Shunt plate for casting aluminum alloy and preparation process of shunt plate

Abstract

The invention relates to the field of molten aluminum purification and casting, in particular to a flow dividing disc for aluminum alloy casting and a preparation process thereof. The raw materials of the flow dividing disc are composed of dry powder and a liquid binding agent, and the weight ratio of the dry powder to the liquid binding agent is 73: 27. Wherein the dry powder comprises the following components in parts by weight: 40-45 parts of fused quartz powder, 30-35 parts of kyanite powder, 5-8 parts of activated alumina powder, 5-7 parts of spherical silicon dioxide, 3-5 parts of an anti-sticking aluminum agent and 5-8 parts of calcium aluminate cement; the liquid binding agent is prepared from the following components in parts by weight: 70 to 80 parts of silica sol, 0.1 to 0.2 part of xanthan gum and 19.8 to 29.9 parts of water. In the preparation process, the mold turnover period is short, and the production efficiency is high; the produced shunting disc is good in volume stability and good in thermal shock resistance, does not crack in an aluminum alloy casting rod process, and is not wet with molten aluminum; the shunting disc subjected to surface treatment is low in porosity, good in corrosion resistance and long in service life.

Description

Technical Field

[0001] The invention relates to the field of aluminum liquid purification casting, and in particular to a diverter plate for aluminum alloy smelting and casting and a preparation process thereof. Background Art

[0002] In the casting process of aluminum alloy, the purified aluminum liquid needs to be injected into the crystallizer through the hot top product. On the aluminum alloy casting rod forming crystallizer, there is a diverter plate. Generally, the diverter plate is formed by vibration molding of refractory castables or high aluminum wool suction filtration and then machined. However, in the process of aluminum alloy casting rods, the diverter plate formed by vibration molding of refractory castables has poor thermal shock resistance, is easy to crack, has a large temperature drop, and has poor thermal insulation. The diverter plate has a large temperature drop, the aluminum liquid temperature is low, and premature solidification causes blockage, resulting in casting failure. The diverter plate cracks, increasing the risk of aluminum liquid leakage. The aluminum liquid leaks into the circulating cooling water return pit. The molten aluminum liquid reacts with water to form hydrogen, releasing a large amount of heat. The water turns into water vapor when it meets the high-temperature aluminum liquid. The two situations occur together, and a large amount of energy is accumulated and cannot be released, causing a violent explosion. The diverter plate formed by suction filtration of high aluminum wool has extremely poor erosion resistance, is not resistant to erosion, and has a short life. Frequent replacement of the diverter plate not only increases the cost, but also the replacement process is cumbersome and dangerous.

[0003] Therefore, the art urgently needs to develop a new diverter plate for aluminum alloy smelting and casting and its preparation process, so as to improve the anti-aluminum sticking, thermal shock resistance and production efficiency of the diverter plate for aluminum alloy smelting and casting, reduce its surface pore defects, and extend its service life. Summary of the invention

[0004] The purpose of the present invention is to provide a diverter plate for aluminum alloy casting with fewer surface pore defects, long service life, high production efficiency, and better anti-aluminum sticking and thermal shock resistance, and a preparation process thereof.

[0005] In order to achieve one of the above purposes, the present invention adopts the following technical solution:

[0006] A preparation process of a flow divider for aluminum alloy smelting and casting, wherein the raw materials of the flow divider for aluminum alloy smelting and casting are composed of dry powder and liquid binder, and the weight ratio of the dry powder to the liquid binder is 73:27; wherein the dry powder comprises the following components in parts by weight: 40-45 parts of fused quartz powder, 30-35 parts of kyanite powder, 5-8 parts of activated alumina powder, 5-7 parts of spherical silica, 3-5 parts of anti-sticking aluminum agent, and 5-8 parts of calcium aluminate cement; the liquid binder comprises the following components in parts by weight: 70-80 parts of silica sol, 0.1-0.2 parts of xanthan gum, and 19.8-29.9 parts of water.

[0007] Preferably, the particle size of the spherical silicon dioxide is 5 to 6 μm.

[0008] Preferably, the anti-adhesive aluminum agent consists of calcium fluoride and barium sulfate, and the mass ratio of calcium fluoride to barium sulfate is 1:1-2.

[0009] Preferably, the silica sol has a solid content of 30% and a particle size of 10 to 15 μm.

[0010] Preferably, the preparation process of the diverter plate for aluminum alloy casting comprises the following steps:

[0011] S1, fused quartz powder, kyanite powder, activated alumina powder, spherical silica, anti-sticking aluminum agent and calcium aluminate cement are mixed uniformly in proportion to obtain a dry powder;

[0012] S2, mixing silica sol, xanthan gum and water in proportion to obtain a liquid binder;

[0013] S3, pasting a water-permeable and air-permeable template cloth on the inner side of a mold for preparing a diverter plate for aluminum alloy casting;

[0014] S4. Add the liquid binder to the dry powder in proportion, and stir rapidly for 30 seconds with a stirrer to obtain a slurry;

[0015] S5, injecting the slurry into the mold of step S3, leaving it to stand for 30 minutes and then demoulding to obtain a splitter plate blank;

[0016] S6, putting the splitter plate blank into a high temperature and high humidity steam curing box for steam curing for 30 minutes and then taking it out to obtain a splitter plate semi-finished product;

[0017] S7. Spray boron nitride on the aluminum liquid contact surface of the semi-finished diverter plate to obtain a finished product.

[0018] Preferably, in step S2, the xanthan gum is first dissolved in hot water at 50°C and then fully mixed with the silica sol.

[0019] Preferably, the rotation speed of the stirrer is 2200 rpm.

[0020] Preferably, the mold material is hard foam;

[0021] Preferably, the mold can be demoulded by natural air curing when left to stand.

[0022] Preferably, during steam curing, the temperature of the high temperature and high humidity steam curing box is 85° C. and the relative humidity is 80%. By fixing the temperature and humidity for high temperature steam curing, the risk of excessive shrinkage of the diverter disc during curing is prevented.

[0023] In order to achieve another object of the present invention, the present invention proposes a diverter plate for aluminum alloy smelting and casting, which is manufactured by using the above-mentioned preparation process of a diverter plate for aluminum alloy smelting and casting.

[0024] Preferably, the bulk density of the aluminum alloy casting diverter plate is 1.35 to 1.45 g·cm -3 , thermal conductivity at 815℃ is 0.4~0.5W·m -1 ·K -1 , flexural strength at room temperature ≥2.5Mpa.

[0025] The present invention also includes other steps that enable it to be used normally, which are all conventional technical means in the field; in addition, the steps not limited in the present invention all adopt conventional means in the field and will not be described in detail here.

[0026] The working principle of the present invention is as follows: by introducing substances such as xanthan gum, spherical silica, activated alumina powder, calcium aluminate cement, etc., the demoulding strength requirement is achieved in a short time, so that the material can be quickly demoulded after being injected into the mold, thereby achieving the purpose of short turnover cycle and high production efficiency; by pasting template cloth in the mold, the purpose of eliminating pores and reducing pore defects on the surface of the diverter plate during the curing process is achieved; by high-temperature steam curing in a high-temperature and high-humidity steam curing box, the purpose of preventing the risk of excessive shrinkage during the curing process of the diverter plate is achieved.

[0027] The beneficial effects of the present invention are as follows: the mold turnover cycle in the preparation process of the present invention is short and the production efficiency is high; the produced diverter disc has good volume stability and good thermal shock resistance, does not crack during the aluminum alloy casting process, and does not wet with aluminum liquid; the diverter disc after surface treatment has very low porosity and good corrosion resistance, and is particularly suitable for use on high-magnesium alloy casting rod mold discs, and the service life can reach 500 to 600 castings. Therefore, the present invention is of great significance in solving many problems existing in the current diverter disc. DETAILED DESCRIPTION

[0028] The present invention is described in detail below in conjunction with the specific embodiments of the present invention. The description herein is only used to explain the present invention, but is not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work, any modifications, equivalent substitutions, improvements, etc., should be included in the protection scope of the present invention.

[0029] Example 1

[0030] This embodiment proposes a process for preparing a diverter plate for aluminum alloy casting, comprising the following steps:

[0031] Step 1: Mix the components of the dry powder evenly according to the proportion to obtain the dry powder. The dry powder includes the following components in parts by weight: 44 parts of fused quartz powder, 34 parts of kyanite powder, 5 parts of activated alumina powder, 7 parts of spherical silica, 5 parts of anti-adhesive aluminum agent, and 5 parts of calcium aluminate cement; wherein the mass ratio of calcium fluoride to barium sulfate in the anti-adhesive aluminum agent is 1:1, and the particle size of the spherical silica is 5-6 μm.

[0032] Step 2: Mix the binder evenly according to the proportion to obtain a liquid binder. The binder includes the following components in parts by weight: 70 parts of silica sol, 0.1 parts of xanthan gum, and 29.9 parts of water; in this step, the xanthan gum is first dissolved in hot water at 50°C, and then fully mixed with the silica sol; the solid content of the silica sol is 30%, and the particle size is 10-15 μm.

[0033] Step 3: Pasting a water-permeable and air-permeable template cloth on the inner side of a mold for preparing a diverter plate for aluminum alloy casting, wherein the mold material is hard foam;

[0034] Step 4: Add the liquid binder to the dry powder, the weight ratio of the dry powder to the liquid binder is 73:27, and stir rapidly for 30 seconds with a stirrer to obtain a slurry; the speed of the stirrer is 2200 rpm;

[0035] Step 5: inject the slurry into the mold of step 3, let it stand for 30 minutes, and demould it after natural air curing to obtain the splitter blank;

[0036] Step 6: Place the splitter plate blank in a high-temperature and high-humidity steam curing box and steam it for 30 minutes, then take it out to obtain a splitter plate semi-finished product; during steam curing, the temperature of the high-temperature and high-humidity steam curing box is 85° C. and the relative humidity is 80%.

[0037] Step 7: Spray boron nitride on the aluminum liquid contact surface of the semi-finished diverter plate to obtain the finished product.

[0038] After testing, the aluminum alloy casting diverter disk prepared in this embodiment has a volume density of 1.43 g·cm -3 , 815℃ thermal conductivity is 0.45W·m -1 ·K -1 , the flexural strength at room temperature is 3.80Mpa.

[0039] Example 2

[0040] This embodiment proposes a process for preparing a diverter plate for aluminum alloy casting, comprising the following steps:

[0041] Step 1: Mix the components of the dry powder evenly according to the proportion to obtain the dry powder. The dry powder includes the following components in parts by weight: 40 parts of fused quartz powder, 35 parts of kyanite powder, 8 parts of activated alumina powder, 7 parts of spherical silica, 3 parts of anti-adhesive aluminum agent, and 7 parts of calcium aluminate cement; wherein the mass ratio of calcium fluoride to barium sulfate in the anti-adhesive aluminum agent is 1:1.5, and the particle size of the spherical silica is 5-6 μm.

[0042] Step 2: Mix the binder evenly according to the proportion to obtain a liquid binder. The binder includes the following components in parts by weight: 80 parts of silica sol, 0.2 parts of xanthan gum, and 19.8 parts of water; in this step, the xanthan gum is first dissolved in hot water at 50°C, and then fully mixed with the silica sol; the solid content of the silica sol is 30%, and the particle size is 10-15 μm.

[0043] Step 3: Pasting a water-permeable and air-permeable template cloth on the inner side of a mold for preparing a diverter plate for aluminum alloy casting, wherein the mold material is hard foam;

[0044] Step 4: Add the liquid binder to the dry powder, the weight ratio of the dry powder to the liquid binder is 73:27, and stir rapidly for 30 seconds with a stirrer to obtain a slurry; the speed of the stirrer is 2200 rpm;

[0045] Step 5: inject the slurry into the mold of step 3, let it stand for 30 minutes, and demould it after natural air curing to obtain the splitter blank;

[0046] Step 6: Place the splitter plate blank in a high-temperature and high-humidity steam curing box and steam it for 30 minutes, then take it out to obtain a splitter plate semi-finished product; during steam curing, the temperature of the high-temperature and high-humidity steam curing box is 85° C. and the relative humidity is 80%.

[0047] Step 7: Spray boron nitride on the aluminum liquid contact surface of the semi-finished diverter plate to obtain the finished product.

[0048] After testing, the aluminum alloy casting diverter plate prepared in this embodiment has a volume density of 1.4 g·cm -3 , 815℃ thermal conductivity is 0.43W·m -1 ·K -1 , the flexural strength at room temperature is 3.5Mpa.

[0049] Example 3

[0050] This embodiment proposes a process for preparing a diverter plate for aluminum alloy casting, comprising the following steps:

[0051] Step 1: Mix the components of the dry powder evenly according to the proportion to obtain the dry powder. The dry powder includes the following components in parts by weight: 45 parts of fused quartz powder, 30 parts of kyanite powder, 7 parts of activated alumina powder, 6 parts of spherical silica, 4 parts of anti-adhesive aluminum agent, and 8 parts of calcium aluminate cement; wherein the mass ratio of calcium fluoride to barium sulfate in the anti-adhesive aluminum agent is 1:2, and the particle size of the spherical silica is 5-6 μm.

[0052] Step 2: Mix the binder evenly according to the proportion to obtain a liquid binder. The binder includes the following components in parts by weight: 75 parts of silica sol, 0.15 parts of xanthan gum, and 24.85 parts of water; in this step, the xanthan gum is first dissolved in hot water at 50°C, and then fully mixed with the silica sol; the solid content of the silica sol is 30%, and the particle size is 10-15 μm.

[0053] Step 3: Pasting a water-permeable and air-permeable template cloth on the inner side of a mold for preparing a diverter plate for aluminum alloy casting, wherein the mold material is hard foam;

[0054] Step 4: Add the liquid binder to the dry powder, the weight ratio of the dry powder to the liquid binder is 73:27, and stir rapidly for 30 seconds with a stirrer to obtain a slurry; the speed of the stirrer is 2200 rpm;

[0055] Step 5: inject the slurry into the mold of step 3, let it stand for 30 minutes, and demould it after natural air curing to obtain the splitter blank;

[0056] Step 6: Place the splitter plate blank in a high-temperature and high-humidity steam curing box and steam it for 30 minutes, then take it out to obtain a splitter plate semi-finished product; during steam curing, the temperature of the high-temperature and high-humidity steam curing box is 85° C. and the relative humidity is 80%.

[0057] Step 7: Spray boron nitride on the aluminum liquid contact surface of the semi-finished diverter plate to obtain the finished product.

[0058] After testing, it was found that the aluminum alloy casting diverter disk prepared in this embodiment has a volume density of 1.38 g·cm -3 , 815℃ thermal conductivity is 0.41W·m -1 ·K -1 , the flexural strength at room temperature is 2.82Mpa.

[0059] In the above embodiments, from pouring to the end of curing, compared with the 48h curing period of the diverter disc prepared by the traditional preparation technology, the curing period of the diverter disc prepared by the present invention is only 1h, which greatly shortens the curing period, speeds up the mold turnover speed, and improves the product production efficiency. In addition, the diverter disc prepared by the present invention has an apparent porosity of more than 40%, good anti-aluminum adhesion, no cracking and peeling after 500 castings on site, and excellent thermal shock resistance.

[0060] The working principle of the present invention is as follows: by introducing substances such as xanthan gum, spherical silica, activated alumina powder, calcium aluminate cement, etc., the demoulding strength requirement is achieved in a short time, so that the material can be quickly demoulded after being injected into the mold, thereby achieving the purpose of short turnover cycle and high production efficiency; by pasting template cloth in the mold, the purpose of eliminating pores and reducing pore defects on the surface of the diverter plate during the curing process is achieved; by high-temperature steam curing in a high-temperature and high-humidity steam curing box with fixed temperature and humidity, the purpose of preventing the risk of excessive shrinkage during the curing process of the diverter plate is achieved.

[0061] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A process for preparing a diverter plate for aluminum alloy casting, characterized in that: The raw materials of the diverter plate for aluminum alloy casting are composed of dry powder and liquid binder, and the weight ratio of the dry powder to the liquid binder is 73:27; wherein the dry powder includes the following components in parts by weight: 40-45 parts of fused quartz powder, 30-35 parts of kyanite powder, 5-8 parts of activated alumina powder, 5-7 parts of spherical silica, 3-5 parts of anti-sticking aluminum agent, and 5-8 parts of calcium aluminate cement; the liquid binder includes the following components in parts by weight: 70-80 parts of silica sol, 0.1-0.2 parts of xanthan gum, and 19.8-29.9 parts of water.

2. The process for preparing a diverter plate for aluminum alloy casting according to claim 1, characterized in that: The particle size of the spherical silicon dioxide is 5 to 6 μm.

3. The process for preparing a diverter plate for aluminum alloy casting according to claim 1, characterized in that: The anti-adhesive aluminum agent consists of calcium fluoride and barium sulfate, and the mass ratio of calcium fluoride to barium sulfate is 1:1-2.

4. The process for preparing a diverter plate for aluminum alloy casting according to claim 1, characterized in that: The solid content of the silica sol is 30% and the particle size is 10-15 μm.

5. The process for preparing a diverter plate for aluminum alloy casting according to claim 1, characterized in that: The following steps are involved: S1, fused quartz powder, kyanite powder, activated alumina powder, spherical silica, anti-sticking aluminum agent and calcium aluminate cement are mixed uniformly in proportion to obtain a dry powder; S2, mixing silica sol, xanthan gum and water in proportion to obtain a liquid binder; S3, pasting a water-permeable and air-permeable template cloth on the inner side of a mold for preparing a diverter plate for aluminum alloy casting; S4. Add the liquid binder to the dry powder in proportion, and stir rapidly for 30 seconds with a stirrer to obtain a slurry; S5, injecting the slurry into the mold of step S3, leaving it to stand for 30 minutes and then demoulding to obtain a splitter plate blank; S6, putting the splitter plate blank into a high temperature and high humidity steam curing box for steam curing for 30 minutes and then taking it out to obtain a splitter plate semi-finished product; S7. Spray boron nitride on the aluminum liquid contact surface of the semi-finished diverter plate to obtain a finished product.

6. The process for preparing a diverter plate for aluminum alloy casting according to claim 5, characterized in that: In step S2, xanthan gum is first dissolved in hot water at 50°C and then fully mixed with silica sol.

7. The process for preparing a diverter plate for aluminum alloy casting according to claim 5, characterized in that: The rotation speed of the stirrer is 2200 rpm.

8. The process for preparing a diverter plate for aluminum alloy casting according to claim 5, characterized in that: When left to stand, the product can be demoulded by natural air curing.

9. A diverter plate for aluminum alloy casting, characterized in that: The diverter plate for aluminum alloy melting and casting is manufactured by using the preparation process of the diverter plate for aluminum alloy melting and casting as described in any one of claims 1 to 8.

10. The aluminum alloy casting diverter plate according to claim 9, characterized in that: The bulk density of the aluminum alloy casting diverter plate is 1.35 to 1.45 g·cm -3 , thermal conductivity at 815℃ is 0.4~0.5W·m -1 ·K -1 , flexural strength at room temperature ≥2.5Mpa.