Release agent for liquid die forging and preparation method thereof

Abstract

This application provides a release agent for liquid die forging and a preparation method thereof, comprising the following components in percentage by weight: inorganic powder: 6.4%-19.7%; organic lubricant: 1.7%-6.7%; water: 73.6%-90%. This release agent can effectively improve the fluidity of liquid metal, reduce casting defects, and increase the yield rate of castings during liquid die forging, without affecting subsequent reprocessing. Furthermore, the release agent is environmentally friendly, low-cost, and simple to prepare.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of release agents, and in particular to a release agent for liquid die forging and a preparation method thereof. Background Art

[0002] Liquid die forging refers to pouring a certain amount of metal liquid directly into an open metal mold, and applying a certain pressure to the metal liquid through a punch to fill, shape, and crystallize and solidify it, and a certain amount of plastic deformation occurs during the crystallization process.

[0003] In the liquid die forging process, since liquid metal has a good wetting effect on the metal mold, the surface of the mold cavity is washed by the high-pressure, high-speed and high-temperature liquid metal during the die-casting process, making the liquid metal easily adhere to the surface of the cavity. In order to maintain the integrity and post-processability of metal die-cast products, while ensuring the quality of castings, the service life of the die-casting mold and production efficiency, a release agent can be used to form a uniform release film on the surface of the die-casting mold, so that the metal die-cast product can be demolded from the mold and successfully removed from the mold. Currently, common release agents usually use a large amount of synthetic organic substances such as silicone oil, wax, and mineral oil. However, a large amount of synthetic organic substances will increase the difficulty of cleaning and painting the castings in the later stage, and the organic substances have poor high-temperature resistance. They are easily decomposed during use to produce carbon deposits and volatile substances, which have an adverse effect on the mechanical properties and molding quality of the castings, and pose a great safety hazard in the casting process. Summary of the Invention

[0004] In view of this, the present application provides a release agent for liquid die forging and a preparation method thereof. The release agent for liquid die forging uses water as a matrix, and is combined with an appropriate amount of inorganic powder and a small amount of organic lubricant. While ensuring the heat insulation and thermal insulation effect of the release agent, it increases the lubrication of the liquid metal, thereby promoting the fluidity of the liquid metal in the forging die. When performing the liquid die forging process, it can help improve the airtightness and density of automotive functional parts with complex shapes and structures, reduce casting defects, and improve the casting yield without affecting subsequent reprocessing and production. In addition, the release agent also has the advantages of being green and environmentally friendly, low cost, and simple preparation method.

[0005] In a first aspect, the present application provides a release agent for liquid die forging, comprising the following components in percentage by mass:

[0006] Inorganic powder: 6.4%-19.7%;

[0007] Organic lubricants: 1.7%-6.7%;

[0008] Water: 73.6%-90%.

[0009] In an embodiment of the present application, the inorganic powder includes a first inorganic powder and a second inorganic powder; the first inorganic powder includes one or more of talc powder and boron nitride; the second inorganic powder includes one or more of diatomaceous earth, calcined kaolin, dolomite powder, aluminum-rich rust stone powder, mullite powder and bauxite.

[0010] In an embodiment of the present application, the mass ratio of the first inorganic powder to the second inorganic powder in the liquid die forging release agent is (1-3):1.

[0011] In an embodiment of the present application, the organic lubricant includes one or more of alkylaryl modified polysiloxane, carnauba wax, polypropylene wax, high-density oxidized polyethylene wax, epoxy soybean oil and trimethylolpropane oleate.

[0012] In the embodiment of the present application, the chemical structure of the alkylaryl-modified polysiloxane is shown in formula (I):

[0013]

[0014] Wherein, 120≤m≤150, 25≤n≤30, and m and n are integers;

[0015] R1 is a C12-C18 alkyl group; R2 is an aromatic group.

[0016] In the embodiment of the present application, the thermal conductivity of the inorganic powder is 0.15W / (m·℃)-3.8W / (m·℃).

[0017] In the embodiment of the present application, the D50 particle size of the inorganic powder is 1.5 μm-2.5 μm.

[0018] In the embodiment of the present application, the liquid die forging release agent further includes an auxiliary agent, and the mass percentage of the auxiliary agent in the liquid die forging release agent is 1.5%-10%;

[0019] The auxiliary agent includes at least one component having the following mass percentage in the liquid die forging release agent:

[0020] Suspension: 0.5%-1.0%;

[0021] Binder: 0.01%-2.0%;

[0022] Rust inhibitor: 0.4%-2.0%;

[0023] Dispersant: 0.5%-1.5%;

[0024] Wetting agent: 0.01%-0.1%;

[0025] Silicone defoamer: 0.1%-0.3%;

[0026] Silicone leveling agent: 0.1%-0.3%.

[0027] In the embodiment of the present application, the suspending agent includes one or more of bentonite, attapulgite, rectorite clay, hydrophilic modified fumed silica and xanthan gum;

[0028] The binder includes one or more of styrene acrylic resin emulsion, phenolic resin, syrup, water glass, dextrin and polysaccharide compound;

[0029] The rust inhibitor comprises triethanolamine and an organic acid, wherein the organic acid comprises one or more of octanoic acid, neodecanoic acid and isononanoic acid;

[0030] The dispersant includes one or more of sodium hexametaphosphate, acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, and naphthalenesulfonate formic acid condensate sodium salt;

[0031] The wetting agent includes one or more of dioctyl sodium sulfosuccinate and isomeric decanol polyoxyethylene ether.

[0032] In the embodiment of the present application, the rotational viscosity of the liquid die forging release agent at 25°C is 2000mPa . s-3000mPa . s.

[0033] The second aspect of the present application further provides a method for preparing the release agent for liquid die forging provided in the first aspect, comprising:

[0034] The liquid die forging release agent is obtained by mixing the various components of the liquid die forging release agent.

[0035] The third aspect of the present application further provides an automobile structural part, which is prepared by using the liquid die forging release agent provided in the first aspect. DETAILED DESCRIPTION

[0036] The present application is further described in detail below in conjunction with preferred embodiments, but the protection scope of the present application is not limited to the following specific embodiments.

[0037] In this application, all professional terms have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of this application.

[0038] With the rapid development of the new energy vehicle industry, the quality requirements for automotive functional parts are becoming increasingly stringent. Since automotive functional parts often need to withstand impact, high temperature, high pressure, high strength, and subsequent surface treatments such as anodizing and passivation, as well as heat treatment, they require the metal to crystallize and solidify under pressure to avoid casting defects such as porosity, shrinkage, and porosity. Therefore, advanced liquid die forging processes are highly favored. Liquid die forged castings have a denser structure and higher mechanical properties than low-pressure castings.

[0039] Liquid die forging involves pouring a quantity of liquid metal directly into an open metal mold. A punch then applies pressure to the liquid metal, causing it to fill, form, and crystallize. This process produces a certain amount of plastic deformation during the crystallization process. This process ensures smooth filling, allowing the metal to crystallize and solidify directly under pressure. Consequently, the resulting castings exhibit advantages such as being free of pores, shrinkage cavities, and porosity. Die-casting molds used in liquid die forging are mostly made of H13 steel. Because liquid metal wets H13 steel well, the high-pressure, high-speed, and high-temperature liquid metal that washes over the mold cavity during the die-casting process easily adheres to the surface. To maintain the integrity and post-processability of the die-cast product, while also ensuring casting quality, mold life, and production efficiency, a release agent is used to form a uniform release film on the die surface, allowing the die-cast product to be released and successfully removed from the mold.

[0040] Currently, release agents are essential for the liquid die forging of precision automotive functional parts such as steering knuckles, compressor mounts, engine mounts, suspension mounts, airbag support arms, and battery compartment end plates. Common release agents are typically composed primarily of organic polymers and inorganic powders such as graphite. However, large amounts of polymers, such as silicone oil, complicate cleaning and painting of the castings. Furthermore, polymers have poor high-temperature resistance and easily decompose during use, producing carbon deposits and volatile substances. These adversely affect the mechanical properties and surface quality of the castings, and pose significant safety risks during the casting process. Graphite-based inorganic powders also generate significant dust, which pollutes the production environment and can lead to safety incidents such as dust explosions.

[0041] In response to the above problems, the present application provides a release agent for liquid die forging. The liquid die forging release agent uses water as a matrix, and is combined with an appropriate amount of inorganic powder and a small amount of organic lubricant. While ensuring the heat insulation and thermal insulation effect of the release agent, it also increases the lubrication of the liquid metal, thereby promoting the fluidity of the liquid metal in the forging die. During the liquid die forging process, the liquid die forging release agent can help improve the airtightness and density of functional parts with complex shapes and structures, while reducing casting defects of castings, improving the casting yield rate, and not affecting subsequent reprocessing and production. In addition, the liquid die forging release agent also has the advantages of being green and environmentally friendly, low cost, and simple preparation method.

[0042] The present embodiment provides a release agent for liquid die forging, comprising the following components in percentage by weight:

[0043] Inorganic powder: 6.4%-19.7%;

[0044] Organic lubricants: 1.7%-6.7%;

[0045] Water: 73.6%-90%.

[0046] The release agent for liquid die forging of the present application uses water as a matrix, which can effectively avoid the adverse effects of carbon deposits on the performance of castings caused by high-temperature decomposition and the safety hazards caused by volatile flammable substances brought about by the existing technology using a large amount of oily organic matter as a matrix. Taking into account the molding method of the liquid die forging process and the high precision requirements for castings, the liquid die forging process takes longer than the conventional low-pressure die casting molding process, and the metal liquid flows slower. Therefore, the release agent provided by the present application is used for a specific liquid die forging process, in which a large amount of water and inorganic powder provide good thermal insulation effect, making the metal liquid difficult to solidify, which is more conducive to the molding of castings, and the addition of a small amount of organic lubricant can further enhance the fluidity of the metal liquid, thereby obtaining precision casting functional parts with complex shapes and structures and good air tightness, density and yield. In some embodiments of the present application, water includes but is not limited to deionized water.

[0047] In the embodiment of the present application, the mass percentage of the inorganic powder in the release agent for liquid die forging is 6.4%-19.7%. In some specific embodiments, the mass percentage of the inorganic powder in the release agent for liquid die forging can be, for example, 6.4%, 6.5%, 6.6%, 6.8%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 19.5%, 19.7%. The present application controls the content of the release agent for liquid die forging within the above-mentioned appropriate range. On the one hand, the good thermal insulation effect provided by the inorganic powder with good thermal insulation performance can prevent the high-temperature molten metal liquid from cooling prematurely, resulting in insufficient filling of the casting, forming defective parts or producing defects such as cold shut, thereby affecting the performance of the casting. On the other hand, inorganic powders can also play a role in high-temperature crack prevention and porosity elimination during the liquid die forging process, thereby further improving the air tightness and density of the casting and improving the production yield.

[0048] In an embodiment of the present application, the inorganic powder includes a first inorganic powder and a second inorganic powder, wherein the first inorganic powder includes one or more of talc and boron nitride; and the second inorganic powder includes one or more of diatomaceous earth, calcined kaolin, dolomite powder, mullite powder, mullite powder, and bauxite. The inorganic powder in the liquid die forging release agent provided in the present application includes a first inorganic powder and a second inorganic powder, wherein the first inorganic powder is mainly used to form an isolation coating to isolate the mold and the metal liquid, and the second inorganic powder is mainly used to adjust the thermal conductivity of the liquid die forging release agent, thereby enabling the release agent coating to have a thermal insulation effect during the high-temperature liquid die forging process, improving the fluidity of the metal liquid and promoting the formation of the casting.

[0049] In some embodiments of the present application, the first inorganic powder includes talc. The volume expansion coefficient of talc is very small. Adding a certain amount of talc to the release agent can effectively improve the high-temperature crack resistance and mechanical strength of the release agent coating, thereby avoiding the problem of cracking due to excessive temperature, resulting in direct contact between the high-temperature molten metal and the mold surface, and making subsequent demolding difficult. In addition, talc can also further reduce the sintering temperature of the release agent coating. In some embodiments of the present application, by selecting talc as the first inorganic powder, the mechanical properties and yield rate of liquid die forging products can be further improved.

[0050] In some specific embodiments of the present application, the second inorganic powder includes diatomaceous earth. Diatomaceous earth has excellent thermal insulation properties. Adding an appropriate amount of diatomaceous earth to the release agent can effectively adjust the thermal conductivity of the release agent coating, thereby making it have good thermal insulation properties, improving the fluidity of the liquid metal, and avoiding the rapid loss of heat of the high-temperature liquid metal during the liquid die forging process, thereby preventing the molten metal from cooling prematurely, resulting in incomplete filling of the molten metal in the mold, thereby causing defects such as incomplete castings or cold shuts, thereby affecting the mechanical properties of the product. Cold shut defects refer to the fact that after the molten metal is filled into the mold, the fusion at the junction of the molten metal is not good, resulting in penetrating or non-penetrating gaps in the casting. In other embodiments of the present application, the second inorganic powder includes calcined kaolin. After calcination, the crystal structure and chemical activity of kaolin change, and the content of crystal water and combined water decreases, which increases its porosity. While the physical and chemical properties are more stable, the stress absorption capacity is also improved. Adding calcined kaolin with good high-temperature performance to the release agent for liquid die forging can effectively avoid thermal cracking of the release agent coating during the high-temperature extrusion stage. At the same time, the structure with a larger porosity also effectively eliminates pores, further improving the density and yield of the product.

[0051] In some embodiments of the present application, the inorganic powder has two or more material types, wherein the first inorganic powder has one or more material types, and the second inorganic powder has one or more material types. In some embodiments of the present application, the inorganic powder includes inorganic powders having two or more different D50 particle sizes. The inorganic powder mixture obtained by compounding different types of inorganic powders or inorganic powders of the same type but different particle sizes in the present application can form a maximum density accumulation of inorganic powder mixtures of different sizes, thereby further improving the density of the release agent coating, increasing its wear resistance and thus increasing its service life.

[0052] In an embodiment of the present application, the mass ratio of the first inorganic powder to the second inorganic powder in the release agent for liquid die forging is (1-3):1. In some specific embodiments, the mass ratio of the first inorganic powder to the second inorganic powder in the release agent for liquid die forging can be, for example, 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, or 2:1. By rationally regulating the mass ratio of the first inorganic powder to the second inorganic powder, the content of the first inorganic powder is controlled within a range slightly larger than the content of the second inorganic powder, thereby further enabling the release agent for liquid die forging to have both good isolation effect and suitable thermal conductivity.

[0053] In the embodiment of the present application, the thermal conductivity of the inorganic powder is 0.15W / (m0℃)-3.8W / (m0℃). In some specific embodiments of the present application, the thermal conductivity of the inorganic powder can be, for example, 0.15W / (m0℃), 0.2W / (m0℃), 0.3W / (m0℃), 0.5W / (m0℃), 0.6W / (m0℃), 0.8W / (m0℃), 1W / (m0℃), 1.5W / (m0℃), 2W / (m0℃), 2.5W / (m0℃), 3W / (m0℃), 3.5W / (m0℃), 3.8W / (m0℃). The release agent for liquid die forging provided in the present application can further ensure the thermal insulation effect of the release agent coating during high-temperature liquid die forging by selecting inorganic powder with a thermal conductivity within the above range, thereby avoiding heat loss, further improving the fluidity of the metal liquid, and promoting the formation of castings.

[0054] In the embodiment of the present application, the D50 particle size of the inorganic powder is 1.5μm-2.5μm. In some specific embodiments of the present application, the D50 particle size of the inorganic powder can be, for example, 1.5μm, 1.6μm, 1.7, 1.8μm, 1.9μm, 2.0μm, 2.1μm, 2.2μm, 2.3μm, 2.4μm, and 2.5μm. By selecting inorganic powders of appropriate particle size, the coating formed by the release agent can be made denser, thereby enhancing the ability to withstand the scouring of high-temperature molten metal. At the same time, the thermal conductivity of the release agent for liquid die forging can also be optimized and adjusted.

[0055] In the embodiment of the present application, the mass percentage of the organic lubricant in the release agent for liquid die forging is 1.7%-6.7%. In some specific embodiments, the mass percentage of the inorganic powder in the release agent for liquid die forging can be, for example, 1.7%, 1.8%, 1.9%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 6.7%. The present application controls the content of the organic lubricant in the release agent for liquid die forging within the above-mentioned appropriate range, ensuring that the organic lubricant can provide sufficient lubricity for the release agent coating, thereby ensuring that the metal liquid has sufficient fluidity for filling and molding, while avoiding problems such as excessive organic lubricant causing carbon deposits or reducing the thermal insulation effect of the release agent coating, thereby improving the surface finish of the casting and the molding rate of the casting.

[0056] In an embodiment of the present application, the organic lubricant includes one or more of alkylaryl modified polysiloxane, carnauba wax, polypropylene wax, high-density oxidized polyethylene wax, epoxy soybean oil and trimethylolpropane oleate.

[0057] In some embodiments of the present application, the organic lubricant includes an alkylaryl-modified polysiloxane and an organic wax, as well as one or more of epoxy soybean oil and trimethylolpropane oleate. In embodiments of the present application, the organic wax includes one or more of carnauba wax, polypropylene wax, and high-density oxidized polyethylene wax. The addition of a small amount of alkylaryl-modified polysiloxane and organic wax can further enhance the lubrication of the molten metal and the film-forming effect of the release agent coating, while ensuring that it does not affect the thermal insulation effect of the liquid die forging release agent, thereby further improving the surface quality of the casting. Different types of organic lubricants have different lubricating durations. Adding two or more organic lubricants can provide lubrication at different temperature periods, ensuring that the molten metal maintains good fluidity throughout the liquid die forging process. Organic waxes such as carnauba wax, polypropylene wax, and high-density polyethylene wax, as well as organic lubricants such as epoxy soybean oil and trimethylolpropane oleate, can provide good lubricity at low temperatures. As the temperature rises further, organic lubricants such as organic waxes carbonize, at which point the alkylaryl-modified polysiloxane exerts its lubricating effect. Therefore, the combination of alkylaryl modified polysiloxane and organic wax can ensure good lubrication of the metal throughout the entire liquid die forging process, thereby promoting its flow forming.

[0058] In the embodiment of the present application, the chemical structure of the alkylaryl-modified polysiloxane is shown in formula (I):

[0059]

[0060] Wherein, 120≤m≤150, 25≤n≤30, and m and n are integers;

[0061] R1 is a C12-C18 alkyl group; R2 is an aromatic group.

[0062] In some embodiments of the present application, the value of m can be, for example, 120, 125, 130, 135, 140, 145, 150, and the value of n can be, for example, 25, 26, 27, 28, 29, 30. In some embodiments of the present application, R1 is a C12-C18 chain alkyl. In some specific embodiments, R1 can be, for example, -C 12 H 25 、-C 14 H 29 , R2 can be, for example, -CH2CHCH3Ph.

[0063] In the embodiment of the present application, the rotational viscosity of the alkylaryl modified polysiloxane at 25°C is 1050mPa.s-1500mPa . In some specific embodiments of the present application, the rotational viscosity of the alkylaryl-modified polysiloxane at 25° C. may be, for example, 1050 mPa. .s, 1100mPa . s, 1150mPa . s, 1200mPa . s, 1250mPa . s, 1300mPa . s, 1350mPa . s, 1400mPa . s, 1450mPa . s, 1500mPa . s, and the rotational viscosity is measured using a rotational viscometer (e.g., NDJ-8S rotational viscometer). By selecting an alkylaryl-modified polysiloxane of suitable viscosity as an organic lubricant, the viscosity of the release agent for liquid die forging can be further controlled, thereby facilitating subsequent film coating of the release agent and increasing the bonding strength between the release agent coating and the mold.

[0064] In the embodiment of the present application, the weight percentage of the auxiliary agent in the liquid die forging release agent is 1.5%-10%. In some specific embodiments, the weight percentage of the auxiliary agent in the liquid die forging release agent can be, for example, 1.5%, 1.6%, 1.62%, 1.7%, 1.8%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%.

[0065] In the embodiment of the present application, at least one component of the auxiliary agent package in the liquid die forging release agent is the following mass percentage:

[0066] Suspension: 0.5%-1.0%;

[0067] Binder: 0.01%-2.0%;

[0068] Rust inhibitor: 0.4%-2.0%;

[0069] Dispersant: 0.5%-1.5%;

[0070] Wetting agent: 0.01%-0.1%;

[0071] Silicone defoamer: 0.1%-0.3%;

[0072] Silicone leveling agent: 0.1%-0.3%.

[0073] In the embodiment of the present application, the mass percentage of the suspending agent in the release agent for liquid die forging is 0.5%-1.0%. In some specific embodiments of the present application, the mass percentage of the suspending agent in the release agent for liquid die forging can be, for example, 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, 0.85%, 0.9%, 0.95%, or 1.0%. In the embodiment of the present application, the suspending agent includes one or more of bentonite, attapulgite, rectorite clay, hydrophilically modified fumed silica, and xanthan gum. The present application selects suitable suspending agents, which have a high specific surface area. By further controlling the amount of suspending agents added, the suspending properties of the release agent can be effectively improved, which plays a role in suspension thickening, thereby making the product more uniform.

[0074] In an embodiment of the present application, the mass percentage of the binder in the release agent for liquid die forging is 0.01%-2.0%. In some specific embodiments of the present application, the mass percentage of the binder in the release agent for liquid die forging can be, for example, 0.01%, 0.02%, 0.05%, 0.1%, 0.2%, 0.5%, 0.6%, 0.8%, 1.0%, 1.2%, 1.5%, 1.6%, 1.8%, 2.0%. In an embodiment of the present application, the binder includes one or more of styrene acrylic resin emulsion, phenolic resin, syrup, water glass, dextrin and polysaccharide compounds. Adding a suitable binder to the release agent for liquid die forging in the present application can further increase the adhesion of the release agent coating to the mold, and improve its tear resistance and resistance to metal liquid scouring.

[0075] In an embodiment of the present application, the mass percentage of the rust inhibitor in the release agent for liquid die forging is 0.4%-2.0%. In some specific embodiments of the present application, the mass percentage of the rust inhibitor in the release agent for liquid die forging can be, for example, 0.4%, 0.5%, 0.6%, 0.8%, 1%, 1.2%, 1.4%, 1.5%, 1.6%, 1.8%, or 2%. In an embodiment of the present application, the rust inhibitor includes triethanolamine and an organic acid, and the organic acid includes one or more of n-octanoic acid, neodecanoic acid, and isononanoic acid. The present application enhances the rust prevention ability of the release agent for liquid die forging by selecting an organic base triethanolamine and compounding it with an organic acid for synergistic rust prevention.

[0076] In an embodiment of the present application, the mass percentage of the dispersant in the release agent for liquid die forging is 0.5%-1.5%. In some specific embodiments of the present application, the mass percentage of the dispersant in the release agent for liquid die forging can be, for example, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, and 1.5%. In an embodiment of the present application, the dispersant includes one or more of sodium hexametaphosphate, acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, and naphthalenesulfonate formaldehyde condensate sodium salt. Selecting the above-mentioned suitable dispersant and controlling its content in the release agent for liquid die forging can effectively disperse the various components in the release agent for liquid die forging, thereby obtaining a release agent with uniform components and uniform performance.

[0077] In an embodiment of the present application, the mass percentage of the wetting agent in the release agent for liquid die forging is 0.01%-0.1%. In some specific embodiments of the present application, the mass percentage of the wetting agent in the release agent for liquid die forging can be, for example, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, or 0.1%. In an embodiment of the present application, the wetting agent includes one or more of sodium salt of dioctyl sulfosuccinate and isomeric decanol polyoxyethylene ether. The wetting agent can further improve the wettability of the release agent coating for liquid metal, thereby further improving its fluidity during the liquid die forging process.

[0078] In an embodiment of the present application, the weight percentage of the organosilicon defoamer in the liquid die forging release agent is 0.1%-0.3%. In some specific embodiments, the weight percentage of the organosilicon defoamer in the liquid die forging release agent can be, for example, 0.1%, 0.15%, 0.2%, 0.25%, or 0.3%. The organosilicon defoamer can eliminate foam generated during the preparation of the release agent system, thereby ensuring more uniform dispersion of the inorganic powder in the release agent.

[0079] In the embodiments of the present application, the weight percentage of the organosilicon leveling agent in the liquid die forging release agent is 0.1%-0.3%. In some specific embodiments, the weight percentage of the organosilicon leveling agent in the liquid die forging release agent can be, for example, 0.1%, 0.15%, 0.2%, 0.25%, or 0.3%. The addition of the organosilicon leveling agent can ensure that the liquid die forging release agent forms a more flat, smooth, and uniform film in the mold.

[0080] In the embodiment of the present application, the rotational viscosity of the liquid die forging release agent at 25°C is 2000 mPa . s-3000mPa .In some embodiments of the present application, the rotational viscosity of the liquid die forging release agent at 25°C may be, for example, 2000 mPa. . s, 2100mPa . s, 2200mPa . s, 2300mPa . s, 2400mPa . s, 2500mPa . s, 2600mPa . s, 2700mPa . s, 2800mPa . s, 2900mPa . s, 3000mPa . The present application controls the viscosity of the release agent for liquid die forging within the above range, which can further promote its subsequent coating in the forging die and effectively improve the bonding force between the release agent coating and the die, thereby facilitating the subsequent demolding of the casting and improving the surface quality of the casting.

[0081] The liquid die forging release agent provided in this application has excellent thermal insulation properties, high-temperature stability, and stress absorption capacity. It can effectively ensure the fluidity of liquid metal during the liquid die forging process, thereby ensuring the dimensional accuracy and mechanical properties of liquid die forged alloy products. In addition, the liquid die forging release agent is environmentally friendly, low-cost, and simple to prepare.

[0082] The present application also provides a method for preparing the release agent for liquid die forging provided above, comprising:

[0083] The liquid die forging release agent is obtained by mixing the various components of the liquid die forging release agent.

[0084] In some embodiments of the present application, the auxiliary agent includes a suspending agent, a binder, a rust inhibitor, a dispersant and a wetting agent, and the raw material mixing process includes: first adding the suspending agent, the rust inhibitor, the dispersant and the wetting agent to deionized water for a first stirring treatment, adding an organosilicon defoamer to eliminate the foam in the mixed slurry, and then adding an inorganic powder, an organic lubricant and a binder for a second stirring treatment and then grinding and dispersing the mixture to obtain a liquid die forging release agent with a D50 particle size of 1.5 μm-2.5 μm (the particle size is tested using an OMEC TOPsizer Plus laser particle size analyzer). In some other embodiments of the present application, the suspending agent is added to deionized water and finally added to the mixed slurry of the liquid die forging release agent to act as a thickener, further enhancing the viscosity of the liquid die forging release agent.

[0085] In some embodiments of the present application, the first stirring process and the second stirring process adopt a high-speed disperser. In some embodiments of the present application, the rotating speed of the first stirring process is 600r / min-800r / min, and the time is 30min-40min. In some specific embodiments, the rotating speed of the first stirring process can be, for example, 600r / min, 650r / min, 700r / min, 750r / min, 800r / min, and the time can be, for example, 30min, 32min, 34min, 35min, 36min, 38min, 40min. In some embodiments of the present application, the rotating speed of the second stirring process is 2500r / min-4000r / min, and the time is 40min-50min. In some specific embodiments, the rotation speed of the second stirring process can be, for example, 2500r / min, 2800r / min, 3000r / min, 3200r / min, 3500r / min, 3600r / min, 3800r / min, 4000r / min, and the time can be, for example, 40min, 42min, 44min, 45min, 46min, 48min, 50min. In some embodiments of the present application, the flow rate of the grinding and dispersion process is 6L / min-8L / min. In some specific embodiments, the flow rate of the grinding and dispersion process can be 6L / min, 6.5L / min, 7L / min, 7.5L / min, 8L / min.

[0086] The present application also provides an automotive structural part, the preparation of which adopts the liquid die forging release agent provided above. In the embodiment of the present application, the automotive structural part is made by liquid die forging, and the liquid die forging release agent provided above is adopted in the liquid die forging process. In the embodiment of the present application, the automotive structural part is a common structural part and functional part in an automobile, including but not limited to a steering knuckle, a compressor bracket, an engine bracket, a suspension bracket, an airbag support arm, a battery compartment end plate, etc. In some specific embodiments, the material of the automotive structural part can be, for example, an aluminum alloy, and the aluminum alloy can be, for example, an Al-Si series aluminum alloy, an Al-Mg series aluminum alloy, an Al-Zn series aluminum alloy, etc., wherein the Al-Si series aluminum alloy includes but is not limited to Al-Si aluminum alloy, Al-Si-Cu aluminum alloy, Al-Si-Mg aluminum alloy, the Al-Mg series aluminum alloy includes Al-Mg aluminum alloy, Al-Mg-Cu aluminum alloy, and the Al-Zn series includes Al-Zn-Si aluminum alloy, Al-Zn-Mg aluminum alloy, etc.

[0087] The present application is further described below with reference to several embodiments:

[0088] Example 1

[0089] A release agent for liquid die forging is prepared from the following components in percentage by weight: 6% talc, 4% calcined kaolin, 2% diatomaceous earth, 1% alkylaryl-modified polysiloxane emulsion, 4% carnauba wax emulsion, 0.5% hydrophilic modified fumed silica, 0.5% xanthan gum, 2% styrene-acrylic resin emulsion, 1% triethanolamine, 0.5% n-octanoic acid, 0.5% neodecanoic acid, 0.5% acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, 0.5% sodium salt of naphthalenesulfonate formic acid condensate, 0.05% sodium salt of dioctyl sulfosuccinate, 0.3% organic silicon leveling agent, and 0.3% organic silicon defoaming agent. The remaining components are deionized water. The corresponding preparation method is described in the following steps:

[0090] (1) triethanolamine, n-octanoic acid, and neodecanoic acid were added to water in sequence, and then stirred for 0.5 hours to obtain a mixed solution;

[0091] (2) adding naphthalenesulfonate formic acid condensate sodium salt, organosilicon leveling agent, acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, dioctyl sulfosuccinate sodium salt, and hydrophilic modified fumed silica to the mixed solution obtained in step (1), and dispersing the mixture uniformly using a high-speed disperser for 15 minutes at a speed of 800 r / min. After the dispersion is completed, an organosilicon defoamer is added;

[0092] (3) adding calcined kaolin, talc, diatomaceous earth, carnauba wax emulsion, alkylaryl modified polysiloxane emulsion, and styrene acrylic resin emulsion to the mixed solution treated in step (2) in sequence, and then stirring evenly in a high-speed disperser for 30 minutes at a speed of 4000 r / min;

[0093] (4) Grinding and dispersing the material obtained in step (3) at a flow rate of 8 L / min until the particle size D50 is 1.5 μm to obtain a release agent slurry;

[0094] (5) Add the pre-dissolved xanthan gum solution to the slurry obtained in step (4), and then stir it at a low speed to obtain a release agent for liquid die forging.

[0095] Example 2

[0096] The difference from Example 1 is that the mass percentage of talc is 8% and the mass percentage of calcined kaolin is 4%.

[0097] Example 3

[0098] The difference from Example 1 is that the mass percentage of talc is 9% and the mass percentage of calcined kaolin is 3%.

[0099] Example 4

[0100] The difference from Example 1 is that the mass percentage of talc is 3.2% and the mass percentage of calcined kaolin is 3.2%.

[0101] Example 5

[0102] The difference from Example 1 is that it is made of the following components in percentage by weight: 10% talc, 7.7% calcined kaolin, 2% diatomaceous earth, 1% alkylaryl-modified polysiloxane emulsion, 1% carnauba wax emulsion, 0.5% hydrophilic modified fumed silica, 2% styrene-acrylic resin emulsion, 0.5% triethanolamine, 0.25% n-octanoic acid, 0.25% neodecanoic acid, 0.5% acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, 0.4% sodium salt of naphthalenesulfonate formic acid condensate, 0.1% sodium salt of dioctyl sulfosuccinate, 0.1% organic silicon leveling agent, 0.1% organic silicon defoamer, and the remaining component is deionized water.

[0103] Example 6

[0104] The difference from Example 1 is that the mass percentage of the carnauba wax emulsion is 0.7%.

[0105] Example 7

[0106] The difference from Example 1 is that the mass percentage of the carnauba wax emulsion is 5.7%.

[0107] Example 8

[0108] The difference from Example 1 is that 6% of talc is replaced by 5% of talc and 1% of hexagonal boron nitride.

[0109] Example 9

[0110] The difference from Example 1 is that 6% of talc is replaced by 3% of talc and 3% of hexagonal boron nitride.

[0111] Example 10

[0112] The difference from Example 1 is that 1% of the alkylaryl-modified polysiloxane emulsion and 4% of the carnauba wax emulsion are replaced by 4% of the high-density oxidized polyethylene wax emulsion and 1% of the carnauba wax emulsion.

[0113] Example 11

[0114] The difference from Example 1 is that 1% of the alkylaryl-modified polysiloxane emulsion and 4% of the carnauba wax emulsion are replaced by 1% of the high-density oxidized polyethylene wax emulsion and 4% of the polypropylene wax emulsion.

[0115] Comparative Example 1

[0116] The difference from Example 1 is that the mass percentage of the alkylaryl-modified polysiloxane emulsion is 10%.

[0117] Comparative Example 2

[0118] The difference from Example 1 is that there is no carnauba wax emulsion.

[0119] Comparative Example 3

[0120] The difference from Example 1 is that the mass percentage of talc is 1%, the mass percentage of calcined kaolin is 1%, and the mass percentage of diatomaceous earth is 1%.

[0121] Comparative Example 4

[0122] The difference from Example 1 is that the mass percentage of talc is 10%, the mass percentage of calcined kaolin is 10%, and the mass percentage of diatomaceous earth is 10%.

[0123] Comparative Example 5

[0124] A release agent for liquid die forging is prepared from the following components by weight: 65% trimethylolpropane oleate, 15% epoxidized soybean oil, 18.0% graphite, and 2% alkylaryl-modified polysiloxane. The corresponding preparation method is as follows:

[0125] Trimethylolpropane oleate, epoxy soybean oil, graphite, and alkylaryl modified polysiloxane were added into a high-speed disperser and stirred evenly. The speed of the high-speed disperser was 3000 r / min and the dispersion time was 30 minutes to obtain a release agent for liquid die forging.

[0126] Liquid die forging release agents prepared in Examples 1 to 11 and Comparative Examples 1 to 5 were used in the liquid die forging process of castings, using the same materials and processes. 60 castings were randomly selected and manually inspected for die sticking, cold shuts, pores, water marks, and carbon deposits.

[0127] Mold sticking refers to the adhesion between liquid metal and the mold surface, causing the metal to form an adherent layer on the inner wall of the mold instead of flowing and filling the shape of the mold securely.

[0128] Cold shut refers to the situation where the metal at the flow front cools too quickly as the liquid metal flows through the mold to fill the cavity, causing it to solidify prematurely, forming a thin solid or semi-solid layer. When the subsequent liquid metal continues to flow and attempts to fill the cavity, this solidified or semi-solidified layer of metal will hinder the flow of the metal, thus forming a cold shut in the final product.

[0129] Porosity refers to the formation of cavities or voids due to the retention of gas or the release of gas inside the metal during the solidification process of the metal;

[0130] Watermarks refer to the wavy texture that appears on the surface of metal, similar to ripples on the surface of water;

[0131] Carbon deposits refer to the formation of carbon deposits on the surface or inside of metals. These deposits are usually formed by the reaction of hydrocarbons and lubricating grease at high temperatures.

[0132] The specific results are shown in Table 1:

[0133] Table 1

[0134] Performance Testing mucous membranes Cold insulation pores Water Ripples carbon deposits Example 1 0 0 0 0 0 Example 2 0 3 0 0 0 Example 3 0 5 0 0 0 Example 4 3 4 1 0 0 Example 5 5 0 3 0 0 Example 6 9 0 0 0 0 Example 7 0 0 0 5 2 Example 8 0 4 0 0 0 Example 9 1 7 0 0 0 Example 10 5 0 0 2 1 Example 11 4 0 0 2 1 Comparative Example 1 2 1 1 17 0 Comparative Example 2 28 1 0 0 0 Comparative Example 3 4 30 0 0 0 Comparative Example 4 20 0 15 0 0 Comparative Example 5 0 60 40 60 60

[0135] It can be seen from the data in Table 1 that, compared with the release agents for liquid die forging of Examples 1 to 11 of the present application, in Example 1, the excessive amount of organic lubricant easily causes water marks and other phenomena in the prepared castings. In Example 2, the organic lubricant is too little, the lubrication effect is insufficient, and the problem of sticking film is easy to occur; in Example 3, the content of inorganic powder is too little, causing cold shut of the casting and easily leading to insufficient filling of the casting. In Example 4, the content of inorganic powder is too much, which makes it difficult for the release agent to form a continuous coating, and the castings are prone to problems such as sticking film and pores. The release agent of Example 5 adopts an oily system, and the castings produce a large number of defects such as cold shut, pores, water marks, and carbon deposits.

[0136] The preferred embodiments are described in detail above, but the present invention is not limited to the above-mentioned specific implementation methods. Under the guidance of this application, technicians in this field can also make various forms of specific changes without departing from the scope of protection of this application, which all fall within the scope of protection of the present invention.

Claims

1. A release agent for liquid die forging, characterized in that: The following components are included in the following mass percentages: Inorganic powder: 6.4%-19.7%; Organic lubricants: 1.7%-6.7%; Water: 73.6%-90%; The organic lubricant includes one or more of alkylaryl modified polysiloxane, carnauba wax, polypropylene wax, high-density oxidized polyethylene wax, epoxy soybean oil and trimethylolpropane oleate.

2. The release agent for liquid die forging according to claim 1, wherein The inorganic powder includes a first inorganic powder and a second inorganic powder; the first inorganic powder includes one or more of talc powder and boron nitride; the second inorganic powder includes one or more of diatomaceous earth, calcined kaolin, dolomite powder, aluminum-rich rust stone powder, mullite powder and bauxite.

3. The release agent for liquid die forging according to claim 2, characterized in that The mass ratio of the first inorganic powder to the second inorganic powder in the liquid die forging release agent is (1-3):

1.

4. The release agent for liquid die forging according to claim 1, wherein The chemical structure of the alkylaryl modified polysiloxane is shown in formula (I): Wherein, 120≤m≤150, 25≤n≤30, and m and n are integers; R1 is a C12-C18 alkyl group; R2 is an aromatic group.

5. The release agent for liquid die forging according to claim 1, wherein The thermal conductivity of the inorganic powder is 0.15W / (m·℃)-3.8W / (m·℃).

6. The release agent for liquid die forging according to claim 1, wherein The D50 particle size of the inorganic powder is 1.5 μm-2.5 μm.

7. The release agent for liquid die forging according to claim 1, wherein The liquid die forging release agent further comprises an auxiliary agent, and the mass percentage of the auxiliary agent in the liquid die forging release agent is 1.5%-10%.

8. The release agent for liquid die forging according to claim 7, characterized in that The auxiliary agent includes at least one component having the following mass percentage in the liquid die forging release agent: Suspension: 0.5%-1.0%; Binder: 0.01%-2.0%; Rust inhibitor: 0.4%-2.0%; Dispersant: 0.5%-1.5%; Wetting agent: 0.01%-0.1%; Silicone defoamer: 0.1%-0.3%; Silicone leveling agent: 0.1%-0.3%.

9. The release agent for liquid die forging according to claim 8, characterized in that The suspending agent includes one or more of bentonite, attapulgite, rectorite clay, hydrophilic modified fumed silica and xanthan gum; The binder includes one or more of styrene acrylic resin emulsion, phenolic resin, syrup, water glass, dextrin and polysaccharide compound; The rust inhibitor comprises triethanolamine and an organic acid, wherein the organic acid comprises one or more of octanoic acid, neodecanoic acid and isononanoic acid; The dispersant includes one or more of sodium hexametaphosphate, acrylic acid-2-acrylamide-2-methylpropanesulfonic acid copolymer, and naphthalenesulfonate formic acid condensate sodium salt; The wetting agent includes one or more of isomeric decanol polyoxyethylene ether, dioctyl sulfosuccinate sodium salt, and isomeric decanol polyoxyethylene ether.

10. The release agent for liquid die forging according to claim 1, wherein The liquid die forging release agent has a rotational viscosity of 2000 mPa at 25°C. . s-3000mPa . s.

11. A method for preparing a release agent for liquid die forging according to any one of claims 1 to 10, characterized in that: include: The liquid die forging release agent is obtained by mixing the various components of the liquid die forging release agent.

12. An automobile structural part, characterized in that: The automobile structural part is prepared by using the liquid die forging release agent according to any one of claims 1 to 10.

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