Die for measuring low-pressure casting solidification rate of aluminum alloy and implementation method of die

Abstract

The invention discloses a mold for measuring the low-pressure casting solidification rate of aluminum alloy and an implementation method of the mold, and the method comprises the following steps: 1, installing a thermocouple, and calibrating the thermocouple; 2, defining experimental parameters, and adjusting a mold cooling system; 3, recording temperature data in real time, and analyzing and evaluating the temperature data; 4, cutting the standard mechanical sample, and carrying out mechanical property test and microstructure characterization; and 5, feeding back to production according to an experimental result, optimizing an experimental process, and improving the product quality. The temperature distribution in the casting can be accurately measured in real time, so that the solidification rate is indirectly controlled and measured, and the quality and the production efficiency of the casting are remarkably improved by monitoring the solidification process in real time.

Description

Technical Field

[0001] The invention relates to the technical field of molds, and in particular to a mold for measuring the solidification rate of aluminum alloy low-pressure casting and an implementation method thereof. Background Art

[0002] In the aviation, automobile manufacturing, construction and electronics industries, A356 aluminum alloy has become a widely used key material due to its excellent mechanical properties, light weight, high strength, good plasticity and excellent corrosion resistance. Especially in the automotive industry, A356 aluminum alloy is widely used to produce load-bearing and non-load-bearing structural parts such as automobile wheels. These parts often have complex geometric shapes, and the quality of their casting is directly related to the performance and safety of the car.

[0003] Despite the excellent properties of A356 aluminum alloy, its component production still mainly relies on traditional casting technologies such as sand casting and die casting. However, these processes have multiple steps and face challenges in casting quality control, material utilization and production efficiency, especially for the control and measurement of solidification rate, which is crucial to ensure the consistency of solidification behavior at various locations of the casting.

[0004] Low-pressure casting technology is favored by the industry because it can produce castings with higher quality, precise dimensions and fewer internal defects. This technology improves the overall performance of the casting by injecting molten aluminum alloy into a preheated mold at a lower pressure and solidifying the metal under controlled conditions. However, controlling and measuring the solidification rate at various locations of the casting is still a technical challenge in the prior art, because the non-uniformity of the solidification rate may cause microstructural defects inside the casting, which in turn affects the overall mechanical properties, mainly in the following aspects:

[0005] (1) Inconsistent solidification characteristics: Although A356 aluminum alloy is widely used in the manufacture of high-performance castings, its fluidity and solidification characteristics under different solidification conditions vary significantly. This inconsistency leads to casting defects such as insufficient pouring, thermal cracks, pores and shrinkage holes in the low-pressure casting process.

[0006] (2) Unpredictability of solidification rate: The inability to accurately control the solidification rate causes large fluctuations in the internal structure and properties of the casting, making it difficult to achieve consistent production.

[0007] (3) Performance optimization limitations: The lack of precise control of the solidification rate restricts further optimization of casting performance, especially in applications requiring higher mechanical properties and better internal quality.

[0008] (4) Difficulty in optimizing casting parameters: Without accurate solidification rate data as feedback, the process of optimizing casting parameters (such as casting temperature, pressure, etc.) lacks scientific basis and has limited effect. Summary of the invention

[0009] The purpose of the present invention is to provide a mold for measuring the solidification rate of aluminum alloy low-pressure casting and its implementation method, which integrates a multi-point temperature sensor system. The system can accurately measure the temperature distribution inside the casting in real time, thereby indirectly controlling and measuring the solidification rate. By real-time monitoring of the solidification process, the quality of the casting and the production efficiency are significantly improved.

[0010] The present invention is implemented by the following technical scheme: a mold for measuring the solidification rate of low-pressure casting of aluminum alloy, comprising an upper mold and a lower mold, wherein:

[0011] The upper mold is equipped with 19 thermocouple temperature measurement points, including: 6 first thermocouples located in the mold and extending to the aluminum liquid, each first thermocouple head has a thermocouple tip protection sleeve for protecting the thermocouple from aluminum liquid corrosion, 6 second thermocouples located at a depth of 1 mm from the aluminum liquid, 6 third thermocouples located at a depth of 7 mm from the aluminum liquid, and 1 fourth thermocouple located on the side of the upper mold; it also includes six cooling pipes for adjusting the cooling rate of the casting by water or air cooling to control the solidification rate of the casting; the upper mold is also provided with a diverter cone for stabilizing the flow of aluminum liquid, and is equipped with a sixth thermocouple to monitor its temperature;

[0012] The lower mold is provided with three cooling pipes symmetrically with respect to the casting, and is also provided with three fifth thermocouples located below the cooling pipes.

[0013] Furthermore, the lower die is provided with a middle pad which can be inserted or removed as required to adjust the thickness of the cavity to adapt to the casting specifications of 35 mm or 25 mm.

[0014] Furthermore, the upper die is provided with an upper die ejector rod to facilitate exhaust during the die-casting process and ejection of the casting.

[0015] Furthermore, the lower mold is used in combination with a pouring cup through a pouring sleeve to ensure that the temperature loss is reduced when the aluminum liquid enters the cavity from the melting furnace below the die-casting machine.

[0016] The present invention also proposes a method for implementing a mold for measuring the solidification rate of aluminum alloy low-pressure casting, comprising the following steps:

[0017] Step 1: Install the thermocouple and calibrate the thermocouple;

[0018] Step 2: Define experimental parameters and adjust the mold cooling system;

[0019] Step 3: Record temperature data in real time and conduct analysis and evaluation;

[0020] Step 4: Cut standard mechanical specimens and conduct mechanical property tests and microstructure characterization;

[0021] Step 5: Based on the experimental results, feedback is provided to production to optimize the experimental process and improve product quality.

[0022] Furthermore, the step 1 is specifically as follows:

[0023] S101: using a designed and manufactured low-pressure casting mold, wherein a plurality of temperature sensors have been installed inside the mold and distributed in key areas of the mold to monitor temperature changes during the casting process;

[0024] S102: Calibrate all temperature sensors in the mold to ensure the accuracy and reliability of the data, and perform preliminary temperature tests to verify the functionality of the sensors and the stability of the data acquisition system.

[0025] Furthermore, the step 2 is specifically as follows:

[0026] S201: define the experimental parameter settings, including casting temperature, pressure and cooling rate; explore the effect of solidification rate on casting properties according to different cooling rate settings;

[0027] S202: Adjust the cooling system of the mold to achieve different cooling rates and ensure that these settings are implemented in the existing mold system.

[0028] Furthermore, the step three is specifically as follows:

[0029] S301: During the low-pressure casting process, the temperature-time curves of all thermocouples are recorded in real time to analyze the effect of cooling rate on the solidification process;

[0030] S302: Analyze the collected temperature data to determine the changes in the mold temperature field at different cooling rates and evaluate how these changes affect the solidification rate and final microstructure of the casting.

[0031] Furthermore, the step 4 is specifically as follows:

[0032] S401: Cut standard specimens from the castings under each cooling rate condition and conduct mechanical property tests, including tensile strength, yield strength and elongation;

[0033] S402: Analyze the microstructure of the specimen, including grain size and defect distribution, using optical microscopy and scanning electron microscopy.

[0034] Furthermore, the step five is specifically as follows:

[0035] S501: adjusting casting parameters according to the experimental results to optimize the mechanical properties and microstructure of the casting, including adjusting the casting temperature or modifying the cooling rate setting;

[0036] S502: Prepare a detailed experimental report summarizing the specific effects of different solidification rates on casting properties.

[0037] Advantages of the present invention:

[0038] (1) The present invention provides a new type of mold design, which has a built-in high-precision temperature measurement system that can monitor temperature changes in real time at key locations, thereby accurately controlling the solidification rate. The mold uses high-precision K-type thermocouples as temperature measurement points, which are distributed at key locations of the casting to ensure that the solidification process of the entire casting is uniform and controllable. This is not only crucial for optimizing casting parameters and improving the solidification consistency of various parts of the casting, but also provides an important reference for parameter optimization and control during the production process, ensuring that the casting can meet higher quality standards and significantly improve the quality and production efficiency of the casting.

[0039] (2) The present invention can provide real-time feedback of solidification rate information, providing data support for temperature and rate control during low-pressure casting. This will not only make casting production higher quality, but also make the process more efficient, meeting the dual requirements of modern foundry industry for high performance and high economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0041] Figure 1 This is a flow chart of the method for measuring the solidification rate of A356 aluminum alloy low pressure casting according to the present invention;

[0042] Figure 2 It is a schematic diagram of the overall front view structure of the mold according to an embodiment of the present invention;

[0043] Figure 3 It is a schematic diagram of the overall cross-sectional structure of a mold according to an embodiment of the present invention;

[0044] Figure 4 A front view of an upper mold according to an embodiment of the present invention;

[0045] Figure 5 A cross-sectional view of an upper mold according to an embodiment of the present invention;

[0046] Figure 6 A front view of a lower mold according to an embodiment of the present invention;

[0047] Figure 7 It is a cross-sectional view of the lower mold of an embodiment of the present invention. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] Example 1

[0050] like Figure 2 As shown, the mold consists of an upper mold 2 and a lower mold 13, including a series of temperature measurement and cooling control systems to ensure the quality of the casting. Upper mold 2: It is equipped with 19 temperature measurement points, of which 6 are located in the mold and extend to the aluminum liquid. The head of each thermocouple 6 has a thermocouple tip protection sleeve 10 for protecting the thermocouple from aluminum liquid corrosion; 6 are located at a depth of 1 mm from the aluminum liquid 5, 6 are located at a depth of 7 mm from the aluminum liquid 7, and 1 is located on the side of the upper mold 15. These thermocouples ensure that the temperature from the aluminum liquid to different positions of the casting can be monitored in real time during the casting process. The upper mold also contains six cooling pipes 3 (cooling pipes with a diameter of 10 mm) for adjusting the cooling rate of the casting by water or air cooling to control the solidification rate of the casting. Lower mold 13: The lower mold is symmetrically provided with three cooling pipes (cooling pipes with a diameter of 10 mm) about the casting, and is also provided with three thermocouples 1 located below the cooling pipes for monitoring the cooling effect of the lower mold. The pad 14 in the lower die can be inserted or removed as needed to adjust the thickness of the cavity to adapt to the casting specifications of 35mm or 25mm. The temperature measurement point is connected to the central control system to collect temperature data in real time. The fluid flow rate in the cooling pipe is automatically adjusted by the control system according to the measurement data to ensure that the minimum cooling rate of the cavity is 5.89K / min and the maximum cooling rate is 80.12K / min. The upper die ejector 4 helps to exhaust and eject the casting during the die casting process. The diverter cone 8 is used to stabilize the flow of molten aluminum and is equipped with a thermocouple 9 to monitor its temperature. The sprue sleeve 11 is used in combination with the sprue cup 12 to ensure that the temperature loss of molten aluminum is minimized when entering the cavity from the smelting furnace below the die casting machine. Before casting begins, confirm that all thermocouples are well connected to the collector. When the molten aluminum is injected into the cavity, the monitoring point transmits temperature data to the collector in real time.

[0051] The mold of the present invention is designed with multi-point temperature monitoring: the mold is specially designed with an upper mold and a lower mold, including a total of 22 temperature measurement points, which are distributed in key areas (such as the aluminum liquid, the mold contact surface and the side of the casting) to comprehensively monitor the temperature changes during the casting process.

[0052] At the same time, the mold is equipped with a cooling pipe with a diameter of 10mm, which is located at the key position of the upper mold and the lower mold. By adjusting the flow rate of ventilation cooling or water cooling, the cooling speed can be precisely controlled, and the cooling speed adjustment can achieve a minimum of 5.89K / min and a maximum of 80.12K / min.

[0053] Again, the thickness of plate castings can be adjusted: the mold can adjust the thickness of plate castings through the pad, providing two thickness options of 35mm and 25mm, increasing the application range of the mold.

[0054] Example 2

[0055] like Figure 1 As shown, the present invention proposes a specific implementation method for mold design for measuring the solidification rate of A356 aluminum alloy low pressure casting, comprising:

[0056] Step 1: Install the thermocouple and calibrate the thermocouple;

[0057] Step 2: Define experimental parameters and adjust the mold cooling system;

[0058] Step 3: Record temperature data in real time and conduct analysis and evaluation;

[0059] Step 4: Cut standard mechanical specimens and conduct mechanical property tests and microstructure characterization;

[0060] Step 5: Based on the experimental results, feedback is provided to production to optimize the experimental process and improve product quality.

[0061] The specific implementation method of step one is as follows:

[0062] S101: Use a low-pressure casting mold that has been designed and manufactured. Multiple temperature sensors (such as K-type thermocouples) have been installed inside the mold, distributed in key areas of the mold to monitor temperature changes during the casting process;

[0063] S102: Calibrate all temperature sensors in the mold to ensure data accuracy and reliability. Perform preliminary temperature tests to verify sensor functionality and data acquisition system stability.

[0064] The specific implementation method of step 2 is as follows:

[0065] S201: Define the experimental parameter settings, including casting temperature, pressure and cooling rate. According to different cooling rate settings, such as 5℃ / s, 10℃ / s and 15℃ / s, explore the effect of solidification rate on casting properties;

[0066] S202: Adjust the cooling system of the mold, such as the flow rate of cooling water and cooling time, to achieve different cooling speeds. Ensure that these settings can be implemented in the existing mold system.

[0067] The specific implementation method of step three is as follows:

[0068] S301: During the low-pressure casting process, the temperature-time curves of all thermocouples are recorded in real time. These data will be used to analyze the effect of cooling rate on the solidification process;

[0069] S302: Analyze the collected temperature data to determine the changes in the mold temperature field at different cooling rates. Evaluate how these changes affect the solidification rate and final microstructure of the casting.

[0070] The specific implementation method of step 4 is as follows:

[0071] S401: Cut standard specimens from castings at each cooling rate condition and conduct mechanical property tests such as tensile strength, yield strength and elongation;

[0072] S402: Use optical microscopy and scanning electron microscopy (SEM) to analyze the microstructure of the sample, especially the grain size and defect distribution.

[0073] The specific implementation method of step five is as follows:

[0074] S501: Adjust casting parameters based on experimental results to optimize the mechanical properties and microstructure of the casting. This may include adjusting the casting temperature or modifying the cooling rate setting;

[0075] S502: Prepare a detailed experimental report summarizing the specific effects of different solidification rates on casting properties. Apply these findings to improve production processes and product quality.

[0076] The present invention utilizes existing molds and equipment, and by adjusting and optimizing casting parameters, not only improves the quality of castings, but also improves the efficiency and economy of production. It has important practical application value for the casting industry and can mainly achieve the following technical effects:

[0077] 1. Accurate solidification rate control

[0078] By integrating high-precision temperature sensors in key areas of the mold, real-time monitoring of temperature changes during the casting process is allowed, thereby achieving precise control of the solidification rate. This control ensures uniform temperature distribution of the casting throughout the solidification process, helping to prevent internal stress and defects such as pores and hot cracks caused by uneven cooling.

[0079] 2. Improve casting quality and consistency

[0080] Achieving fine control of the solidification rate can significantly improve the microstructural quality of the casting, reduce defects, and enhance mechanical properties. The castings exhibit better mechanical properties, including improved tensile strength and elongation, because control during the solidification process reduces stress concentrations within the material. In addition, the consistency of the solidification rate ensures repeatability and predictability from casting to casting, which is particularly important for large-scale production.

[0081] 3. Optimize post-processing and processing requirements

[0082] By precisely controlling the solidification process of the casting, the dimensional accuracy and surface quality of the casting are improved, thereby reducing the need for subsequent processing. This not only reduces processing costs, but also shortens the production cycle, making the entire production process more efficient.

[0083] 4. Reduce material waste and production costs

[0084] Due to the improvement of casting quality and the reduction of subsequent processing requirements, the scrap rate is significantly reduced. In addition, the precise temperature and solidification rate control reduces rework and scrap caused by casting quality problems, which directly reduces the consumption of raw materials and production costs.

[0085] 5. Improve production efficiency and flexibility

[0086] This technical solution enables faster and more precise production adjustments through real-time data feedback and temperature control. This flexibility allows the production line to quickly adapt to the needs of different casting designs, improving overall production efficiency.

[0087] 6. Enhance environmental adaptability and stability

[0088] By accurately controlling the solidification rate, the casting process is less sensitive to environmental changes, such as temperature fluctuations and humidity variations. This allows casting operations to maintain greater stability and reliability under different environmental conditions.

[0089] 7. Data-driven continuous improvement

[0090] Data collected in real time can support the continuous improvement and optimization of casting processes. This data-driven approach can continuously identify potential areas for improvement and promote technological innovation and process upgrades.

[0091] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A mold for measuring the solidification rate of aluminum alloy low-pressure casting, characterized in that: It comprises an upper die (2) and a lower die (13), wherein: The upper mold (2) is provided with 19 thermocouple temperature measurement points, including: 6 first thermocouples (6) located in the mold and extending to the aluminum liquid, each first thermocouple (6) having a thermocouple tip protection sleeve (10) at the head thereof for protecting the thermocouple from corrosion by the aluminum liquid, 6 second thermocouples (5) located at a depth of 1 mm from the aluminum liquid, 6 third thermocouples (7) located at a depth of 7 mm from the aluminum liquid, and 1 fourth thermocouple (15) located at the side of the upper mold; it also includes six cooling pipes (3) for adjusting the cooling rate of the casting by water or air cooling to control the solidification rate of the casting; the upper mold (2) is also provided with a diverter cone (8) for stabilizing the flow of the aluminum liquid, and is provided with a sixth thermocouple (9) for monitoring its temperature; The lower mold (13) is provided with three cooling pipes symmetrically with respect to the casting, and is also provided with three fifth thermocouples (1) located below the cooling pipes.

2. The mold for measuring the solidification rate of aluminum alloy low pressure casting according to claim 1, characterized in that: The lower die (13) is provided with a lower die center pad (14) which is inserted or removed as required to adjust the thickness of the die cavity to adapt to the casting specifications of 35 mm or 25 mm.

3. The mold for measuring the solidification rate of aluminum alloy low pressure casting according to claim 1, characterized in that: The upper die (2) is provided with an upper die ejector rod (4) to facilitate exhaust during the die-casting process and ejection of the casting.

4. The mold for measuring the solidification rate of aluminum alloy low pressure casting according to claim 1, characterized in that: The lower die (13) is used in combination with the pouring cup (12) through the pouring sleeve (11) to ensure that the temperature loss is reduced when the aluminum liquid enters the mold cavity from the melting furnace below the die-casting machine.

5. The implementation method of the mold for measuring the solidification rate of aluminum alloy low pressure casting is characterized in that: The following steps are involved: Step 1: Install the thermocouple and calibrate the thermocouple; Step 2: Define experimental parameters and adjust the mold cooling system; Step 3: Record temperature data in real time and conduct analysis and evaluation; Step 4: Cut standard mechanical specimens and conduct mechanical property tests and microstructure characterization; Step 5: Based on the experimental results, feedback is provided to production to optimize the experimental process and improve product quality.

6. The implementation method of the mold for measuring the solidification rate of aluminum alloy low-pressure casting according to claim 5, characterized in that: The step 1 is specifically as follows: S101: Use a low-pressure casting mold that has been designed and manufactured. Multiple temperature sensors have been installed inside the mold, distributed in key areas of the mold, to monitor temperature changes during the casting process; S102: Calibrate all temperature sensors in the mold to ensure data accuracy and reliability, and conduct preliminary temperature tests to verify sensor functionality and data acquisition system stability.

7. The implementation method of the mold for measuring the solidification rate of aluminum alloy low-pressure casting according to claim 5, characterized in that: The step 2 is specifically as follows: S201: Define the experimental parameter settings, including casting temperature, pressure and cooling rate; explore the effect of solidification rate on casting properties according to different cooling rate settings; S202: Adjust the cooling system of the mold to achieve different cooling rates and ensure that these settings are implemented in the existing mold system.

8. The implementation method of the mold for measuring the solidification rate of aluminum alloy low pressure casting according to claim 5, characterized in that: The step three is specifically as follows: S301: During the low-pressure casting process, the temperature-time curves of all thermocouples are recorded in real time to analyze the effect of cooling rate on the solidification process; S302: Analyze the collected temperature data to determine the changes in the mold temperature field at different cooling rates and evaluate how these changes affect the solidification rate and final microstructure of the casting.

9. The implementation method of the mold for measuring the solidification rate of aluminum alloy low pressure casting according to claim 5, characterized in that: The step 4 is specifically as follows: S401: Standard specimens were cut from the castings at each cooling rate and subjected to mechanical property tests, including tensile strength, yield strength and elongation; S402: Analyze the microstructure of the specimens, including grain size and defect distribution, using optical microscopy and scanning electron microscopy.

10. The implementation method of the mold for measuring the solidification rate of aluminum alloy low pressure casting according to claim 5, characterized in that: The step five is specifically as follows: S501: Adjust casting parameters according to experimental results to optimize the mechanical properties and microstructure of the casting, including adjusting the casting temperature or modifying the cooling rate setting; S502: Prepare a detailed experimental report summarizing the specific effects of different solidification rates on casting properties.

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