A method for fine-grain strengthening of aluminum bronze alloys, aluminum bronze alloys

Abstract

This application relates to the field of alloy materials technology, and provides a method for refining the grain size of aluminum bronze alloys and an aluminum bronze alloy. By adding a boron-iron alloy for modification treatment during the smelting process of aluminum bronze raw materials, using iron as a carrier, it is easier for the alloy to integrate into the aluminum bronze and form δ-particles within it, thus refining the grain size. Compared to other modifiers applied to aluminum bronze, the alloying effect is better. Furthermore, by using a casting cavity with a chilling material for pouring the molten aluminum bronze, the supercooling of the casting is increased, further improving the grain size of the material. In the post-treatment process after the casting solidifies, to inhibit further grain growth and obtain specific phases and structures, rapid cooling is performed within a temperature range of 500-700°C, significantly strengthening the matrix structure.

Description

Technical Field

[0001] This application belongs to the field of alloy materials technology, and in particular relates to a method for fine-grain strengthening of aluminum bronze alloy and aluminum bronze alloy. Background Technology

[0002] Aluminum bronze is a copper alloy with aluminum as the main strengthening element. It has a long history and its mechanical properties are higher than brass and tin bronze. Cu-Al binary alloys with an aluminum content of 5%-7% can generally be cold-worked, while aluminum bronze with an aluminum content >7% requires hot working. For deep drawing dies and some wear-resistant applications, the aluminum content can be >14%. Commonly used aluminum bronzes have an aluminum content between 5% and 12% and are used in gears, bushings, propellers, pumps, valve bodies, worm gears, and other parts requiring high wear resistance and corrosion resistance.

[0003] Aluminum bronze has superior mechanical properties compared to phosphor bronze, enabling it to withstand heavy-duty wear conditions. However, its higher coefficient of friction limits its application in continuous friction environments, such as bearings. Under lubricated conditions, aluminum bronze exhibits a significantly lower wear rate than lead and tin bronze, but slightly higher than beryllium bronze. Under unlubricated conditions, its low adhesion makes it superior to other copper alloys when used with steel.

[0004] However, existing aluminum bronze alloys suffer from low strength and poor elongation. Summary of the Invention

[0005] The purpose of this application is to provide a method for strengthening aluminum bronze alloys by refining their grains, thereby addressing the problems of low strength and poor elongation in existing aluminum bronze alloys.

[0006] The embodiments of this application are implemented as follows: a method for fine-grain strengthening of aluminum bronze alloys includes:

[0007] Boron-iron alloy is added during the smelting process of aluminum bronze raw materials to carry out modification treatment, thereby obtaining aluminum bronze smelting liquid; the amount of boron-iron alloy added is 0.1%-0.15% of the smelting weight;

[0008] The aluminum bronze molten metal is poured into a casting cavity with a chilling material to obtain an aluminum bronze casting.

[0009] During the solidification and forming process of the aluminum bronze casting, when the aluminum bronze casting cools to 500-700℃, it undergoes an unpacking and cooling treatment to obtain an aluminum bronze alloy.

[0010] Another objective of this application is to provide an aluminum bronze alloy, which is prepared by the aforementioned aluminum bronze alloy fine-grain strengthening method.

[0011] The method for refining the grain size of aluminum bronze alloy provided in this application involves adding a boron-iron alloy for modification treatment during the smelting process of aluminum bronze raw materials. Using iron as a carrier, it is easier to integrate into aluminum bronze and can form δ particles in the aluminum bronze, thus refining the grain size. Compared with other modifiers acting on aluminum bronze, the alloying effect is better. In addition, by using a casting cavity with a chilling material for pouring the molten aluminum bronze, the supercooling of the casting is increased, further improving the grain size of the material. In the post-treatment process of the casting solidification, in order to inhibit further grain growth and obtain specific phases and structures, rapid cooling is performed in the temperature range of 500-700℃, which significantly strengthens the matrix structure.

[0012] This application combines three processes: modification treatment in the smelting process, quenching in the molding process, and rapid cooling within a controlled temperature range in the solidification process. This combination provides a nucleation drive for increasing the number of nuclei, creating supercooling, and suppressing grain growth. The resulting product exhibits excellent production performance. The aluminum bronze alloy produced using this application has significantly smaller grains than aluminum bronze produced by existing processes, resulting in higher strength, better toughness and elongation, and superior impact resistance and wear resistance. Attached Figure Description

[0013] Figure 1 These are comparative morphological images of the grain size of the C95900 alloy provided in the embodiments of this application and the C95900 alloy obtained without using the fine grain strengthening process technology of this application.

[0014] Figure 2 This is a comparison diagram of grain refinement of C95900 aluminum bronze alloy obtained by using boron-copper alloy as a modifier and C95900 aluminum bronze alloy obtained by using boron-iron alloy as a modifier, provided in the embodiments of this application. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0016] To address the problems of low strength and poor elongation in existing aluminum bronze alloys, this application provides a method for strengthening aluminum bronze alloys by refining their grains. This method involves adding a boron-iron alloy during the smelting process of aluminum bronze raw materials to perform a modification treatment, resulting in an aluminum bronze molten liquid. The molten aluminum bronze is then poured into a casting cavity equipped with a chilling material to obtain an aluminum bronze casting. During the solidification process of the aluminum bronze casting, when the casting cools to 500-700°C, it undergoes an unpacking and cooling treatment to obtain an aluminum bronze alloy.

[0017] In the embodiments of this application, during the smelting process, the amount of ferroborone added is 0.1%-0.15% of the smelting weight; if the amount of ferroborone added is too small (below 0.1%), the modification effect is not obvious, and if the amount added is too large (above 0.15%), it is difficult to dissolve and absorb, and black spots are likely to appear on the surface of the casting.

[0018] Specifically, the aluminum bronze smelting equipment uses a medium-frequency induction furnace. The raw materials are batched according to the composition of the target material plus the loss due to burning. The main raw materials for aluminum bronze are copper, pure aluminum, low-carbon steel, and metallic manganese. During the batching process, a boron-iron alloy with a boron content of 13% is added. With the help of the electromagnetic stirring effect of the induction furnace, it is well fused into the alloy liquid during the smelting process. The smelting temperature is 1150-1200℃. The composition is adjusted and the temperature is maintained to stabilize the quality of the molten metal. The pouring temperature is around 1190℃. After the furnace inspection is completed, it is ready for pouring. Through the modification effect of boron-iron, the aluminum bronze molten metal provides the necessary non-spontaneous nucleation conditions during the solidification process.

[0019] In this embodiment, during the casting process, a large amount of high thermal conductivity materials are used as chills, such as graphite blocks, silicon carbide materials, or sprayed copper alloys. If casting large flat aluminum bronze plates, a cast iron plate with a thickness >150mm can be used as the bottom. All quenching devices must be used in conjunction with risers. The purpose of using these cooling blocks is to reduce the casting modulus of the casting, and it is important to ensure that the feeding function of the risers is not affected.

[0020] Specifically, the chilling material used in the casting process should be selected based on the casting technology. Here, graphite blocks or silicon carbide, with high thermal conductivity, are chosen as the chilling material. Graphite has a thermal conductivity of 151 W / (m·K), and silicon carbide has a thermal conductivity of 83.6 W / m·K. In contrast, cast iron and cast steel have thermal conductivity of only 40-60 W / (m·K). Graphite has a melting point of 3850±50℃ and a boiling point of 4250℃. Even after being subjected to ultra-high temperature arc burning, the weight loss is minimal, and its coefficient of thermal expansion is also very small. Graphite strength increases with temperature; at 2000℃, its strength doubles. Graphite products have excellent thermal conductivity and thermal shock resistance. Therefore, graphite blocks are a better chilling material than cast steel or cast iron, and their application size should be no less than 2 / 3 of the thickness at the hot spot requiring chilling. The casting process for aluminum bronze employs a bottom-pouring gating system. A riser is placed on top of the casting, while chilling material is placed on the bottom and sides of the casting, using as much as possible. Precautions: 1) Chilling material cannot be used on the top surface, as this will affect the feeding effect of the riser. 2) When applied to the sides, check whether it will obstruct the feeding channel of the molten metal. 3) When applying a large area to the bottom surface, fully consider the reduction in horizontal feeding distance and promptly replenish the number of top risers. The size specifications for chilling material selection are as follows: For casting thickness less than 100mm, select chilling material with a thickness of 50-100mm. Available dimensions are: 100*100*50, 100*100*60, etc. Graphite or silicon carbide with dimensions such as 00*100*80 and 400*100*80 can be used as chillers. If the thickness of the casting is greater than 100mm, high-density graphite or silicon carbide can be selected, with dimensions of 100*100*100, 200*200*100, 200*200*150, 400*200*150, etc. In addition, for cost considerations, cast iron plates with a thickness greater than 150mm can be selected as chilling materials. For example, one or several 2000*1500*150 or 2000*750*150 cast iron plates can be selected as the base box according to the size of the casting. Increasing the use of chilling materials can reduce the modulus of the casting itself. The lower box is a chilling material, which can provide supercooling for rapid cooling. This is a key measure to promote spontaneous nucleation.

[0021] During the cooling process of castings, controlling the solidification rate within a specific temperature range is crucial to prevent grain growth and the eutectoid reaction of aluminum bronze. This necessitates opening the casting bath for cooling 30-60 minutes after riser solidification, depending on the product's dimensions and tooling characteristics. While most castings are allowed to cool naturally for several hours before cleaning, high-performance aluminum bronzes must be opened much earlier to prevent grain growth and eutectoid reactions that could degrade material properties. Therefore, a specific temperature range is critical. Opening the bath at temperatures above 700℃ can easily lead to cracking and deformation, while opening it below 500℃ has minimal impact on the microstructure and properties. The optimal temperature range is approximately 500-650℃, and riser solidification typically occurs within this range within 30-60 minutes, though the exact range depends on the specific product characteristics.

[0022] Specifically, despite the aforementioned smelting modification treatment and rapid cooling casting methods, the initial grains may still continue to grow over time under prolonged heat preservation after casting, further pursuing optimal grain size and performance. Controlling the cooling time after unpacking can further inhibit continued grain growth. For aluminum bronze alloys, after casting, air cooling can be performed 30-60 minutes after the riser solidifies. The ideal temperature for unpacking is 500-700℃. The specific procedure is as follows: After 30 minutes of riser solidification, clean out a corner of the casting to expose the main body, and use a forging infrared thermometer to check the casting temperature. Unpacking too early (casting temperature below 500℃) can result in insufficient thermal strength or incomplete solidification, easily leading to cracking or even scrapping. Unpacking too late (casting temperature above 700℃) is ineffective or may cause eutectoid reactions in the aluminum bronze, increasing alloy brittleness and reducing strength. Aluminum bronze with an aluminum content below 11% can be cooled by water mist, while aluminum bronze alloys with an aluminum content above 11% can be rapidly cooled by a fan. This step is an important measure to suppress grain growth and prevent the formation of brittle eutectoids that could degrade alloy properties.

[0023] The following are embodiments of some implementations of this application, which are not intended to limit the scope of this application.

[0024] Example 1: Production of Cu-Al-Mn series alloys, such as national standard grade CuAl9Mn2 alloy castings or plates, with dimensions of 1500*500*50mm. Melting equipment: Medium-frequency coreless induction furnace. Raw materials: 9.5% pure aluminum ingots, 2% metallic manganese flakes, the remainder being electrolytic copper. All materials are cut into small pieces as much as possible. The modifier ferroboron (FeB 13) is used in a 0.1% amount, and the mixture is prepared as powder.

[0025] Step 1: First, add aluminum ingots, then place metallic manganese on top of the ingots, and fill the remaining space with electrolytic copper, ensuring as few gaps as possible are left in the furnace. Begin smelting and gradually add electrolytic copper until it is completely melted into a liquid state. Add ferroborone alloy, controlling the smelting temperature below 1200℃ to prevent the molten metal from absorbing gas. Begin sampling to adjust the chemical composition. After the composition and furnace pre-testing are completed, wait for casting. The casting temperature is 1190℃.

[0026] Step Two: The simultaneous molding process is as follows: Prepare the casting mold and the necessary gating and riser system. The chilling material is selected as graphite blocks. A bottom-pouring gating system is used. The riser is placed on the top. The chilling material is placed at the bottom and sides of the casting. The bottom is lined with 400*100*80mm graphite blocks, and the sides are lined with 100*100*50mm graphite blocks. The graphite blocks can be made from either the thick or wide side. The gap between the graphite blocks is 10-20mm. Furan resin sand is used for molding. After the resin sand has solidified, the mold is removed to form a casting cavity with chilling material. Zircon powder coating is applied and dried. The mold is cleaned and closed, ready for pouring.

[0027] Step 3: After pouring, wait 30 minutes after the riser solidifies, clean out one corner of the casting body, use an infrared thermometer to detect the temperature, and open the box for cooling when the temperature cools down to 600-700℃. For CuAl9Mn2 alloy, an axial flow fan can be used for rapid cooling until the temperature of the casting body is below 200℃.

[0028] Example 2: Production of Cu-Al-Fe aluminum bronze alloy, such as national standard grade CuA110Fe3 or American grade C95200 alloy castings or plates, with dimensions of 1500*500*80mm. Smelting equipment: Medium-frequency coreless induction furnace. Raw materials: 10.6% pure aluminum ingots, 3.4% low-carbon steel sheets, the remainder being electrolytic copper. All materials are cut into small pieces as much as possible. The modifier ferroboron (FeB13) is used at 0.12%, and the materials are crushed into powder form.

[0029] Step 1: First, add aluminum ingots, then place low-carbon steel sheets on top of the ingots, filling the remaining space with electrolytic copper, ensuring as few gaps as possible are left in the furnace. Begin smelting and gradually add electrolytic copper until it is completely melted into a liquid state. Add ferroborone alloy, controlling the smelting temperature below 1200℃ to prevent the molten metal from absorbing gas. Begin sampling to adjust the chemical composition. After the composition and furnace pre-testing are completed, wait for casting. The casting temperature is 1170℃.

[0030] Step Two: The simultaneous molding process is as follows: Prepare the casting mold and the necessary gating and riser system. The chilling material is selected as graphite blocks. A bottom-pouring gating system is adopted. The riser is placed on the top. The chilling material is placed at the bottom and sides of the casting. The bottom is lined with 400*100*80mm graphite blocks, and the sides are lined with 100*100*60mm graphite blocks. The graphite blocks can be made from either the thick or wide side. The gap between the graphite blocks is 10-20mm. Furan resin sand is used for molding. After the resin sand has solidified, the mold is removed to form a casting cavity with chilling material. Zircon powder coating is applied and dried. The mold is cleaned and closed, ready for pouring.

[0031] Step 3: Because this alloy has a slightly high aluminum content, slow cooling below 560℃ will cause a eutectoid reaction, which will deteriorate the material's performance, reduce its tensile strength and elongation after fracture. Therefore, it should be unpacked in the range of 600-700℃. At 600℃, it should be cooled quickly by an axial fan, and the effect of water mist will be better.

[0032] Example 3: Production of Cu-Al-Fe-Mn series alloys, such as national standard grade CuAl10Fe3Mn2 alloy castings or plates, with dimensions of 1500*500*100mm. Melting equipment: medium-frequency coreless induction furnace. Raw materials: 10.5% pure aluminum ingots, 3.5% low-carbon steel sheets, 2% metallic manganese, and the remainder is electrolytic copper. All materials are cut into small pieces as much as possible. The amount of modifier ferroboron (FeB13) is 0.13%. The materials are crushed into powder form.

[0033] Step 1: First, add aluminum ingots, then place low-carbon steel sheets on top, followed by metallic manganese. Fill the remaining space with electrolytic copper, ensuring minimal gaps in the furnace. Begin smelting and gradually add electrolytic copper until completely molten. Add ferroborone alloy, controlling the smelting temperature below 1200℃ to prevent gas absorption by the molten metal. Begin sampling to adjust the chemical composition. After composition and furnace pre-testing are completed, await casting at 1180℃.

[0034] Step Two: The simultaneous molding process is as follows: Prepare the casting mold and the necessary gating and riser system. Select graphite blocks as the chilling material. Use a bottom-pouring gating system. Place the riser at the top. Position the chilling material at the bottom and sides of the casting. Use 400*100*80mm graphite blocks to line the bottom box. Use 100*100*80mm graphite blocks on the sides. The graphite blocks can be made from either the thick or wide side. The gap between the graphite blocks is 10-20mm. Mold with furan resin sand. After the resin sand has solidified, remove the mold to form a casting cavity with the chilling material. Apply zircon powder coating and dry it. Clean and close the mold to prepare for pouring.

[0035] Step 3: Since manganese has been added to this alloy, the performance degradation due to slow cooling is better than that of the alloy in Example 2. However, slow cooling below 480°C will also cause a eutectoid reaction, which will reduce the tensile strength and elongation after fracture of the material. Therefore, it is also unpacked in the range of 600-700°C. At 600°C, it is necessary to cool it quickly with an axial fan.

[0036] Example 4: Production of Cu-Al-Fe-Ni(-Mn) series alloys, such as the national standard grade CuAl10Fe4Ni4 alloy, CuAl9Fe4Ni4Mn2, and American grades C95510, C95500, C95520, etc., castings or plates, with dimensions of 1500*500*100mm. Smelting equipment: Medium-frequency coreless induction furnace. Raw materials: 10.8% pure aluminum ingots, 4-5% low-carbon steel sheets, 4.5% nickel plates, 1.5-2% metallic manganese, with the remainder being electrolytic copper. All materials are cut into small pieces as much as possible. The modifier ferroboron (FeB13) is used at 0.13%, and the materials are crushed into powder. Due to the high melting point of nickel, it is generally recommended to use an intermediate alloy.

[0037] Step 1: First, add aluminum ingots, place low-carbon steel sheets on top of the ingots, then add nickel plates and metallic manganese, and a small amount of electrolytic copper plates. Directly heat and smelt at 1350℃. Once the nickel, iron, and aluminum are completely melted into a liquid intermediate alloy, add electrolytic copper and smelt, adjusting the smelting temperature to 1190℃ until all materials are completely melted into a liquid state. Then, start adding ferroborone alloy, controlling the smelting temperature below 1200℃ to prevent the molten metal from absorbing gas. Take samples to adjust the chemical composition. After the composition and furnace pre-testing are completed, wait for casting at 1190℃.

[0038] Step Two: The simultaneous molding process is as follows: Prepare the casting mold and the necessary gating and riser system. The chilling material is selected as graphite blocks. A bottom-pouring gating system is used. The riser is placed on the top. The chilling material is placed at the bottom and sides of the casting. The bottom is lined with 400*100*80mm graphite blocks, and the sides are lined with 100*100*80mm graphite blocks. The graphite blocks can be made from either the thick or wide side. The gap between the graphite blocks is 10-20mm. Furan resin sand is used for molding. After the resin sand has solidified, the mold is removed to form a casting cavity with the chilling material. Zircon powder coating is applied and dried. The mold is cleaned and closed, ready for pouring.

[0039] Step 3: Since manganese has been added to this alloy, the performance degradation due to slow cooling is better than that of the alloy in Example 2. However, slow cooling below 480°C will also cause a eutectoid reaction, which will reduce the tensile strength and elongation after fracture of the material. Therefore, it is also unpacked in the range of 600-700°C. At 600°C, it is necessary to cool it quickly with an axial fan.

[0040] Example 5: Production of high-aluminum-content US grade C95900 alloy castings or plates, 1500*500*150mm in size. Melting equipment: Medium-frequency coreless induction furnace. Raw materials: 13.6% pure aluminum ingots, 4.8% low-carbon steel sheets, 1.3% metallic manganese, with the remainder being electrolytic copper. All materials were cut into small pieces as much as possible. The modifier ferroboron (FeB13) was used at 0.15%, and the materials were crushed into powder form.

[0041] Step 1: First, add aluminum ingots, then place low-carbon steel sheets on top, followed by metallic manganese. Fill the remaining space with electrolytic copper, ensuring minimal gaps in the furnace. Begin smelting, gradually adding electrolytic copper until completely molten. Add ferroborone alloy, controlling the smelting temperature below 1200℃ to prevent gas absorption by the molten metal. Begin sampling to adjust the chemical composition. After composition and furnace pre-testing are completed, await casting at 1170℃.

[0042] Step Two: The simultaneous molding process is as follows: Prepare the casting mold and the necessary gating and riser system. The chilling materials are cast iron plates and graphite blocks, each with a size of 2000*1500*150mm, or two 2000*750*150mm blocks joined together to form a 2000*1500*150mm area. Use a bottom-pouring gating system, with the cast iron plate as the bottom box. Place the riser on top of the casting. Place the graphite blocks on the side of the casting, using 100*100*80mm blocks. Select the width of the graphite blocks as the application surface, and space the graphite blocks 10-20mm apart, taking care to avoid obstructing the gating system during placement. Mold with furan resin sand. After the resin sand has solidified, remove the mold to form a casting cavity with the chilling material. Apply zircon powder coating and dry. Clean and close the mold, awaiting pouring.

[0043] Step 3: Since this alloy is unpacked in the 600-700℃ range, it needs to be cooled quickly by an axial fan at 600 degrees Celsius. Water mist cooling cannot be used to assist in cooling, as it is easy to cause stress cracking.

[0044] Figure 1 The image shows a comparison of the grain size morphology (35 mm thickness) between the C95900 alloy prepared in Example 5 of this application and the C95900 alloy obtained without the fine-grain strengthening process technology of this application. Figure 1 (a) is the C95900 alloy prepared in Example 5 of this application. Figure 1(b) The C95900 alloy obtained without using the fine-grain strengthening process technology of this application; relevant mechanical property tests were conducted on the aluminum bronze alloys prepared in Examples 1-5 above and the aluminum bronze alloys obtained without using the fine-grain strengthening process technology of this application. The fine-grain strengthening process technology of this application is not applied, which means normal sand casting, that is, no modifier is used for modification treatment during the melting process, no graphite or silicon carbide chilling material is used in the molding process, only resin sand is used for molding, no graphite or silicon carbide chilling material is added, the modulus of the casting is larger, the riser size is larger than the riser size of the new technology, the cooling process is 3-4 hours after the riser solidifies, normal cooling is performed, and no rapid cooling measures are used after opening the box. The test results are shown in Table 1 below.

[0045] Table 1

[0046]

[0047]

[0048] In summary, from Figure 1 As shown in Table 1, by applying the fine-grain strengthening process technology of this application, the molten metal undergoes a metamorphic treatment during the smelting process, creating numerous nucleation points. Combined with the selected chilling material during molding, the cooling and solidification rate is increased, and the resulting supercooling increases the nucleation rate, accelerating the crystallization speed of the aluminum bronze alloy and producing a denser microstructure. During the casting cooling stage, rapid cooling within a specific temperature range further inhibits grain growth and improves the strength of the aluminum bronze. Compared with traditional sand casting or the use of only a single fine-grain strengthening technology, the aluminum alloy produced using the fine-grain strengthening process technology of this application has a grain size reduced by at least 30%, better elongation after fracture, and greater impact resistance. The strength and wear resistance of the produced aluminum bronze material are improved by at least 20%. In addition, the fine-grain strengthening process technology of this application uses simple and inexpensive materials, and some processes are easy to implement. Furthermore, the application of specific chilling materials during the molding process of this application can significantly reduce the modulus of the casting, reduce the design size and actual weight of the riser, improve the process yield of the casting, and shorten the solidification time of the casting, thereby improving production efficiency. This application proposes a process method for artificially intervening in the cooling rate during solidification, which shortens the production cycle, allows for faster cooling to room temperature, and facilitates the next production stage, thereby improving production efficiency. This process consumes minimal energy, and the chilled material can be reused.

[0049] Furthermore, in the preliminary experiments of this application, a boron-copper alloy was added to replace the boron-iron alloy during the smelting process. However, the grain refinement effect of this alloy was not as good as that of the boron-iron alloy, where iron acts as a carrier for the dissolved metal. A comparison of grain refinement effects using C95900 aluminum bronze casting with a diameter of φ82mm is shown below. Figure 2 As shown, Figure 2(a) is the C95900 aluminum bronze alloy obtained by using boron-copper alloy as a modifier. Figure 2 (b) C95900 aluminum bronze alloy obtained by using ferroboron alloy as a modifier. Although ferroboron alloy has a certain effect on grain refinement, it is not uniformly distributed. Ferroboron alloy has a significant effect on grain refinement and is cheaper.

[0050] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

[0051] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method of fine grain strengthening of an aluminum bronze alloy, characterized in that, The application relates to an aluminum-bronze alloy fine-grain strengthening method. In the process of melting aluminum-bronze raw materials, boron-iron alloy is added for modification treatment to obtain aluminum-bronze melting liquid; the boron-iron alloy is added in an amount of 0.1%-0.15% of the melting weight; A casting cavity with chilling material is used for pouring treatment of the aluminum-bronze melting liquid to obtain aluminum-bronze castings; During the solidification and molding process of the aluminum-bronze castings, when the aluminum-bronze castings are cooled to 500-700 DEG C, the open-box cooling treatment is carried out to obtain aluminum-bronze alloy.

2. The aluminum bronze alloy fine grain strengthening method according to claim 1, characterized by, The chilling material is a heat-conducting material with a thermal conductivity not less than 70 W / (m.K).

3. The aluminum bronze alloy fine grain strengthening method according to claim 1 or 2, characterized by, The chilling material is graphite or silicon carbide.

4. The aluminum bronze alloy fine grain strengthening method of claim 1, wherein, In the step of using the casting cavity with chilling material for pouring treatment of the aluminum-bronze melting liquid to obtain aluminum-bronze castings, a pouring system in a bottom pouring mode is used, the aluminum-bronze castings are provided with risers at the top, and the chilling material is arranged at the bottom and the side of the aluminum-bronze castings.

5. The aluminum bronze alloy fine grain strengthening method of claim 1, wherein, In the step of using the casting cavity with chilling material for pouring treatment of the aluminum-bronze melting liquid to obtain aluminum-bronze castings, when the thickness of the aluminum-bronze castings is less than 100 mm, graphite or silicon carbide with a thickness of 50-100 mm is selected as the chilling material; when the thickness of the aluminum-bronze castings is greater than 100 mm, a cast steel or cast iron iron plate with a thickness greater than 150 mm is selected as the chilling material.

6. The aluminum bronze alloy fine grain strengthening method of claim 1, wherein, In the step of adding boron-iron alloy for modification treatment in the process of melting aluminum-bronze raw materials to obtain aluminum-bronze melting liquid, the melting temperature is 1150-1200 DEG C.

7. The aluminum bronze alloy fine grain strengthening method of claim 1, wherein, In the step of adding boron-iron alloy for modification treatment in the process of melting aluminum-bronze raw materials to obtain aluminum-bronze melting liquid, the melting equipment is a medium-frequency coreless induction furnace.

8. The aluminum bronze alloy fine grain strengthening method of claim 1, wherein, In the step of using the casting cavity with chilling material for pouring treatment of the aluminum-bronze melting liquid to obtain aluminum-bronze castings, the pouring treatment temperature is 1170-1190 DEG C.

9. The aluminum bronze alloy fine grain strengthening method of claim 1, wherein, In the step of carrying out open-box cooling treatment when the aluminum-bronze castings are cooled to 500-700 DEG C during the solidification and molding process of the aluminum-bronze castings to obtain aluminum-bronze alloy, the aluminum-bronze castings with an aluminum content less than 11% are cooled by water mist, and the aluminum-bronze castings with an aluminum content greater than 11% are cooled by a fan.

10. An aluminum bronze alloy characterized by, The aluminum-bronze alloy is prepared by the aluminum-bronze alloy fine-grain strengthening method in any one of claims 1-9.

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