Alloy die-casting fluidity die capable of testing high-vacuum different wall thicknesses

Abstract

The invention discloses an alloy die-casting flowability die capable of testing high-vacuum different wall thicknesses. The die comprises a fixed die, a movable die and a die holder. Wherein the movable mold is provided with a cavity, and the cavity comprises an overflow groove, three flowability samples with different thicknesses, a material cake, a vacuum test groove, a shunting hole and an ESCs collector. In order to avoid turbulent air entrapment caused by a large corner and ensure that the tail end is communicated with the exhaust thin plate, the flowability channel is designed to be annular, the corner angle of the die is smooth and smooth, and shrinkage porosity, shrinkage cavity and air entrapment almost do not exist through intelligent casting super-cloud die flow analysis, so that the flowability of the alloy can be correctly reflected. In addition, the mold can also be used for testing the flowability of alloys with different thicknesses, and the flowing stopping length of the sample serves as the basis for judging the flowability. In conclusion, the flowability of the alloy under different wall thicknesses can be tested at the same time in the high-vacuum die-casting state, and the flowability of the alloy can be correctly reflected.

Description

Technical Field

[0001] The invention relates to the technical field of die-casting dies, in particular to a die-casting die for testing the fluidity of alloys with different wall thicknesses under high vacuum. Background Art

[0002] In recent years, as the integration and complexity of integrated die castings continue to increase, the size of the mold has become larger and larger, and the thickness differences of the components included have become more and more significant, which makes improving the fluidity of alloys an important challenge in the die casting industry, and the influencing factors related to this have become a corresponding research hotspot. Fluidity is a basic performance for evaluating the filling capacity of casting alloys. It is defined as the distance that the molten metal flows before solidification. The length of the metal liquid stopping flowing in the cavity can be used as a basis for judging the fluidity.

[0003] There are two main methods for testing the fluidity of die-casting alloys. The first is the Ragone method developed at MIT, also known as the vacuum suction column method. This method is to suck the alloy liquid into a room temperature ceramic tube at a given temperature, and this method is considered to be the most accurate method for studying the fluidity of alloys under gravity casting conditions (reference: John Campbell. Castings. Elsevier Science & Technology, 2003.). However, this method is not suitable for die-casting conditions, mainly because it cannot meet the high-speed and high-pressure requirements in the die-casting process, and has limitations in maintaining a vacuum state and gas discharge. The second method is a spiral fluidity test mold designed based on sand casting. For example, Han et al. designed a die-casting mold for returning to test fluidity and hot cracking, but this mold cannot communicate with the exhaust wave plate, cannot form a vacuum channel, and cannot accurately measure the true fluidity of the alloy (reference: Qingyou Han, Scripta Materialia 53 (2005) 7–10). With the continuous deepening of alloy fluidity research, many molds have evolved based on the spiral mold. For example, ABFile et al. designed a three-step fluidity mold, but the mold can only qualitatively evaluate the fluidity of the alloy and cannot provide accurate quantitative data (reference: ABFile et.al.NADCA Transactions, 2009, T09-031.); Chinese patent CN106513624A discloses a die-casting mold for alloy hot crack sensitivity coefficient and fluidity testing, but the corner of the fluidity channel is 180 degrees. This design will reduce the flow rate. Mold flow analysis shows that this design is prone to air entrapment and shrinkage holes at the corners. Ultimately, the fluidity of the alloy itself is seriously underestimated.

[0004] In the current integrated die-casting process, the flowing molten metal is filled at high speed under vacuum conditions, and it has to pass through different cavity wall thicknesses during the flow process. Therefore, in order to better meet the needs of die-casting production, it is necessary to develop a die-casting mold that can simultaneously test the fluidity of alloys with different wall thicknesses under high vacuum conditions. Summary of the invention

[0005] The present invention provides a die-casting fluidity mold for testing alloys with different wall thicknesses in high vacuum, which is used to test the fluidity of alloys with different wall thicknesses under vacuum conditions, and the length of the sample flow is used as a basis for judging the fluidity. The mold is provided with fluidity samples with three wall thicknesses, the ends of which are connected to an exhaust sheet and a vacuum test channel, and the fluidity of alloys with different wall thicknesses can be accurately tested under vacuum conditions.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A die-casting fluidity mold for testing alloys with different wall thicknesses in high vacuum, comprising:

[0008] A fixed mold, the fixed mold is arranged on the mold base;

[0009] A movable mold, wherein the movable mold is arranged on the mold base;

[0010] When the fixed mold and the movable mold are closed, the fixed mold and the movable mold abut against each other and a die casting cavity is formed between the fixed mold and the movable mold, and the die casting cavity is used to receive the metal liquid. When the mold is closed, the die casting machine injects the molten metal into the mold cavity under high pressure through the injection system. The injection speed and pressure will be adjusted according to the characteristics of the casting to ensure that the metal is filled completely. The molten metal cools and solidifies in the mold to form a casting. After the mold is opened, the ejector on the movable mold ejects the casting from the mold cavity with a certain force, and the die casting is completed.

[0011] Furthermore, the fixed mold includes a barrel, which is arranged on the fixed mold and is used to transport molten metal from the smelting furnace or the storage area to the mold.

[0012] Furthermore, the movable die includes a mounting hole, and the mounting hole is arranged on the fixed die, and the mounting hole is used to accurately dock the movable die with a movable die seat of the die-casting machine.

[0013] Furthermore, the movable mold includes a diverter cone, which is arranged on the movable mold and is used to control the flow direction and flow rate of the molten metal in the mold.

[0014] Furthermore, the movable mold includes a guide column, and the guide column is used to ensure accurate centering and positioning between the movable mold and the fixed mold.

[0015] Furthermore, the die-casting alloy fluidity mold for testing different wall thicknesses under high vacuum conditions also includes a cavity, which is arranged on the movable mold and includes an overflow groove, a fluidity sample with a thickness of 2 mm, a fluidity sample with a thickness of 3 mm, a fluidity sample with a thickness of 4 mm, a material cake, a vacuum test groove, a diversion hole, and two ESCs collectors. The material cake guides the molten metal from the nozzle of the injection system into the mold, and the molten metal can smoothly flow into the vertical runner of the mold through the channel of the material cake. The ESCs collectors designed at both ends of the vertical runner are a pair of symmetrically distributed hook-shaped structures designed at the narrowing point of the runner mouth, which can be used to collect coarse grain ESCs in the pressure chamber to reduce the number of large-sized grain ESCs entering the cavity, thereby playing a role in refining the grains and improving the organization. The molten metal enters three fluidity samples with different wall thicknesses from the runner under the high pressure applied by the injection machine, and the diversion hole is to balance the feeding speed and ensure the consistency of the initial feeding conditions of the three fluidity samples. The thickness of the fluidity test specimen is 2mm and the width is 6mm; the thickness of the fluidity test specimen is 3mm and the width is 9mm; the thickness of the fluidity test specimen is 4mm and the width is 12mm. These three fluidity test specimens with different thicknesses are used to test the fluidity of the alloy. The flow length of the molten metal after entering the fluidity test specimen from the inner gate can be used as a criterion for judging the fluidity. The vacuum test tank connected to the rear end of the fluidity test specimen is used to test the vacuum degree in the cavity. The tail ends of the three fluidity test specimens with different thicknesses are connected to the overflow tank. During the process of injecting molten metal into the mold, gas and inclusions may be brought into the mold. The overflow tank provides an outlet to allow these gases and inclusions to discharge from the mold, thereby reducing the impact of pores and inclusions on the quality of the casting, and can optimize metal flow, relieve pressure and reduce the impact of cold materials to ensure the integrity and performance of the casting.

[0016] A further improvement of the present invention is that the ESCs collectors designed at both ends of the cross runner are a pair of symmetrically distributed hook-shaped structures designed at the place where the runner mouth changes from wide to narrow, which can be used to collect coarse-grained ESCs in the pressure chamber to reduce the number of large-sized grains ESCs entering the cavity, thereby playing a role in refining the grains and improving the organization.

[0017] The further improvement of the present invention is that an overflow groove is designed at the very end, which provides an outlet for gas and inclusions during the process of molten metal being injected into the mold, allowing these gases and inclusions to be discharged from the mold, thereby reducing the impact of pores and inclusions on the quality of the casting, and optimizing metal flow, relieving pressure and reducing the impact of cold materials, ensuring the integrity and performance of the casting. In addition, overflow grooves of three different thicknesses and fluidities are designed separately to effectively prevent the occurrence of backflow.

[0018] A further improvement of the present invention is that the rear end of the fluidity sample is connected to a vacuum test slot, and a vacuum sensor can be inserted into the tail of the vacuum test slot to detect the vacuum degree of the cavity in real time, thereby testing the fluidity of the die-casting alloy under a high vacuum state.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] 1. The 180° large corner design of the previous fluidity mold will reduce the flow rate, which will seriously underestimate the fluidity of the alloy itself. In response to this, the mold was improved. Compared with the 180° corner, which is easy to produce shrinkage and shrinkage holes, the corner angle of the mold of the present invention is more gentle and smooth. After Zhizhu Chaoyun mold flow analysis, it was found that shrinkage and shrinkage holes are almost non-existent, and no air entrainment was found on the fluidity sample, so the fluidity of the alloy itself can be correctly reflected.

[0021] 2. Secondly, mechanical specimens can be taken from flow specimens, and there is no need to design tensile test bars. Tensile specimens can be cut along the flow direction to study the mechanical properties along the flow direction.

[0022] 3. This mold can not only study the effects of different process parameters and alloy components on fluidity, but also be used to test the fluidity of alloys at different thicknesses. The length of the sample that stops flowing is used as the basis for judging the fluidity. By understanding the fluidity of alloys under different conditions, the alloy formula and process flow can be optimized, and the performance and reliability of the material can be improved, which is of great significance in actual production.

[0023] 4. Ensure the simultaneity of feeding. Diverter holes are set in the main runner to balance the feeding state, ensuring the consistency of the initial feeding conditions of the three fluidity samples with different wall thicknesses after the molten metal passes through the runner under the high pressure applied by the injection molding machine. The subsequent Zhizhu Chaoyun mold flow analysis also confirmed the consistency of the feeding state. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplifications do not constitute limitations on the embodiments. Unless otherwise stated, the pictures in the drawings do not constitute proportional limitations.

[0025] Figure 1 A schematic diagram of a cavity structure of a die-casting mold for testing the fluidity of alloys with different wall thicknesses in high vacuum provided by an embodiment of the present invention.

[0026] Figure 2 A schematic diagram of the three-dimensional structure of a die-casting mold for testing the fluidity of alloys with different wall thicknesses under high vacuum provided by one embodiment of the present invention.

[0027] Figure 3 A schematic diagram of the exploded structure of a part of a die-casting mold for testing the fluidity of alloys with different wall thicknesses in a high vacuum provided by an embodiment of the present invention.

[0028] Figure 4 A front view of a movable mold structure of a high vacuum die-casting mold for testing the fluidity of alloys with different wall thicknesses provided by one embodiment of the present invention.

[0029] Figure 5 A front view of a fixed die structure during die casting of a high vacuum die casting mold capable of testing the fluidity of alloys with different wall thicknesses provided by one embodiment of the present invention.

[0030] Figure 6 A schematic diagram of the simulation of molten metal feeding state by the Zhizhu Chaoyun mold flow analysis software provided in one embodiment of the present invention.

[0031] Figure 7 A schematic diagram of simulating the formation of shrinkage porosity and shrinkage voids using the Zhizhu Chaoyun mold flow analysis software provided in one embodiment of the present invention.

[0032] Figure 8 A schematic diagram of simulating air entrainment generation using the Zhizhu Chaoyun mold flow analysis software provided in one embodiment of the present invention.

[0033] In the figure: 100-fixed mold; 110-barrel;

[0034] 200-movable mold, 210-movable mold base, 211-mounting hole, 220-diverter cone, 230-guide column, 240-cavity, 241-overflow groove, 242-fluidity sample with a thickness of 2 mm, 243-fluidity sample with a thickness of 3 mm, 244-fluidity sample with a thickness of 4 mm, 245-cake, 246-vacuum test tank, 247-diverter hole, 248-ESCs collector. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The elements and features described in one embodiment of the present invention may be combined with the elements and features shown in one or more other embodiments. It should be noted that for the purpose of clarity, the representation and description of components and processes that are not related to the present invention and are known to those of ordinary skill in the art are omitted in the description. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present invention.

[0036] The present invention is further described below in conjunction with the accompanying drawings:

[0037] The present invention is a die-casting mold for testing the fluidity of alloys with different wall thicknesses in high vacuum.

[0038] like Figures 1 to 5 As shown, an alloy die-casting fluidity mold capable of testing different wall thicknesses in high vacuum is provided in one embodiment of the present invention for die-casting metal liquid; in this embodiment, an alloy die-casting fluidity mold capable of testing different wall thicknesses in high vacuum comprises a fixed mold 100 and a movable mold 200, the fixed mold 100 and the movable mold 200 are precisely aligned through the mounting hole 211 and the guide column 230 on the fixed mold 100, and after the molds are closed, the fixed mold 100 and the movable mold 200 form a die-casting cavity 240, and the die-casting cavity 240 is used to receive the metal liquid. When the mold is closed, the die-casting machine injects the molten metal into the mold cavity under high pressure through the injection system. The injection speed and pressure will be adjusted according to the characteristics of the casting to ensure that the metal is filled completely. The molten metal is cooled and solidified in the mold to form a casting. After the metal liquid fills the cavity 240, after a period of time, the fixed mold 100 and the movable mold 200 are opened, and the casting can be ejected by means of an ejector to complete demolding.

[0039] When the metal liquid has finished filling the cavity 240, after a period of time, the fixed mold 100 and the movable mold 200 are opened, and the casting can be ejected by means of an ejector to complete demolding.

[0040] In a further embodiment, a diverter cone is provided on the movable mold 200, and a diverter cone 220 is provided on the movable mold. The diverter cone 220 is used to control the flow direction and flow rate of the metal melt in the mold.

[0041] In some embodiments, a guide column 230 is provided on the movable mold 200, and the fixed mold 100 and the movable mold 200 are connected through the guide column 230. Specifically, when the molds are closed, the fixed mold 100 and the movable mold 200 are aligned under the guidance of the guide column 230.

[0042] In a further embodiment, a cavity 240 is provided on the movable mold 200, and the cavity 240 is provided on the movable mold 200, and includes an overflow groove 241, a fluidity sample 242 with a thickness of 2 mm, a fluidity sample 243 with a thickness of 3 mm, a fluidity sample 244 with a thickness of 4 mm, a material cake 245, a vacuum test groove 246, a diversion hole 247, and two ESCs collectors 248. The material cake 245 guides the molten metal from the nozzle of the injection system into the mold, and the molten metal can smoothly flow into the vertical runner of the mold through the channel of the material cake 245. The ESCs collectors 248 designed at both ends of the vertical runner are a pair of symmetrically distributed hook-shaped structures designed at the narrowing point of the runner mouth, which can be used to collect the coarse grain ESCs in the pressure chamber to reduce the number of large-sized grain ESCs entering the cavity, thereby playing a role in refining the grains and improving the organization. Under the high pressure applied by the injection molding machine, the molten metal enters three fluidity samples with different wall thicknesses from the runner, where the diverter hole 247 is to balance the feeding speed and ensure the consistency of the initial feeding conditions of the three fluidity samples. The three fluidity samples with different thicknesses, 2mm thick and 6mm wide, 3mm thick and 9mm wide, and 4mm thick and 12mm wide, are used to test the fluidity of the alloy. The flow length of the molten metal after entering the fluidity sample from the inner gate can be used as a criterion for judging the fluidity. The vacuum test tank 246 connected to the rear end of the fluidity sample is used to test the vacuum degree in the cavity. The tail ends of the three fluidity samples with different thicknesses are connected to the overflow tank 241. During the process of molten metal being injected into the mold, gas and inclusions may be brought into the mold. The overflow tank 241 provides an outlet to allow these gases and inclusions to discharge from the mold, thereby reducing the impact of pores and inclusions on the quality of the casting, and can optimize metal flow, relieve pressure and reduce the impact of cold materials, ensuring the integrity and performance of the casting.

[0043] like Figures 6 to 8 As shown, a diversion hole is set in the main runner to balance the feeding state, ensuring the consistency of the initial feeding conditions of the molten metal entering the three fluidity samples with different wall thicknesses after passing through the runner under the high pressure applied by the injection molding machine. Figure 6 The mold flow analysis of Zhizhu Chaoyun also confirmed the consistency of the feeding state. The 180° large corner design of the previous fluidity mold would reduce the flow rate, which would seriously underestimate the fluidity of the alloy itself. In response to this, the mold was improved. Compared with the 180° corner, which is prone to shrinkage and shrinkage, the corner angle of the mold of the present invention is more gentle and smooth. Figure 7 Zhizhu Chaoyun mold flow analysis found that shrinkage and shrinkage holes are almost non-existent. Figure 8 In Zhizhu Chaoyun's air entrainment simulation, no air entrainment is formed on the fluidity sample, so the fluidity of the alloy itself can be correctly reflected.

[0044] The present invention discloses a die-casting fluidity mold for testing alloys with different wall thicknesses in high vacuum, the mold comprising a fixed mold, a movable mold, and a mold base. The movable mold is provided with a cavity, the cavity comprising an overflow groove, a fluidity sample with a thickness of 2 mm, a fluidity sample with a thickness of 3 mm, a fluidity sample with a thickness of 4 mm, a material cake, a vacuum test groove, a diversion hole, and two ESCs collectors. In order to avoid turbulent air entrainment caused by large corners and ensure that the end is connected to the exhaust thin plate, the present invention designs the fluidity channel into a ring shape, and the corner angle of the mold is also gentle and smooth. Compared with the 180° corner, shrinkage and shrinkage cavities are prone to occur, and the corner angle of the mold of the present invention is more gentle and smooth, and after Zhizhu Chaoyun mold flow analysis, it is found that shrinkage and shrinkage cavities are almost non-existent, and there is no air entrainment in the mold flow analysis, so the fluidity of the alloy itself can be correctly reflected. Secondly, mechanical samples can be taken on the fluidity samples, and there is no need to design a tensile test bar. The tensile sample can be cut along the flow direction to study the mechanical properties along the flow direction. In addition, the mold can not only study the effects of different process parameters and different alloy components on fluidity, but also be used to test the fluidity of alloys at different thicknesses, and the length at which the sample stops flowing is used as the basis for judging the fluidity. By understanding the fluidity of the alloy under different conditions, the alloy formula and process flow can be optimized, and the performance and reliability of the material can be improved, which is of great significance in actual production. In terms of fluidity accuracy, the design of the mold ensures the consistency of the feeding state, and diverter holes are set in the main runner to balance the feeding speed and temperature, ensuring that the molten metal enters the three fluidity samples with different wall thicknesses through the vertical runner under the high pressure applied by the injection molding machine. The initial feeding conditions are consistent. The subsequent Zhizhu Chaoyun mold flow analysis also confirmed the consistency of the feeding state. In summary, the present invention can simultaneously test the fluidity of alloys with three different wall thicknesses under high vacuum die-casting conditions, and can correctly reflect the fluidity of the alloy itself.

[0045] Finally, it should be noted that: although the present invention and its advantages have been described in detail above, it should be understood that various changes, substitutions and transformations can be made without exceeding the spirit and scope of the present invention as defined by the appended claims. Moreover, the scope of the present invention is not limited to the specific embodiments of the processes, devices, means, methods and steps described in the specification. It will be easily understood by those of ordinary skill in the art from the disclosure of the present invention that existing and future processes, devices, means, methods or steps that perform substantially the same functions as the corresponding embodiments described herein or obtain substantially the same results as the corresponding embodiments described herein can be used according to the present invention. Therefore, the appended claims are intended to include such processes, devices, means, methods or steps within their scope.

Claims

1. A die-casting fluidity mold for alloys with different wall thicknesses under high vacuum, wherein the mold cavity comprises three fluidity test channels of different thicknesses connected to a vacuum system, a vacuum test slot connected to the channels, and a gate for ensuring that the metal liquid enters the three test channels at the same time; when the fixed mold and the movable mold are closed, the fixed mold and the movable mold abut against each other and a die-casting cavity is formed between the fixed mold and the movable mold, and the die-casting cavity is used to receive the metal liquid. When the mold is closed, the die-casting machine injects the molten metal into the mold cavity under high pressure through the injection system; the injection speed and pressure are adjusted according to the characteristics of the casting to ensure that the metal is completely filled, and the molten metal is cooled and solidified in the mold to form a casting. After the mold is opened, the ejector pin on the movable mold ejects the casting from the mold cavity by a certain force, and the die-casting is completed.

2. The alloy die-casting fluidity mold capable of testing high vacuum with different wall thicknesses according to claim 1, characterized in that: The fixed mold includes a barrel, which is arranged on the fixed mold and is used to transport molten metal from a smelting furnace or a material storage area to the mold.

3. The alloy die-casting fluidity mold capable of testing high vacuum with different wall thicknesses according to claim 1, characterized in that: The movable mold includes a mounting hole, which is arranged on the fixed mold and is used to accurately connect the movable mold with the movable mold seat of the die-casting machine; the movable mold includes a guide column, which is used to ensure accurate centering and positioning between the movable mold and the fixed mold.

4. The alloy die-casting fluidity mold capable of testing high vacuum with different wall thicknesses according to claim 1, characterized in that: The alloy die-casting fluidity mold capable of testing different wall thicknesses in high vacuum also includes a cavity, which is arranged on the movable mold, and the die-casting cavity is used to receive molten metal to form a casting.

5. The alloy die-casting fluidity mold capable of testing high vacuum with different wall thicknesses according to claim 4, characterized in that: The cavity includes a material cake, which guides molten metal from the nozzle of the injection system into the mold. Through the channel of the material cake, the molten metal can smoothly flow into the vertical runner of the mold.

6. The alloy die-casting fluidity mold capable of testing high vacuum with different wall thicknesses according to claim 4, characterized in that: The cavity includes two ESCs collectors, which are a pair of symmetrically distributed hook-shaped structures designed at the narrowing point of the flow channel. The ESCs collectors can be used to collect coarse grain ESCs in the pressure chamber to reduce the number of large-sized grain ESCs entering the cavity, thereby refining the grains and improving the organization.

7. The alloy die-casting fluidity mold capable of testing high vacuum with different wall thicknesses according to claim 4, characterized in that: The cavity includes a diverter hole, which is used to control the flow direction and flow rate of the metal melt in the mold, balance the feeding speed, and ensure the consistency of the initial feeding conditions of the three fluidity samples.

8. The alloy die-casting fluidity mold capable of testing high vacuum with different wall thicknesses according to claim 4, characterized in that: The cavity includes fluidity samples with a thickness of 2 mm and a width of 6 mm, a fluidity sample with a thickness of 3 mm and a width of 9 mm, and a fluidity sample with a thickness of 4 mm and a width of 12 mm. These three fluidity samples with different thicknesses are used to test the fluidity of the alloy. The flow length of the molten metal after entering the fluidity sample from the inner gate can be used as a standard for judging the fluidity.

9. The alloy die-casting fluidity mold capable of testing high vacuum with different wall thicknesses according to claim 8, characterized in that: The cavity includes a vacuum test slot, which is connected to the rear end of the fluidity sample. A vacuum sensor can be inserted into the rear end of the vacuum test slot to detect the vacuum degree of the cavity in real time, thereby testing the fluidity of the die-casting alloy under a high vacuum state.

10. The alloy die-casting fluidity mold capable of testing high vacuum with different wall thicknesses according to claim 8, characterized in that: The cavity includes an overflow groove, which is connected to the tail ends of three fluidity samples with different thicknesses. When molten metal is injected into the mold, gas and inclusions may be brought into the mold; the overflow groove provides an outlet to allow these gases and inclusions to discharge from the mold, thereby reducing the impact of pores and inclusions on the quality of the casting, and can optimize metal flow, relieve pressure and reduce the impact of cold materials, ensuring the integrity and performance of the casting, and the overflow grooves of three different fluidity thicknesses are designed separately to effectively prevent the occurrence of backflow.

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