Mold wash composition for lost foam pattern

Abstract

To provide a mold wash composition for a lost foam pattern capable of further suppressing burning.SOLUTION: The coating agent composition for the lost foam pattern contains refractory aggregates and carbon fibers, wherein the refractory aggregates contain refractory aggregates (A) having a refractoriness of SK1a or more and 15 or less and black lead.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a mold wash composition for lost foam casting used in lost foam casting. [Background technology]

[0002] Lost foam casting is a casting method in which a synthetic resin foam pattern of the same shape as the product is replaced with molten metal (hereinafter referred to as "molten metal"). It offers numerous advantages, including no need for cores, no need for complicated work like mold matching, easy design changes, and short delivery times. However, issues remain, such as reducing residue defects and burn-in defects, and various research efforts are being conducted to improve the process. Residual defects occur when thermal decomposition gases are not sufficiently released when a synthetic resin foam pattern is replaced with molten metal, resulting in thermal decomposition residue that becomes entrained in the upper part of the product. Burn-in defects occur when the molten metal breaks down the mold coating and leaks into the sand mold. Preventing burn-in defects is particularly important; when they occur in large or thick-walled products, the removal process becomes complicated, leading to major problems such as increased labor hours, increased workload for workers, and delayed delivery.

[0003] As examples of wash compositions for evaporative patterns that improve adhesion defects, Patent Document 1 discloses a wash composition for evaporative patterns containing an ore whose DTA endothermic peak temperature (°C) is within a specific range; Patent Document 2 discloses a wash using an inorganic or organic fibrous material having a length of 6 to 30 mm; Patent Document 3 discloses a wash containing wollastonite (CaO·SiO2) as a refractory aggregate; and Patent Document 4 discloses a wash composition containing one or more selected from calcium bentonite and ammonium nitrate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-290869 [Patent Document 2] Japanese Patent Application Publication No. 11-285778 [Patent Document 3] Japanese Patent Application Laid-Open No. 2014-73504 [Patent Document 4] Japanese Patent Application Laid-Open No. 2001-334346 Summary of the Invention [Problem to be solved by the invention]

[0005] However, conventional mold wash compositions are not sufficient in preventing burn-on defects, and further improvements are needed.

[0006] An object of the present invention is to provide a mold wash composition for vanishing patterns that can further suppress burn-on defects. [Means for solving the problem]

[0007] The present invention provides Contains refractory aggregate and carbon fiber, The refractory aggregate (A) has a refractoriness of SK1a or more and SK15 or less, and the refractory aggregate (A) contains graphite. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a mold wash composition for evaporative models that can further suppress burn-in defects. [Brief explanation of the drawings]

[0009] [Figure 1] Schematic diagram showing the shape of the evaporative model used to evaluate the adhesion defects in the examples. DETAILED DESCRIPTION OF THE INVENTION

[0010] <Wash composition for evaporative pattern> The vanishing pattern wash composition of this embodiment (hereinafter also simply referred to as "vanishing pattern wash composition") contains a refractory aggregate and carbon fiber, and the refractory aggregate contains a refractory aggregate (A) having a refractoriness of SK1a or more and 15 or less, and graphite. According to the vanishing pattern wash composition of this embodiment, it is possible to further suppress burning defects. The reason why the vanishing pattern wash composition of this embodiment exhibits such an effect is partially unknown, but is presumed to be as follows.

[0011] During casting, the coating film is subjected to the thermal expansion of the molding sand and the pressure of the molten metal, so it needs to have physical properties that can withstand severe pressure differences. Refractory aggregate (A) with a refractoriness rating of SK1a or higher but not higher than 15 softens and melts with the heat of the molten metal, mitigating the pressure on the coating film. Furthermore, the presence of carbon fiber, which is easily dispersed uniformly and functions as a reinforcing material, in the coating film makes it less susceptible to damage and suppresses burn-on.

[0012] [Fire-resistant aggregate] From the viewpoint of suppressing sintering defects, the refractory aggregate contains refractory aggregate (A) having a refractoriness of SK1a or more and 15 or less. Examples of the refractory aggregate (A) include mica (SK14), obsidian (SK6a), perlite (SK6a), colophonite (SK5a), orthoclase (SK9), albite (SK9), nepheline (SK10), anorthite (SK9), etc., and among these, from the same viewpoint, at least one selected from obsidian, perlite, and mica is preferred.

[0013] The content of the refractory aggregate (A) in the refractory aggregate is preferably 1% by mass or more, more preferably 10% by mass or more, and even more preferably 30% by mass or more, from the viewpoint of suppressing firing defects. The content of the refractory aggregate (A) in the refractory aggregate is preferably 60% by mass or less, more preferably 50% by mass or less, from the viewpoint of improving the smoothness of the surface of the casting. The content of the refractory aggregate (A) in the refractory aggregate is preferably 1% by mass or more and 60% by mass or less, more preferably 10% by mass or more and 50% by mass or less, and even more preferably 30% by mass or more and 50% by mass or less, from the viewpoint of suppressing firing defects and improving the smoothness of the surface of the casting.

[0014] The refractoriness of the refractory aggregate (A) is SK1a or higher, preferably SK3a or higher, and more preferably 5a or higher, from the viewpoint of suppressing firing defects. The refractoriness of the refractory aggregate (A) is SK15 or lower, preferably SK11 or lower, and more preferably 9 or lower, from the viewpoint of suppressing firing defects. In this specification, the refractoriness refers to the refractoriness (SK value) measured according to JIS R2204:1999 "Testing method for refractoriness of refractories and refractory raw materials."

[0015] The refractory aggregate may contain refractory aggregate (B) having a refractoriness exceeding SK 15. Examples of the refractory aggregate (B) include silica (SK 35), alumina (SK 37 or higher), mullite (SK 37 or higher), shaft bankets (SK 37 or higher), spinel (SK 37 or higher), magnesia (SK 37 or higher), zircon (SK 37 or higher), and kaolin (SK 35). Among these, at least one selected from silica, mullite, and alumina is preferred from the viewpoints of economy and supply stability.

[0016] The refractory aggregate contains graphite to improve the releasability of the coated mold from the sand mold. Note that graphite burns in an oxygen-containing environment and therefore cannot be used for the fire resistance measurement according to JIS R2204:1999 "Testing Method for Fire Resistance of Refractories and Refractory Raw Materials." In other words, graphite does not have a fire resistance SK value.

[0017] The graphite content in the refractory aggregate is preferably 5% by mass or more, more preferably 10% by mass or more, from the viewpoint of improving the releasability of the wash from the sand mold. The graphite content in the refractory aggregate is preferably 50% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less, from the viewpoint of suppressing burning defects. The graphite content in the refractory aggregate is preferably 5% by mass or more and 50% by mass or less, more preferably 5% by mass or more and 30% by mass or less, even more preferably 5% by mass or more and 20% by mass or less, and even more preferably 10% by mass or more and 20% by mass or less, from the viewpoint of improving the releasability of the wash from the sand mold and suppressing burning defects.

[0018] The content of the refractory aggregate in the vanishing pattern wash composition is preferably 40% by mass or more, more preferably 50% by mass or more, from the viewpoints of drying properties and prevention of defects in the wash film such as cracks. The content of the refractory aggregate in the vanishing pattern wash composition is preferably 80% by mass or less, more preferably 70% by mass or less, from the viewpoints of application workability. The content of the refractory aggregate in the vanishing pattern wash composition is preferably 40% by mass or more and 80% by mass or less, more preferably 50% by mass or more and 70% by mass or less, from the viewpoints of drying properties and prevention of defects in the wash film such as cracks, and application workability.

[0019] [Carbon fiber] The average fiber length of the carbon fibers is preferably 0.1 mm or more, more preferably 0.2 mm or more, from the viewpoint of suppressing burning defects. The average fiber length of the carbon fibers is preferably 10 mm or less, more preferably 5 mm or less, from the viewpoint of suppressing burning defects. The average fiber length of the carbon fibers is preferably 0.1 mm or more and 10 mm or less, more preferably 0.2 mm or more and 5 mm or less, from the viewpoint of suppressing burning defects.

[0020] The average fiber diameter of the carbon fibers is preferably 2 μm or more, more preferably 5 μm or more, from the viewpoint of suppressing burning defects. The average fiber diameter of the carbon fibers is preferably 20 μm or less, more preferably 10 μm or less, from the viewpoint of suppressing burning defects. The average fiber diameter of the carbon fibers is preferably 2 μm or more and 20 μm or less, more preferably 5 μm or more and 10 μm or less, from the viewpoint of suppressing burning defects.

[0021] The content of the carbon fiber is preferably 0.03 parts by mass or more, more preferably 0.05 parts by mass or more, and even more preferably 0.1 parts by mass or more, relative to 100 parts by mass of the refractory aggregate, from the viewpoint of suppressing burn-on defects. The content of the carbon fiber is preferably 4.5 parts by mass or less, more preferably 1.0 parts by mass or less, and even more preferably 0.4 parts by mass or less, relative to 100 parts by mass of the refractory aggregate, from the viewpoint of improving the ease of application to form a uniform coating film. The content of the carbon fiber is preferably 0.03 parts by mass or more and 4.5 parts by mass or less, more preferably 0.05 parts by mass or more and 1.0 parts by mass or less, and even more preferably 0.1 parts by mass or more and 0.4 parts by mass or less, relative to 100 parts by mass of the refractory aggregate, from the viewpoint of suppressing burn-on defects and improving the ease of application to form a uniform coating film.

[0022] The content of the carbon fiber in the mold wash composition for evaporative models is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, from the viewpoint of suppressing burn-on defects. The content of the carbon fiber in the mold wash composition for evaporative models is preferably 10% by mass or less, more preferably 2.0% by mass or less, from the viewpoint of improving application workability to form a uniform coating film and suppressing burn-on defects. The content of the carbon fiber in the mold wash composition for evaporative models is preferably 0.01% by mass or more and 10% by mass or less, more preferably 0.05% by mass or more and 2.0% by mass or less, from the viewpoint of suppressing burn-on defects and improving application workability to form a uniform coating film.

[0023] The mold wash composition may contain other components that are typically used in mold washes for evaporative patterns, provided that the effects of this embodiment are not impaired.

[0024] [Dispersion medium] The mold wash composition may contain a dispersion medium commonly used in vanishing pattern washes. When the mold wash composition is an aqueous mold wash composition, water serves as the main dispersion medium. When the mold wash composition is an alcohol-based mold wash composition, lower alcohols such as methanol, ethanol, and isopropyl alcohol are preferred, with ethanol being more preferred, from the viewpoint of improving drying properties. In the case of an alcohol-based mold wash composition, an aromatic solvent or a hydrocarbon solvent may be used as an auxiliary dispersion medium.

[0025] In the case of an aqueous mold-wash composition, the amount of water in the aqueous mold-wash composition is preferably 10 parts by mass or more, and more preferably 20 parts by mass or more, relative to 100 parts by mass of the refractory aggregate, from the viewpoint of improving application workability. In the case of an aqueous mold-wash composition, the amount of water in the aqueous mold-wash composition is preferably 80 parts by mass or less, and more preferably 70 parts by mass or less, relative to 100 parts by mass of the refractory aggregate, from the viewpoint of improving drying performance. Furthermore, in the case of an aqueous mold-wash composition, the amount of water in the aqueous mold-wash composition is preferably 10 parts by mass or more and 80 parts by mass or less, and more preferably 20 parts by mass or more and 70 parts by mass or less, relative to 100 parts by mass of the refractory aggregate, from the viewpoint of improving application workability and drying performance.

[0026] The amount of the dispersion medium in the alcohol-based mold wash composition can be appropriately changed depending on the type of dispersion medium used. For example, when the dispersion medium is a lower alcohol, from the viewpoint of improving application workability, the amount is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, relative to 100 parts by mass of the refractory aggregate. When the dispersion medium is a lower alcohol, from the viewpoint of improving drying properties and preventing coating defects such as cracks, the amount of the dispersion medium in the alcohol-based mold wash composition is preferably 80 parts by mass or less, more preferably 70 parts by mass or less, relative to 100 parts by mass of the refractory aggregate. Furthermore, when the dispersion medium is a lower alcohol, from the viewpoint of improving application workability and forming a sound coating film, the amount of the dispersion medium in the alcohol-based mold wash composition is preferably 10 parts by mass or more and 80 parts by mass or less, more preferably 20 parts by mass or more and 70 parts by mass or less, relative to 100 parts by mass of the refractory aggregate.

[0027] [Binding agent] The mold wash composition may contain a binder commonly used in mold washes for evaporative patterns. Examples of binders that can be used in aqueous systems include water-soluble polymers such as sodium polyacrylate, starch, methyl cellulose, polyvinyl alcohol, sodium alginate, and gum arabic, as well as various resin emulsions. For alcohol-based systems, adding various resins that are soluble or dispersible in alcohol is preferred from the viewpoint of improving the strength of the mold wash film. From the viewpoints of improving the coating film strength and economic efficiency, the content of the binder is preferably 0.1 parts by mass or more and 30 parts by mass or less per 100 parts by mass of the refractory aggregate.

[0028] [Sintering agent] The mold wash composition may contain a sintering agent typically used in mold washes for evaporative patterns, provided that the effects of this embodiment are not impaired. Examples of such sintering agents include bentonites such as sodium bentonite and calcium bentonite, clays such as kibushi clay, and ethyl silicate. Among these, bentonite is preferred because it functions not only as a binder but also as a sintering agent at high temperatures. The amount of sintering agent added is preferably 0.5 parts by mass or more, more preferably 1.0 parts by mass or more, per 100 parts by mass of the refractory aggregate, from the viewpoint of improving the strength of the mold wash at high temperatures. The amount of sintering agent added is preferably 30 parts by mass or less, more preferably 15 parts by mass or less, per 100 parts by mass of the refractory aggregate, from the viewpoint of improving the strength of the mold wash at high temperatures. The amount of sintering agent added is preferably 0.5 parts by mass or more, more preferably 1.0 parts by mass or more, per 100 parts by mass of the refractory aggregate, from the viewpoint of improving the strength of the mold wash at high temperatures. The amount of sintering agent added is preferably 0.5 parts by mass or more, more preferably 30 parts by mass or more, more preferably 15 parts by mass or less, per 100 parts by mass of the refractory aggregate, from the viewpoint of improving the strength of the mold wash at high temperatures. The amount of sintering agent added is preferably 0.5 parts by mass or more, more preferably 30 parts by mass or more, more preferably 1.0 parts by mass or more, per 100 parts by mass of the refractory aggregate, from the viewpoint of improving the strength of the mold wash at high temperatures.

[0029] Other components that can be blended in the mold wash composition include dispersants such as sodium salt of β-naphthalenesulfonic acid formalin condensate and polyvinylpyrrolidone, surfactants, preservatives, and the like.

[0030] The mold wash composition can be produced by blending the refractory aggregate, the carbon fiber, and other components. The term "blending" includes mixing the components simultaneously or in any order. When the mold wash composition contains carbon fibers of a predetermined length, the carbon fibers may be blended in, or the carbon fibers may be adjusted to the predetermined length by applying shear during mixing.

[0031] The mold wash composition can be used to produce castings by lost foam casting, and more specifically, can be suitably used as a mold wash composition to be adhered to the periphery of a lost foam.

[0032] <Method of manufacturing lost foam for casting> In the method for manufacturing a lost form pattern for casting of this embodiment, conventional methods for manufacturing a lost form pattern for casting can be applied. The method for manufacturing a lost form pattern for casting of this embodiment is a method for manufacturing a lost form pattern for casting having a mold wash film around the periphery of the lost form pattern, and includes a step of adhering the mold wash composition for the lost form pattern to the periphery of the lost form pattern to form a mold wash film.

[0033] The lost model to which the mold wash composition of this embodiment is applied can be a typical synthetic resin foam model. Examples of the synthetic resin foam include foams of polystyrene, polymethyl methacrylate, copolymers thereof, and the like. When the lost model to which the mold wash composition of this embodiment is applied is expanded polystyrene, the effects of the mold wash composition of this embodiment can be more effectively achieved. The method for applying the mold wash composition to the lost model to form a mold wash film may be any of the conventional methods such as flow coating (spray coating), immersion (hot dip coating), brush coating, and spray coating.

[0034] The lost foam pattern for casting obtained by the method for manufacturing a lost foam pattern for casting of the present embodiment can be suitably used in the manufacturing method of a mold by lost foam casting.

[0035] <Casting manufacturing method> The method for producing a casting by the lost foam casting method of this embodiment can be applied to the method for producing a casting by the conventional lost foam casting method. The method for producing a casting of this embodiment is a method for producing a casting using the lost foam pattern for casting obtained by the method for producing a lost foam pattern for casting, and includes the steps of embedding the lost foam pattern for casting in molding sand and casting molten metal into the lost foam pattern for casting embedded in the molding sand.

[0036] The molding sand used in the step of embedding the lost pattern for casting in molding sand includes silica sand, which is mainly composed of quartz, as well as new or recycled sand such as zircon sand, chromite sand, synthetic ceramic sand, etc. Molding sand can be used without adding a binder, in which case the filling properties are good, but when a high-strength mold is required, it is preferable to add a conventionally known binder and harden it with a hardener.

[0037] The manufacturing method of a casting in the embodiment in which a binder is added is a manufacturing method of a casting using the lost foam pattern for casting obtained by the manufacturing method of the lost foam pattern for casting, and includes the steps of adding a binder and a curing agent for curing the binder to the molding sand and kneading them to prepare a mixture, embedding the lost foam pattern for casting in the mixture, and casting molten metal into the lost foam pattern for casting embedded in the mixture.

[0038] The binder may be any commonly used binder. Examples of such binders include furan resin, phenolic resin, phenol-furan resin, urethane resin, and alkaline phenolic resin. From the viewpoints of mold strength improvement and economic efficiency, the binder content is preferably 0.1 parts by mass or more, and more preferably 0.4 parts by mass or more, per 100 parts by mass of molding sand. From the viewpoints of mold strength improvement and economic efficiency, the binder content is preferably 5.0 parts by mass or less, and more preferably 2.0 parts by mass or less, per 100 parts by mass of molding sand. From the viewpoints of mold strength improvement and economic efficiency, the binder content is preferably 0.1 parts by mass or more and 5.0 parts by mass or less, and more preferably 0.4 parts by mass or more and 2.0 parts by mass or less, per 100 parts by mass of molding sand.

[0039] In the casting manufacturing method of this embodiment, the pouring temperature varies depending on the metal used, but is generally 1280 to 1480°C for cast iron, 700 to 750°C for aluminum, and 1480 to 1680°C for cast steel. The lost foam casting method of this embodiment can particularly reduce burn-in defects that occur in cast iron. Furthermore, because burn-in defects are easily suppressed, casting at higher temperatures is possible in order to reduce residual defects.

[0040] When a casting is produced using the aforementioned mold wash composition for a lost pattern, the resulting casting has little burn-on and a beautiful casting surface, and is therefore suitable for applications requiring complex structures, beautiful casting surfaces, etc. Specific examples of castings include components and parts used in automobile dies, machine tools, industrial machinery, hydraulic valves for construction machinery, motors, engine frames, building materials, etc. [Example]

[0041] Examples that specifically illustrate the present invention will be described below.

[0042] <Examples 1 to 10 and Comparative Example 1> [Preparation of Mold Wash Composition] 100 parts by mass of the refractory aggregate shown in Table 1 was mixed with carbon fiber, 5 parts by mass of bentonite, 12 parts by mass of binder, 3 parts by mass of nonionic surfactant, and 40 parts by mass of ion-exchanged water in the amounts shown in Table 1 to prepare the mold wash compositions of Examples 1 to 10 and Comparative Example 1. The raw materials used are as follows: [Fire-resistant aggregate] Mullite: Cerabeads #1750 (refractory grade SK37 or higher) manufactured by Itochu Ceratec Co., Ltd. Obsidian: Kinseimatec Co., Ltd. Obsidian-80mesh (fire resistance SK6a) Mica: Kirara Mica KC200 (fire resistance SK14) Graphite: Mihara Carbon Co., Ltd., flake graphite-185 [fiber] Carbon fiber: Morimura Shoji Co., Ltd. SMT-201 (fiber length 2 mm, fiber diameter 7 μm) Glass fiber: Nitto Boseki Glass Chopped Strand SC3J-888 (fiber length 3 mm, fiber diameter 10 μm) Wollastonite fiber: SH-400 (fiber length 0.3 mm, fiber diameter 10 μm) manufactured by Kinseimatec Co., Ltd. [others] Bentonite: Kunibond, manufactured by Kunimine Industries Co., Ltd. Binder: Vinyblan 1096, manufactured by Nissin Chemical Industry Co., Ltd. Nonionic surfactant: Emulgen (registered trademark) 106, manufactured by Kao Corporation

[0043] <Evaluation of burn-on defects> A lost form for casting, having the shape shown in FIG. 1, was prepared using expanded polystyrene (expansion ratio: 60). The surface of this lost form was coated with the wash composition of each Example and Comparative Example (dry film thickness: 1.0 mm), to prepare a lost form for casting. After the wash application, the casting was dried for 12 hours under conditions of 50°C and 25% RH. Then, 0.32 parts by mass of an organic sulfonic acid curing agent (TK-2, manufactured by Kao-Quaker Corporation) was added to 100 parts by mass of Fremantle silica sand (No. 5). After mixing, 0.8 parts by mass of furan resin (EF-5302, manufactured by Kao-Quaker Corporation) was mixed with 100 parts by mass of the silica sand. The lost form for casting was embedded in the resulting mixed sand, and molten metal was poured through a gate at a speed that would prevent overflow (cast iron: FC-250, pouring temperature: 1470°C). After 24 hours, the mold was disassembled and the casting was removed. The pocket of the resulting casting (volume 660 cm 3 For burn-on defects that occurred in the pocket (size: 6 × 10 × 11 cm), the burn-on rate was calculated using the following formula from the amount of water that entered the pocket. Adhesion rate (%) = (660 - amount of water in the pocket (g)) / 660 x 100

[0044] The evaluation results are shown in Table 1.

[0045] [Table 1]

Claims

1. Contains refractory aggregate and carbon fiber, The refractory aggregate (A) has a refractoriness of SK1a or more and SK15 or less, and the refractory aggregate (A) contains graphite.

2. 2. The mold wash composition for a evaporative pattern according to claim 1, wherein the content of the carbon fiber is 0.03 parts by mass or more and 4.5 parts by mass or less per 100 parts by mass of the refractory aggregate.

3. 2. The vanishing pattern wash composition according to claim 1, wherein the content of the refractory aggregate in the vanishing pattern wash composition is 40% by mass or more and 80% by mass or less.

4. 2. The evaporative model wash composition according to claim 1, wherein the content of the carbon fiber in the evaporative model wash composition is 0.01% by mass or more and 10% by mass or less.

5. 2. The mold wash composition for a evaporative pattern according to claim 1, wherein the content of the refractory aggregate (A) in the refractory aggregate is 1 mass % or more.

6. 2. The wash composition for an evaporative model according to claim 1, wherein the refractory aggregate (A) contains at least one selected from the group consisting of obsidian, perlite, and mica.

7. 2. The mold wash composition for a evaporative pattern according to claim 1, wherein the content of graphite in the refractory aggregate is 5% by mass or more and 50% by mass or less.

8. 2. The mold wash composition for a evaporative model according to claim 1, wherein the carbon fibers have an average fiber length of 0.1 μm or more and 10 mm or less.

9. 2. The mold wash composition for a evaporative model according to claim 1, wherein the carbon fibers have an average fiber diameter of 2 μm or more and 20 μm or less.

10. The vanishing pattern wash composition according to claim 1, further comprising bentonite.

11. The wash composition for a evaporative pattern according to claim 1, further comprising a surfactant.

12. A method for manufacturing a lost form pattern for casting having a coating film on the surface of the lost form pattern, comprising: A method for producing a venant pattern for casting, comprising a step of adhering the venant pattern wash composition according to any one of claims 1 to 11 to the periphery of the venant pattern to form a mold wash film.

13. A method for manufacturing a casting using the lost foam for casting obtained by the manufacturing method according to claim 12, A method for manufacturing a casting, comprising the steps of: embedding the evaporative pattern for casting in molding sand; and pouring molten metal into the evaporative pattern for casting embedded in the molding sand.

14. Use of a composition containing a refractory aggregate and carbon fiber, wherein the refractory aggregate contains a refractory aggregate (A) having a refractoriness of SK1a or more and SK15 or less, and graphite, for producing a casting by an lost foam casting method.

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