces the sintering temperature of the coating to 750 ℃.
Preferably, the porogen consists of resorcinol, terephthalaldehyde and a triblock polymer F127.
Preferably, the resorcinol: terephthalaldehyde: the mass ratio of F127 is 0.5-5: 3-10: 1.
preferably, the drying temperature of the coating is 105-115 ℃.
Preferably, the LiF, SrCO3、ZnO、B2O3The weight ratio of the refractory base material to the refractory base material is 1:3:2:1, and the granularity of the refractory base material is 200 meshes.
A preparation method of the aluminum bronze lost foam casting environment-friendly coating comprises the following specific steps:
(A) weighing resorcinol, terephthalaldehyde and a triblock polymer F127 according to a formula, then carrying out vacuum grinding and mixing, adding water accounting for 30-40% of the total weight of the resorcinol, the terephthalaldehyde and the F127 in the grinding process, fully grinding and mixing to obtain a pore-foaming agent, and storing in a dry environment;
(B) preparation of the refractory substrate: weighing LiF and SrCO according to the proportion3、ZnO、B2O3Fully grinding and mixing the mixture to be used as a sintering aid for later use, and then grinding and mixing the mica, the diatomite and the bauxite, and then adding the sintering aid to fully mix to obtain the refractory base material;
(C) weighing the refractory base material, sodium bentonite, CMC, silica sol, PAM, JFC, n-butanol and formalin according to a burdening table, fully grinding and mixing to obtain a mixture, calculating and deducting the moisture content in a pore-forming agent, adding the residual water in the raw materials into the mixture, and uniformly stirring to obtain a coating base material;
(D) half an hour before coating, adding the pore-foaming agent into the coating base material, and uniformly mixing for subsequent lost foam coating.
The invention has the following beneficial effects:
the pore-forming agent is self-assembled to form an orderly-arranged structure in the dry-curing process, so that the coating is carbonized to form orderly-arranged pores during high-temperature sintering, the pores are communicated to facilitate the discharge of gaseous and liquid decomposition products, the air permeability is good, the sintering temperature of the refractory base material is reduced to about 750 ℃ through the sintering aid, the collapse of the orderly porous structure formed by the pore-forming agent during high-temperature casting is prevented, and the coating keeps good air permeability while the high-temperature sintering strength and the density are ensured. The mechanical strength of the coating is better whether after drying and sintering.
Drawings
FIG. 1 is a micro-contrast diagram of the sintered structure of the porogen and the complete coating at 1300 deg.C sintering temperature.
Wherein, A is the complete coating of the invention, B is a pore-foaming agent.
Detailed Description
The following examples are included to provide further detailed description of the present invention and to provide those skilled in the art with a more complete, concise, and exact understanding of the principles and spirit of the invention.
Example 1: the aluminum bronze lost foam casting environment-friendly coating is prepared by the following method:
(A) resorcinol, terephthalaldehyde and a triblock polymer F127 are mixed according to a mass ratio of 0.5: 3: 1, weighing and proportioning, then grinding and mixing in vacuum, adding 30 percent of water of the total weight of resorcinol, terephthalaldehyde and F127 in the grinding process, fully grinding and mixing to 150 meshes to obtain a pore-foaming agent, and storing in a dry environment; because resorcinol has strong moisture absorption capacity, the grinding needs to be carried out in a dry vacuum environment, and the influence of excessive moisture on the self-assembly of the pore-forming agent caused by water absorption in the grinding process is prevented.
(B) Preparation of the refractory substrate: according to the weight ratio of LiF: SrCO3：ZnO：B2O3The materials are mixed according to the ratio of 1:1:1:1, fully ground and mixed to be used as a sintering aid for later use, and then 5 wt% of the sintering aid, 5 wt% of mica, 20 wt% of diatomite and 70 wt% of bauxite are ground and mixed, added with the sintering aid, fully mixed and sieved by a 200-mesh sieve to obtain the refractory base material;
selection of refractory base materials
When the aluminum bronze is cast, oxides are generated on the surface during pouring, and the products are alkaline and are easy to react with acid refractory base materials such as quartz powder, mullite and the like to corrode the coating and the surface of a casting mold, so that an alkaline silicate material is selected as the base material. The temperature of the cast aluminum bronze is 1250-1280 ℃, under the condition of ensuring enough fire resistance, the cost can be saved as a principle, and expensive zirconium refractory materials such as corundum powder, zirconite powder and the like are avoided as much as possible, so diatomite, mica and bauxite are finally selected as the refractory base materials.
Copper, aluminum and oxides thereof do not react with diatomite, mica and bauxite chemically, the heat conductivity of the diatomite is 0.14W/(m x: K), the heat conductivity of the diatomite is minimum, and a plurality of uniform and regularly arranged microscopic holes exist in the diatomite, so that the coating layer has good heat insulation performanceCan be used. Bauxite is also called alumina or bauxite, the main component of which is alumina, which is hydrated alumina containing impurities and is a soil-like mineral. White or off-white, brownish yellow or reddish due to iron. The density is 3.9-4 g/cm3The hardness is 1-3, and the paint is opaque and crisp. It is extremely difficult to melt. It is insoluble in water, and can be dissolved in sulfuric acid and sodium hydroxide solution, and the bauxite is named bauxite or bauxite. The composition of the water-containing alumina ore is extremely complex, and is a general term of various water-containing alumina ores with extremely different geological sources. Such as boehmite, diaspore and gibbsite (Al)2O33H2O)(Al2O33H2O); some are diaspore and kaolinite (2 SiO)2Al2O32H2O)(2SiO2Al2O32H2O) a concomitant constituent; some aluminum bronze lost foam casting paint aggregates are composed mainly of kaolinite, and as the content of kaolinite increases, the aluminum bronze lost foam casting paint aggregates are composed of general bauxite or kaolinite clay. The filling of aluminum bronze is not only related to the thermal insulation of the coating, but also to its gas permeability. The mica structure is loose and porous, the high-temperature air permeability of the coating can be improved, and the air permeability of the coating can be adjusted by adding the binder and the suspending agent in the later period. The coating adopts diatomite, mica and bauxite as refractory powder. The tensile strength of the coating reaches 0.035MPs, and the casting molding and pouring requirements can be met. And after the casting is cooled and boxed, the coating layer automatically cracks and automatically falls off from the surface of the casting, so that the casting is easy to clean.
(C) Weighing 100 parts by weight of refractory base material, 2 parts by weight of sodium bentonite, 0.3 part by weight of CMC, 3 parts by weight of silica sol, 0.05 part by weight of PAM, 50 parts by weight of water, 0.4 part by weight of JFC, 1 part by weight of n-butyl alcohol and 0.1 part by weight of formalin according to a formulation table, fully grinding and mixing to obtain a mixture, calculating and deducting the water content in a pore-forming agent, adding the rest water in the raw materials into the mixture, and uniformly stirring to obtain a coating base material;
(D) half an hour before coating, adding 2 parts by weight of pore-foaming agent into the coating base material, and uniformly mixing for subsequent lost foam coating. The paint drying temperature in this example was 105 ℃.
Selection of suspending agents
Sodium bentonite and sodium carboxymethyl cellulose (CMC) are selected as composite suspending agents. The particle mass point of the sodium bentonite is very small, water molecules are adsorbed on the surface of the sodium bentonite and enter the crystal layers to form colloid mass points, and the mass points form a space network structure in a colloid solution, so that the bentonite slurry has a yield value, and the refractory aggregate particle mass points are not easy to sink. The sodium carboxymethylcellulose (CMC) is divided into 3 types of high, medium and low according to the viscosity, wherein the CMC with medium viscosity is prepared into 2 percent aqueous solution, and the viscosity of the aqueous solution is (300-600) multiplied by 103Pa · s, which is inexpensive and abundant in source, is widely used as a suspending agent for water-based paints. The CMC and the sodium bentonite are matched for use, and a reticular structure is easier to form than that when the CMC is singly used, so that the yield value of the coating is obviously improved, and the coating has better suspension property.
Selection of the Binder
The strength of the coating layer is mainly determined by the adhesive strength of the adhesive. The lost foam coating layer has proper air permeability and high coating strength, so that a high-low temperature composite binder is adopted. 0.01 to 0.1 percent of Polyacrylamide (PAM) is added into the aqueous solution, so that high viscosity can be obtained, and meanwhile, the PAM and bentonite particles have strong adsorption action, so that the coating has good suspension property. However, the adhesive can be decomposed when the temperature exceeds 120 ℃, so that the adhesive can be used as a low-temperature adhesive, and silica sol can be used as a high-temperature adhesive.
Selection of liquid carriers and aids
Proper amount of water is used as carrier liquid, JFC is used as wetting dispersant, n-butyl alcohol is used as defoaming agent, and formalin is used as preservative.
Example 2: the aluminum bronze lost foam casting environment-friendly coating is prepared by the following method:
(A) resorcinol, terephthalaldehyde and a triblock polymer F127 are mixed according to a mass ratio of 5: 10: 1, weighing and proportioning, then grinding and mixing in vacuum, adding resorcinol, terephthalaldehyde and water accounting for 40 percent of the total weight of F127 in the grinding process, fully grinding and mixing to 200 meshes to obtain a pore-foaming agent, and storing in a dry environment; because resorcinol has strong moisture absorption capacity, the grinding needs to be carried out in a dry vacuum environment, and the influence of excessive moisture on the self-assembly of the pore-forming agent caused by water absorption in the grinding process is prevented.
(B) Preparation of the refractory substrate: according to the weight ratio of LiF: SrCO3：ZnO：B2O3The materials are mixed according to the proportion of 5:3:2:2, are fully ground and mixed to be used as a sintering aid for later use, 10 wt% of the sintering aid, 10 wt% of mica, 30 wt% of diatomite and 50 wt% of bauxite are ground and mixed, then the sintering aid is added, and the mixture is fully mixed and then is sieved by a 200-mesh sieve, so that the refractory base material is obtained;
(C) weighing 100 parts by weight of refractory base material, 3 parts by weight of sodium bentonite, 0.3 part by weight of CMC, 5 parts by weight of silica sol, 0.05 part by weight of PAM, 80 parts by weight of water, 1.5 parts by weight of JFC, 3 parts by weight of n-butyl alcohol and 0.5 part by weight of formalin according to a formulation, fully grinding and mixing to obtain a mixture, calculating and deducting the water content in a pore-forming agent, adding the rest water in the raw materials into the mixture, and uniformly stirring to obtain a coating base material;
(D) half an hour before coating, adding 40 parts by weight of pore-foaming agent into the coating base material, and uniformly mixing for subsequent lost foam coating. The drying temperature of the coating in this example was 115 ℃.
Example 3: the aluminum bronze lost foam casting environment-friendly coating is prepared by the following method:
(A) resorcinol, terephthalaldehyde and a triblock polymer F127 are mixed according to a mass ratio of 2.5: 4: 1, weighing and proportioning, then grinding and mixing in vacuum, adding resorcinol, terephthalaldehyde and 35 percent of water of the total weight of F127 in the grinding process, fully grinding and mixing to 150 meshes to obtain a pore-foaming agent, and storing in a dry environment; because resorcinol has strong moisture absorption capacity, the grinding needs to be carried out in a dry vacuum environment, and the influence of excessive moisture on the self-assembly of the pore-forming agent caused by water absorption in the grinding process is prevented.
(B) Preparation of the refractory substrate: according to the weight ratio of LiF: SrCO3：ZnO：B2O3Mixing materials in a ratio of 1:3:2:1, fully grinding and mixing the materials to be used as a sintering aid for later use, grinding and mixing 8 wt% of the sintering aid, 8 wt% of mica, 24 wt% of diatomite and 60 wt% of bauxite, adding the sintering aid, fully mixing the materials, and sieving the mixture by a 200-mesh sieve to obtain a refractory base material;
(C) weighing 100 parts by weight of refractory base material, 2 parts by weight and 5 parts by weight of sodium bentonite, 0.3 part by weight of CMC, 4 parts by weight of silica sol, 0.05 part by weight of PAM, 65 parts by weight of water, 1 part by weight of JFC, 2 parts by weight of n-butyl alcohol and 0.3 part by weight of formalin according to a formulation table, fully grinding and mixing to obtain a mixture, calculating and deducting the water content in a pore-foaming agent, adding the rest water in the raw materials into the mixture, and uniformly stirring to obtain a coating base material;
(D) and adding 30 parts by weight of pore-foaming agent into the coating base material half an hour before coating, and uniformly mixing for subsequent lost foam coating. The drying temperature of the coating in this example was 110 ℃.
Comparative example 1: the rest is the same as the example 3, except that the pore-foaming agent is replaced by expandable graphite, and the coating is used as a control group for subsequent performance test.
Comparative example 2: the existing mixture of mica powder, talcum powder, potassium feldspar powder and calcium feldspar powder is used as a sintering aid to replace the sintering aid in example 3 to prepare the lost foam coating for subsequent tests.
To test the properties of the coating, the following tests were carried out:
test of the effect of the sintering aid on the sintering temperature of the coating:
the sintering temperatures of the lost foam paints prepared in examples 1 to 3 and comparative example 2 were measured, respectively, and the results were as follows:
TABLE 1 sintering temperature measurement results for various coatings
| Group of | Sintering aid | Sintering temperature (. degree. C.) |
| Example 1 | LiF、SrCO3、ZnO、B2O3 | 720 |
| Example 2 | LiF、SrCO3、ZnO、B2O3 | 740 |
| Example 3 | LiF、SrCO3、ZnO、B2O3 | 750 |
| Comparative example 2 | Mica powder, talcum powder, potassium feldspar powder and calcium feldspar powder | 1200 |
The results in table 1 show that the sintering aid prepared in the invention can significantly reduce the sintering temperature of the coating compared with the existing common sintering aid.
The pore-forming agent and the coating in example 3 were uniformly coated on the surface of the carrier, the thickness was 2.5mm, the carrier was dried and solidified at 110 ℃, the sintering temperature was used as a variable, the sintering time was the same, the sintering condition of the pore-forming agent and the coating as a whole was examined, the apparent porosity of the coating sample block was measured using a special air permeability measuring device such as an air permeability analyzer, and the results are shown in table 2:
TABLE 2 detection of air permeable structure after sintering of porogens and coatings
The results in table 2 show that the porogen prepared by the present invention is not resistant to high temperature, collapse of the ordered pore structure occurs at a temperature higher than 800 ℃, and pores are adhered and disappear (as shown in fig. 1B), so that the air permeability is significantly reduced at a temperature higher than 800 ℃, if the sintering temperature of other components in the coating is also higher than 800 ℃ (as in comparative example 2), then the rest components in the coating are not sintered before collapse of the ordered pore structure and cannot provide external support for the ordered pore structure, the ordered pore structure disappears, the apparent porosity is significantly reduced, the air permeability is reduced, and when the temperature reaches 1200 ℃, the rest components can be sintered, but no pore structure exists at this time, and the density is increased after sintering, the air permeability of the coating is further reduced, and the air permeability cannot meet the requirements.
The pore-forming agent disclosed by the invention is self-assembled into an ordered structure after the coating is dried and solidified, when the sintering temperature is within the range of 400-1300 ℃, a solvent in the coating is completely volatilized, the pore-forming agent is carbonized into a porous ordered structure, the formation of the porous ordered structure enables the apparent porosity to be obviously improved, other components in the coating can be sintered at a lower temperature (about 750 ℃) and provide support for the periphery of the ordered structure, the ordered porous structure is reserved after the pore-forming agent is carbonized at a high temperature, collapse cannot occur, and therefore, the coating still has a relatively complete ordered porous structure (as shown in figure 1A) and good air permeability when the temperature reaches 1300 ℃. The sintering temperature is reduced, so that the sintering of other components in the coating does not cause the reduction of the air permeability of the coating, and the ordered porous structure at high temperature is effectively maintained, so that the existence of the sintering aid in the invention plays an essential role in the pore-forming agent.
The coatings in examples 1 to 3 and the control group were uniformly coated on the surface of the carrier with a thickness of 2.5mm, dried under respective dry-curing conditions, and sintered at 1250 ℃ to test the mechanical strength and the apparent porosity of the coatings, respectively:
TABLE 3 mechanical Strength of the dried and sintered coatings
The results in table 3 show that the ordered non-porous structure formed by self-assembly of the pore-forming agent after melting and drying at 105-115 ℃ can effectively increase the mechanical strength of the coating after drying, and the ordered porous structure formed after sintering the coating can effectively improve the mechanical strength of the coating after sintering while increasing the air permeability. After the pore-foaming agent is replaced by the expandable graphite, the air permeability of the expandable graphite can be improved to a certain degree at high sintering temperature, but the mechanical strength of the coating is greatly reduced.
When the sintering temperature is too high, sintering of the rest components does not provide support for the ordered pore structure, so that the strength of the coating after sintering is not changed greatly, but the compactness of the coating after sintering is increased, and the air permeability of the coating is seriously reduced.
The coating in example 1 was subjected to the following measurements of physical and chemical indexes:
TABLE 4 physicochemical indices of the foundry coating
In conclusion, the pore-forming agent is self-assembled to form an orderly-arranged structure in the dry-curing process, so that the coating is carbonized to form orderly-arranged pores during high-temperature sintering, the pores are communicated to facilitate the discharge of gaseous and liquid decomposition products, the air permeability is good, and the sintering property of the rest components of the coating ensures the stability and non-collapse of the orderly pore-channel structure, so that the mechanical strength of the coating is better no matter the coating is dried and cured or sintered.
The above embodiments are only for illustrating the technical idea of the present invention, and the protection scope of the present invention cannot be limited thereby, and any modification made on the basis of the technical scheme according to the technical idea proposed by the present invention falls within the protection scope of the present invention; the technology not related to the invention can be realized by the prior art.
Claims (6)
1. Aluminum bronze lost foam casting ringThe protective coating is characterized by being prepared from the following components in parts by weight: 100 parts of a refractory base material, 2-3 parts of sodium bentonite, 0.3 part of CMC, 3-5 parts of silica sol, 0.05 part of PAM, 50-80 parts of water, 0.4-1.5 parts of JFC, 1-3 parts of n-butyl alcohol, 0.1-0.5 part of formalin and 20-40 parts of a pore-forming agent, wherein the pore-forming agent is self-assembled into an ordered structure after the coating is dried and solidified, and is carbonized into a porous ordered structure at the temperature of 700-1300 ℃; the fireproof base material comprises 5-10 wt% of a sintering aid, 5-10 wt% of mica, 20-30 wt% of diatomite and 50-70 wt% of bauxite, wherein the sintering aid comprises LiF and SrCO3、ZnO、B2O3The sintering aid reduces the sintering temperature of the coating to 750 ℃.
2. The aluminum bronze lost foam casting environment-friendly coating as claimed in claim 1, wherein the coating comprises the following components in percentage by weight: the pore-foaming agent consists of resorcinol, terephthalaldehyde and a triblock polymer F127.
3. The aluminum bronze lost foam casting environment-friendly coating as claimed in claim 2, wherein the aluminum bronze lost foam casting environment-friendly coating comprises the following components in percentage by weight: the resorcinol: terephthalaldehyde: the mass ratio of F127 is 0.5-5: 3-10: 1.
4. the aluminum bronze lost foam casting environment-friendly coating as claimed in claim 1, wherein the coating comprises the following components in percentage by weight: the drying temperature of the coating is 105-115 ℃.
5. The aluminum bronze lost foam casting environment-friendly coating as claimed in claim 1, wherein the coating comprises the following components in percentage by weight: the LiF and SrCO3、ZnO、B2O3The weight ratio of the refractory base material to the refractory base material is 1:3:2:1, and the granularity of the refractory base material is 200 meshes.
6. The preparation method of the aluminum bronze lost foam casting environment-friendly coating as claimed in any one of claims 1 to 5, which is characterized by comprising the following specific steps of:
(A) weighing resorcinol, terephthalaldehyde and a triblock polymer F127 according to a formula, then carrying out vacuum grinding and mixing, adding water accounting for 30-40% of the total weight of the resorcinol, the terephthalaldehyde and the F127 in the grinding process, fully grinding and mixing to obtain a pore-foaming agent, and storing in a dry environment;
(B) preparation of the refractory substrate: weighing LiF and SrCO according to the proportion3、ZnO、B2O3Fully grinding and mixing the mixture to be used as a sintering aid for later use, and then grinding and mixing the mica, the diatomite and the bauxite, and then adding the sintering aid to fully mix to obtain the refractory base material;
(C) weighing the refractory base material, sodium bentonite, CMC, silica sol, PAM, JFC, n-butanol and formalin according to a burdening table, fully grinding and mixing to obtain a mixture, calculating and deducting the moisture content in a pore-forming agent, adding the residual water in the raw materials into the mixture, and uniformly stirring to obtain a coating base material;
(D) half an hour before coating, adding the pore-foaming agent into the coating base material, and uniformly mixing for subsequent lost foam coating.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011419597.5A CN112517837B (en) | 2020-12-07 | 2020-12-07 | Aluminum bronze lost foam casting environment-friendly coating and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011419597.5A CN112517837B (en) | 2020-12-07 | 2020-12-07 | Aluminum bronze lost foam casting environment-friendly coating and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112517837A true CN112517837A (en) | 2021-03-19 |
| CN112517837B CN112517837B (en) | 2022-04-08 |
Family
ID=74997992
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011419597.5A Active CN112517837B (en) | 2020-12-07 | 2020-12-07 | Aluminum bronze lost foam casting environment-friendly coating and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112517837B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105834354A (en) * | 2016-05-27 | 2016-08-10 | 马鞍山市兴隆铸造有限公司 | High-hardness anti-cracking mica powder modified silica matrix EPC coating and preparation method thereof |
| CN105855460A (en) * | 2016-05-27 | 2016-08-17 | 马鞍山市兴隆铸造有限公司 | High-bending-strength quartz-based expendable pattern paint modified by mica powder and preparation method of high-bending-strength quartz-based expendable pattern paint |
| CN105983650A (en) * | 2016-01-11 | 2016-10-05 | 明光市留香泵业有限公司 | Nano hydroxyl magnesium silicate containing high-lubricity low-carbon-residue water-based paint for lost foam casting and preparation method thereof |
| CN110449547A (en) * | 2019-08-20 | 2019-11-15 | 安徽信息工程学院 | A kind of Novel lost foam water base environmental protection coating material of WCB cast steel |
| CN110614343A (en) * | 2019-10-24 | 2019-12-27 | 安徽信息工程学院 | Lost foam coating for producing automobile panel die and preparation and use methods thereof |
| CN111618236A (en) * | 2020-06-08 | 2020-09-04 | 安徽信息工程学院 | Water-based paint for aluminum-copper alloy casting lost foam |
-
2020
- 2020-12-07 CN CN202011419597.5A patent/CN112517837B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105983650A (en) * | 2016-01-11 | 2016-10-05 | 明光市留香泵业有限公司 | Nano hydroxyl magnesium silicate containing high-lubricity low-carbon-residue water-based paint for lost foam casting and preparation method thereof |
| CN105834354A (en) * | 2016-05-27 | 2016-08-10 | 马鞍山市兴隆铸造有限公司 | High-hardness anti-cracking mica powder modified silica matrix EPC coating and preparation method thereof |
| CN105855460A (en) * | 2016-05-27 | 2016-08-17 | 马鞍山市兴隆铸造有限公司 | High-bending-strength quartz-based expendable pattern paint modified by mica powder and preparation method of high-bending-strength quartz-based expendable pattern paint |
| CN110449547A (en) * | 2019-08-20 | 2019-11-15 | 安徽信息工程学院 | A kind of Novel lost foam water base environmental protection coating material of WCB cast steel |
| CN110614343A (en) * | 2019-10-24 | 2019-12-27 | 安徽信息工程学院 | Lost foam coating for producing automobile panel die and preparation and use methods thereof |
| CN111618236A (en) * | 2020-06-08 | 2020-09-04 | 安徽信息工程学院 | Water-based paint for aluminum-copper alloy casting lost foam |
Non-Patent Citations (3)
| Title |
|---|
| 刘攀博等: "有序介孔聚合物的研究进展 ", 《中国塑料》 * |
| 谢兆军等: "低温烧结BaTiO_3基介电陶瓷的研究进展 ", 《陶瓷学报》 * |
| 陈学更等: "消失模铸造涂料性能影响因素的研究 ", 《铸造设备与工艺》 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112517837B (en) | 2022-04-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113059115B (en) | Refractory coating for sand-resistant lost foam casting and preparation method thereof | |
| Liang et al. | Preparation of SiC reticulated porous ceramics with high strength and increased efficient filtration via fly ash addition | |
| Zhao et al. | Transient liquid phase diffusion process for porous mullite ceramics with excellent mechanical properties | |
| JP5367157B2 (en) | Dispersion, slurry, and method for producing casting mold for precision casting using the slurry | |
| RU2456056C2 (en) | Ceramic filter with carbon coat, and method of its production | |
| CN104311116B (en) | A kind of magnesium aluminate spinel foamed ceramics and preparation method thereof | |
| CN106830958B (en) | Low-aluminum low-heat-conduction alkali-resistant castable | |
| CN109503197B (en) | Preparation method of calcium hexaluminate porous ceramic | |
| CN107698246A (en) | A kind of corundum-mullite base foamed ceramics of multilayer skeleton structure and preparation method thereof | |
| CN112517836B (en) | Tin bronze lost foam casting environment-friendly coating and preparation method thereof | |
| CN110918869B (en) | High-temperature-resistant coating for resin sand casting and preparation method thereof | |
| CN112658199B (en) | Environment-friendly paint for casting aluminum-silicon alloy by lost foam and preparation method thereof | |
| CN108793911B (en) | Method for preparing magnesium lightweight aggregate by foaming method | |
| CN112517837B (en) | Aluminum bronze lost foam casting environment-friendly coating and preparation method thereof | |
| Guo et al. | A facile approach for preparing Al2O3 reticulated porous ceramics with optimized closed-cell struts and excellent mechanical properties | |
| CN110668828A (en) | Magnesium binder for cement-free castable and preparation method thereof | |
| CN110885572A (en) | Casting aluminum-silicon alloy water-based environment-friendly coating for lost foam and preparation method thereof | |
| CN111393156A (en) | Preparation method of cordierite porous ceramic | |
| CN113149671B (en) | Casting molding process of light mullite-alumina hollow sphere-aluminum titanate sagger | |
| CN113800944A (en) | Method for preparing micron-pore heat insulation material by virtue of loss on ignition method | |
| CN111618236A (en) | Water-based paint for aluminum-copper alloy casting lost foam | |
| Hanna et al. | Oxidation resistance, compressive strength and thermal shock resistance of SiC ceramics prepared by two processing routes | |
| Chakrabarti | Drying conditions and their effect on ceramic shell investment casting process | |
| CN112893768B (en) | Environment-friendly lost foam casting coating and preparation method and application thereof | |
| CN115724631B (en) | Preparation method of multifunctional porous castable |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| EE01 | Entry into force of recordation of patent licensing contract |
Application publication date: 20210319 Assignee: Anhui Yuanhao Environmental Protection Technology Co.,Ltd. Assignor: ANHUI INSTITUTE OF INFORMATION TECHNOLOGY Contract record no.: X2022980021122 Denomination of invention: An environment-friendly coating for aluminum bronze lost foam casting and its preparation method Granted publication date: 20220408 License type: Common License Record date: 20221112 |
|
| EE01 | Entry into force of recordation of patent licensing contract |