KR100215198B1 - Turbine blade manufactured with ceramic shell casting method - Google Patents

Abstract

The present invention relates to a Tibin blade manufactured by a ceramic shell casting method, and more particularly, cobalt aluminate (C ovabalt aluminate, CoAl2O4) is added to the manufacture of the turbine blades in-situ treatment and wetting molds to manufacture the casting parts In order to manufacture high quality Dubine blades due to the fineness, it is a ceramic shell molding method for producing turbine blades by adding 3 to 15% of cobalt aluminate, which is an inoculant added for particle microscopy during the production of precision casting retaining molds. Manufactured turbine blades.

Description

Turbine Blade Manufactured by Ceramic Shell

1 is a cross-sectional photograph of a turbine blade arm not added inoculum

Figure 2 is a cross-sectional photograph of the turbine blade inoculated with cobalt aluminate

3 is a ceramic shell mold of the present invention

4 is a detailed view showing the coating sequence of the ceramic shell mold;

[Purpose of invention]

The present invention relates to a turbine blade which is manufactured by a ceramic shell casting method, and more particularly, cobalt aluminate (Cobalt Aluminate, CoA1204) is added to the manufacture of the turbine blades by contacting and producing a suitable mold to produce a fine particle The purpose is to produce high quality turbine blades due to shock.

[Technical field to which the invention belongs and the prior art in that field]

Since general turbine blades are used in high temperature, high pressure and corrosive environments, it is necessary to operate castings having high materials as well as using materials having high temperature strength combined with corrosion resistance. In order to manufacture such high-quality castings, the casting structure should be microscopically possible, and a suitable method of selecting and manufacturing a master material is required when manufacturing a mold. The method of finely graining the cast iron includes selecting the appropriate casting conditions such as injection temperature and preheating temperature of the mold, controlling the cooling rate after completion of injection, and turning the inoculum as a nucleation material. Among these, the use of the nucleation material is based on the principle of nucleation, and the metal calculation and water contained in the alloy act as seeds of crystal nucleation upon coagulation, producing many crystal grains at the same time to fine-tune particles. to be.

As for the casting mold for turbine blades, it is important to select the proper casting material and the manufacturing method together with the selection and addition amount of the material. The main names of the turbine blades must have reaction and reinforcement, rapid strength, and air permeability due to the Ongtang, and must be thermally and academically stable due to thermal stratification because there is no leak. In addition, some molds are manufactured in consideration of the weight of castings and the rate of suppression of defects during casting of molds. The vertebrae are made of ceramic shell coatings using a properly designed wax model, which includes a round first face coating, a back-up coating after the second and a final seal coating. It is composed of, and finished by repeating the shell thickness requiring three steps of slurry infiltration and drying the inner water coating, and then the wax is removed, and the mold is produced through the step of firing the mold.

Conventionally, in the method of manufacturing a turbine blade, in vacuum vacuum casting using a ceramic shell, when a mold is manufactured by refining crystal grains, an inoculant is added to a slurry during primary coating.

However, the excessive use of point materials will not only lead to an increase in cost due to the use of expensive inoculants, but will also have a significant effect on the mechanical properties of casting mists over certain periods of time. It is important to use an appropriate amount of inoculant considering the characteristics and non-obstruction of the casting to be manufactured, because it lowers the properties of the mold.

[Technical problem to be achieved]

SUMMARY OF THE INVENTION The present invention has been made to solve the problems described above, and the use of the aptitude tackifier in a ceramic shell mold for precision casting, which is a method of manufacturing a turbine blade, results in particle microwaving and aptitude molding material of a turbine blade which is a cast product. It is to select casting method and manufacture casting of high quality turbine bullade.

[Configuration and Function of Invention]

The construction and operation of the present invention will be described in detail with reference to the accompanying drawings. FIG. 2 is a cross-sectional photograph of a turbine blade treated by cobalt aluminate, and FIG. 3 is a ceramic shell mold diagram of the present invention. Figure 4 is a detailed view showing the coating sequence of the ceramic shell mold.

EXAMPLE

The present embodiment relates to a turbine blade for a turbocharger manufactured by vacuum precision casting using a ceramic shell mold prepared using an inoculant.

Like turbocharged turbine blades, blades have a uniform thickness between the airfoil part and the root part. Since it was difficult to fine-tune the tenants by adjustment alone, the media were used.

Cobalt aluminite was used as the tackifier, and a dropping amount was added to the slurry during the first coating. The amount of inoculant added was 3 to 15% as a result of various experiments, and microscopic gain of particles was obtained.

Figure 1 is a cross-sectional photograph of the upper end of the conventional casting state turbine blade airfoil (Airfoi1) without adding the inoculum material, Figure 2 shows a cross-sectional image of the turbine blade subjected to a tack treatment of about 10%. It was confirmed that the surface treatment was not inoculated, and the arm was finer than the blade.

In addition, the turbine blade casting ceramic shell mold manufacturing method including the inoculation treatment is as follows.

First of all, each wax model wool is fabricated by shaping the wax blade for the turbine blade wax model manufacturing, and a wax pattern tree is manufactured. It consists of the third stage of drying, water and fine powder drying.

In addition, the mold of the ceramic shell is produced by the appropriate material selection and manufacturing method in consideration of the characteristics of the casting pain, the thickness of the mold can be determined by adjusting the number of coatings.

In the present invention, the slurry used in the primary coating was 325 mesh (지 1esh) of zirconic powder as filler, cororidal silica aqueous solution (SiO2 3O%), surfactant, and antifoaming agent as binder. Cobatant aluminate was added as a point mediator to coat a Daum 125 mesh zircon sand, which produced a slurry of appropriate viscosity. In the second coating, 200 mesh zircon powder was used as the filler, and after the third, 200 mesh Chamotte powder was used, and cororidal silica, a surfactant, and an antifoaming agent were used as the binder. At this time, the second Yiwu left Chamot Sand. As shown in FIG. 4, sand is 125 mesh in the first coating, 0.25 to 0.5 mm in the second and third coatings, 0.5 to 1.0 nnn in the fourth and fifth coatings, and 1.0 to 1.5 mm in the sixth coating. As used.

The sand attachment method was a F1uidized Bed Nlethod, and each drying step was allowed to air dry for 4 to 8 hours in a room where a constant temperature and humidity were maintained, followed by using an autoclave. Pressurized for 15 minutes at a pressure of 7 ~ 8 kg / cm 2 to remove the wax in the mold, and calcined at 1,050 kPa for about 2 hours to complete the mold.

The mold manufactured by the VEN manufacturing method was poor in the manufacture of a good turbine blade with the coating of about 6 to 8th order, and satisfied the proper requirements as follows.

As a practical condition, the raw mold strength was measured at room temperature (20t), and the firing strength was measured using a specimen cooled after firing at 900t for 60 minutes, and the air permeability was measured by injecting nitrogen gas at a pressure of 5psi at 900t.

According to the present invention, the strength and moldability of the mold can be improved by adding 3 to 15% of cobalt aluminate, which is an inoculant added to refine the crystal grains of the turbine blade casting product. Turbine blades with improved characteristics were possible.

[Effects of the Invention]

Therefore, the present invention is a highly invention that can inoculate the amount of cobalt aluminite to improve the quality of the casting turbine blades to a high quality, resulting in the substitution effect as well as an advantage in competitiveness.

Claims (3)

Tibin blade manufactured by the ceramic shell casting method characterized in that the turbine blade is produced by adding 3 to l5% of cobalt aluminate, which is added to the fine-grained mold during the production of precision casting retaining mold. In turbine bollard fabrication, the slurry in the primary coating is a filler of 325 mesh. Using zircon powder, cororidal silica aqueous solution (SiO2, 3O%), surfactant, antifoaming agent as binder, and adding cobalt aluminate as inoculum to slurry, slurry was prepared. Zirken sand is applied, in the second coating, 200 mesh zircon powder as filler, tertiary powder is 200 mesh chamotte powder, corridor silica, surfactant, antifoaming agent as binder. After the second stage, the Tibin blade is manufactured by a ceramic shell casting method, characterized in that turbine blades are made of chamotte sand of 0.25 to 1.5 mm. The pressure of 7-8 Pa / Pa is carried out by the medium pressure furnace for 15 minutes by performing 6-8 coatings on the surface of a turbine blade, 4-8 hours of natural drying in the room with constant temperature, and humidity. Tibin blades produced by the ceramic shell casting method, characterized in that the production of a turbine blades by firing at 1000 to 1100 ℃.