Method for vertically placing slender tree-assembling structure formwork

Abstract

The invention relates to a method for vertically placing a slender tree assembly structure mold shell, which comprises the following steps that a tree assembly wax mold module performs surface layer shell making, then performs multiple times of back layer shell making, then adheres an original foot support made of a wax rod to the bottom of the mold shell, the length of the original foot support is larger than that of a target foot support, and the length of the target foot support is larger than that of the original foot support. The method comprises the following steps of: performing back layer shell making on an original kickstand for multiple times, sealing slurry, cutting off the part, longer than a target kickstand, of the kickstand, performing dewaxing treatment, filling the filling slurry into an opening in the bottom of the kickstand of a dewaxed module, drying, curing and sintering to obtain a sintered module, and enabling the kickstand in the sintered module to be used for upright placement of a mold shell. And the mold shell is of a slender group tree structure. Compared with the prior art, by additionally arranging the foot supports, the accuracy of the placement position of the mold shell in the roasting and pouring process and the stability of mold shell placement in the pouring process of alloy liquid are achieved.

Description

Technical Field

[0001] This invention relates to the field of investment casting, and in particular to a method for vertically placing a slender, tree-structured mold shell. Background Technology

[0002] In the field of investment casting, for castings with small part structures, a commonly used gating system is bottom pouring and / or side pouring. A simplified diagram of this gating system is shown below. Figure 1 As shown (illustrating bottom-pouring and side-pouring systems), this casting system has advantages such as stable filling and high yield. However, in actual production, due to the long, thin strip structure of the bottom plane and the presence of protruding slag-collecting cylinders, the bottom of the mold cannot be placed stably, causing many problems in the actual production and use of this casting system. 1. During the process of transferring the mold shell from the preheating furnace to the casting furnace after preheating by placing it upside down, the employees need to flip the mold shell, which increases the risk of mold shell damage and also affects the safety of the operators. 2. During the process of placing the mold shell in the casting furnace, special tooling fixtures are required for fixation, which results in high production costs; 3. The clamping and disassembly of the mold shell on special tooling or fixtures require a certain amount of time, which increases the exposure time of the mold shell to air, resulting in poor process stability during the casting process and greatly affecting the stability of product quality.

[0003] Due to the different tree assembly methods, in order to ensure the good function of the blades and the integrity of the mold filling, some blades cannot be supported independently. As a result, it is not easy to accurately transfer and position the mold shell during transportation and subsequent firing and casting, which can easily lead to mold shell damage; affect personnel safety; cause tipping and tilting during casting; and make it impossible to place stably after casting.

[0004] Therefore, there is an urgent need for a method that can achieve the upright placement of slender tree-structure mold shells, and ensure the accuracy of the mold shell placement during the firing and casting process. Summary of the Invention

[0005] The purpose of this invention is to overcome the defects of the prior art and provide a method for vertically placing a slender tree-structure mold shell. By adding foot supports, the accuracy of the mold shell's placement during the baking and pouring process and the stability of the mold shell's placement during the pouring of the alloy liquid are achieved.

[0006] The objective of this invention can be achieved through the following technical solutions: This invention provides a method for vertically placing a slender, tree-structured mold shell. The method achieves vertical placement of the mold shell by adding foot supports (without changing the original tree structure of the slender product). The foot supports are non-through (i.e., the foot supports do not damage the original tree structure of the slender product and are connected to the outer surface of the shell). The preparation process of the foot supports is synchronized with the shell-making process. The foot supports are prepared simultaneously during the shell-making stage, and the prepared foot supports are high-strength supports.

[0007] Furthermore, the method includes the following steps: S1. Immerse the wax model of the tree into the surface slurry, apply the surface slurry, then apply sand and dry it to form a surface shell to obtain model A. S2. The module A obtained in step S1 is subjected to multiple back layer shell making processes to obtain module Bn. The module Bn includes a mold shell and a group tree wax mold set inside the mold shell. Each time the back layer shell is made, the previous module is immersed in the back layer slurry, picks up the back layer slurry, and then is sanded and dried. S3. The original foot support made by attaching wax rods to the bottom of the mold shell of module Bn obtained in step S2, wherein the length of the original foot support is longer than the length of the target foot support, thus obtaining a module with an increased original foot support; S4. Perform back layer shelling multiple times on the original support in the module with added original support obtained in step S3 to obtain the module with added original support after shelling. Each time the back layer shelling is performed, the previous module is immersed in the back layer slurry, and then the back layer slurry is applied and dried. S5. Immerse the module with added original feet after shelling obtained in step S4 into the sealing layer slurry, apply the sealing layer slurry, and then dry it to obtain the sealed module. S6. Cut off the part of the leg support in the sealed module obtained in step S5 that is longer than the target leg support, put it into the dewaxing kettle for dewaxing treatment, and obtain the dewaxed leg support and the dewaxed module. S7. Fill the bottom opening of the dewaxed module obtained in step S6 with filling grout, fill the hollow pipe of the module, and then dry and cure to obtain the grouted module of the module. S8. The grouting module obtained in step S7 is sintered to obtain a sintered module. The legs in the sintered module are used for the upright placement of the mold shell, and the mold shell is a slender tree structure.

[0008] Furthermore, step S1 specifically includes the following process: S1-1. Immerse the tree wax model into the surface slurry and rotate it slowly to ensure that the surface of the tree wax model is fully coated with the surface slurry. After taking it out, rotate it slowly to let the excess surface slurry on the surface of the tree wax model flow away, so that the surface of the tree wax model is evenly coated with one layer of surface slurry. S1-2. Place the wax mold assembly with the surface slurry on it in the electrofused alumina sandblasting machine so that the surface of the assembly is fully coated with electrofused alumina sand. S1-3. After the sand coating is completed, place the wax model assembly in the surface drying area for drying to obtain assembly A.

[0009] Furthermore, in steps S1-2, the fused alumina abrasive is 100-120 mesh.

[0010] Furthermore, in steps S1-3, the drying conditions are: temperature at 21-25℃, humidity at 40%-60%, and drying time of 6-8 hours.

[0011] Further, in step S2, the back layer shell fabrication includes the following process: Immerse module A or the previous module in the backing slurry and rotate it slowly to ensure that the surface of module A or the previous module is fully coated with the backing slurry. After taking it out, rotate it slowly to let the excess backing slurry on the surface of module A or the previous module flow away, so that the surface of module A or the previous module is evenly coated with one layer of backing slurry. Place the wax mold assembly coated with the back layer slurry into the electrofused corundum sandblasting machine so that the surface of the assembly is fully coated with electrofused corundum sand. After the sandblasting process, the wax mold assembly is placed in the back drying area for drying.

[0012] Furthermore, in step S2, the back layer shell is formed 3 to 4 times.

[0013] Furthermore, in step S2, the mesh size of the sand used in the first back layer shell preparation process is less than the mesh size of the sand used in the top layer shell preparation process in step S1.

[0014] Furthermore, in step S2, the mesh size of the sand used in the subsequent backing shell preparation process is less than or equal to the mesh size of the sand used in the subsequent backing shell preparation process in step S2.

[0015] Furthermore, the mesh size of the sand used in the final back-layer shell preparation process in step S2 is equal to the mesh size of the sand used in the back-layer shell preparation process in step S4.

[0016] Furthermore, in step S3, red wax is used to adhere the wax stick.

[0017] Furthermore, in step S3, the wax rod is a pouring wax.

[0018] Furthermore, in step S3, the length of the original foot support is 5-10 mm longer than the length of the target foot support.

[0019] Further, in step S4, the back layer shell fabrication includes the following process: Immerse the module with the original support or the previous module into the backing slurry and rotate it slowly to ensure that the surface of the module with the original support or the previous module is fully coated with the backing slurry. After taking it out, rotate it slowly to let the excess backing slurry on the surface of the module with the original support or the previous module flow away, so that the surface of the module with the original support or the previous module is evenly coated with one layer of backing slurry. Place the wax mold assembly coated with the back layer slurry into the electrofused corundum sandblasting machine so that the surface of the assembly is fully coated with electrofused corundum sand. After the sandblasting process, the wax mold assembly is placed in the back drying area for drying.

[0020] Furthermore, in step S4, at least four back-layer shell fabrication processes are performed.

[0021] More preferably, in step S4, the back layer shell is formed 5 to 6 times.

[0022] Furthermore, the raw materials of the surface slurry include nano-silica sol, polymer and zircon powder, wherein the powder-to-liquid ratio of nano-silica sol, polymer and zircon powder is approximately 1:0.04-0.12:3.8-4.5.

[0023] Furthermore, the raw materials of the backing slurry include nano-silica sol, polymer, and zircon powder, wherein the powder-to-liquid ratio of nano-silica sol, polymer, and zircon powder is approximately 1:0.04-0.12:2.8-3.5.

[0024] Furthermore, in step S5, the sealing layer slurry includes nano-silica sol and zircon powder, and the powder-to-liquid ratio of the nano-silica sol and zircon powder is 1:1.8-2.0.

[0025] Further, in step S7, the filling slurry is a mixture of slurry and fused alumina sand in a mass ratio of 2:1, and the raw materials of the base slurry include nano silica sol, zircon powder, wetting agent, defoamer and bactericide.

[0026] Furthermore, the base slurry is a slurry that is prepared and used within 1 hour.

[0027] Further, the preparation of the base slurry includes the following steps: first, zircon powder is added to the nano-silica sol and stirred; then, a wetting agent, an antifoaming agent, and a bactericide are added sequentially to obtain the base slurry. The base slurry is best prepared and used immediately; it cannot be used after 1 hour. Further, in step S5, the drying conditions are as follows: drying is carried out in the back layer drying area using a strong airflow method, with the wind speed controlled at 4-8 m / s, the ambient temperature at 21-25℃, and the humidity at <30%, for 20 hours.

[0028] Furthermore, in step S7, the drying and curing conditions are: standing still for 2-3 hours, drying environment humidity of 40-60%, and temperature of 20-25℃.

[0029] Furthermore, in step S8, the sintering is carried out in a gas-fired sintering furnace.

[0030] Furthermore, in step S8, the sintering conditions are to slowly heat to 850-900°C and then cool with the furnace.

[0031] Compared with the prior art, the present invention has the following advantages: (1) The present invention provides a method for vertically placing a slender tree structure mold shell, which can achieve vertical placement of the mold shell without changing the tree structure of the original slender product, simply by adding foot supports.

[0032] (2) The present invention provides a method for placing a slender tree structure mold shell upright. By adding foot supports, the accuracy of the placement of the mold shell during the baking and pouring process and the stability of the mold shell placement during the pouring process of the alloy liquid are achieved.

[0033] (3) The present invention provides a method for placing a slender tree structure mold shell upright, which conforms to the mechanical support structure and the mold shell, and can solve the problem that the mold shell cannot be placed upright in the roasting chamber, resulting in accidents or damage to the mold shell during the transfer process due to the flipping of the mold shell.

[0034] (4) The present invention provides a method for placing a slender tree-structure mold shell upright, which ensures that the mold shell can be placed stably after the metal filling and pouring are completed, so as to better realize the metal sequential filling and sequential solidification preset by the pouring system and reduce the defects of casting porosity and excessive grain size.

[0035] (5) The present invention provides a method for placing a slender tree structure mold shell upright, which solves the problem of workers needing to hold the high-temperature mold shell and rotate it, and improves production safety.

[0036] (6) The present invention provides a method for vertically placing a slender tree-shaped mold shell. By using a mixture of slurry and corundum sand, the mold shell-shaped composite structure has high mechanical strength and can support the vertical placement of the mold shell throughout the entire process from high temperature to metal casting and cooling. Attached Figure Description

[0037] Figure 1 The gating system is defined as follows: (a) is a side-pouring system, and (b) is a bottom-pouring system.

[0038] Figure 2 This is a schematic diagram of the first four layers of the shell model in an embodiment of the present invention.

[0039] Figure 3This is a schematic diagram illustrating the addition of the original foot support in an embodiment of the present invention.

[0040] Figure 4 This is a schematic diagram of the foot support after the shell is made in an embodiment of the present invention.

[0041] Figure 5 This is a schematic diagram of the dewaxing foot support in an embodiment of the present invention.

[0042] Figure 6 This is a schematic diagram of the roasted foot support in an embodiment of the present invention. Detailed Implementation

[0043] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0044] This invention relates to a method for vertically placing a slender, tree-like structure mold shell, comprising the following steps: a surface shell is formed on the tree-like wax mold assembly, followed by multiple back shell formations. Then, original supports made of wax rods are adhered to the bottom of the mold shell. The length of the original supports is longer than the target supports. Multiple back shell formations are then performed on the original supports, followed by sealing with slurry. The portion of the supports longer than the target supports is cut off, and dewaxing is performed. Filling slurry is poured into the bottom openings of the supports after dewaxing, and the mold assembly is dried, cured, and sintered to obtain a sintered mold assembly. The supports in the sintered mold assembly are used for the vertical placement of the mold shell, which is a slender, tree-like structure. Compared with existing technologies, this invention, by adding supports, achieves greater accuracy in the placement of the mold shell during firing and casting, as well as greater stability in the placement of the mold shell during the casting of the alloy molten metal.

[0045] In this invention, any component models, material names, connection structures, control methods, etc., not explicitly stated are considered common technical features disclosed in the prior art.

[0046] Example 1 This embodiment provides a method for vertically placing a slender tree structure mold shell, which achieves vertical placement of the slender tree structure mold shell by adding foot supports to the mold shell.

[0047] The method includes the following steps: S1. Immerse the wax model of the tree into the surface slurry, apply the surface slurry, then apply sand and dry it to form a surface shell to obtain model A. S2. The module A obtained in step S1 is subjected to multiple back layer shell making processes to obtain module Bn. The module Bn includes a mold shell and a group tree wax mold set inside the mold shell. Each time the back layer shell is made, the previous module is immersed in the back layer slurry, picks up the back layer slurry, and then is sanded and dried. S3. The bottom of the mold shell of module Bn obtained in step S2 is made of the original foot support by adhering the wax rod with red wax (casting wax). The length of the original foot support is 5-10mm longer than the length of the target foot support, thus obtaining a module with an increased original foot support. S4. Perform back layer shelling multiple times on the original support in the module with added original support obtained in step S3 to obtain the module with added original support after shelling. Each time the back layer shelling is performed, the previous module is immersed in the back layer slurry, and then the back layer slurry is applied and dried. S5. Immerse the module with added original feet after shelling obtained in step S4 into the sealing layer slurry, apply the sealing layer slurry, and then dry it to obtain the sealed module. S6. Cut off the part of the leg support in the sealed module obtained in step S5 that is longer than the target leg support, put it into the dewaxing kettle for dewaxing treatment, and obtain the dewaxed leg support and the dewaxed module. S7. Fill the bottom opening of the dewaxed module obtained in step S6 with filling grout, fill the hollow pipe of the module, and then dry and cure to obtain the grouted module of the module. S8. The grouting module obtained in step S7 is sintered to obtain a sintered module. The legs in the sintered module are used for the upright placement of the mold shell, and the mold shell is a slender tree structure.

[0048] Step S1 specifically includes the following process: S1-1. Immerse the tree wax model into the surface slurry and rotate it slowly to ensure that the surface of the tree wax model is fully coated with the surface slurry. After taking it out, rotate it slowly to let the excess surface slurry on the surface of the tree wax model flow away, so that the surface of the tree wax model is evenly coated with one layer of surface slurry. S1-2. Place the wax mold assembly with the surface slurry in a 100-120 mesh fused alumina sandblasting machine so that the surface of the assembly is fully coated with 100-120 mesh fused alumina sand. S1-3. Place the wax model assembly after sanding in the surface drying area, control the temperature of the surface drying area at 21-25℃ and the humidity at 40%-60%, and dry for 6-8 hours to obtain module A. In step S2, the back layer shell fabrication includes the following process: Immerse module A or the previous module in the backing slurry and rotate it slowly to ensure that the surface of module A or the previous module is fully coated with the backing slurry. After taking it out, rotate it slowly to let the excess backing slurry on the surface of module A or the previous module flow away, so that the surface of module A or the previous module is evenly coated with one layer of backing slurry. Place the wax mold assembly coated with the back layer slurry into the electrofused corundum sandblasting machine so that the surface of the assembly is fully coated with electrofused corundum sand. After the sandblasting process, the wax mold assembly is placed in the back drying area for drying.

[0049] In step S2, the back layer shell is formed 3 to 4 times.

[0050] In step S2, the mesh size of the sand used in the first back layer shell preparation process is less than the mesh size of the sand used in the first surface layer shell preparation process in step S1; in step S2, the mesh size of the sand used in the subsequent back layer shell preparation process is less than or equal to the mesh size of the sand used in the subsequent back layer shell preparation process in step S2; in step S2, the mesh size of the sand used in the last back layer shell preparation process is equal to the mesh size of the sand used in the back layer shell preparation process in step S4.

[0051] In step S3, red wax is used to adhere the wax stick; in step S3, the wax stick is cast wax; in step S3, the length of the original foot support is 5-10mm longer than the length of the target foot support.

[0052] In step S4, the back layer shell fabrication includes the following process: Immerse the module with the added original support or the previous module into the backing slurry, and slowly rotate it to ensure that the surface of the module with the added original support or the previous module is fully coated with the backing slurry. After taking it out, slowly rotate it to let the excess backing slurry on the surface of the module with the added original support or the previous module flow away, so that the surface of the module with the added original support or the previous module is evenly coated with one layer of backing slurry. Place the wax mold assembly coated with the back layer slurry into the electrofused corundum sandblasting machine so that the surface of the assembly is fully coated with electrofused corundum sand. After the sandblasting process, the wax mold assembly is placed in the back drying area for drying.

[0053] In step S4, at least four back-layer shell fabrication processes are performed.

[0054] In step S5, the drying conditions are as follows: drying is carried out in the back layer drying area, using a strong wind blowing method with a wind speed controlled at 4-8 m / s, an ambient temperature of 21-25℃, a humidity of <30%, and drying for 20 hours.

[0055] In step S7, the drying and curing conditions are: stand still for 2-3 hours, humidity of the drying environment is 40-60%, and temperature is 20-25℃.

[0056] In step S8, the sintering is carried out in a gas-fired sintering furnace; in step S8, the sintering conditions are to slowly heat to 850-900℃ and then cool with the furnace.

[0057] Example 2 This embodiment provides a method for vertically placing a slender tree structure mold shell. Based on Embodiment 1, this embodiment also includes the following settings: The raw materials of the surface slurry include nano-silica sol, polymer and zircon powder, wherein the powder-to-liquid ratio of nano-silica sol, polymer and zircon powder is 1:0.04-0.12:3.8-4.5.

[0058] The raw materials of the backing slurry include nano-silica sol, polymer, and zircon powder, wherein the powder-to-liquid ratio of nano-silica sol, polymer, and zircon powder is 1:0.04-0.12:2.8-3.5.

[0059] The preparation of the surface layer slurry and the back layer slurry includes the following steps: first, zircon powder and polymer are added to the nano-silica sol, and stirred at a speed of 100 r / min.

[0060] In step S5, the sealing layer slurry includes nano-silica sol and zircon powder, and the powder-to-liquid ratio of the nano-silica sol and zircon powder is 1:1.8-2.0.

[0061] The preparation of the sealing layer slurry includes the following steps: first, zircon powder is added to the nano-silica sol and stirred at a speed of 100 r / min.

[0062] In step S7, the filling slurry is mixed with the base slurry and fused alumina sand in a mass ratio of 2:1. The raw materials of the base slurry include nano silica sol, zircon powder, wetting agent, defoamer and bactericide.

[0063] The base slurry is a slurry that is to be used within 1 hour of preparation. The preparation of the base slurry includes the following steps: first, add zircon powder to nano-silica sol and stir at 100 rpm; then, add a wetting agent, defoamer, and bactericide sequentially to obtain the base slurry. The base slurry is best prepared and used immediately; it cannot be used after 1 hour. Specifically, it can be prepared as follows: first, add 0.2~0.4 kg of 200-325 mesh zircon powder to approximately 100 ml of nano-silica sol and stir at 100 rpm; then, add 10 ml of wetting agent (name: nonionic composite phosphate ester), 10 ml of defoamer (name: hydroxyethyl cellulose, pH value: approximately 7.00), and 5 ml of bactericide (name: MBS 5050) sequentially. The base slurry is best prepared and used immediately; it cannot be used after 1 hour.

[0064] Example 3 This embodiment provides a method for vertically placing a slender tree structure mold shell, which achieves vertical placement of the slender tree structure mold shell by adding foot supports to the mold shell.

[0065] The method includes the following steps: (1) Immerse the wax model into the surface slurry and rotate it slowly to ensure that the surface of the wax model is fully coated with the surface slurry. After taking it out, rotate it slowly to let the excess slurry on the surface of the wax model flow away, so that the surface of the model is evenly coated with one layer of slurry.

[0066] (2) Place the wax mold assembly with the surface slurry in a 100-120 mesh electrofused corundum sandblasting machine so that the surface of the assembly is fully coated with 100-120 mesh electrofused corundum sand.

[0067] (3) Place the wax model after the sanding is completed in the surface drying area, control the temperature of the surface drying area at 21-25℃ and the humidity at 40%-60%, and dry for 6-8 hours.

[0068] (4) Immerse the module in the backing slurry and rotate it slowly to ensure that the surface of the module is fully coated with the backing slurry. After taking it out, rotate it slowly to let the excess slurry on the surface of the wax model module flow away, so that the surface of the module is evenly coated with one layer of backing slurry.

[0069] (5) Place the wax mold assembly with the back layer slurry in the 54-70 mesh electrofused corundum sandblasting machine so that the surface of the assembly is fully coated with 54-70 mesh electrofused corundum sand.

[0070] (6) Place the wax mold assembly after sanding in the back drying area, control the temperature of the back drying area at 21-25℃ and the humidity at 40%-60%, and dry for 6-8 hours.

[0071] (7) Immerse the module in the backing slurry and rotate it slowly to ensure that the surface of the module is fully coated with the backing slurry. After taking it out, rotate it slowly to let the excess slurry on the surface of the wax model module flow away, so that the surface of the module is evenly coated with one layer of backing slurry.

[0072] (8) Place the wax mold assembly with the back layer slurry in the 36-54 mesh electrofused corundum sandblasting machine so that the surface of the assembly is fully coated with 36-54 mesh electrofused corundum sand.

[0073] (9) Place the wax mold assembly after sanding in the back drying area, control the temperature of the back drying area at 21-25℃ and the humidity at 30-50%, and dry for 8-10 hours.

[0074] (10) Immerse the module in the backing slurry and rotate it slowly to ensure that the surface of the module is fully coated with the backing slurry. After taking it out, rotate it slowly to let the excess slurry on the surface of the wax model module flow away, so that the surface of the module is evenly coated with one layer of backing slurry.

[0075] (11) Place the wax mold assembly with the back layer slurry in the 14-28 mesh electrofused corundum sandblasting machine so that the surface of the assembly is fully coated with 14-28 mesh electrofused corundum sand.

[0076] (12) Place the wax mold assembly after sanding in the back drying area, control the temperature of the back drying area at 21-25℃ and the humidity at 30-50%, and dry for 8-10 hours.

[0077] (13) After completing steps (1) to (12), the shape of the module after shell making is as follows: Figure 2 As shown.

[0078] (14) After drying in step (12), the bottom of the mold shell is supported by a foot made of red wax and a wax stick (casting wax); the size and shape of the foot can be adjusted according to the actual size and height of the tree model. It is recommended to make it 5-10mm longer than the designed foot length (as allowance for removal during wax removal); Figure 3 As shown.

[0079] (15) For the foot support part, repeat the operation of steps 10-12 (different objects, same conditions) to copy the shell at least 4 layers, and it is recommended to copy the shell 5-6 layers.

[0080] (16) Immerse the module obtained after completing step (15) into the sealing slurry (see step (19) for the mixing ratio) to ensure that the outer surface of the module is evenly coated with the sealing slurry and the surface sand is completely wrapped.

[0081] (17) Place the module in the back drying area for drying, using a strong airflow method with a wind speed controlled at 4-8 m / s, an ambient temperature of 21-25℃, and a humidity of <30%, for 20 hours; the schematic diagram of the dried mold shell is shown below. Figure 4 As shown.

[0082] (18) Remove the completely dried mold, cut off the bottom of the added support legs, and place it in a dewaxing kettle for dewaxing (using conventional dewaxing treatment); the schematic diagram of the dewaxed mold shell is shown below. Figure 5 As shown.

[0083] (19) Preparation of slurry: Filling grout ratio: Mix base grout and 54-mesh fused alumina sand at a ratio of 2:1 and fill the gap evenly; The grouting mixture consists of nano-silica sol and zircon powder, with a powder-to-liquid ratio of approximately 1:1.8-2.0.

[0084] Preparation of basic slurry: First, add 0.2~0.4kg of 200-325 mesh zircon powder to about 100ml of silica sol and stir at 100r / min. Then, add 10ml of wetting agent (name: nonionic composite phosphate Victawet 12), 10ml of defoamer (name: hydroxyethyl cellulose, pH value: about 7.00), and 5ml of bactericide (name: MBS 5050) in sequence. It is best to prepare the basic slurry immediately before use. It cannot be used after 1 hour.

[0085] The preparation of the sealing layer slurry includes the following steps: first, zircon powder is added to the nano-silica sol and stirred at a speed of 100 r / min.

[0086] (20) Pour the filling slurry prepared in step (19) into the bottom opening of the foot support. After completely filling the hollow pipe of the foot support, let it stand for 2 to 3 hours to ensure that the slurry is completely dry and cured. The humidity of the drying environment is 40 to 60% and the temperature is 20 to 25℃.

[0087] (21) The mold shell obtained in step (20) is placed in a gas-fired firing furnace for sintering to enhance the strength of the mold shell and burn off residual wax, thereby obtaining a ceramic mold shell (the fired mold shell). The sintering conditions are to slowly raise the temperature to 850-900℃ and cool it with the furnace; the fired mold shell is as follows: Figure 6 As shown, the load-bearing capacity of the foot support reaches its maximum after firing, and it can withstand the weight of the mold shell and alloy.

[0088] (22) Inspect the inner and outer surfaces of the sintered ceramic mold shell to determine whether cracks have been generated.

[0089] In this embodiment, the surface slurry and the back slurry can be conventional slurries used for ceramic mold shells.

[0090] Example 4 This embodiment provides a method for vertically placing a slender tree structure mold shell. Based on embodiment 3, this embodiment also includes the following settings: The raw materials of the surface slurry include nano-silica sol, polymer and zircon powder, wherein the powder-to-liquid ratio of nano-silica sol, polymer and zircon powder is 1:0.04-0.12:3.8-4.5.

[0091] The raw materials of the backing slurry include nano-silica sol, polymer, and zircon powder, wherein the powder-to-liquid ratio of nano-silica sol, polymer, and zircon powder is 1:0.04-0.12:2.8-3.5.

[0092] The preparation of the surface layer slurry and the back layer slurry includes the following steps: first, zircon powder and polymer are added to the nano-silica sol, and stirred at a speed of 100 r / min.

[0093] The polymer mentioned above is a latex.

[0094] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

[0095] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A method for vertically placing a slender tree structure mold shell, characterized in that, The method achieves upright placement of the mold shell by adding foot supports, and the method includes the following steps: S1. Immerse the wax model of the tree into the surface slurry, apply the surface slurry, then apply sand and dry it to form a surface shell to obtain model A. S2. The module A obtained in step S1 is subjected to multiple back layer shell making processes to obtain module Bn. The module Bn includes a mold shell and a group tree wax mold set inside the mold shell. Each time the back layer shell is made, the previous module is immersed in the back layer slurry, picks up the back layer slurry, and then is sanded and dried. S3. The original foot support made by attaching wax rods to the bottom of the mold shell of module Bn obtained in step S2, wherein the length of the original foot support is longer than the length of the target foot support, thus obtaining a module with an increased original foot support; S4. Perform back layer shelling multiple times on the original support in the module with added original support obtained in step S3 to obtain the module with added original support after shelling. Each time the back layer shelling is performed, the previous module is immersed in the back layer slurry, and then the back layer slurry is applied and dried. S5. Immerse the module with added original feet after shelling obtained in step S4 into the sealing layer slurry, apply the sealing layer slurry, and then dry it to obtain the sealed module. S6. Cut off the part of the leg support in the sealed module obtained in step S5 that is longer than the target leg support, put it into the dewaxing kettle for dewaxing treatment, and obtain the dewaxed leg support and the dewaxed module. S7. Fill the bottom opening of the dewaxed module obtained in step S6 with filling grout, fill the hollow pipe of the module, and then dry and cure to obtain the grouted module of the module. S8. The grouting module obtained in step S7 is sintered to obtain a sintered module. The legs in the sintered module are used for the upright placement of the mold shell, and the mold shell is a slender tree structure.

2. The method for vertically placing a slender tree structure mold shell according to claim 1, characterized in that, Step S1 specifically includes the following process: S1-1. Immerse the tree wax model into the surface slurry and rotate it to ensure that the surface of the tree wax model is fully coated with the surface slurry. After taking it out, rotate it to let the excess surface slurry on the surface of the tree wax model flow away, so that the surface of the tree wax model is evenly coated with one layer of surface slurry. S1-2. Place the wax mold assembly with the surface slurry on it in the electrofused alumina sandblasting machine so that the surface of the assembly is fully coated with electrofused alumina sand. S1-3. After the sandblasting is completed, place the wax model assembly in the surface drying area for drying to obtain model A; In steps S1-2, the fused alumina abrasive is 100-120 mesh. In steps S1-3, the drying conditions are: temperature 21-25℃, humidity 40%-60%, and drying time 6-8 hours.

3. The method for vertically placing a slender tree structure mold shell according to claim 1, characterized in that, In step S2, the back layer shell fabrication includes the following process: Immerse module A or the previous module in the backing slurry, rotate it to ensure that the surface of module A or the previous module is fully coated with the backing slurry, remove it and rotate it to let the excess backing slurry on the surface of module A or the previous module flow away, so that the surface of module A or the previous module is evenly coated with one layer of backing slurry. Place the wax mold assembly coated with the back layer slurry into the electrofused corundum sandblasting machine so that the surface of the assembly is fully coated with electrofused corundum sand. After the sandblasting process is completed, the wax mold assembly is placed in the back drying area for drying. In step S2, the back layer shell is formed 3 to 4 times.

4. The method for vertically placing a slender tree structure mold shell according to claim 1, characterized in that, In step S2, the mesh size of the sand used in the first back layer shell preparation process is less than the mesh size of the sand used in the surface layer shell preparation process in step S1. In step S2, the mesh size of the sand used in the subsequent back layer shell preparation process is less than or equal to the mesh size of the sand used in the subsequent back layer shell preparation process in step S2. In step S2, the mesh size of the sand used in the final backing shell preparation process is equal to the mesh size of the sand used in the backing shell preparation process in step S4.

5. The method for vertically placing a slender tree structure mold shell according to claim 1, characterized in that, In step S3, red wax is used to adhere the wax stick; In step S3, the wax rod is a casting wax; In step S3, the length of the original foot support is 5-10 mm longer than the length of the target foot support.

6. The method for vertically placing a slender tree structure mold shell according to claim 1, characterized in that, In step S4, the back layer shell fabrication includes the following process: Immerse the module with the original support or the previous module into the backing slurry, rotate it to ensure that the surface of the module with the original support or the previous module is fully coated with the backing slurry, remove it and rotate it to let the excess backing slurry on the surface of the module with the original support or the previous module flow away, so that the surface of the module with the original support or the previous module is evenly coated with one layer of backing slurry. Place the wax mold assembly coated with the back layer slurry into the electrofused corundum sandblasting machine so that the surface of the assembly is fully coated with electrofused corundum sand. After the sandblasting process is completed, the wax mold assembly is placed in the back drying area for drying. In step S4, at least four back-layer shell fabrication processes are performed.

7. The method for vertically placing a slender tree structure mold shell according to claim 1, characterized in that, The raw materials of the surface slurry include nano-silica sol, polymer and zircon powder, wherein the powder-to-liquid ratio of nano-silica sol, polymer and zircon powder is 1:0.04-0.12:3.8-4.5; The raw materials of the backing slurry include nano-silica sol, polymer, and zircon powder, wherein the powder-to-liquid ratio of nano-silica sol, polymer, and zircon powder is 1:0.04-0.12:2.8-3.5; In step S5, the sealing layer slurry includes nano-silica sol and zircon powder, and the powder-to-liquid ratio of the nano-silica sol and zircon powder is 1:1.8-2.0; In step S7, the filling slurry is mixed with the base slurry and fused alumina sand in a mass ratio of 2:

1. The raw materials of the base slurry include nano silica sol, zircon powder, wetting agent, defoamer and bactericide. The base slurry is a slurry that is prepared and used within 1 hour.

8. The method for vertically placing a slender tree structure mold shell according to claim 1, characterized in that, In step S5, the drying conditions are as follows: drying is carried out in the back layer drying area, using a strong wind blowing method with a wind speed controlled at 4-8 m / s, an ambient temperature of 21-25℃, a humidity of <30%, and drying for 20 hours.

9. The method for vertically placing a slender tree structure mold shell according to claim 1, characterized in that, In step S7, the drying and curing conditions are: stand still for 2-3 hours, humidity of the drying environment is 40-60%, and temperature is 20-25℃.

10. A method for vertically placing a slender tree structure mold shell according to claim 1, characterized in that, In step S8, the sintering is carried out in a gas-fired sintering furnace; In step S8, the sintering condition is to raise the temperature to 850-900℃.

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