Wax mold for high-temperature alloy fluidity testing device, testing device and testing method thereof

Abstract

The application discloses a wax mold of a high-temperature alloy fluidity testing device, the testing device and a testing method thereof, the wax mold comprises a ceramic pouring cup, an adapter structure, a hemispherical buffer structure and three spiral lines which are sequentially connected, and the three spiral lines have different diameters; the testing method comprises the following steps: placing a high-temperature alloy master alloy ingot and the high-temperature alloy fluidity testing device in a vacuum induction melting furnace; after the high-temperature alloy master alloy ingot is melted by power supply, refining treatment is carried out, and meanwhile, the high-temperature alloy fluidity testing device is subjected to preheating treatment; pouring the high-temperature alloy liquid into the testing device; after pouring is completed, power supply is cut off, and the vacuum is broken to take the furnace out; the filling lengths of the three spiral lines are counted by means of a distance measuring counter, and the fluidity of the high-temperature alloy is evaluated. The application compares the filling lengths of the three spiral lines with different diameters under the same casting conditions to compare the fluidity of different high-temperature alloys and the influence of different wall thicknesses on the fluidity of the high-temperature alloy, and the testing result is accurate.

Description

Technical Field

[0001] This invention belongs to the field of high-temperature alloy investment casting technology, specifically relating to a wax pattern, testing device and testing method for a high-temperature alloy fluidity testing device. Background Technology

[0002] Aero-engines are the core equipment of aircraft. Cast nickel-based superalloys are widely used in aero-engines due to their excellent comprehensive properties, and they are one of the key materials for hot-section components of aero-engines. Advanced aero-engines are increasingly using components with complex thin-walled structures to improve overall performance, reduce structural weight, and increase reliability. Superalloy integral structural castings, represented by casing castings, are developing towards larger sizes, more complex structures, and thinner, lighter weights. Furthermore, significant differences in wall thickness in different parts of the casting can easily lead to problems such as under-casting and cold shuts during the filling and solidification processes, reducing the casting yield.

[0003] The fluidity of high-temperature alloys is one of the key properties for manufacturing large, complex, thin-walled structural castings such as casings, and it is an important factor affecting the quality of castings. In actual production, the better the fluidity of the high-temperature alloy, the stronger its ability to fill the cavity of the large, complex, thin-walled structural casting, while reducing the occurrence of defects such as under-casting and cold shuts, and improving the yield rate of castings.

[0004] Currently, publicly available alloy flowability testing devices and methods mainly include the spiral sample method, vacuum suction method, star-shaped sample method, and multi-groove sample method. Among them, the vacuum suction method is suitable for laboratory testing and for testing the flowability of alloys using anti-gravity casting methods in actual production; the star-shaped sample method and the multi-groove sample method are mainly suitable for metal mold casting of aluminum alloys and magnesium alloys, but not suitable for vacuum induction investment casting of high-temperature alloys; the spiral sample method is suitable for testing the flowability of high-temperature alloys, but the existing spiral sample method still has some shortcomings.

[0005] Utility model patent CN88204038U discloses a concentric triple-helix alloy flowability measuring device, comprising a direct-sprue pattern, an upper sand box, a lower sand box, an outer-sprue sand box, a locking positioning pin, an outer-sprue pattern, and a concentric triple-helix pattern. The outer-sprue pattern consists of an outer-sprue pool, a low dam, a direct-sprue channel, a high dam, an overflow pool, and an overflow channel, arranged in a stepped manner. The concentric triple-helix pattern consists of a fully pressurized well and three isosceles cross-section helices with small semi-circular bosses. Although this technical solution can overcome the shortcomings of single-helix testing devices, which suffer from large errors due to changes in casting working conditions, it cannot reflect the changes in alloy flowability with wall thickness.

[0006] Chinese patent application CN114279802A discloses a high-temperature alloy flowability testing mold and a method for preparing test samples. The testing mold includes a pouring cup, a sprue communicating with an opening at the bottom of the pouring cup, a spiral flow channel communicating with an opening at the side wall of the sprue, and a pouring socket communicating with the end of the sprue. The spiral flow channel extends radially along the sprue in an involute pattern, and the total length of the spiral flow channel is not less than 980 mm. The height of the spiral flow channel and... The width ratio is 1-25; the spiral flow channel is provided with n consecutive flow channels of different widths, namely the 1st flow channel, the 2nd flow channel, ..., the nth flow channel. When n is 2, the length ratio of the 1st flow channel to the 2nd flow channel is 1:2. When n is 3, the length ratio of the 1st flow channel, the 2nd flow channel and the 3rd flow channel is 1:2:3. When n≥4, the length ratio of the 1st flow channel to the 4th flow channel is 1:2:3:4. The length of each flow channel from the 5th flow channel to the nth flow channel is equal to the length of the 4th flow channel. The technical solution has a complex structure, and the more complex the structure, the greater the error. The spiral flow channel is set with n consecutive channels of different widths. When n≥2, when the high-temperature alloy liquid passes through the (n-1)th channel, the high-temperature alloy liquid will solidify and nucleate on the relatively low-temperature surface of the channel, and form grains. The formed grains will reduce the cross-sectional area of ​​the (n-1)th channel, thus reducing the flow rate of the high-temperature alloy liquid that subsequently passes through the channel. Ultimately, this affects the initial speed and filling length of the high-temperature alloy liquid filling the nth channel, making it unsuitable for accurately evaluating the fluidity of the alloy. Summary of the Invention

[0007] To address the problems existing in the prior art, this invention provides a wax model for a high-temperature alloy flowability testing device, comprising a ceramic pouring cup, a transition structure, and a hemispherical buffer structure connected in sequence; it also includes three spiral lines connected to the hemispherical buffer structure, the three spiral lines having different diameters. In this invention, the ceramic pouring cup is a ceramic preform, and the transition structure, hemispherical buffer structure, and three spiral lines are all made of wax.

[0008] Preferably, the ceramic pouring cup has a large end diameter of 170-190mm, a small end diameter of 80-90mm, a wall thickness of 8-12mm, and a height of 110-130mm.

[0009] Preferably, in any of the above embodiments, the outer surface of the ceramic pouring cup is provided with five grooves. The distances of the five grooves from the large end are 45mm, 60mm, 81mm, 94mm, and 107mm, respectively; the widths are 2mm, 2mm, 6mm, 6mm, and 6mm, respectively; and the depths are 2mm, 3mm, 3mm, 4mm, and 4mm, respectively. Extensive testing has proven that designing the grooves according to the method of this invention optimizes the outer surface area of ​​the ceramic pouring cup. If a large area of ​​smooth surface exists, the adhesion between the coating and the outer surface of the ceramic pouring cup will be weak after the wax model is prepared, and the coating will easily peel off during the subsequent shell preparation process. With grooves of the above dimensions and number provided on the outer surface of the ceramic pouring cup, the adhesion between the coating and the outer surface of the ceramic pouring cup is enhanced, preventing coating peeling and thus improving the yield rate of shell preparation.

[0010] In any of the above embodiments, preferably, the adapter structure includes a support wax block, a positioning plate plug, a positioning plate, and a positioning ring plug connected in sequence; the positioning plate has a large end diameter of 80-90mm, a small end diameter of 35-45mm, and a height of 45-55mm; the positioning plate plug matches the small end of the ceramic pouring cup, and its height is 15-20mm; the support wax block has a large end diameter that is 2-4mm smaller than the diameter of the positioning plate plug, a small end diameter that is 8-10mm smaller than its large end diameter, and a height of 30-35mm; the outer surface of the support wax block is provided with six semi-cylindrical grooves, the grooves having a diameter of 6-10mm. This invention designs a supporting wax block, which has the following functions: After assembling the ceramic pouring cup and the adapter structure, wax liquid is injected into the gap between the ceramic pouring cup and the adapter structure to the large end of the supporting wax block. After the wax liquid solidifies, the ceramic pouring cup and the adapter structure are firmly bonded together. The six semi-cylindrical grooves on the outer surface of the supporting wax block can further enhance the bonding force between the ceramic pouring cup and the adapter structure, thereby avoiding the scrapping of the wax mold and the mold shell due to the weak bonding between the ceramic pouring cup and the adapter structure during the subsequent shell preparation process.

[0011] In any of the above embodiments, preferably, the hemispherical buffer structure includes a hemispherical component, a cylindrical component, a fan blade, and a positioning ring; the diameter of the hemispherical component is 37-43 mm; the cylindrical component is connected to the hemispherical component, and its diameter is 37-43 mm and its height is 8-12 mm; the positioning ring is embedded in the cylindrical component, and its large end diameter is 23-25 ​​mm, its small end diameter is 20-22 mm, and its height is 9-12 mm, and the positioning ring matches the positioning ring plug; the fan blade is disposed on the outside of the hemispherical component.

[0012] The main function of the hemispherical buffer structure is to buffer the poured high-temperature alloy molten metal, allowing the molten metal to flow smoothly into the three concentric spiral lines of different diameters. It also prevents the molten metal from splashing and avoids turbulence, thus eliminating the influence of factors such as molten metal splashing and turbulence on the high-temperature alloy fluidity test results and improving the test accuracy.

[0013] The wax mold of the high-temperature alloy flowability testing device of the present invention is designed with two positioning and plugging structures to facilitate wax mold assembly and improve the efficiency and consistency of wax mold preparation. The first positioning and plugging structure is a positioning ring on a hemispherical buffer structure, which is matched and connected with a positioning ring plug on a transition structure; the second positioning and plugging structure is a positioning plate and a positioning plate plug, which are matched and connected with the small end of a ceramic pouring cup.

[0014] In any of the above embodiments, it is preferred that the three helices are respectively connected to the three fan blades of the hemispherical buffer structure; the three helices have the same center, and the central axes of the three helices are on the same horizontal plane.

[0015] Preferably, in any of the above embodiments, the diameters of the three helices are 4mm, 6mm, and 8mm, respectively, and the length of each helix is ​​not less than 450mm, with a spacing of 14-16mm between adjacent helices; at least nine ranging counting hemispheres are arranged vertically downwards on the three helices, with a diameter of 2.8-3.2mm, and the arc length between the centers of two adjacent ranging counting hemispheres on each helix is ​​50mm. Extensive testing has proven that, due to the large length of the helices, when the cross-sectional diameter of the helices is less than 4mm, the samples are prone to breakage during wax pattern and shell preparation; therefore, a minimum diameter of 4mm is designed. When the cross-sectional diameter of the helices is greater than 8mm, casting defects such as under-casting and cold shuts are generally avoided.

[0016] In this invention: the ceramic pouring cup is a preform, the transition structure is formed by pressing a wax mold, the hemispherical buffer structure, the three spiral lines and the distance measuring and counting hemispheres on the spiral lines are formed as a whole by pressing a wax mold once; the preform and the two wax molds are combined as a whole structure to prepare the shell.

[0017] The present invention also provides a testing device for the fluidity of high-temperature alloys, wherein the testing device is prepared by a wax mold of the high-temperature alloy fluidity testing device described in any of the above claims.

[0018] After the wax model design for the aforementioned high-temperature alloy fluidity testing device is completed, wax model preparation is required. The wax model preparation process includes steps such as wax model pressing, wax model trimming, and wax model assembly. The main parameters for wax model pressing are as follows: wax model pressing is performed on a wax press; the mold temperature is 20-30℃; the wax storage tank temperature is 80-90℃; the injection pressure is 10-15 bar; the injection time is 15-20 seconds; and the holding time is 40-50 seconds.

[0019] After the wax model for the aforementioned high-temperature alloy fluidity testing device is prepared, the mold shell needs to be prepared. The mold shell preparation process includes steps such as paint preparation, paint application and drying, mold shell grinding and reinforcement, mold shell dewaxing, and mold shell firing. The main parameters of the mold shell preparation process are as follows:

[0020] (1) Shell dewaxing: Shell dewaxing is carried out in a high-pressure steam dewaxing kettle. The dewaxing pressure is 0.6-1.0MPa and the dewaxing time is 9-11min.

[0021] (2) Shell firing: The shell is fired in the shell firing furnace at a temperature of 910-930℃ for 115-125 minutes. After the power is turned off and the temperature of the shell firing furnace drops below 150℃, the furnace door is opened and the shell is removed.

[0022] This invention also provides a method for testing the fluidity of high-temperature alloys. The testing device used in the method is prepared from a wax mold of the high-temperature alloy fluidity testing device described in any of the above claims. The testing method includes the following steps in sequence:

[0023] Step 1: Place the high-temperature alloy master alloy ingot and the high-temperature alloy fluidity testing device in the corresponding positions of the vacuum induction melting furnace.

[0024] Step 2: After melting the high-temperature alloy master alloy ingot by applying electricity, it undergoes refining treatment;

[0025] Step 3: Preheat the high-temperature alloy fluidity testing device;

[0026] Step 4: Pour the refined high-temperature alloy liquid into the preheated testing device;

[0027] Step 5: After pouring is completed, turn off the power, wait for a certain period of time, then break the vacuum and remove the casting from the furnace. Cut, clean the shell, and blow sand onto the casting.

[0028] Step Six: The filling length of the three spiral lines is counted by measuring the distance and counting hemispheres to evaluate the fluidity of the high-temperature alloy.

[0029] Preferably, the vacuum degree in the vacuum induction melting furnace is no greater than 2 Pa; the refining temperature after melting the high-temperature alloy master alloy ingot is 1530-1550℃, and the refining time is no less than 3 min; the preheating temperature of the high-temperature alloy fluidity testing device is 890-910℃, and the preheating time is no less than 60 min; the pouring temperature of the high-temperature alloy liquid is 1390-1410℃, the pouring speed is 0.9-1.1 kg / s, and the pouring weight is 4.9-5.1 kg; after pouring is completed, the power is cut off, and the dwell time is no less than 5 min. Steps two and three can be performed simultaneously.

[0030] During the filling process of the high-temperature alloy melt in the testing device, the temperature drops rapidly, the viscosity increases, and the flow is hindered. The length of the high-temperature alloy melt filling the spiral reflects the alloy's fluidity; that is, the longer the spiral filling, the better the flowability of the high-temperature alloy. Simultaneously, the filling pattern of spirals with different diameters can reflect the influence of wall thickness on the fluidity of the high-temperature alloy, thus providing a reference for the structural design of large, complex, thin-walled castings such as casings (mainly the wall thickness and thin-wall area of ​​the casting).

[0031] To avoid the influence of casting process parameters on alloy fluidity, the aforementioned unified casting process parameters are used for different high-temperature alloys. These casting process parameters, especially the preheating temperature of the high-temperature alloy fluidity testing device (mold shell) and the pouring temperature of the high-temperature alloy liquid, are crucial for comparing the fluidity of different grades of high-temperature alloys. When the preheating temperature of the high-temperature alloy fluidity testing device (mold shell) and the pouring temperature of the high-temperature alloy liquid are too high, the molten metal from different grades of high-temperature alloys can fill the fluidity testing device, thus failing to achieve the purpose of fluidity comparison. Furthermore, for the same grade of high-temperature alloy, the high-temperature alloy fluidity testing device of this invention can also perform another function: studying the influence of different casting process parameters on alloy fluidity, thereby obtaining optimized casting process parameters.

[0032] The wax mold, testing device, and testing method of the high-temperature alloy fluidity testing apparatus of this invention adopt a modular design, have a simple structure, and facilitate wax mold production and assembly. By comparing the filling lengths of three spiral lines with different diameters under the same casting conditions, the fluidity properties of different high-temperature alloys and the influence of different wall thicknesses on the fluidity of high-temperature alloys are compared. The design is reasonable, the operation is convenient, the test results are accurate, and it has good application prospects. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the overall structure of a preferred embodiment of the wax mold of the high-temperature alloy fluidity testing device according to the present invention;

[0034] Figure 2 for Figure 1 A schematic diagram of the ceramic pouring cup in the embodiment shown;

[0035] Figure 3 for Figure 1 A schematic diagram of the adapter structure in the illustrated embodiment;

[0036] Figure 4 for Figure 1 Front view of the transition structure in the illustrated embodiment;

[0037] Figure 5 for Figure 1 A schematic diagram of the hemispherical buffer structure in the embodiment shown;

[0038] Figure 6 for Figure 1 A schematic diagram of the fan blades and positioning ring of the hemispherical buffer structure in the embodiment shown;

[0039] Figure 7 for Figure 1 The diagram shows the structure of the three test spirals in the embodiment shown.

[0040] Figure 8 for Figure 1 The flow performance test results of high-temperature alloys for large, complex, thin-walled structure castings of different grades are shown in the embodiments, where: (a) alloy K439B, (b) alloy CM939, and (c) alloy K4169.

[0041] Explanation of annotations in the diagram:

[0042] 1-Ceramic pouring cup; 11-Groove;

[0043] 2-Adapter structure, 21-Support wax block, 22-Positioning plate plug, 23-Positioning plate, 24-Positioning ring plug, 25-Groove;

[0044] 3-Hemispherical buffer structure, 31-Hemispherical component, 32-Cylindrical component, 33-Fan blade, 34-Positioning ring;

[0045] 4-Helix, 41-Distance counting hemisphere. Detailed Implementation

[0046] To further understand the invention, the following detailed description of the invention will be provided in conjunction with specific embodiments.

[0047] Example 1:

[0048] like Figure 1-7As shown, a preferred embodiment of the wax mold for the high-temperature alloy flowability testing device of the present invention includes a ceramic pouring cup 1, a transition structure 2, and a hemispherical buffer structure 3 connected in sequence; it also includes three spiral lines 4 connected to the hemispherical buffer structure 3, and the three spiral lines 4 have different diameters. In this embodiment, the ceramic pouring cup is a ceramic preform, and the transition structure, the hemispherical buffer structure, and the three spiral lines are all made of wax.

[0049] The ceramic pouring cup 1 has a large end diameter of 180mm, a small end diameter of 85mm, a wall thickness of 10mm, and a height of 120mm. Five grooves 11 are provided on the outer surface of the ceramic pouring cup 1. The distances of the five grooves 11 from the large end are 45mm, 60mm, 81mm, 94mm, and 107mm respectively; the widths are 2mm, 2mm, 6mm, 6mm, and 6mm respectively; and the depths are 2mm, 3mm, 3mm, 4mm, and 4mm respectively. Extensive testing has proven that designing the grooves according to the method of this embodiment optimizes the outer surface area of ​​the ceramic pouring cup. If a large smooth surface exists, the adhesion between the paint and the outer surface of the ceramic pouring cup will be weak after the wax model is prepared, and the paint will easily peel off during the subsequent shell preparation process. By providing grooves of the above-mentioned size and number on the outer surface of the ceramic pouring cup, the adhesion between the paint and the outer surface of the ceramic pouring cup is enhanced, preventing paint peeling and thus improving the yield rate of the shell preparation.

[0050] The adapter structure 2 includes a support wax block 21, a positioning plate plug 22, a positioning plate 23, and a positioning ring plug 24 connected in sequence; the positioning plate 23 has a large end diameter of 85mm, a small end diameter of 40mm, and a height of 50mm; the positioning plate plug 22 matches the small end of the ceramic pouring cup 1, and the height of the positioning plate plug 22 is 15mm; the large end diameter of the support wax block 21 is 2mm smaller than the diameter of the positioning plate plug 22, the small end diameter of the support wax block 21 is 8mm smaller than its large end diameter, and the height is 35mm; the outer surface of the support wax block 21 is provided with six semi-cylindrical grooves 25, and the diameter of each groove 25 is 8mm. This embodiment features a supporting wax block with the following functions: After assembling the ceramic pouring cup and the adapter structure, liquid wax is injected into the gap between the ceramic pouring cup and the adapter structure up to the large end of the supporting wax block. After the wax solidifies, the ceramic pouring cup and the adapter structure are firmly bonded together. The six semi-cylindrical grooves on the outer surface of the supporting wax block further enhance the bonding force between the ceramic pouring cup and the adapter structure, thereby preventing the wax mold and the mold shell from being scrapped due to a weak bond between the ceramic pouring cup and the adapter structure during the subsequent shell preparation process.

[0051] The hemispherical buffer structure 3 includes a hemispherical component 31, a cylindrical component 32, a fan blade 33, and a positioning ring 34. The diameter of the hemispherical component 31 is 40 mm. The cylindrical component 32 is connected to the hemispherical component 31 and has a diameter of 40 mm and a height of 10 mm. The positioning ring 34 is embedded in the cylindrical component 32, with a large end diameter of 24 mm, a small end diameter of 21 mm, and a height of 11 mm. The positioning ring 34 matches the positioning ring plug 24. The fan blade 33 is disposed on the outside of the hemispherical component 31. The main function of the hemispherical buffer structure is to buffer the poured high-temperature alloy molten metal, allowing the molten metal to flow smoothly into three concentric spiral lines of different diameters. It also prevents molten metal from splashing and avoids turbulence, eliminating the influence of molten metal splashing and turbulence on the high-temperature alloy fluidity test results and improving test accuracy.

[0052] The wax mold of the high-temperature alloy flowability testing device in this embodiment is designed with two positioning and plugging structures to facilitate wax mold assembly and improve the efficiency and consistency of wax mold preparation. The first positioning and plugging structure is a positioning ring on a hemispherical buffer structure, which is matched and connected to a positioning ring plug on a transition structure; the second positioning and plugging structure is a positioning plate and a positioning plate plug, which are matched and connected to the small end of a ceramic pouring cup.

[0053] The three spiral lines 4 are respectively connected to the three fan blades 33 of the hemispherical buffer structure 3; the three spiral lines 4 have the same center, and the central axes of the three spiral lines 4 are on the same horizontal plane. The diameters of the three spiral lines 4 are 4mm, 6mm and 8mm respectively, and the length of each is 450mm, with a spacing of 15mm between adjacent spiral lines 4; nine ranging counting hemispheres 41 are arranged vertically downwards on the three spiral lines 4, the diameter of the ranging counting hemispheres 41 is 3.0mm, and the arc length between the centers of two adjacent ranging counting hemispheres 41 on each spiral line 4 is 50mm. This embodiment has been proven through extensive testing that when the cross-sectional diameter of the spiral line is less than 4mm, the sample is prone to breakage during wax pattern preparation and shell preparation; when the cross-sectional diameter of the spiral line is greater than 8mm, casting defects such as under-casting and cold shuts usually do not occur.

[0054] In this embodiment: the ceramic pouring cup is a preform, the transition structure is formed by pressing a wax mold, and the hemispherical buffer structure, the three spiral lines and the distance measuring and counting hemispheres on the spiral lines are formed as a whole by pressing a wax mold once; the preform and the two wax molds are combined as a whole structure to prepare the shell.

[0055] This embodiment also provides a testing device for the fluidity of high-temperature alloys, which is prepared from the wax mold of the above-mentioned high-temperature alloy fluidity testing device.

[0056] After the wax model design for the aforementioned high-temperature alloy fluidity testing device is completed, wax model preparation is required. The wax model preparation process includes steps such as wax model pressing, wax model trimming, and wax model assembly. The main parameters for wax model pressing are as follows: wax model pressing is performed on a wax pressing machine, the mold temperature is 25℃, the wax storage tank temperature is 85℃, the injection pressure is 12 bar, the injection time is 18 s, and the holding time is 45 s.

[0057] After the wax model of the above-mentioned high-temperature alloy fluidity testing device is prepared, the shell needs to be prepared. The shell preparation process includes coating preparation, coating application and drying, shell grinding and reinforcement, shell dewaxing, and shell baking. The main parameters of the shell preparation process are as follows: (1) Shell dewaxing: Shell dewaxing is carried out in a high-pressure steam dewaxing kettle. The dewaxing pressure is 0.8MPa and the dewaxing time is 10min; (2) Shell baking: Shell baking is carried out in a shell baking furnace. The baking temperature is 920℃ and the baking time is 120min. After the power is turned off and the temperature of the shell baking furnace drops below 150℃, the furnace door is opened and the shell is taken out.

[0058] This embodiment also provides a method for testing the fluidity of high-temperature alloys. The testing device used in the method is prepared from a wax mold of the aforementioned high-temperature alloy fluidity testing device. The testing method includes the following steps in sequence:

[0059] Step 1: Place the high-temperature alloy master alloy ingot and the high-temperature alloy fluidity testing device in the corresponding positions of the vacuum induction melting furnace.

[0060] Step 2: After melting the high-temperature alloy master alloy ingot by applying electricity, it undergoes refining treatment;

[0061] Step 3: Preheat the high-temperature alloy fluidity testing device;

[0062] Step 4: Pour the refined high-temperature alloy liquid into the preheated testing device;

[0063] Step 5: After pouring is completed, turn off the power, wait for a certain period of time, then break the vacuum and remove the casting from the furnace. Cut, clean the shell, and blow sand onto the casting.

[0064] Step Six: The filling length of the three spiral lines is counted by measuring the distance and counting hemispheres to evaluate the fluidity of the high-temperature alloy.

[0065] The vacuum degree in the vacuum induction melting furnace is 2 Pa; the refining temperature after melting the high-temperature alloy master alloy ingot is 1540℃, and the refining time is 3 min; the preheating temperature of the high-temperature alloy fluidity testing device is 900℃, and the preheating time is 60 min; the pouring temperature of the high-temperature alloy liquid is 1400℃, the pouring speed is 1.0 kg / s, and the pouring weight is 5.0 kg; after pouring is completed, the power is turned off, and the dwell time is 5 min. Steps two and three can be performed simultaneously.

[0066] The length of the filling of the high-temperature alloy melt in three concentric spirals of different diameters reflects the alloy's fluidity; the longer the spiral is filled, the better the fluidity of the high-temperature alloy. Simultaneously, the filling pattern of spirals of different diameters reflects the influence of wall thickness on the fluidity of the high-temperature alloy, thus providing a basis for the structural design of large, complex, thin-walled castings such as casings (mainly the wall thickness and thin-wall area). Furthermore, for the same grade of high-temperature alloy, the high-temperature alloy fluidity testing device in this embodiment can also perform another function: studying the influence of different casting process parameters on alloy fluidity, thereby obtaining optimized casting process parameters. The aforementioned casting process parameters, especially the preheating temperature of the high-temperature alloy fluidity testing device (mold shell) and the pouring temperature of the high-temperature alloy liquid, are crucial for comparing the fluidity of different grades of high-temperature alloys. The vacuum induction melting furnace, dewaxing equipment, and calcining equipment used in this embodiment are all commonly used equipment in the field, and there are no special requirements for specific models.

[0067] To avoid the influence of casting process parameters on alloy fluidity, the aforementioned unified casting process parameters were used for different grades of high-temperature alloys. This embodiment tests the fluidity properties of different grades of high-temperature alloys used in castings of large, complex, thin-walled structures such as casings. The tested alloy grades were K439B, CM939, and K4169. The test results are as follows: Figure 8 As shown in Table 1, the statistical results of the filling length of the spiral are presented.

[0068] Table 1. Spiral fill length for flowability tests of alloys K439B, CM939, and K4169

[0069]

[0070]

[0071] from Figure 8 As can be seen from Table 1, the fluidity of alloy K439B is comparable to that of alloy CM939; the fluidity of alloys K439B and CM939 is better than that of alloy K4169.

[0072] The solidification temperature range of cast superalloys is a crucial factor affecting their fluidity. Table 2 shows the solidification temperature ranges of alloys K439B, CM939, and K4169, determined using differential scanning calorimetry (DSC). As can be seen from Table 2, the solidification temperature range of alloy K439B is comparable to that of alloy CM939, and shorter than that of alloy K4169. Generally, a smaller solidification temperature range corresponds to better alloy fluidity and a longer filling length.

[0073] Table 2 Solidification temperature ranges of alloys K439B, CM939, and K4169

[0074] K439B 66.7 CM939 69.9 K4169 116.0

[0075] Comparison of alloy fluidity test results ( Figure 8 As shown in Table 1 and the solidification temperature range of the alloy (Table 2), it can be seen that the fluidity test results of the alloy are consistent with the trend of its solidification temperature range data, indicating that the evaluation test results of the fluidity of the cast high-temperature alloy in this embodiment are accurate and reliable.

[0076] The wax mold, testing device, and testing method of the high-temperature alloy fluidity testing apparatus in this embodiment adopt a modular design, have a simple structure, and facilitate wax mold production and assembly. By comparing the filling lengths of three spiral lines with different diameters under the same casting conditions, the fluidity properties of different high-temperature alloys and the influence of different wall thicknesses on the fluidity of high-temperature alloys are compared. The design is reasonable, the operation is convenient, the test results are accurate, and it has good application prospects.

[0077] Example 2:

[0078] According to another preferred embodiment of the wax model, testing device, and testing method of the high-temperature alloy fluidity testing device of the present invention, its structure, connection relationship between the components, preparation method, testing method, principle, and beneficial effects are basically the same as those of Embodiment 1, except that:

[0079] For the wax mold of the high-temperature alloy flowability testing device: the ceramic pouring cup has a large end diameter of 170mm, a small end diameter of 80mm, a wall thickness of 8mm, and a height of 110mm. The positioning plate has a large end diameter of 80mm, a small end diameter of 35mm, and a height of 45mm; the positioning plate plug has a height of 18mm; the large end diameter of the supporting wax block is 3mm smaller than the diameter of the positioning plate plug, the small end diameter of the supporting wax block is 9mm smaller than its large end diameter, and the height is 30mm; the outer surface of the supporting wax block is provided with six semi-cylindrical grooves, each groove having a diameter of 6mm. The hemispherical component has a diameter of 37mm; the cylindrical component is connected to the hemispherical component, and has a diameter of 37mm and a height of 8mm; the positioning ring is embedded in the cylindrical component, and has a large end diameter of 23mm, a small end diameter of 20mm, and a height of 9mm. The diameters of the three spirals are 4mm, 6mm and 8mm respectively, and the length of each is 500mm. The distance between two adjacent spirals is 14mm. The diameter of the ranging counting hemisphere is 2.8mm, and the arc length between the centers of two adjacent ranging counting hemispheres on each spiral is 50mm.

[0080] For the preparation of wax molds for the high-temperature alloy fluidity testing device: wax molds are pressed on a wax press machine. The temperature of the mold is 20℃, the temperature of the wax storage tank is 80℃, the injection pressure is 10 bar, the injection time is 15s, and the holding time is 40s.

[0081] For the preparation of the high-temperature alloy fluidity testing device (shell): (1) Shell dewaxing: Dewaxing of the shell is carried out in a high-pressure steam dewaxing kettle. The dewaxing pressure is 0.6 MPa and the dewaxing time is 9 min. (2) Shell baking: Shell baking is carried out in a shell baking furnace. The baking temperature is 910℃ and the baking time is 115 min. The power is turned off and the furnace door is opened to take out the shell when the temperature of the shell baking furnace drops below 150℃.

[0082] The test method for the fluidity of high-temperature alloys is as follows: the vacuum degree in the vacuum induction melting furnace is 2 Pa; the refining treatment temperature after melting the high-temperature alloy master alloy ingot is 1530℃ and the refining treatment time is 5 min; the preheating treatment temperature of the high-temperature alloy fluidity testing device is 890℃ and the preheating treatment time is 80 min; the pouring temperature of the high-temperature alloy liquid is 1390℃, the pouring speed is 0.9 kg / s, and the pouring weight is 4.9 kg; after pouring is completed, the power is turned off, and the dwell time is 6 min.

[0083] Example 3:

[0084] According to another preferred embodiment of the wax model, testing device, and testing method of the high-temperature alloy fluidity testing device of the present invention, its structure, connection relationship between the components, preparation method, testing method, principle, and beneficial effects are basically the same as those of Embodiment 1, except that:

[0085] For the wax mold of the high-temperature alloy flowability testing device: the ceramic pouring cup has a large end diameter of 190mm, a small end diameter of 90mm, a wall thickness of 12mm, and a height of 130mm. The positioning plate has a large end diameter of 90mm, a small end diameter of 45mm, and a height of 55mm; the positioning plate plug has a height of 20mm; the large end diameter of the supporting wax block is 4mm smaller than the diameter of the positioning plate plug, the small end diameter of the supporting wax block is 10mm smaller than its large end diameter, and the height is 33mm; the outer surface of the supporting wax block is provided with six semi-cylindrical grooves, each groove having a diameter of 10mm. The hemispherical component has a diameter of 43mm; the cylindrical component is connected to the hemispherical component, and has a diameter of 43mm and a height of 12mm; the positioning ring is embedded in the cylindrical component, and has a large end diameter of 25mm, a small end diameter of 22mm, and a height of 12mm. The diameters of the three spirals are 4mm, 6mm and 8mm respectively, and the length of each is 550mm. The distance between two adjacent spirals is 16mm. The diameter of the ranging counting hemisphere is 3.2mm, and the arc length between the centers of two adjacent ranging counting hemispheres on each spiral is 50mm.

[0086] For the preparation of wax molds for the high-temperature alloy fluidity testing device: wax molds are pressed on a wax press machine. The temperature of the mold is 30℃, the temperature of the wax storage tank is 90℃, the injection pressure is 15 bar, the injection time is 20 s, and the holding time is 50 s.

[0087] For the preparation of the high-temperature alloy fluidity testing device (shell): (1) Shell dewaxing: Dewaxing of the shell is carried out in a high-pressure steam dewaxing kettle. The dewaxing pressure is 1.0 MPa and the dewaxing time is 11 min. (2) Shell baking: Shell baking is carried out in a shell baking furnace. The baking temperature is 930℃ and the baking time is 125 min. The power is turned off and the furnace door is opened to take out the shell when the temperature of the shell baking furnace drops below 150℃.

[0088] The test method for the fluidity of high-temperature alloys is as follows: the vacuum degree in the vacuum induction melting furnace is 2 Pa; the refining treatment temperature after melting the high-temperature alloy master alloy ingot is 1550℃ and the refining treatment time is 6 min; the preheating treatment temperature of the high-temperature alloy fluidity testing device is 910℃ and the preheating treatment time is 90 min; the pouring temperature of the high-temperature alloy liquid is 1410℃, the pouring speed is 1.1 kg / s, and the pouring weight is 5.1 kg; after pouring is completed, the power is turned off, and the dwell time is 8 min.

[0089] 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.

[0090] Those skilled in the art will readily understand that the wax mold, testing device, and testing method of the high-temperature alloy fluidity testing apparatus of the present invention include any combination of the inventive content and specific embodiments described in the above specification and the parts shown in the 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, improvements, etc., 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 wax mold for a high-temperature alloy flowability testing device, comprising a ceramic pouring cup, a transition structure, and a hemispherical buffer structure connected in sequence, characterized in that, It also includes three spirals, which are connected to the hemispherical buffer structure, and the three spirals have different diameters; The outer surface of the ceramic pouring cup is provided with five grooves. The distances of the five grooves from the large end are 45mm, 60mm, 81mm, 94mm and 107mm respectively. The widths of the five grooves are 2mm, 2mm, 6mm, 6mm and 6mm respectively. The depths of the five grooves are 2mm, 3mm, 3mm, 4mm and 4mm respectively. The adapter structure includes a support wax block, a positioning plate plug, a positioning plate, and a positioning ring plug connected in sequence; the positioning plate has a large end diameter of 80-90mm, a small end diameter of 35-45mm, and a height of 45-55mm; the positioning plate plug matches the small end of the ceramic pouring cup, and its height is 15-20mm; the support wax block has a large end diameter that is 2-4mm smaller than the diameter of the positioning plate plug, a small end diameter that is 8-10mm smaller than its large end diameter, and a height of 30-35mm; the outer surface of the support wax block is provided with six semi-cylindrical grooves, the grooves having a diameter of 6-10mm; The hemispherical buffer structure includes a hemispherical component, a cylindrical component, fan blades, and a positioning ring; the diameter of the hemispherical component is 37-43 mm; the cylindrical component is connected to the hemispherical component, and its diameter is 37-43 mm and its height is 8-12 mm; the positioning ring is embedded in the cylindrical component, and its large end diameter is 23-25 ​​mm, its small end diameter is 20-22 mm, and its height is 9-12 mm, and the positioning ring matches the positioning ring plug; the fan blades are disposed on the outside of the hemispherical component; The diameters of the three spirals are 4mm, 6mm and 8mm respectively, and the length of each spiral is not less than 450mm. The distance between two adjacent spirals is 14-16mm. At least nine distance-measuring counting hemispheres are arranged vertically downward on the three spirals. The diameter of each distance-measuring counting hemisphere is 2.8-3.2mm, and the arc length between the centers of two adjacent distance-measuring counting hemispheres on each spiral is 50mm. The three spirals are respectively connected to the three blades of the hemispherical buffer structure; the three spirals have the same center, and the central axes of the three spirals are on the same horizontal plane.

2. The wax mold of the high-temperature alloy fluidity testing device according to claim 1, characterized in that, The ceramic pouring cup has a large end diameter of 170-190mm, a small end diameter of 80-90mm, a wall thickness of 8-12mm, and a height of 110-130mm.

3. A testing device for the fluidity of high-temperature alloys, characterized in that, The testing device is prepared from a wax mold of the high-temperature alloy fluidity testing device as described in claim 1 or 2.

4. A method for testing the fluidity of high-temperature alloys, characterized in that, The testing device used in the testing method is prepared from a wax mold of the high-temperature alloy fluidity testing device as described in claim 1 or 2, and the testing method includes the following steps in sequence: Step 1: Place the high-temperature alloy master alloy ingot and the high-temperature alloy fluidity testing device in the corresponding positions of the vacuum induction melting furnace. Step 2: After melting the high-temperature alloy master alloy ingot by applying electricity, it undergoes refining treatment; Step 3: Preheat the high-temperature alloy fluidity testing device; Step 4: Pour the refined high-temperature alloy liquid into the preheated testing device; Step 5: After pouring is completed, turn off the power, wait for a certain period of time, then break the vacuum and remove the casting from the furnace. Cut, clean the shell, and blow sand onto the casting. Step Six: The filling length of the three spiral lines is counted by measuring the distance and counting hemispheres to evaluate the fluidity of the high-temperature alloy.

5. The method for testing the fluidity of high-temperature alloys according to claim 4, characterized in that, The vacuum degree in the vacuum induction melting furnace is no greater than 2 Pa; the refining treatment temperature after melting the high-temperature alloy master alloy ingot is 1530-1550℃, and the refining treatment time is no less than 3 min; the preheating treatment temperature of the high-temperature alloy fluidity testing device is 890-910℃, and the preheating treatment time is no less than 60 min; the pouring temperature of the high-temperature alloy liquid is 1390-1410℃, the pouring speed is 0.9-1.1 kg / s, and the pouring weight is 4.9-5.1 kg; after pouring is completed, the power is cut off, and the dwell time is no less than 5 min.

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