Method for confirming interface heat exchange coefficient of precision casting and application thereof

Abstract

The present application relates to the technical field of precision casting, in particular to a method for confirming the interface heat transfer coefficient of precision casting and application thereof. The method for confirming the interface heat transfer coefficient of precision casting provided by the present application compares the actual metal liquid temperature with the simulated metal liquid temperature and compares the actual mold shell temperature with the simulated mold shell temperature, and if the temperature difference can be controlled within 10 DEG C, it is indicated that the interface heat transfer coefficient obtained is real and reliable. Only the reliability of the interface heat transfer coefficient is verified, the accuracy of the simulation result can be ensured, and then higher quality qualified castings can be obtained.

Description

Technical Field

[0001] This invention relates to the field of investment casting technology, and more specifically, to a method for determining the interfacial heat transfer coefficient in precision casting and its application. Background Technology

[0002] The solidification process in casting begins with the transfer of heat from the molten metal. When the molten metal is poured into a relatively cool mold, the heat contained in the molten metal is transferred through the metal, the metal-mold interface, and the mold. The heat transfer coefficient between the molten metal and the mold is defined as the interfacial heat transfer coefficient. This interfacial heat transfer coefficient is related to the material properties, casting process design, and cooling environment during solidification, and cannot be directly measured using equipment. Currently, the interfacial heat transfer coefficient is solved using the inverse heat conduction algorithm. The basic principle of this algorithm is to use measured temperature data, known boundary conditions, and thermophysical parameters to inversely calculate unknown boundary conditions or thermophysical parameters, transforming the problem of solving the interfacial heat transfer coefficient into an inverse heat transfer problem. This inverse problem can be transformed into an unconstrained optimization problem. The objective of this optimization problem is to find the interfacial heat transfer coefficient h such that the objective function f(h), i.e., the sum of the squared differences between the simulated temperature and the measured temperature at different temperature measurement points, reaches its minimum value.

[0003] With the development of computers, ProCAST simulation software has been widely used in the casting industry. However, current technologies mostly rely on the software's built-in database to set casting parameters during simulation. Since casting processes vary, this leads to significant discrepancies between the simulation results and actual conditions. The interfacial heat transfer coefficient is a crucial parameter in the simulation settings, directly affecting the temperature field during casting solidification. Therefore, its accurate setting directly impacts the reliability of the simulation results. Consequently, the accuracy and effectiveness of the calculated interfacial heat transfer coefficient need to be verified.

[0004] The existing verification method involves loading the back-calculated interfacial heat transfer coefficient into the Procast simulation library to simulate the casting, and then using the simulated process parameters to obtain a qualified casting. The drawback of this method is that it does not compare the actual molten metal temperature and mold temperature with the numerically simulated temperature; it only obtains a qualified casting but cannot guarantee the reliability of the interfacial heat transfer coefficient.

[0005] Furthermore, patent CN202011486286.0 discloses a method for confirming the boundary heat transfer system in casting. This method involves making a wax model, breaking it to insert a thermocouple, sealing the wax model with wax, and then making the shell. However, this shell-making process is inconvenient, cumbersome, and prone to causing shell cracking. Additionally, while it uses thermocouples to measure mold temperature, the thickness of investment casting shells is generally 6-8 mm. For investment casting shells, using thermocouples for temperature measurement presents problems such as unstable thermocouple fixation, inability to measure the thermocouple insertion depth, and the need for localized thickening of the shell at the thermocouple measurement location.

[0006] In view of this, the present invention is hereby proposed. Summary of the Invention

[0007] The primary objective of this invention is to provide a method for confirming the interfacial heat transfer coefficient in precision casting. This method involves comparing the actual molten metal temperature with the simulated molten metal temperature, and comparing the actual mold temperature with the simulated mold temperature. If the temperature difference can be controlled within 10°C, the obtained interfacial heat transfer coefficient is considered reliable. Only by verifying the reliability of the interfacial heat transfer coefficient can the accuracy of the simulation results be guaranteed, thereby better guiding production and obtaining high-quality, qualified castings.

[0008] The second objective of this invention is to provide the application of the method for confirming the interfacial heat transfer coefficient in precision casting in investment casting, sand casting, metal mold casting and lost foam casting.

[0009] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0010] This invention provides a method for confirming the interfacial heat transfer coefficient in precision casting, comprising the following steps:

[0011] One end of the wax rod is connected to the position of the molten metal to be tested on the wax model to obtain the assembled wax model; refractory material is coated on the surface of the assembled wax model, and then dewaxing and firing are performed to obtain a shell. The shell includes the shell body formed by the wax model after coating and the tubular shell formed by the wax rod after coating. The tubular shell has a free end at the end away from the shell body.

[0012] Remove the shell at the free end to form a hole, insert the measuring end of the thermocouple into the hole and into the cavity of the shell body, then use adhesive material to fix the measuring end of the thermocouple and seal the gap between the measuring end of the thermocouple and the hole.

[0013] The cold junction of the thermocouple is connected to the inspection instrument, and the mold body is preheated. Then, the mold body is poured, and the inspection instrument is turned on to detect and record the temperature of the molten metal inside the mold body, obtaining a curve showing the actual temperature of the molten metal changing over time during the solidification process of the casting. At the same time, a thermal imager is used to detect and record the temperature of the mold body, obtaining a curve showing the actual temperature of the mold body changing over time during the solidification process of the casting.

[0014] The actual molten metal temperature and the actual mold shell temperature are calculated using the back calculation module of Procast software to obtain the interface heat transfer coefficient. The interface heat transfer coefficient is then imported into Procast software to simulate the solidification process of the casting, and curves showing the change of simulated molten metal temperature over time and simulated mold shell temperature over time are obtained.

[0015] Compare the curves of the actual molten metal temperature changing over time with the curves of the simulated molten metal temperature changing over time, and compare the curves of the actual shell temperature changing over time with the curves of the simulated shell temperature changing over time. If the absolute value of the temperature difference at each time point is ≤10℃, then the interface heat transfer coefficient is determined to be reliable; otherwise, it is determined to be unreliable.

[0016] Preferably, the number of wax rods is at least one.

[0017] Preferably, the number of wax rods is at least three.

[0018] Preferably, the number of thermocouples is the same as the number of wax rods.

[0019] Preferably, the wax rod is cylindrical in shape, and the diameter of the wax rod is larger than the diameter of the measuring end of the thermocouple.

[0020] Preferably, the difference between the diameter of the wax rod and the diameter of the measuring end of the thermocouple is 0.5 to 1.5 mm.

[0021] Preferably, the bonding material includes casting putty and / or refractory putty.

[0022] Preferably, when the bonding material is the casting putty, the method of fixing and sealing specifically includes: placing the casting putty between the thermocouple and the hole so that there is no gap between the thermocouple and the hole, and then drying the casting putty, thereby completing the fixing of the thermocouple and the sealing of the gap.

[0023] Preferably, the method for connecting the wax stick to the wax mold specifically includes: heating the wax stick to melt it, and then bonding it to the wax mold.

[0024] This invention also provides the application of the method for confirming the interfacial heat transfer coefficient of precision casting as described above in investment casting, sand casting, metal mold casting and lost foam casting.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] (1) This invention compares the actual temperature of the molten metal and the actual temperature of the mold shell with the temperature of the numerical simulation. If the temperature difference can be controlled within 10℃, it indicates that the obtained interface heat transfer coefficient is true and reliable. Only by verifying the reliability of the interface heat transfer coefficient can the accuracy of the simulation results be guaranteed, and thus high-quality qualified castings can be obtained.

[0027] (2) In this invention, a wax rod is attached to the wax mold at the temperature measurement point of the molten metal, which facilitates the insertion of the thermocouple after shell preparation. The operation is simple and easy, and it is less likely to cause the mold shell to crack. This solves the problems of inconvenience in shell preparation and easy cracking of the mold shell caused by inserting the thermocouple first and then preparing the shell in the prior art.

[0028] (3) The present invention uses thermocouples to collect the temperature during the solidification process of castings and uses thermal imagers to collect the temperature change of the shell during the solidification process, which solves the problems of thermocouples not being firmly fixed, the inability to measure the depth of thermocouple insertion into the shell, the need to locally thicken the shell at the thermocouple measurement position, and the cumbersome shell making operation in the prior art when using thermocouples to measure the temperature of the investment casting shell. Attached Figure Description

[0029] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the structure of the wax model provided by the present invention;

[0031] Figure 2 This is a schematic diagram of the assembled wax model provided by the present invention;

[0032] Figure 3 A cross-sectional view of the shell provided by the present invention;

[0033] Figure 4 A cross-sectional view of the housing with a thermocouple inserted, provided by the present invention;

[0034] Figure 5 A comparison graph showing the actual temperature of molten metal changing over time and the simulated temperature of molten metal changing over time, provided for the present invention.

[0035] Figure 6 A comparison graph showing the actual shell temperature changing over time and the simulated shell temperature changing over time, provided for the present invention. Detailed Implementation

[0036] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the embodiments described below are only some embodiments of the present invention, not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0037] In a first aspect, the present invention provides a method for confirming the interfacial heat transfer coefficient in precision casting, comprising the following steps:

[0038] First, make a wax model and then make a wax stick in the shape of a rod (cylindrical).

[0039] The present invention does not limit the shape of the wax model; it can be set according to specific needs.

[0040] In this invention, as shown in Figure 1 The wax model shown is used as an example for explanation, but it is worth noting that the shape of the wax model is not limited to this. See also Figure 1 The wax model includes a sprue cup, a main runner, a runner, a cylindrical bar, a fixed cylindrical bar runner, and a ceramic spacer disposed between the sprue cup and the fixed cylindrical bar runner. The axis of the main runner and the axis of the cylindrical bar are parallel and perpendicular to the runner. During pouring, the molten metal flows from the bottom (runner) into the cylindrical bar, and the ceramic spacer prevents the molten metal from flowing into the cylindrical bar from the top. This cylindrical wax model prevents the molten metal from cooling too quickly, which could lead to inaccurate temperature measurement, and also avoids the problem of excessively long Procast reverse engineering time caused by the complexity of the wax model.

[0041] After the wax model and wax rod are made, connect one end of the wax rod to the position of the molten metal to be tested on the wax model, such as... Figure 2 As shown, the assembled wax model is obtained. In this invention, a wax rod is adhered to the wax model at the temperature measurement point of the molten metal, facilitating the insertion of the thermocouple after shell fabrication.

[0042] Subsequently, a refractory material is coated onto the outer surface of the assembled wax model, followed by dewaxing and firing to obtain a shell. The shell comprises a main body formed after coating (applying refractory material, dewaxing, and firing) of the wax model, and a tubular shell formed after coating (applying refractory material, dewaxing, and firing) of the connected wax rod. The cross-sectional view of the shell is shown below. Figure 3 As shown, the tubular shell has a free end at the end furthest from the shell body (i.e., the end that is not connected to the shell body is a free end).

[0043] That is, after the wax model is coated with refractory material, dewaxed and fired, it forms the main body of the mold shell, and after the wax rod is coated with refractory material, dewaxed and fired, it forms a tubular mold shell, wherein the main body of the mold shell and the tubular mold shell are connected.

[0044] In this invention, there is no limitation on the connection position between the wax rod and the wax model. It can be set and adjusted according to the specific temperature measurement requirements. The wax rod can be connected at the position where the temperature is to be measured (the position to be measured).

[0045] The present invention does not limit the number of wax sticks; the number of wax sticks can be placed according to the number of data sets to be measured.

[0046] Further, the shell at the free end (preferably the shell at the tail end of the free end; note that the tubular shell should not be completely removed, a portion needs to be retained to fix the thermocouple) is removed to form a hole. The measuring end (i.e., the hot end, or the working end) of the thermocouple is inserted (placed or passed through) into the hole and enters the cavity of the shell body, as shown below. Figure 4 As shown. Then, the measuring end of the thermocouple is fixed with an adhesive material, and the gap between the measuring end of the thermocouple and the hole is sealed.

[0047] In some preferred embodiments of the present invention, the tail end of the thermocouple measuring terminal is located at the axis of the shell portion, for example... Figure 4 The axis of the circular bar shown is located here, which facilitates more accurate temperature measurement.

[0048] The cold junction of the thermocouple is connected to the inspection instrument, and the main body of the mold shell is preheated. Then, the main body of the mold shell is poured, and the inspection instrument is turned on to detect and record the temperature of the molten metal inside the main body of the mold shell, obtaining a curve showing the actual temperature of the molten metal changing with time during the solidification process of the casting. At the same time, a thermal imager is used to detect and record the temperature of the main body of the mold shell, obtaining a curve showing the actual temperature of the mold shell changing with time during the solidification process of the casting.

[0049] The actual molten metal temperature and the actual shell temperature are calculated using the inverse calculation module of Procast software to obtain the interface heat transfer coefficient. Specifically, the obtained actual molten metal temperature and actual shell temperature are imported into Procast software and their inverse calculation module is used to obtain the optimized interface heat transfer coefficient.

[0050] The calculation method of the interface heat transfer coefficient adopts the existing method. The specific calculation process of the interface heat transfer coefficient inverse algorithm is as follows: (1) Establish a three-dimensional model including information such as model and casting; (2) Establish an experimental model with the same three-dimensional model and conduct solidification experiments to collect the temperature curve of certain specific points on the casting or model as a function of time; (3) Import the three-dimensional model into Procast for mesh generation, and pre-set the initial value of the unknown interface heat transfer coefficient. Then, enable the Procast inverse calculation module and import the measured data into the numerical model as one of the initial conditions; (4) Perform forward simulation calculation to solve the temperature field of the mold and casting respectively; (5) Calculate the value of the objective function f(h); (6) Determine whether the objective function has converged. If it has, stop the calculation and output the optimal solution. Otherwise, adjust the interface heat transfer coefficient h according to the optimization algorithm and then go to step (4).

[0051] The interface heat transfer coefficient is then imported into the Procast software to simulate the solidification process of the casting, and curves showing the change of the simulated molten metal temperature over time and the change of the simulated shell temperature over time are obtained.

[0052] Finally, compare the curve of the actual molten metal temperature changing with time with the curve of the simulated molten metal temperature changing with time, and compare the curve of the actual shell temperature changing with time with the curve of the simulated shell temperature changing with time. If the absolute value of the temperature difference at each time point is ≤10℃, then the interface heat transfer coefficient is determined to be reliable; otherwise, it is determined to be unreliable.

[0053] The absolute value of the temperature difference at each time point is ≤10℃, which means that the absolute value of the temperature difference at each time point in the curve of the actual molten metal temperature changing with time and the curve of the simulated molten metal temperature changing with time are both ≤10℃, and the absolute value of the temperature difference at each time point in the curve of the actual shell temperature changing with time and the curve of the simulated shell temperature changing with time are both ≤10℃.

[0054] In some specific embodiments of the present invention, comparative data of the curves showing the actual molten metal temperature changing over time and the simulated molten metal temperature changing over time are shown below. Figure 5 As shown, this includes three sets of comparative data. The temperature comparison curve can be used to determine the difference between the measured and simulated temperatures of the molten metal.

[0055] In some specific embodiments of the present invention, the comparison data of the curves showing the actual shell temperature changing over time and the simulated shell temperature changing over time are as follows: Figure 6 As shown, this includes two sets of comparative data. The temperature comparison curve allows us to determine the difference between the measured and simulated temperatures of the shell.

[0056] from Figure 5 and Figure 6 It can be seen that the difference between the measured temperature and the simulated temperature in each group is controlled within 10℃, which means that the obtained interface heat transfer coefficient is reliable.

[0057] This invention compares the actual temperature of the molten metal and the actual temperature of the mold shell with the temperature simulated in numerical simulation. If the temperature difference can be controlled within 10℃, it indicates that the calculated interfacial heat transfer coefficient is true and reliable (the smaller the temperature difference, the more reliable the interfacial heat transfer coefficient; if the temperature difference is greater than 10℃, the reliability of the interfacial heat transfer coefficient is questionable). Only by verifying the reliability of the interfacial heat transfer coefficient can the accuracy of the simulation results be guaranteed, better guiding production and obtaining high-quality, qualified castings.

[0058] Specifically, in this invention, a wax rod is pre-attached to the wax model at the location where the thermocouple needs to be inserted. After the wax is removed from the mold shell, the wax rod cavity is opened from one end, and then the thermocouple is inserted. This operation is simple and easy, and it is less likely to cause the mold shell to crack. Compared with the existing technology that involves destroying the wax model, inserting an R-type thermocouple with a ceramic protective tube, sealing the wax model, and then making the mold shell (inserting the thermocouple into the wax model before making the mold shell), this invention solves the problems of inconvenient mold shell making and easy mold shell cracking.

[0059] Furthermore, this invention utilizes thermocouples to collect the temperature during the solidification process of the casting and uses a thermal imager to collect the temperature change of the mold shell during the solidification process. This solves the problems in the prior art where thermocouples are used to measure the temperature of the investment casting mold shell, such as unstable thermocouple fixation, inability to measure the depth of thermocouple insertion into the mold shell, the need to locally thicken the mold shell at the thermocouple measurement location, and cumbersome shell making operations.

[0060] Preferably, the number of wax rods is at least one, including but not limited to any one of two, three, four, five, six, seven, eight, nine, ten, fifteen, or twenty point values ​​or a range of values ​​between any two. The specific number can be determined according to the number of temperature measurement groups required.

[0061] Preferably, the number of wax sticks is at least three, for example... Figure 2 As shown.

[0062] Preferably, the number of thermocouples is the same as the number of wax rods. That is, after removing the free end of the tubular shell formed at each wax rod position, a thermocouple should be inserted.

[0063] Preferably, the wax rod is cylindrical, and its diameter is larger than the diameter of the measuring end of the thermocouple. This facilitates the insertion of the thermocouple into the cavity of the tubular shell.

[0064] Preferably, the difference between the diameter of the wax rod and the diameter of the measuring end of the thermocouple is 0.5 to 1.5 mm, including but not limited to the point value of any one of 0.6 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.3 mm, and 1.4 mm, or the range between any two.

[0065] In some specific embodiments of the present invention, the thermocouple is manufactured by Xinghua Jianghai Electric Heating Instrument Trading Co., Ltd., and its model number is WRN-010. The diameter of the measuring end of the thermocouple is 5mm, and the diameter of the wax rod is 6mm.

[0066] In some specific embodiments of the present invention, the thermal imager is manufactured by Shanghai Dutai Imaging Technology Co., Ltd., and its model is SK-BX1640.

[0067] Preferably, the bonding material includes casting putty and / or refractory putty.

[0068] The casting putty can be any conventional casting putty that can be purchased, such as SP-NJ01 casting putty produced by Zhucheng Shengping Casting Materials Co., Ltd., but is not limited to this.

[0069] The refractory mortar can be any conventional refractory mortar that can be purchased, or it can be homemade. For example, mullite powder, mullite sand and silica sol can be used as raw materials. After mixing and stirring these three raw materials evenly, the mixture can be kneaded into a ball by hand and placed on a horizontal surface so that it does not fall apart or collapse. This is how homemade refractory mortar is obtained.

[0070] In some specific embodiments of the present invention, the adhesive material may also be a conventional refractory material with adhesive properties in the prior art.

[0071] Preferably, when the bonding material is the casting putty, the method of fixing and sealing specifically includes: placing the casting putty between the thermocouple and the hole so that there is no gap between the thermocouple and the hole, and then heating and drying (baking) the casting putty to complete the fixing of the thermocouple and the sealing of the gap.

[0072] Preferably, the method for connecting the wax stick to the wax model specifically includes: heating one end of the wax stick to melt it, and then bonding it to the corresponding position on the wax model.

[0073] In some specific embodiments of the present invention, the refractory material can be any conventional refractory material, such as surface refractory material, transition layer refractory material, and backing layer refractory material. Specifically, the surface refractory material includes at least one of zircon sand (ZrSiO4), fused alumina (Al2O3), and fused silica (SiO2); the transition layer refractory material and the backing layer refractory material include at least one of mullite (3Al2O3·2SiO2) and kaolinite clinker, but are not limited thereto.

[0074] Secondly, the present invention provides the application of the method for confirming the interfacial heat transfer coefficient of precision casting as described above in investment casting, sand casting, metal mold casting and lost foam casting.

[0075] Applying the method for confirming the interfacial heat transfer coefficient provided by this invention to investment casting, sand casting, metal mold casting, and lost foam casting can yield castings of higher quality.

[0076] Although the present invention has been illustrated and described with reference to specific embodiments, it should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Those skilled in the art should understand that modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein, without departing from the spirit and scope of the present invention. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention. Therefore, this means that all such substitutions and modifications that fall within the scope of the present invention are included in the appended claims.

Claims

1. A method for confirming the interfacial heat transfer coefficient in precision casting, characterized in that, Includes the following steps: One end of a wax rod is connected to the position of the molten metal to be tested on the wax model to obtain an assembled wax model; a refractory material is coated on the surface of the assembled wax model, and then dewaxing and firing are performed to obtain a shell. The shell includes the shell body formed by the wax model after coating and the tubular shell formed by the wax rod after coating. The end of the tubular shell away from the shell body is a free end; the number of wax rods is at least three. Remove the shell at the free end to form a hole, insert the measuring end of the thermocouple into the hole and into the cavity of the shell body, then use adhesive material to fix the measuring end of the thermocouple and seal the gap between the measuring end of the thermocouple and the hole. The cold junction of the thermocouple is connected to the inspection instrument, and the mold body is preheated. Then, the mold body is poured, and the inspection instrument is turned on to detect and record the temperature of the molten metal inside the mold body, obtaining a curve showing the actual temperature of the molten metal changing over time during the solidification process of the casting. At the same time, a thermal imager is used to detect and record the temperature of the mold body, obtaining a curve showing the actual temperature of the mold body changing over time during the solidification process of the casting. The actual molten metal temperature and the actual mold shell temperature are calculated using the back calculation module of Procast software to obtain the interface heat transfer coefficient. The interface heat transfer coefficient is then imported into Procast software to simulate the solidification process of the casting, and curves showing the change of simulated molten metal temperature over time and simulated mold shell temperature over time are obtained. Compare the curves of the actual molten metal temperature changing over time with the curves of the simulated molten metal temperature changing over time, and compare the curves of the actual shell temperature changing over time with the curves of the simulated shell temperature changing over time. If the absolute value of the temperature difference at each time point is ≤10℃, then the interface heat transfer coefficient is determined to be reliable; otherwise, it is determined to be unreliable.

2. The method for confirming the interfacial heat transfer coefficient in precision casting according to claim 1, characterized in that, The number of thermocouples is the same as the number of wax rods.

3. The method for confirming the interfacial heat transfer coefficient in precision casting according to claim 1, characterized in that, The wax rod is cylindrical in shape, and its diameter is larger than the diameter of the measuring end of the thermocouple.

4. The method for confirming the interfacial heat transfer coefficient in precision casting according to claim 1, characterized in that, The difference between the diameter of the wax rod and the diameter of the measuring end of the thermocouple is 0.5~1.5mm.

5. The method for confirming the interfacial heat transfer coefficient in precision casting according to claim 1, characterized in that, The bonding material includes casting putty and / or refractory putty.

6. The method for confirming the interfacial heat transfer coefficient in precision casting according to claim 5, characterized in that, When the bonding material is the casting putty, the method of fixing and sealing specifically includes: placing the casting putty between the thermocouple and the hole so that there is no gap between the thermocouple and the hole, and then drying the casting putty, thereby completing the fixing of the thermocouple and the sealing of the gap.

7. The method for confirming the interfacial heat transfer coefficient in precision casting according to claim 1, characterized in that, The method for connecting the wax stick to the wax model specifically includes: heating the wax stick to melt it, and then bonding it to the wax model.

8. The method for determining the interfacial heat transfer coefficient of precision casting as described in any one of claims 1 to 7, applied in investment casting, sand casting, metal mold casting, and lost foam casting.

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