Mold for manufacturing ultra-small shrinkage cavity ingot, casting method, and manufactured ingot

Abstract

The application discloses a casting mold for manufacturing super-small shrinkage hole ingot, which comprises a first section mold, a second section mold, a third section mold and a fourth section mold from top to bottom, and the molds are connected through splicing structure, and the bottom of the fourth section mold is provided with a chill; the length and the thermal conductivity of the first section mold, the second section mold, the third section mold and the fourth section mold increase gradually; in order to further improve the shrinkage hole condition, the wall thickness of each section mold is adjusted, and the wall thickness of each section mold increases gradually from top to bottom. The casting method for manufacturing the super-small shrinkage hole ingot by using the mold comprises the steps of mold splicing, preheating and pouring. The mold is divided into multiple sections, the length and / or the wall thickness of each section mold are different, each section mold is made of materials with different thermal conductivities, and the thermal conductivities of the section molds increase gradually from top to bottom, so that the high-temperature alloy liquid generates a positive temperature gradient from top to bottom, and the shrinkage hole and shrinkage porosity conditions of the high-temperature alloy ingot are improved significantly.

Description

Technical Field

[0001] This invention belongs to the field of casting equipment and casting process technology, specifically relating to a mold, casting method, and ingot obtained for manufacturing ultra-small shrinkage ingots. Background Technology

[0002] In the manufacturing process of high-temperature alloy ingots, molten high-temperature alloy is poured into the mold through an tundish. During this process, the molten high-temperature alloy in contact with the mold wall and bottom chills solidifies preferentially, while the molten high-temperature alloy in other areas solidifies later, forming hot spots. Due to the thermal expansion and contraction property of molten high-temperature alloy, the molten high-temperature alloy at the hot spots cannot be compensated for, resulting in voids. Small and scattered voids are called shrinkage porosity, while large and concentrated voids are called shrinkage cavities. Shrinkage porosity is often distributed near shrinkage cavities. Shrinkage cavities appearing at the center of the top of the ingot are usually called primary shrinkage cavities, while shrinkage cavities appearing inside the ingot are called secondary shrinkage cavities. Primary shrinkage cavities are exposed at the top of the ingot and can be observed from the outside, and they are eventually cut off. Secondary shrinkage cavities are contained inside the ingot and cannot be seen from the outside. Therefore, secondary shrinkage cavities are a key factor determining the overall quality of the ingot.

[0003] In the actual manufacturing process of high-temperature alloy ingots, the presence of shrinkage porosity and shrinkage cavities directly affects the quality and yield of the ingots. Severe shrinkage porosity and shrinkage cavities, especially secondary shrinkage cavities, significantly reduce the yield, leading to a substantial increase in industrial costs and waste of raw materials. To avoid the formation of shrinkage porosity and shrinkage cavities, most industrial alloy ingot manufacturers employ measures such as chills and refractory risers to create a self-generated temperature gradient by altering the thermal conductivity of different parts of the alloy, enabling the high-temperature alloy liquid to solidify sequentially during the solidification process. However, if the solidification shrinkage rate of the high-temperature alloy liquid is large and / or the length-to-diameter ratio of the high-temperature alloy ingot is large, the temperature gradient generated by chills, refractory risers, etc., is insufficient to eliminate shrinkage porosity and shrinkage cavities within the ingot.

[0004] The most fundamental reason for the formation of shrinkage cavities and porosity in high-temperature alloy ingots is that the process of injecting high-temperature alloy liquid into the mold is a dynamic process. The difference in thermal conductivity between the mold wall and the bottom chill alone cannot create a temperature gradient that would prevent the high-temperature alloy liquid from solidifying without shrinkage cavities. Therefore, to fundamentally eliminate shrinkage cavities and porosity, it is necessary to consider the temperature changes of different parts of the high-temperature alloy liquid during the pouring process.

[0005] Chinese patent application CN114260431A discloses a module for reducing shrinkage cavities in high-temperature alloy master alloy ingots and its usage method. The module includes a mold tube with an insulating riser at the top and a graphite base at the bottom. The inner diameter of the mold tube gradually decreases from top to bottom within a range of 50-280 mm, and the thickness between the inner and outer walls of the mold tube gradually increases from top to bottom. The insulating riser includes an injection section, a transition section, and an annular section connected in sequence. The injection section is inverted conical, the inner diameter of the transition section is smaller than the inner diameter of the annular section, and the inner wall of the annular section is in close contact with the outer wall of the mold tube. This patent achieves sequential solidification of the alloy liquid from bottom to top by combining a special design of the insulating riser with a design where the mold tube wall thickness gradually increases from top to bottom. If the insulating riser is not specially designed and a traditional riser is used, even if the mold tube wall thickness gradually increases from top to bottom, sequential solidification of the alloy liquid cannot be achieved. Because the mold tube is a single piece, although the wall thickness changes, it uses the same material and the thermal conductivity does not change much, so it is difficult to generate a temperature gradient that allows the high-temperature alloy liquid to solidify without shrinkage cavities.

[0006] Patent application CN113333691A discloses a mold for casting high-temperature alloy ingots with large aspect ratios and its application. The mold includes a mold unit with an open top and a riser unit externally fitted to it. The riser unit has a gating and rising layer and an insulation layer arranged sequentially from the inside out. The mold unit has a first section, a second section, and a third section arranged sequentially from top to bottom. The inner walls of the first, second, and third sections are flush vertically, while the outer wall of the second section is recessed horizontally relative to the first and third sections. This patent uses a design scheme combining longitudinal thickness variation of the mold with an upper insulation riser to adjust the thermal field distribution during alloy solidification, achieving sequential solidification of the alloy from bottom to top. With a traditional riser structure, even with changes in the longitudinal thickness of the mold, sequential solidification of the alloy cannot be achieved. Although the mold is divided into three sections with different wall thicknesses, the same material is used, resulting in little change in thermal conductivity, making it difficult to generate a temperature gradient that allows the high-temperature alloy to solidify without shrinkage cavities. Summary of the Invention

[0007] To address the problems existing in the prior art, the present invention provides a mold for manufacturing ultra-small shrinkage ingots. The mold comprises, from top to bottom, a first mold, a second mold, a third mold, and a fourth mold. Adjacent mold sections are connected by a splicing structure. The bottom of the fourth mold is provided with chills. The lengths of the first, second, third, and fourth mold sections increase sequentially, as does their thermal conductivity.

[0008] To improve the shrinkage porosity and shrinkage cavity problems inside high-temperature alloy ingots, this invention divides the entire mold into several sections, each with a different length, different materials, and different thermal conductivity. The mold sections with different thermal conductivity are arranged in a designed order so that the high-temperature alloy liquid in the mold presents a positive temperature gradient from top to bottom along the axial direction, thereby achieving sequential solidification of the high-temperature alloy liquid.

[0009] Preferably, the length of the first mold segment is 210-290mm, the length of the second mold segment is 230-300mm, the length of the third mold segment is 250-310mm, the length of the fourth mold segment is 270-320mm, and the length difference between two adjacent mold segments is within the range of 20-50mm.

[0010] In any of the above embodiments, it is preferred that the thermal conductivity of the first-stage mold is 50-110 W / m·K, the thermal conductivity of the second-stage mold is 140-200 W / m·K, the thermal conductivity of the third-stage mold is 210-260 W / m·K, and the thermal conductivity of the fourth-stage mold is 370-410 W / m·K.

[0011] The first stage mold is made of cast iron or brass; the second stage mold is made of duralumin or cast aluminum; the third stage mold is made of pure aluminum or 1070 type aluminum alloy; and the fourth stage mold is made of silver or pure copper. The chill is made of cast iron or copper, or the same material as the fourth stage mold.

[0012] In any of the above embodiments, it is preferred that the inner diameter of the first-stage mold, the second-stage mold, the third-stage mold, and the fourth-stage mold is 50-100mm.

[0013] In any of the above schemes, it is preferred that the wall thickness of the first-stage mold, the second-stage mold, the third-stage mold, and the fourth-stage mold is 10-20mm.

[0014] In any of the above embodiments, it is preferred that the thickness of the chill is 20-25 mm, wherein the thickness inserted into the mold is 15-20 mm.

[0015] Preferably, in any of the above solutions, the wall thickness of the first-stage mold is 10-40 mm, the wall thickness of the second-stage mold is 20-50 mm, the wall thickness of the third-stage mold is 35-60 mm, and the wall thickness of the fourth-stage mold is 50-70 mm, with the wall thickness difference between adjacent mold stages within the range of 10-15 mm. To further improve the shrinkage porosity and voids within the high-temperature alloy ingot, the wall thickness of each mold stage can be modified based on the above technical solution. This increases the thermal conductivity at the bottom of the high-temperature alloy melt and decreases the thermal conductivity at the top, providing a better environment for the sequential solidification of the high-temperature alloy melt.

[0016] If the wall thickness of each mold segment is equal, the splicing structure between two adjacent mold segments is as follows: the top surface of the lower mold segment has a right-angle structure, and this right-angle structure is located on the inner side of the mold; the bottom surface of the upper mold segment has a right-angle structure, and this right-angle structure is located on the outer side of the mold; the right-angle structures of the two adjacent mold segments match, and the inner and outer surfaces of each mold segment are on the same circular surface; the vertical side length of the right-angle structure is 10-20mm. After the mold segments are spliced ​​together, they can be further secured with clips. In this case, the length of each mold segment is calculated based on the distance between the highest point of its top surface and the highest point of its bottom surface.

[0017] If the wall thicknesses of the different mold segments are unequal, the splicing structure between adjacent mold segments is as follows: the top surface of the lower mold segment is a right-angled structure, located on the inside of the mold, with the horizontal side length of the right-angled structure equal to the wall thickness of the upper mold segment; the bottom surface of the upper mold segment is directly spliced ​​onto the right-angled structure of the lower mold segment, and the inner surfaces of each mold segment are on the same circular surface; the vertical side length of the right-angled structure is 10-20mm. After the mold segments are spliced ​​together, they can be further secured with clips. In this case, the length of each mold segment is calculated as the distance from the highest point of its top surface to its bottom surface.

[0018] The present invention also provides a casting method for manufacturing ultra-small shrinkage cavity ingots, using any of the above-mentioned molds for manufacturing ultra-small shrinkage cavity ingots, comprising the following steps:

[0019] (1) Place the chill in a horizontal position, place the four-section mold on the chill, and then assemble the four-section mold, three-section mold, two-section mold and one-section mold together in sequence.

[0020] (2) Preheat the assembled mold and chills at a temperature of 450-750℃ for 1-4 hours.

[0021] (3) Pour the high-temperature alloy liquid into the mold.

[0022] The present invention also provides an ultra-small shrinkage ingot, which is manufactured from any of the above-mentioned molds used for manufacturing ultra-small shrinkage ingots.

[0023] The technical solution of the present invention has the following beneficial effects:

[0024] 1. This invention divides the mold into multiple segments, each with a different length and / or wall thickness. Each segment is made of a material with different thermal conductivity, and the thermal conductivity of each segment increases sequentially from top to bottom. This generates a positive temperature gradient from top to bottom in the high-temperature alloy liquid, achieving good sequential solidification and significantly improving shrinkage cavities and porosity in high-temperature alloy ingots. The prepared ingots contain only ultra-small shrinkage cavities, or even completely eliminate shrinkage cavities and porosity.

[0025] 2. The mold of the present invention is universal and has no special requirements for the structure and material of the heat-insulating riser at the top of the mold. It can be made using traditional or existing heat-insulating risers.

[0026] 3. Each section of the mold is an independent structure, allowing for free assembly of molds made of different materials. If a problem occurs in a section of the mold, it can be replaced and repaired individually, thereby reducing industrial production costs.

[0027] 4. Depending on the material of the high-temperature alloy being cast, the number of mold segments, the length of each segment, and the wall thickness will vary. This invention can flexibly provide suitable temperature gradients for different grades of high-temperature alloys. This invention is more suitable for nickel-based high-temperature alloy ingots with a casting length not exceeding 1.5m. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of a mold structure in a preferred embodiment of a mold for manufacturing ultra-small shrinkage ingots according to the present invention;

[0029] Figure 2 This is a schematic diagram of the mold structure in another preferred embodiment of the mold for manufacturing ultra-small shrinkage ingots according to the present invention;

[0030] Figure 3 for Figure 1 A schematic diagram of the cross-section of the ingot in the illustrated embodiment;

[0031] Figure 4 for Figure 1 A schematic diagram of the longitudinal section of the ingot in the illustrated embodiment;

[0032] Figure 5 for Figure 2 A schematic diagram of the cross-section of the ingot in the illustrated embodiment;

[0033] Figure 6 for Figure 2 A schematic diagram of the longitudinal section of the ingot in the illustrated embodiment.

[0034] The diagram is labeled as follows: 1-first stage mold, 2-second stage mold, 3-third stage mold, 4-fourth stage mold, 5-chill, 6-jointed structure. Detailed Implementation

[0035] To further understand the invention, the following detailed description of the invention will be provided in conjunction with specific embodiments.

[0036] Example 1:

[0037] like Figure 1As shown, according to a preferred embodiment of the mold for manufacturing ultra-small shrinkage cavity ingots of the present invention, the mold comprises, from top to bottom, a first mold 1, a second mold 2, a third mold 3, and a fourth mold 4. Adjacent mold sections are connected by a splicing structure 6. A chill 5 is provided at the bottom of the fourth mold 4. The lengths of the first mold 1, the second mold 2, the third mold 3, and the fourth mold 4 increase sequentially, as do their thermal conductivity. To improve the shrinkage porosity and shrinkage cavity problems inside the high-temperature alloy ingot, this embodiment divides the entire mold into four sections, each with a different length, different materials, and different thermal conductivity. The mold sections with different thermal conductivity are arranged in a designed order, so that the high-temperature alloy liquid in the mold presents a positive temperature gradient from top to bottom along the axial direction, thereby achieving sequential solidification of the high-temperature alloy liquid.

[0038] The length of the first mold section is 260mm, the length of the second mold section is 280mm, the length of the third mold section is 300mm, the length of the fourth mold section is 320mm, and the length difference between any two adjacent mold sections is 20mm.

[0039] The thermal conductivity of the first-stage mold is 110 W / m·K, the thermal conductivity of the second-stage mold is 200 W / m·K, the thermal conductivity of the third-stage mold is 260 W / m·K, and the thermal conductivity of the fourth-stage mold is 410 W / m·K.

[0040] The first stage mold is made of cast iron; the second stage mold is made of hard aluminum; the third stage mold is made of 1070 aluminum alloy; the fourth stage mold is made of pure copper; and the chill is made of the same material as the fourth stage mold.

[0041] The inner diameter of each of the first-stage, second-stage, third-stage, and fourth-stage molds is 50 mm, and the wall thickness is 20 mm. The thickness of the chill is 25 mm, with 20 mm of the chill inserted into the mold.

[0042] The splicing structure between two adjacent mold sections is as follows: the top surface of the lower mold section has a right-angle structure, and this right-angle structure is located on the inner side of the mold; the bottom surface of the upper mold section has a right-angle structure, and this right-angle structure is located on the outer side of the mold; the right-angle structures of the two adjacent mold sections match, and the inner and outer surfaces of each mold section are on the same circular surface; the vertical side length of the right-angle structure is 10mm. After the mold sections are spliced ​​together, they can be further secured with clips. The length of each mold section is calculated based on the distance between the highest point of its top surface and the highest point of its bottom surface.

[0043] This embodiment also provides a casting method for manufacturing ultra-small shrinkage cavity ingots, using the above-mentioned mold for manufacturing ultra-small shrinkage cavity ingots, including the following steps:

[0044] (1) Place the chill in a horizontal position, place the four-section mold on the chill, and then assemble the four-section mold, three-section mold, two-section mold and one-section mold together in sequence.

[0045] (2) Preheat the assembled mold and chills at a temperature of 450-750℃ for 1-4 hours.

[0046] (3) Pour the nickel-based high-temperature alloy liquid into the mold.

[0047] like Figure 3-4 As shown, this embodiment also provides an ultra-small shrinkage cavity ingot, which is manufactured by the above-mentioned mold for manufacturing ultra-small shrinkage cavity ingots. The prepared ingot is of good quality, with only ultra-small shrinkage cavities and shrinkage porosity inside. This ingot is an excellent product and can be used normally for subsequent processing and use.

[0048] The technical solution of this embodiment has the following beneficial effects: The mold is divided into four sections, each with a different length and made of materials with different thermal conductivity. The thermal conductivity of each section increases sequentially from top to bottom, thereby creating a positive temperature gradient from top to bottom in the high-temperature alloy liquid. This achieves good sequential solidification, significantly improving shrinkage cavities and porosity in the high-temperature alloy ingot. The resulting ingot contains only ultra-small shrinkage cavities. The mold is versatile, with no special requirements on the structure or material of the insulating riser at the top of the mold; traditional or existing insulating risers are sufficient. Each section of the mold is an independent structure, allowing for free assembly of molds made of different materials. If a section of the mold malfunctions, it can be replaced and repaired individually, thereby reducing industrial production costs.

[0049] Example 2:

[0050] According to another preferred embodiment of the mold for manufacturing ultra-small shrinkage ingots of the present invention, its structure, the connection relationship between the components, the principle, the beneficial effects, the casting method for manufacturing ultra-small shrinkage ingots, and the quality of the manufactured ultra-small shrinkage ingots are basically the same as those of Embodiment 1, except that:

[0051] The length of the first mold section is 210mm, the length of the second mold section is 230mm, the length of the third mold section is 250mm, and the length of the fourth mold section is 290mm. The length difference between the first and second mold sections is 20mm, the length difference between the second and third mold sections is 20mm, and the length difference between the third and fourth mold sections is 40mm.

[0052] The thermal conductivity of the first-stage mold is 50 W / m·K, the thermal conductivity of the second-stage mold is 140 W / m·K, the thermal conductivity of the third-stage mold is 240 W / m·K, and the thermal conductivity of the fourth-stage mold is 370 W / m·K.

[0053] The first stage mold is made of brass; the second stage mold is made of cast aluminum; the third stage mold is made of pure aluminum; the fourth stage mold is made of silver; and the chill is made of cast iron.

[0054] The inner diameter of each of the first, second, third, and fourth mold sections is 100 mm, and the wall thickness is 10 mm. The thickness of the chill is 22 mm, with 18 mm inserted into the mold. In the splicing structure between adjacent mold sections, the vertical side length of the right-angle structure is 15 mm.

[0055] Example 3:

[0056] According to another preferred embodiment of the mold for manufacturing ultra-small shrinkage ingots of the present invention, its structure, the connection relationship between the components, the principle, the beneficial effects, the casting method for manufacturing ultra-small shrinkage ingots, and the quality of the manufactured ultra-small shrinkage ingots are basically the same as those of Embodiment 1, except that:

[0057] The length of the first mold section is 240mm, the length of the second mold section is 260mm, the length of the third mold section is 280mm, and the length of the fourth mold section is 320mm. The length difference between the first and second mold sections is 20mm, the length difference between the second and third mold sections is 20mm, and the length difference between the third and fourth mold sections is 40mm.

[0058] The thermal conductivity of the first-stage mold is 80 W / m·K, the thermal conductivity of the second-stage mold is 170 W / m·K, the thermal conductivity of the third-stage mold is 210 W / m·K, and the thermal conductivity of the fourth-stage mold is 390 W / m·K.

[0059] The first stage mold is made of brass; the second stage mold is made of cast aluminum; the third stage mold is made of pure aluminum; the fourth stage mold is made of pure copper; and the chill is made of copper.

[0060] The inner diameter of each of the first, second, third, and fourth mold sections is 75 mm, and the wall thickness is 15 mm. The thickness of the chill is 20 mm, with 15 mm inserted into the mold section. In the splicing structure between adjacent mold sections, the vertical side length of the right-angle structure is 20 mm.

[0061] Example 4:

[0062] like Figure 2As shown, another preferred embodiment of the mold for manufacturing ultra-small shrinkage ingots according to the present invention has the same structure, connection relationship between various components, principle, beneficial effects, and casting method for manufacturing ultra-small shrinkage ingots as embodiments one to three, except that:

[0063] The wall thickness of the first mold 1 is 25mm, the wall thickness of the second mold 2 is 40mm, the wall thickness of the third mold 3 is 55mm, and the wall thickness of the fourth mold 4 is 70mm. The wall thickness difference between any two adjacent mold sections is 15mm. The thickness of the chill 5 is 25mm, with a thickness of 15mm when inserted into the fourth mold 4. To further improve the shrinkage porosity and shrinkage cavity problems inside the high-temperature alloy ingot, the wall thickness of each mold section can be changed based on Examples 1 to 3, increasing the thermal conductivity rate at the bottom of the high-temperature alloy liquid and decreasing the thermal conductivity rate at the top, thus providing a better environment for the sequential solidification of the high-temperature alloy liquid.

[0064] The splicing structure 6 between two adjacent mold segments is as follows: the top surface of the lower mold segment is a right-angled structure, located on the inside of the mold segment, with the horizontal side length of the right-angled structure equal to the wall thickness of the upper mold segment; the bottom surface of the upper mold segment is directly spliced ​​onto the right-angled structure of the lower mold segment, and the inner surfaces of each mold segment are on the same circular surface; the vertical side length of the right-angled structure is 10mm. After the mold segments are spliced ​​together, they can be further secured with clips. The length of each mold segment is calculated based on the distance from the highest point of its top surface to its bottom surface.

[0065] like Figure 5-6 As shown, this embodiment also provides an ultra-small shrinkage cavity ingot, which is manufactured by the above-mentioned mold for manufacturing ultra-small shrinkage cavity ingots. The prepared ingot has good quality and has completely eliminated shrinkage cavities and porosity inside the ingot.

[0066] Example 5:

[0067] According to another preferred embodiment of the mold for manufacturing ultra-small shrinkage ingots of the present invention, its structure, the connection relationship between the components, the principle, the beneficial effects, the casting method for manufacturing ultra-small shrinkage ingots, and the quality of the prepared ultra-small shrinkage ingots are basically the same as those of Embodiment 4, except that:

[0068] The wall thickness of the first mold section is 20mm, the second mold section is 35mm, the third mold section is 45mm, and the fourth mold section is 60mm. The wall thickness difference between the first and second mold sections is 15mm, between the second and third mold sections is 10mm, and between the third and fourth mold sections is 15mm. The chill has a thickness of 22mm, with a thickness of 20mm when inserted into the fourth mold section. In the splicing structure between adjacent mold sections, the vertical side length of the right-angled structure is 20mm.

[0069] Example 6:

[0070] According to another preferred embodiment of the mold for manufacturing ultra-small shrinkage ingots of the present invention, its structure, the connection relationship between the components, the principle, the beneficial effects, the casting method for manufacturing ultra-small shrinkage ingots, and the quality of the prepared ultra-small shrinkage ingots are basically the same as those of Embodiment 4, except that:

[0071] The wall thickness of the first mold section is 30mm, the second mold section is 45mm, the third mold section is 60mm, and the fourth mold section is 70mm. The wall thickness difference between the first and second mold sections is 15mm, the difference between the second and third mold sections is 15mm, and the difference between the third and fourth mold sections is 10mm. The thickness of the chill is 20mm, with an insertion thickness of 18mm into the fourth mold section. In the splicing structure between adjacent mold sections, the vertical side length of the right-angle structure is 10mm.

[0072] Special Note: The technical solution of this invention involves numerous parameters, and the synergistic effects between these parameters must be comprehensively considered to achieve the beneficial effects and significant progress of this invention. Furthermore, the value ranges of each parameter in the technical solution were obtained through extensive experimentation. For each parameter and the combinations thereof, the inventors have recorded a large amount of experimental data; however, due to space limitations, the specific experimental data is not disclosed here.

[0073] Those skilled in the art will readily understand that the mold, casting method, and resulting ingot for manufacturing ultra-small shrinkage ingots of the present invention comprise any combination of the inventive description and specific embodiments outlined in the foregoing specification and accompanying drawings. Due to space limitations and for the sake of brevity, not all of these combinations have been described in detail. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A mold for manufacturing ultra-small shrinkage ingots, the mold comprising, from top to bottom, a first mold, a second mold, a third mold, and a fourth mold, with adjacent mold sections connected by a splicing structure, and chills provided at the bottom of the fourth mold section, characterized in that: The length and thermal conductivity of the first-section mold, the second-section mold, the third-section mold, and the fourth-section mold increase sequentially. The length of the first mold section is 210-290mm, the length of the second mold section is 230-300mm, the length of the third mold section is 250-310mm, and the length of the fourth mold section is 270-320mm. The thermal conductivity of the first-stage mold is 50-110 W / m·K, the thermal conductivity of the second-stage mold is 140-200 W / m·K, the thermal conductivity of the third-stage mold is 210-260 W / m·K, and the thermal conductivity of the fourth-stage mold is 370-410 W / m·K. The inner diameter of each of the first, second, third, and fourth mold sections is 50-100 mm; the wall thickness of the first mold section is 10-40 mm, the wall thickness of the second mold section is 20-50 mm, the wall thickness of the third mold section is 35-60 mm, and the wall thickness of the fourth mold section is 50-70 mm; the thickness of the chill is 20-25 mm. The material of the first-stage mold is cast iron or brass; the material of the second-stage mold is hard aluminum or cast aluminum; the material of the third-stage mold is pure aluminum or 1070 type aluminum alloy; the material of the fourth-stage mold is silver or pure copper; the material of the chill is cast iron or copper. The splicing structure is as follows: the top surface of the lower mold is a right-angle structure, which is set inside the mold, and the horizontal side length of the right-angle structure is equal to the wall thickness of the upper mold; the bottom surface of the upper mold is directly spliced ​​onto the right-angle structure of the lower mold, and the inner surfaces of each mold segment are on the same circular surface; the vertical side length of the right-angle structure is 10-20mm. The material of the ingot is a nickel-based high-temperature alloy.

2. A casting method for manufacturing ultra-small shrinkage cavity ingots, characterized in that: Using the mold for manufacturing ultra-small shrinkage ingots as described in claim 1, the casting method includes the following steps: Step (1): Place the chill in a horizontal position, place the four-section mold on the chill, and then assemble the four-section mold, three-section mold, two-section mold and one-section mold together in sequence. Step (2): Preheat the assembled mold and chills; Step (3): Pour the high-temperature alloy liquid into the mold.

3. A type of ultra-small shrinkage ingot, characterized in that: It is manufactured from the mold for manufacturing ultra-small shrinkage ingots as described in claim 1.

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