A water-based magnesium-aluminum alloy metal release agent and preparation method thereof

Abstract

The present invention discloses a water-based magnesium-aluminum alloy metal release agent and a preparation method thereof. The agent comprises the following raw materials in parts by weight: 25-30 parts of attapulgite / micron iron oxide composite powder, 10-15 parts of sodium bentonite, 5-10 parts of bauxite, 2-3 parts of nano-zirconia powder, 10-15 parts of ethanol, 35-40 parts of deionized water, 3-5 parts of a binder, 1-3 parts of an active agent, 2-4 parts of a dispersant, and 0.1-0.5 parts of a defoamer. The release agent can be attached to a mold through simple processes such as dipping, brushing, and spraying. The process is simple and easy to implement industrial production. The prepared water-based release agent has good stability and retains 99.5% suspension after 15 days, which facilitates uniform coating of the release agent on various mold surfaces.

Description

Technical Field

[0001] The invention belongs to the technical field of coating preparation, and particularly relates to a water-based magnesium-aluminum alloy metal release agent and a preparation method thereof. Background Art

[0002] Magnesium-aluminum alloy metal structural materials, characterized by high strength, excellent rigidity, impact resistance, and superior shock absorption, are widely used in the aerospace and defense industries, the automotive industry, and the electronics industry. Magnesium-aluminum alloy metal castings are produced using traditional sand casting methods. During the casting process, reactive slag pores are easily generated on the mold contact surface, which not only affects the quality of the casting but also leads to waste of aluminum alloy raw material. Applying a layer of mold release agent to the working surface of the casting sand mold can effectively prevent and reduce defects such as sand adhesion, sand inclusions, and sand holes, thereby reducing the surface roughness of the casting. Existing metal mold casting coatings can effectively address the problem of aluminum alloy's susceptibility to oxidation and combustion, but the coatings are suitable for metal mold molds and have high requirements. In particular, existing water-based aluminum alloy casting coatings use modified attapulgite clay powder, lithium-based bentonite, nano-zirconia powder, graphite powder, and chromite powder as fillers. These ingredients are complex and difficult to ensure uniform mixing. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a water-based magnesium-aluminum alloy metal release agent and a preparation method thereof in response to the above-mentioned deficiencies in the prior art. The water-based release agent can be attached to the mold through simple processes such as dipping, brushing and spraying. The process is simple and easy to realize industrial production. The prepared water-based release agent has good stability and still has 99.5% suspension after being placed for 15 days, which is conducive to the uniform coating of the release agent on various mold surfaces.

[0004] In order to achieve the above technical objectives, the technical solution adopted by the present invention is:

[0005] A water-based magnesium-aluminum alloy metal release agent, characterized by comprising the following raw materials in parts by weight: 25-30 parts of attapulgite / micron iron oxide composite powder, 10-15 parts of sodium bentonite, 5-10 parts of bauxite, 2-3 parts of nano zirconium oxide powder, 10-15 parts of ethanol, 35-40 parts of deionized water, 3-5 parts of binder, 1-3 parts of active agent, 2-4 parts of dispersant and 0.1-0.5 parts of defoamer.

[0006] The adhesive is formed by compounding polyvinyl butyral (PVB) and sodium silicate nonahydrate in a ratio of 1:1 to 1.5.

[0007] The above-mentioned active agent is epoxy polysiloxane.

[0008] The above-mentioned dispersant is a homemade product SD-00 produced by Nanjing Xiaoke Nano-ceramics Technology Development Co., Ltd., and its main component is ammonium polyacrylate.

[0009] The above-mentioned defoaming agent is dimethyl polysiloxane.

[0010] A method for preparing a water-based magnesium-aluminum alloy metal release agent, characterized in that it comprises the following steps:

[0011] Step 1: Prepare attapulgite / micron iron oxide composite powder according to the above weight percentage, add deionized water and stir at a stirring speed of 1500-3000 rpm and a stirring time of 1-2 hours to obtain a suspension A;

[0012] Step 2: Add nano-zirconia powder to ethanol and stir at a stirring speed of 1500 to 3000 rpm and a stirring time of 1 to 2 hours to obtain a suspension B;

[0013] Step 3: Stir the suspension A again at a stirring speed of 1500 to 3000 rpm, add suspension B dropwise during stirring to promote nano-zirconium oxide flocculation on the surface of the attapulgite / micron iron oxide composite powder, then add sodium bentonite and bauxite to the solution and stir, add adhesive, surfactant, dispersant and defoaming agent, and then stir thoroughly with a cross-blade stirrer at a stirring speed of 500 to 1000 rpm for 1 to 2 hours to obtain a release agent water-based magnesium-aluminum alloy metal release agent for standby use.

[0014] The attapulgite / micronized iron oxide composite powder in step 1 is prepared by the following steps:

[0015] Step 1: Prepare a attapulgite clay suspension by mixing 200-400 mesh attapulgite with water and stirring. Heat and stir the suspension at 100 degrees Celsius until the suspension boils. Then, add 1-2 ml of saturated FCl3 solution dropwise and boil until the liquid turns reddish brown.

[0016] Step 2: Cooling and aging the solution for 2 to 4 hours, then centrifuging the attapulgite clay suspension in a centrifuge for 2 to 5 times, each time for 5 minutes, and filtering to recover the solid matter;

[0017] Step 3: calcining the recovered solid in a high-temperature furnace at 450-500° C. for 2-3 hours to obtain attapulgite / micron iron oxide composite powder.

[0018] The advantages of the present invention are as follows:

[0019] (1) It does not decompose at high temperatures, is easy to demould, and the forgings are smooth and flat. There is no smoke, fire, poison, odor, or dust during the molding process, which reduces mold wear and extends the service life of the mold.

[0020] (2) High-temperature resistant inorganic mineral powder release agent, which can be used in various metal castings and can withstand high temperatures of 1000 degrees. The release agent is a gray liquid with no irritating odor, a density of 1.23 to 1.31 g / cm3, and a pH value in the neutral range. It is suitable for magnesium and aluminum alloy molding demolding, steel building materials, and processing of workpieces with large elongation, high deformation rate, and complex curves;

[0021] (3) It can be attached to the mold through simple processes such as dipping, brushing and spraying. The process is simple and easy to realize industrial production. The prepared water-based release agent has good stability and still has 99.5% suspension after being placed for 15 days, which is conducive to the uniform coating of the release agent on various mold surfaces. DETAILED DESCRIPTION

[0022] The specific embodiments of the present invention are further described below:

[0023] A water-based magnesium-aluminum alloy metal release agent, characterized by comprising the following raw materials in parts by weight: 25-30 parts of attapulgite / micron iron oxide composite powder, 10-15 parts of sodium bentonite, 5-10 parts of bauxite, 2-3 parts of nano zirconium oxide powder, 10-15 parts of ethanol, 35-40 parts of deionized water, 3-5 parts of binder, 1-3 parts of active agent, 2-4 parts of dispersant and 0.1-0.5 parts of defoaming agent.

[0024] Preferably, the adhesive is formed by compounding polyvinyl butyral (PVB) and sodium silicate nonahydrate in a ratio of 1:1 to 1.5.

[0025] Preferably, the active agent is epoxy polysiloxane.

[0026] Preferably, the dispersant is SD-00, a homemade product produced by Nanjing Xiaoke Nano-Ceramic Technology Development Co., Ltd., the main component of which is ammonium polyacrylate.

[0027] Preferably, the defoaming agent is dimethylpolysiloxane.

[0028] A method for preparing a water-based magnesium-aluminum alloy metal release agent, characterized in that it comprises the following steps:

[0029] Step 1: Prepare attapulgite / micron iron oxide composite powder according to the above weight percentage, add deionized water and stir at a stirring speed of 1500-3000 rpm and a stirring time of 1-2 hours to obtain a suspension A;

[0030] Step 2: Add nano-zirconia powder to ethanol and stir at a stirring speed of 1500 to 3000 rpm and a stirring time of 1 to 2 hours to obtain a suspension B;

[0031] Step 3: Stir the suspension A again at a stirring speed of 1500 to 3000 rpm, add suspension B dropwise during stirring to promote nano-zirconium oxide flocculation on the surface of the attapulgite / micron iron oxide composite powder, then add sodium bentonite and bauxite to the solution and stir, add adhesive, surfactant, dispersant and defoaming agent, and then stir thoroughly with a cross-blade stirrer at a stirring speed of 500 to 1000 rpm for 1 to 2 hours to obtain a release agent water-based magnesium-aluminum alloy metal release agent for standby use.

[0032] Preferably, the attapulgite / micron iron oxide composite powder in step 1 is prepared by the following steps:

[0033] Step 1: Prepare a attapulgite clay suspension by mixing 200-400 mesh attapulgite with water and stirring. Heat and stir the suspension at 100 degrees Celsius until the suspension boils. Then, add 1-2 ml of saturated FCl3 solution dropwise and boil until the liquid turns reddish brown.

[0034] Step 2: Cooling and aging the solution for 2 to 4 hours, then centrifuging the attapulgite clay suspension in a centrifuge for 2 to 5 times, each time for 5 minutes, and filtering to recover the solid matter;

[0035] Step 3: calcining the recovered solid in a high-temperature furnace at 450-500° C. for 2-3 hours to obtain attapulgite / micron iron oxide composite powder.

[0036] The prepared metal die-casting release agent is sprayed on the surface of the sand mold, the spraying times are 1 time, and the coating thickness is 0.08mm-0.09mm. The magnesium-aluminum alloy liquid is poured into the sand mold for molding.

[0037] Table 1 Performance index of metal die casting release agent prepared in Example

[0038]

[0039]

[0040] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions based on the principles of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, various improvements and modifications that do not depart from the principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A water-based magnesium-aluminum alloy metal release agent, characterized by: The invention comprises the following raw materials in parts by weight: 25 to 30 parts of attapulgite / micron iron oxide composite powder, 10 to 15 parts of sodium bentonite, 5 to 10 parts of bauxite, 2 to 3 parts of nano zirconium oxide powder, 10 to 15 parts of ethanol, 35 to 40 parts of deionized water, 3 to 5 parts of adhesive, 1 to 3 parts of active agent, 2 to 4 parts of dispersant and 0.1 to 0.5 parts of defoaming agent.

2. The water-based magnesium-aluminum alloy metal release agent according to claim 1, characterized in that: The adhesive is formed by compounding polyvinyl butyral (PVB) and sodium silicate nonahydrate in a ratio of 1:1 to 1.

5.

3. The water-based magnesium-aluminum alloy metal release agent according to claim 1, characterized in that: The active agent is epoxy polysiloxane.

4. The water-based magnesium-aluminum alloy metal release agent according to claim 1, characterized in that: The defoaming agent is dimethyl polysiloxane.

5. A method for preparing a water-based magnesium-aluminum alloy metal release agent according to any one of claims 1 to 4, characterized in that: The following steps are involved: Step 1: Prepare attapulgite / micron iron oxide composite powder according to the above weight percentage, add deionized water and stir at a stirring speed of 1500-3000 rpm and a stirring time of 1-2 hours to obtain a suspension A; Step 2: The nano-zirconia powder was added to ethanol and stirred at a stirring speed of 1500 to 3000 rpm and a stirring time of 1 to 2h to obtain a suspension B; Step 3: Stir the suspension A again at a stirring speed of 1500 to 3000 rpm, add the suspension B dropwise during stirring to promote the flocculation of nano-zirconium oxide on the surface of the attapulgite / micron iron oxide composite powder, then add sodium bentonite and bauxite to the solution and stir, add adhesive, surfactant, dispersant and defoaming agent, and then stir thoroughly with a cross-blade stirrer at a stirring speed of 500 to 1000 rpm for 1 to 2 hours to obtain a water-based magnesium-aluminum alloy metal release agent for standby use.

6. The method for preparing a water-based magnesium-aluminum alloy metal release agent according to claim 5, characterized in that: The attapulgite / micron iron oxide composite powder in step 1 is prepared by the following steps: Step 1: Prepare a attapulgite clay suspension by mixing 200-400 mesh attapulgite with water and stirring. Heat and stir the suspension at 100 degrees Celsius until the suspension boils. Then, add 1-2 ml of saturated FCl3 solution dropwise and boil until the liquid turns reddish brown. Step 2: Cooling and aging the solution for 2 to 4 hours, then centrifuging the attapulgite clay suspension in a centrifuge for 2 to 5 times, each time for 5 minutes, and filtering to recover the solid matter; Step 3: calcining the recovered solid in a high-temperature furnace at 450-500° C. for 2-3 hours to obtain attapulgite / micron iron oxide composite powder.

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