A method and apparatus for effectively preventing cracks in casting wax patterns.

Abstract

The present invention is a method and apparatus for effectively avoiding cracks in casting wax molds. The method first heats and melts aluminum alloy powder in a vacuum environment and vaporizes it, and then condenses it to form metal droplets. The metal droplets are located above the surface of the wax mold (2), and the metal droplets are dragged to the surface of the wax mold (2) by the electric field of the eddy current formed above the surface of the wax mold (2) by the electromagnetic generator (5). After the metal droplets (3) come into contact with the surface of the wax mold (2), they cool rapidly and form a uniform aluminum alloy film to avoid cracks in the wax mold (2).

Description

Technical Field

[0001] This invention relates to a method and apparatus for effectively preventing cracks in casting wax patterns, belonging to the field of wax pattern manufacturing technology in casting processes. Background Technology

[0002] Researchers at Saratov State Technical University in Russia have developed a new process for applying an ultra-hard titanium carbide coating to the working surfaces of metal tools to slow wear and increase material lifespan. By strictly controlling the temperature, power of the induction heating device, spraying distance, and duration of the protective layer during the experimental process, the hardness of pure metals and carbon alloys can be increased several times over.

[0003] Building upon this foundation, titanium-containing protective coatings are widely used abroad in fields such as medical devices, microelectronics, and electromagnetic radiation detectors. This thin film, approximately twenty times thinner than a human hair, can prevent rapid wear of metallic materials and improve their biocompatibility. In most cases, these coatings are applied to the working surface using vapor deposition, where the vapor phase consists of clusters of titanium atoms—interconnected groups of atoms. To form this particle flow for the film, the process is carried out in a vacuum heating environment at 1200–1250°C. However, this method often leads to cracks in the protective layer or the metal substrate, thus reducing product quality. Summary of the Invention

[0004] This invention utilizes the aforementioned research findings and potential problems, and applies them to the wax pattern manufacturing technology in the casting process. It designs and provides a method and apparatus to effectively avoid cracks in casting wax patterns, with the aim of preventing cracks from forming on the surface of the casting wax pattern.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] The present invention proposes a method to effectively avoid cracks in casting wax molds. The method first heats and melts aluminum alloy powder in a vacuum environment and vaporizes it. After condensation, it forms metal droplets. The metal droplets are located above the surface of the wax mold 2. The electric field of the eddy current formed above the surface of the wax mold 2 by the electromagnetic generator 5 drags the metal droplets to the surface of the wax mold 2. After the metal droplets 3 come into contact with the surface of the wax mold 2, they cool rapidly and form a uniform aluminum alloy film to avoid cracks in the wax mold 2.

[0007] In practice, the particle size of the aluminum alloy powder is -400 to -450 mesh.

[0008] During implementation, the interior of the wax mold 2 is supported by a rigid material to ensure the flatness of the surface of the wax mold 2.

[0009] In practice, the aluminum alloy powder is heated and melted, and then vaporized using an ultrasonic method.

[0010] In practice, before preparing the aluminum alloy film on the surface of the wax mold 2, the wax mold 2 is preheated at a temperature of 40-60°C.

[0011] In practice, the thickness of the aluminum alloy film is 10 to 20 micrometers.

[0012] The present invention also proposes an apparatus for the above-mentioned method of effectively avoiding cracks in casting wax molds. The apparatus is characterized by a wax mold heating device 1 at the bottom of the wax mold 2, a vacuum-sealed space I3 above the surface of the wax mold 2 for filling with molten metal droplets, an electromagnetic generator 5 above the vacuum-sealed space I3, a molten metal droplet guide 4 connected to one end of the side of the vacuum-sealed space I3, a condenser 8 connected to the other end of the molten metal droplet guide 4, another vacuum-sealed space II10 below the condenser 8 for filling with aluminum alloy powder, an ultrasonic rotating stage 6 at the bottom of the vacuum-sealed space II10, a heating device 7 on the side, and a sieve 9 between the vacuum-sealed space II10 and the condenser 8.

[0013] In practice, when the aluminum alloy powder is heated and melted and then vaporized by ultrasonic means, the rotation speed of the ultrasonic rotating table 6 is 60-120 rad / s, and the heating temperature of the heating device 7 is increased to 2400-2600℃.

[0014] The features and beneficial effects of the technical solution of this invention are as follows:

[0015] 1. The present invention provides a method for protecting casting wax molds from cracks by using temperature and electromagnetic field to liquefy, vaporize and condense aluminum alloy powder, which is then spread evenly on the surface of the wax mold to prevent cracks from forming.

[0016] 2. In the present invention, the forming process of the metal protective layer on the surface of the wax film is different from that of vapor deposition. Considering the physical characteristics of the wax film, the forming process of the metal protective layer is carried out at 40-60°C. The entire process will not cause defects such as cracks or melting of the wax film substrate.

[0017] 3. In the present invention, the metal protective layer can be evenly spread on the surface of the wax film. This is ensured by using a sieve to sieve metal droplets of sufficiently small volume and an electromagnetic field generated by an electromagnetic generator. The moment the metal droplets enter through the guide, the metal droplets are coupled with the electromagnetic field and are spread evenly on the surface of the wax film. During this process, the wax film does not rotate, in order to prevent the metal droplets from damaging the surface of the wax film under the action of centripetal force and friction. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the device structure in the technical solution of the present invention. Detailed Implementation

[0019] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments:

[0020] In this embodiment, the device for preventing cracks in casting wax patterns using the method of the present invention is as follows: Figure 1 As shown, in this device, a wax model heating device 1 is set at the bottom of the wax model 2. Above the surface of the wax model 2 is a vacuum-sealed space I3, which is used to fill metal droplets. An electromagnetic generator 5 is set above the vacuum-sealed space I3. One end of the metal droplet guide 4 is connected to the side of the vacuum-sealed space I3, and the other end of the metal droplet guide 4 is connected to the condenser 8. Below the condenser 8 is another vacuum-sealed space II10, which is used to fill aluminum alloy powder. An ultrasonic rotating stage 6 is set at the bottom of the vacuum-sealed space II10, and a heating device 7 is set on the side. A sieve 9 is set between the vacuum-sealed space II10 and the condenser 8. The steps of implementing the method of the present invention using the above device are as follows:

[0021] Step 1: Preparation of wax model

[0022] Prepare a steel plate, preheat the steel plate to 200-300℃, put it into the wax pool, take it out and let it cool, and the wax model 2 is completed.

[0023] Step 2: Powder Preparation

[0024] Prepare pure, uncontaminated aluminum alloy powder with a particle size of -400 to -450 mesh, and place it into the vacuum-sealed space II10 of the above-mentioned device;

[0025] Step 3: Powder Liquefaction

[0026] The aluminum alloy powder heating device 7 is started to heat the aluminum alloy powder at a temperature of 700-800℃. When the aluminum alloy powder becomes molten, the ultrasonic rotating table 6 is started at a speed of 60-120 rad / s. Then the heating temperature of the heating device 7 is increased to 2400-2600℃. At this time, the molten aluminum alloy powder begins to partially vaporize. The vaporized aluminum alloy powder passes through the sieve 9 and liquefies into metal droplets after encountering the condenser 8.

[0027] Step 4: Powder Sputtering

[0028] The liquefied aluminum alloy powder metal droplets flow downward through the metal droplet guide 4 and enter the vacuum sealed space I3. At this time, the wax model heating device 1 is started to preheat the wax model 2 at a preheating temperature of 40-60℃. At the same time, the electromagnetic generator 5 is started. The electromagnetic generator 5 forms an eddy current above the wax model 2. The electric field drags the metal droplets to the surface of the wax model 2. When the metal droplets come into contact with the surface of the wax model 2, the metal droplets cool down rapidly and cover the surface of the wax model 2.

[0029] Step 5: Post-processing

[0030] When the metal droplets on the surface of the wax mold 2 reach a certain thickness, the wax mold heating device 1 is stopped. After the wax mold 2 is completely cooled to room temperature, a 10-20 micrometer aluminum alloy film is obtained on the surface of the wax mold 2. This film can effectively prevent the wax mold 2 from cracking.

[0031] If necessary, flip the wax model 2 over and repeat the above steps to coat the other side with an aluminum alloy film to protect the entire outer surface of the wax model 2.

Claims

1. A method for effectively avoiding cracks in casting wax patterns, characterized in that, The method first heats and melts aluminum alloy powder in a vacuum environment and vaporizes it. After condensation, it forms metal droplets. The metal droplets are located above the surface of the wax mold (2). The electric field of the eddy current formed above the surface of the wax mold (2) by the electromagnetic generator (5) drags the metal droplets to the surface of the wax mold (2). After the metal droplets come into contact with the surface of the wax mold (2), they cool rapidly and form a uniform aluminum alloy film to avoid cracks in the wax mold (2). The particle size of the aluminum alloy powder is -400 to -450 mesh. The aluminum alloy powder is vaporized by ultrasonic means after being heated and melted. Before preparing the aluminum alloy film on the surface of the wax mold (2), the wax mold (2) is preheated at a temperature of 40 to 60°C.

2. The method for effectively avoiding cracks in casting wax patterns according to claim 1, characterized in that, The interior of the wax model (2) is supported by a rigid material to ensure the flatness of the surface of the wax model (2).

3. The method for effectively avoiding cracks in casting wax patterns according to claim 1, characterized in that, The thickness of the aluminum alloy film is 10 to 20 micrometers.

4. An apparatus for the method of effectively avoiding cracks in casting wax patterns as described in claim 1, characterized in that, A wax model heating device (1) is set at the bottom of the wax model (2). Above the surface of the wax model (2) is a vacuum sealed space I (3), which is used to fill metal droplets. An electromagnetic generator (5) is set above the vacuum sealed space I (3). One end of the metal droplet guide (4) is connected to the side of the vacuum sealed space I (3). The other end of the metal droplet guide (4) is connected to the condenser (8). Below the condenser (8) is another vacuum sealed space II (10), which is used to fill aluminum alloy powder. An ultrasonic rotating table (6) is set at the bottom of the vacuum sealed space II (10), and a heating device (7) is set on the side. A sieve (9) is set between the vacuum sealed space II (10) and the condenser (8).

5. The apparatus for effectively avoiding cracks in casting wax patterns according to claim 4, characterized in that, When the aluminum alloy powder is heated and melted and then vaporized by ultrasonic means, the rotation speed of the ultrasonic rotary table (6) is 60-120 rad / s, and the heating temperature of the heating device (7) is increased to 2400-2600℃.

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