SU865488A1 - Method of making moulds by the investment pattern method - Google Patents

Description

(54) METHOD OF MANUFACTURING THE CASTING FORMS BY THE MELTED MODELS The invention relates to the foundry industry, in particular to the manufacture (jiopM, produced by the melted (destructible) models. The known method of manufacturing the molded molds for the smelted (destructible) or by the use of the fumes used) applying silica slurry to the model, powder each layer with granular ferro-impregnation followed by curing, melting (removing) the model and burning the form. The model is coated with a silicate binder. This hardens each layer (suspensions take 2-5 hours. There is also a method in which, due to the use of air-ammonia, ammonia-vacuum drying or drying of the shell in the pseudo-boiling layer of the active absorber, the process is slowed down. costly and proper use

silicate binder; each layer of curing takes about 25 hours, which creates a long drying cycle, and the use of organic solvents (acetone, alcohol) worsens the sanitary and hygienic working conditions and creates a fire explosion hazard of production. Most technically the invention (technical and achievable result is a method of making foundry on melted (destructible) models, including layer-by-layer deposition on the Amor slip model (| shag of silica and granular refractory with after hardening 1-1m hardening of the slurry ,. model and firing. The disadvantage of this method is the use of two different bonding agents - silicate, KOTOpcie is applied to the model, in the aqueous slurry of amorphous silica for subsequent layers of the shell. to get various technological equipment for the implementation of similar operations f8 preparation of molding materials and manufacture of forms, and the use of an expensive silky compressed binder (ethyl acetate with organic solvents) creates a fire hazard and deteriorates sanitary and hygienic working conditions. fire and explosion safety of production. The goal is achieved by the fact that, according to the method including layer-by-layer application to the KpeNffleoeMa amorphous xchel shlichler model and granular refractory, followed by shlichler curing, removing the model and firing the form before applying to the slurry model of amorosil silica it is treated with a solution of the composition, wt.%: Naphthalene sulphonates with hydrocarbon radical (QHu) u, where −1 -1 0-35,0 Caustic soda 8,0-12,0 VodaEstalnaya As a nafgalensulfonate with the specified hydrocarbon radical, test the wetting agent NB (non-cal), the wetting agent CB-101, performing the functions of surface-active substances. Their use allows the use of non-concentrated alkaline solutions, which in turn ensures safe operation when applying the solution to the model with subsequent qualitative coating with amorphous silica slurry. When making paiCTBOpa on a wetted NB body, foam properties are observed, therefore, after it is cured, the foam sets and no undesirable effects arise during the process, it can be used to prepare 8. The method is carried out as follows. A solution (30% by weight,% NB wetting agent (not rolled), 10% by weight of caustic soda and 60% by weight of water) is dipped onto a melted (for example, steam (} n-stearinic) model by dipping. 10% by weight of caustic soda and 60% by weight of water are then drained. .. After this, an aqueous slurry of amorphous silica is applied, which is prepared by wet grinding of quartz in a ball mill lined with the same material, and sprinkled with a granular refractory material, for example, quartz sand, or fused silica of 0.16 for the first layer and 02-0.4 for subsequent layers and dry the shell in a known manner. Thus, five layers are applied.Each layer A layer is 35 minutes. The model composition of the obtained ceramic form is melted in hot water, and after drying, it is calcined at 90 ~ 950 C. The composition of the solutions is given in Table. , obtained by the proposed method, are given in Table 2. Forms are poured with steel with a temperature of 1550-1560 C. Visual inspection of castings shows good quality of their surface, and cutting, castings do not reveal casting defects (cracks, cracks, metal discontinuity), tab. 3 shows the cost savings for materials with a five-layer form. The implementation of the invention makes it possible to reduce the costs of shaping materials, improve sanitary and hygienic working conditions and ensure explosion and fire safety of production. Table

thirty

ten

8 10

12

Poor wetting of the model slip

Active coagulation (coagulability) of the clicker on the model surface

Insufficient wetting with model clicker

Claims (3)

Invention Formula A method of making casting molds based on melted models, including the continuation of the table. layer deposition on the slurry model of amorphous silica and ernite | g), followed by hardening of the slurry, removing the model and firing the mold, about 7,8654, which is due to the fact that, in order to reduce the cost, ensure the fire and explosion safety of production and improve the sanitary and hygienic labor, applying to the models a slip of amorphous silica is not treated with a solution of the composition, wt.%: Naphthalene sulfonates with hydrocarbon radi-. feces (SdN), 10 where 25tp-35, p Caustic soda 8.0-12.6 Water Else 888 Sources of information taken into account during the examination 1. Casting on melted models, Ed. Shklennik Ya. I. and Ozerov V.A., M., Mechanical Engineering, 1971, p. 231-255. 2. Ya. I. Shklennik. Modern Growth and Prospects for the Development of Technology for Casting on Melted Model m.- Sb. . Prospects of development for the above models, seminar materials M., Knowledge, 1975, p. eleven. 3. USSR author's certificate number 719784. class. B 22 C 9 / O4, l977.