CN113351828A

CN113351828A - Investment casting forming process for embedded ceramic core

Info

Publication number: CN113351828A
Application number: CN202110567105.5A
Authority: CN
Inventors: 严西亭; 李红才; 王海东; 李晏涛
Original assignee: Guizhou Anji Aviation Precision Casting Co Ltd
Current assignee: Guizhou Anji Aviation Precision Casting Co Ltd
Priority date: 2021-05-24
Filing date: 2021-05-24
Publication date: 2021-09-07

Abstract

The invention relates to an investment casting molding process with an embedded ceramic core, which comprises the following steps: preparing a mold core according to pattern shape characteristics in a design drawing provided by a user, and forming at least one heat dissipation hole in the surface of the mold core; providing a mould, wherein a mould cavity is arranged in the mould, the mould core is placed in the mould cavity, then wax materials are filled in the mould cavity, the wax materials are condensed to form a wax mould, and the wax mould and the mould core form a mould set; coating a refractory material on the surface of the module by using a coating, and roasting the module to melt and remove the wax pattern to obtain a mould shell; and pouring and filling the metal material smelted into a liquid state into the formwork, and condensing the metal material to obtain a casting. By adopting the technical scheme of the invention, the heat dissipation holes are formed in the surface of the mold core, so that heat can be quickly dissipated through the heat dissipation holes during casting molding, the difference of condensation speeds of metal materials in various regions is reduced, and the defects of casting shrinkage and porosity are reduced by arranging the feeding head in an over-arranged manner, and the molding quality is improved.

Description

Investment casting forming process for embedded ceramic core

Technical Field

The invention relates to the technical field of investment casting, in particular to an investment casting molding process with an embedded ceramic core.

Background

In the casting and forming process, firstly, a casting mold is prepared according to the shape of a product, then a liquid metal material is poured and smelted into the casting mold through a pouring cup, casting and forming are carried out after the metal material is condensed, along with the continuous development of the casting process technology, the shape structure of the casting is more and more complex, when a cavity is preset in the casting, the corresponding casting mold also has a corresponding cavity structure, when the poured metal material is condensed, the condensing speed of each local area of the metal material is inconsistent, particularly, at the position corresponding to the cavity structure, the heat dissipation speed is slow due to the small contact area of the metal material and the external environment, the time required for the metal material to completely condense is longest, excessive heat shrinkage holes and loose defects are easily generated at the corresponding position of the finally formed casting, the casting forming quality is influenced, the casting is scrapped, or the casting must be repaired and processed in the later period, resulting in increased worker labor intensity.

Disclosure of Invention

In order to solve the technical problem, the invention provides an investment casting molding process with an embedded ceramic core.

The invention provides an investment casting molding process with an embedded ceramic core, which comprises the following steps:

the method comprises the following steps: preparing a mold core according to pattern shape characteristics in a design drawing provided by a user, and forming at least one heat dissipation hole in the surface of the mold core;

step two: providing a mould, wherein a mould cavity is arranged in the mould, the mould core in the step one is placed in the mould cavity, wax materials are filled in the mould cavity, then the wax materials are condensed to form a wax mould, and the wax mould and the mould core form a module;

step three: coating a refractory material on the surface of the module by using a coating, and roasting the module to melt and remove the wax pattern to obtain a mould shell;

step four: and pouring and filling the metal material smelted into a liquid state into the formwork, and preparing a casting after the metal material is condensed.

The core is made of ceramic.

The aperture of the heat dissipation hole is phi 6 mm-phi 10 mm.

In the first step, the heat dissipation holes are formed by adopting a rotary file and a file.

The investment casting molding process of the embedded ceramic core further comprises the following steps: and step two, adhering a feeding head on the surface of the mold core, wherein the feeding head is communicated with the heat dissipation holes, so that the wax material is filled in the heat dissipation holes through the feeding head.

The feeding head is in an inverted cone-shaped tubular shape with a large upper end and a small lower end, and the ratio of the caliber of the lower end port to the caliber of the upper end port is 1: 3.

And transition fillets are further arranged at the joints of the feeding risers and the heat dissipation holes.

The transition round angle is R3-R5.

The invention has the beneficial effects that: by adopting the technical scheme of the invention, the core is inserted into the wax mould in the process of preparing the mould set, and the heat dissipation holes are arranged on the surface of the core, so that the heat at the cavity can be quickly transferred to the outside through the heat dissipation holes by the core in the condensation process of the poured metal material, the difference of the condensation speed of the metal material at each area is reduced, and meanwhile, the shrinkage cavity and the loosening defects at the inner cavity part of the casting are effectively eliminated by arranging the feeding head, thereby laying a foundation for improving the molding quality of the casting, being beneficial to improving the qualification rate of the finished casting, avoiding or reducing the times of repairing and processing the casting at the later stage, and lightening the labor intensity of workers.

Drawings

FIG. 1 is a process flow diagram of the present invention;

fig. 2 is a schematic view showing the structure of the core, the wax pattern and the feeding head of the present invention.

In the figure: 1-core, 2-wax pattern, 3-feeding head and 4-radiating hole.

Detailed Description

The technical solution of the present invention is further explained with reference to the accompanying drawings, but the claimed protection scope is not limited thereto;

the invention provides an investment casting molding process with an embedded ceramic core, as shown in figures 1 and 2, which comprises the following steps:

the method comprises the following steps: preparing a mold core 1 according to pattern shape characteristics in a design drawing provided by a user, and forming at least one heat dissipation hole 4 on the surface of the mold core 1; further, the material of the core 1 is preferably ceramic. The aperture of the heat dissipation hole 4 is 6 mm-10 mm. In the first step, the heat dissipation holes 4 are formed by adopting a rotary file and a file.

Step two: providing a mould, wherein a mould cavity is arranged in the mould, the mould core 1 in the step one is placed in the mould cavity, then wax materials are filled in the mould cavity, the wax materials are condensed to form a wax mould 2, and the wax mould 2 and the mould core 1 form a module; in addition, the investment casting molding process of the embedded ceramic core further comprises the following steps: and in the second step, a feeding head 3 is adhered to the surface of the mold core 1, the feeding head 3 is communicated with the heat dissipation holes 4, and the wax material is filled in the heat dissipation holes 4 through the feeding head 3. The feeding head 3 is in a shape of an inverted cone with a large upper end and a small lower end, and the ratio of the caliber of a lower end port to the caliber of an upper end port is 1: 3. Transition fillets are further arranged at the joints of the feeding heads 3 and the heat dissipation holes 4. The transition round angle is R3-R5.

Step three: coating a refractory material on the surface of the module by using a coating, and roasting the module to melt and remove the wax mold 2 to obtain a mold shell;

step four: and pouring and filling the metal material smelted into a liquid state into the formwork, and condensing the metal material to obtain a casting.

By adopting the technical scheme of the invention, the core 1 is inserted into the wax mould 2 in the process of preparing the mould set, and the heat dissipation holes 4 are arranged on the surface of the core 1, so that the heat at the cavity can be quickly transferred to the outside through the heat dissipation holes 4 by the core 1 in the condensation process of the poured metal material, the difference of the condensation speed of the metal material at each area is reduced, and meanwhile, the feeding head 3 is arranged, the defects of shrinkage cavity and looseness at the inner cavity part of the casting are effectively eliminated, a foundation is laid for improving the molding quality of the casting, the qualification rate of the finished casting is favorably improved, the frequency of repairing and processing the casting at the later stage is avoided or reduced, and the labor intensity of workers is reduced.

Claims

1. An investment casting molding process with an embedded ceramic core is characterized in that: the method comprises the following steps:

the method comprises the following steps: preparing a mold core (1) according to pattern shape characteristics in a design drawing provided by a user, and forming at least one heat dissipation hole (4) on the surface of the mold core (1);

step two: providing a mould, wherein a mould cavity is arranged in the mould, the mould core (1) in the step one is placed in the mould cavity, then wax materials are filled in the mould cavity, the wax materials are condensed to form a wax mould (2), and the wax mould (2) and the mould core (1) form a module;

step three: coating a refractory material on the surface of the module by using a coating, and roasting the module to melt and remove the wax mold (2) to obtain a mold shell;

2. The in-line ceramic core investment casting process of claim 1 wherein: the material of the core (1) is ceramic.

3. The in-line ceramic core investment casting process of claim 1 wherein: the aperture of the heat dissipation hole (4) is 6 mm-10 mm.

4. The in-line ceramic core investment casting process of claim 1 wherein: in the step one, the heat dissipation holes (4) are formed by adopting a rotary file and a file.

5. The in-line ceramic core investment casting process of claim 1 wherein: the investment casting molding process of the embedded ceramic core further comprises the following steps: and in the second step, a feeding head (3) is adhered to the surface of the mold core (1), the feeding head (3) is communicated with the heat dissipation hole (4), and the heat dissipation hole (4) is filled with the wax material through the feeding head (3).

6. The in-line ceramic core investment casting process of claim 5 wherein: the feeding head (3) is in an inverted cone-shaped tube shape with a large upper end and a small lower end, and the ratio of the caliber of a lower end port to the caliber of an upper end port is 1: 3.

7. The in-line ceramic core investment casting process of claim 5 wherein: and transition fillets are further arranged at the joints of the feeding heads (3) and the heat dissipation holes (4).

8. The in-line ceramic core investment casting process of claim 7 wherein: the transition round angle is R3-R5.