A casting mold with rapid and uniform cooling and a manufacturing method thereof

Abstract

The present invention discloses a casting mold with rapid and uniform cooling and a manufacturing method thereof. The casting mold cavity is composed of a mold block and a powder metallurgy composite surface layer. The mold block is a porous metal block formed by sintering metal wires, which is machined to obtain a shape that matches the upper mold and the lower mold, and its entire surface is covered with a metal powder composite surface layer; the upper mold and the lower mold are respectively equipped with a cooling fluid inlet pipe and a cooling fluid outlet pipe; the cooling fluid inlet pipe is connected to the cooling fluid inlet, communicates with the mold block, and forms a cooling fluid channel with the cooling fluid outlet pipe. This manufacturing method includes pressing and sintering of a metal block, preparation of a powder metallurgy composite surface layer, and rolling extrusion. The present invention has a simple structure, a convenient manufacturing method, is easy to implement, and has a low production cost; it significantly improves the heat exchange efficiency between the fluid and the mold, realizes rapid solidification of the forming material, and improves production efficiency; and has good market application prospects.

Description

Technical Field

[0001] The invention relates to a metal mold preparation technology, in particular to a casting mold with rapid and uniform cooling and a manufacturing method thereof. Background Art

[0002] The mold is a commonly used tool in industrial production. In the actual production process, it is usually made of ordinary mold steel machining. If you want the melt to solidify and form quickly, you need to cool it down quickly. This is the cooling system of the mold. Patent 200620015517.9 describes a water-cooled die-casting punch. The high-temperature aluminum liquid transfers heat to the mold, causing the mold temperature to continue to rise. At this time, the mold needs to be cooled; Patent 200920207288.4 introduces a low-pressure casting mold oil cooling device. For the cooling of the mold, the cooling medium is generally passed into the cooling pipe, and the cooling medium exchanges heat with the specific position of the mold to reduce the mold temperature. However, the current method of accelerating mold cooling and heat exchange is mainly achieved by increasing the inlet flow rate and reducing the inner diameter of the channel. Increasing the inlet flow rate will inevitably increase the power of the water pump, and reducing the role of the inner diameter of the channel is also limited. In addition to finding a fluid with rapid heat exchange capacity, improving the heat exchange capacity of the fluid can also be achieved through mechanical stirring, oscillation, insert turbulence and other methods. For example, patent 201320532431.3 introduces a heat exchange enhancement device using a combined tie insert, which can replace the central fluid and the boundary layer fluid in different regions, improve the mixing effect of the central fluid and the boundary layer fluid, and achieve the purpose of enhancing heat exchange. However, although the insert in the pipeline is conducive to enhancing heat exchange, it also brings a certain pressure loss, and the scaling of the insert reduces the heat exchange capacity, which is also an important factor restricting its use. Summary of the invention

[0003] The object of the present invention is to overcome the deficiencies and disadvantages of the prior art and to provide a casting mold with a simple structure, rapid solidification of the forming material, and rapid and uniform cooling;

[0004] Another object of the present invention is to provide a method for manufacturing a casting mold with rapid and uniform cooling, which has simple process steps, convenient operation, easy implementation and low production cost.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A casting mold with rapid and uniform cooling, characterized in that: the mold cavity formed by the combination of an upper mold and a lower mold is composed of a mold block and a powder metallurgy composite surface layer, the mold block is a porous metal block sintered from metal wire and machined to obtain a shape that matches the upper mold and the lower mold, and its entire surface is covered with a metal powder composite surface layer; the upper mold and the lower mold are respectively equipped with a cooling fluid inlet pipe and a cooling fluid outlet pipe, and a sealing ring is provided at the connection; the cooling fluid inlet pipe is connected to the cooling fluid inlet, communicates with the mold block, and forms a cooling fluid channel with the cooling fluid outlet pipe.

[0007] An ultrasonic vibrator is installed in the cooling fluid inlet pipe and is connected to the ultrasonic generator through a wire.

[0008] A method for manufacturing a casting mold with rapid and uniform cooling, characterized in that the casting mold manufacturing method comprises the following process steps:

[0009] 1. Metal block pressing and sintering:

[0010] The chopped metal wires are pressed and sintered to prepare a metal block containing multiple pores inside, wherein the porosity of the metal block containing multiple pores inside is 65% to 80%;

[0011] 2. Preparation of powder metallurgy composite surface layer:

[0012] The metal block with multiple pores inside is processed by conventional machining to obtain the mold cavity and the auxiliary installation structure, and then the heat-resistant metal powder is sprayed on the entire surface of the mold block to form a powder metallurgy composite surface layer, and then secondary sintering is performed;

[0013] 3. Rolling extrusion powder metallurgy composite surface:

[0014] The powder metallurgy composite surface layer covering the surface of the rolling extrusion die block seals the pores on the surface of the die block;

[0015] 4. Forming cooling fluid channels:

[0016] A cooling fluid inlet is provided on one side of the mold block and connected to the cooling fluid inlet pipe, and a cooling fluid outlet is provided on the other side and connected to the cooling fluid outlet pipe to form a cooling fluid channel.

[0017] Preferably, the metal wire is an alloy wire or a stainless steel wire, and the wire diameter thereof is 50 to 500 microns, and the length of the chopped metal wire is 5 to 15 millimeters.

[0018] Preferably, the sintering temperature of the chopped metal wire in step 1 is 1300 degrees Celsius to 1450 degrees Celsius.

[0019] Preferably, the metal powder in step 2 is heat-resistant alloy powder or stainless steel powder.

[0020] Preferably, the secondary sintering temperature in step 2 is 1300 degrees Celsius to 1450 degrees Celsius.

[0021] Preferably, the thickness of the metal powder composite layer in step 2 is 0.5 to 3 mm.

[0022] Preferably, in the cooling fluid channel described in step 4, an ultrasonic vibrator 10 for causing the cooling fluid to generate ultrasonic vibration is installed in the cooling fluid inlet pipe 9, so that the cooling fluid generates ultrasonic vibration.

[0023] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0024] 1. The cooling fluid of the casting mold with rapid and uniform cooling described in the present invention can reach the interface between the metal powder and the metal wire, the area of ​​the interface is large, and the distance from the mold cavity surface is short; the heat exchange between the fluid and the mold is sufficient, the temperature difference on the mold is reduced, and the temperature of the mold is relatively uniform, which can significantly improve the heat exchange efficiency between the fluid and the mold, and realize rapid cooling of the mold, which can shorten the production cycle of a single product and improve production efficiency.

[0025] 2. The fast and uniformly cooled casting mold of the present invention can quickly cool the formed material in the mold cavity, obtain a fast solidified structure, and improve the mechanical properties of the formed parts; the casting is discharged from the mold cavity at a low temperature, and the thermal deformation of the casting is small, which is conducive to improving the dimensional accuracy of thin-walled castings that are easy to deform;

[0026] 3. The casting mold with rapid and uniform cooling described in the present invention can be connected to an ultrasonic generator on the inlet pipe. The ultrasonic vibration generated by the cooling fluid can improve the heat exchange efficiency between the fluid and the mold, and can also increase the flow rate of the fluid in the porous material and prevent the formation of scale.

[0027] 4. The casting mold manufacturing method of the present invention can also be applied to the manufacture of plastic polymer material molding molds.

[0028] 5. The casting mold manufacturing method of the present invention has simple process steps, is stable and reliable, is easy to operate, easy to implement, has low production cost, has a large number of application fields, has a good market application prospect, and can create significant economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the cavity structure of a casting mold with rapid and uniform cooling. DETAILED DESCRIPTION

[0030] The present invention is further described below in conjunction with a number of specific embodiments and the accompanying drawings.

[0031] Example 1

[0032] like Figure 1 As shown, a schematic diagram of the cavity structure of a casting mold for rapid and uniform cooling (excluding the mold frame and installation connection parts), Figure 1 Among them, 1 is the cooling fluid inlet, 2 is the sealing ring, 3 is the powder metallurgy composite surface layer, 4 is the mold block, 5 is the upper mold, 6 is the mold cavity, 7 is the cooling fluid outlet pipe, 8 is the lower mold, 9 is the cooling fluid inlet pipe, 10 is the ultrasonic vibrator, 11 is the wire, and 12 is the ultrasonic generator. The upper mold 5 and the lower mold 8 are composed of a mold block 4 and a powder metallurgy composite surface layer 3. The mold block 4 is a porous metal block formed by sintering metal wire, which is machined to obtain a shape that matches the upper mold 5 and the lower mold 8, and the powder metallurgy composite surface layer 3 is covered on its entire surface by a rolling extrusion method; the upper mold 5 and the lower mold 8 are respectively equipped with a cooling fluid inlet pipe 9 and a cooling fluid outlet pipe 7, and a sealing ring 2 is provided at the connection; the cooling fluid inlet pipe 9 is connected to the cooling fluid inlet 1, communicates with the mold block 4, and forms a cooling fluid channel with the cooling fluid outlet pipe 7. The upper mold 5 and the lower mold 8 are combined together to form a mold cavity 6; the ultrasonic vibrator 10 is installed in the cooling fluid inlet pipe 9 and is connected to the ultrasonic generator 12 through a wire 11.

[0033] A method for manufacturing a casting mold with rapid and uniform cooling, comprising the following process steps:

[0034] 1. Metal block pressing and sintering:

[0035] 120 stainless steel metal long fiber wires with a wire diameter of 50 microns are woven into a rope by a rope-making machine, so that the metal long fibers are plastically bent and twisted, and then cut into 5 mm long chopped metal wires. The cut rope will automatically spread out to form chopped metal wires with bending and plastic deformation; the twisted chopped metal wires are evenly distributed in a pressing mold, and a press is used to press them into a metal block containing multiple pores inside, wherein the porosity of the metal block containing multiple pores inside is 65% to 80%, and then vacuum sintered at a sintering temperature of 1300 to 1350 degrees Celsius and a sintering time of 2 hours. After sintering, the porosity of the block remains basically unchanged, and a porous metal block with an internal porosity of 65% to 80% is prepared.

[0036] 2. Preparation of powder metallurgy composite surface layer:

[0037] The metal block containing multiple pores inside is subjected to conventional mechanical processing to obtain a mold block 4 having a mold cavity and an auxiliary installation structure; a heat-resistant H13 alloy powder or 304 stainless steel powder composite surface layer 3 is thermally sprayed on the entire surface of the mold block 4, the thickness of the composite surface layer is 0.5 to 3 mm, and the entire surface of the porous mold metal block is covered, and secondary vacuum sintering is performed, the sintering temperature is 1300 degrees Celsius to 1450 degrees Celsius, and the sintering time is 2 hours.

[0038] 3. Rolling extrusion powder metallurgy composite surface:

[0039] The heat-resistant alloy powder or stainless steel powder is rolled on the entire surface of the die block 4 to plastically deform the metal powder, improve the surface quality, and seal the pores on the surface to obtain the upper die 5 and the lower die 8 of the cavity die block.

[0040] 4. Forming cooling fluid channels:

[0041] A cooling fluid inlet 1 is opened on one side of the mold block 4 and connected to a cooling fluid inlet pipe 9, and an outlet is opened on the other side and connected to a cooling fluid outlet pipe 7 and sealed; the cooling fluid flows from the cooling fluid inlet 1 through the cooling fluid inlet pipe 9 into the metal wire sintered porous material 4 sealed by the rolled extruded powder metallurgy surface layer 3, and forms a cooling fluid channel with the cooling fluid outlet pipe 7.

[0042] The ultrasonic vibrator 10 is installed in the cooling fluid inlet pipe 9 and is connected to the ultrasonic generator 12 through the wire 11. The ultrasonic vibrator of the ultrasonic generator 12 causes the cooling water to generate ultrasonic vibrations, which can further improve the heat exchange efficiency between the water and the mold, and can also increase the flow rate of water in the porous material and prevent the generation of scale.

[0043] The same method is used to manufacture the upper mold 5 and the lower mold 8 of the casting mold, which are combined together to form the mold cavity 6. During casting, the mold cavity 6 is filled with aluminum alloy or zinc alloy, and the mold temperature is relatively high. When cooling water enters the porous material from the inlet pipe, it will diffuse and fill the porous material part to reach the interface between the metal powder and the metal wire. The interface has a large area and a short distance from the mold cavity surface, which can significantly improve the heat exchange efficiency between the fluid and the mold, and realize rapid cooling of the mold, which can shorten the production cycle of a single product and improve production efficiency; the porosity of the material sintered by the metal wires is easy to control, and the material has high mechanical properties; the heat-resistant H13 alloy powder is used as the surface layer, and the alloy wire and alloy powder sintered material are used for a long service life of the casting mold.

[0044] Example 2

[0045] The difference from Example 1 is that in step 1 of this example, the metal wire is an alloy wire with a wire diameter of 500 microns, which is cut into short metal wires with a length of 15 mm. Step 2: Stainless steel powder is thermally sprayed on the entire surface of the mold cavity.

[0046] The embodiments described above are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. Therefore, all changes made according to the shape and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for manufacturing a casting mold with rapid and uniform cooling, characterized in that: The casting mold manufacturing method includes the following process steps:

1. Metal block pressing and sintering: The short-cut metal wires with a length of 5 to 15 mm are pressed and sintered to prepare a metal block with multiple pores inside, wherein the porosity of the metal block with multiple pores inside is 65% to 80%; 2. Preparation of powder metallurgy composite surface layer: The metal block with multiple pores inside is subjected to conventional mechanical processing to obtain a mold cavity and an auxiliary installation structure, and then metal powder is sprayed on the entire surface of the mold block (4) to form a powder metallurgy composite surface layer (3), and then secondary sintering is performed; 3. Rolling extrusion powder metallurgy composite surface: The powder metallurgy composite surface layer (3) covering the surface of the rolling extrusion die block (4) blocks the pores on the surface of the die block; 4. Forming cooling fluid channels: A cooling fluid inlet (1) is provided on one side of the mold block and connected to a cooling fluid inlet pipe (9), and a cooling fluid outlet is provided on the other side and connected to a cooling fluid outlet pipe (7), thereby forming a cooling fluid channel.

2. The method for manufacturing a casting mold with rapid and uniform cooling according to claim 1, characterized in that: The metal wire is an alloy wire with a wire diameter of 50 to 500 microns, and the length of the chopped metal wire is 5 to 15 millimeters.

3. The method for manufacturing a casting mold with rapid and uniform cooling according to claim 1, characterized in that: The sintering temperature of the chopped metal wire in step 1 is 1300 degrees Celsius to 1450 degrees Celsius.

4. The method for manufacturing a casting mold with rapid and uniform cooling according to claim 1, characterized in that: The metal powder in step 2 is heat-resistant alloy powder or stainless steel powder.

5. The method for manufacturing a casting mold with rapid and uniform cooling according to claim 1, characterized in that: The secondary sintering temperature in step 2 is 1300 degrees Celsius to 1450 degrees Celsius.

6. The method for manufacturing a casting mold with rapid and uniform cooling according to claim 1, characterized in that: The thickness of the powder metallurgy composite surface layer (3) in step 2 is 0.5 to 3 mm.

7. The method for manufacturing a casting mold with rapid and uniform cooling according to claim 1, characterized in that: In step 4, the cooling fluid inlet pipe (9) is connected to an ultrasonic generator (12).

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