A method for high frequency induction melting of an energetic alloy

Abstract

A high-frequency induction melting method for preparing energetic alloys, applicable to Zr-Cu-Ni-Al alloy systems, comprises the following steps: raw material selection, raw material placement, vacuum melting, casting, and unloading. This invention utilizes conventional high-frequency vacuum induction melting equipment. By selecting and placing specific raw materials, the melting and homogenization of all materials can be completed within 30–600 seconds. After casting and furnace cooling, ingots or castings with uniform microstructure and composition are obtained. This method is characterized by its simple operation and short process. Through a single melting and casting process, high-strength, high-hardness energetic alloy components with partially amorphous characteristics can be obtained, significantly simplifying traditional manufacturing processes. The prepared energetic alloys can be used for components such as energetic fragments of warheads, energetic shells, and energetic propellant liner, possessing significant practical value.

Description

Technical Field

[0001] This invention belongs to the technical field of energetic damage materials for warheads, and relates to a high-frequency induction melting preparation method suitable for Zr-Cu-Ni-Al energetic alloys. Background Technology

[0002] The warhead is the part of an munition that produces a predetermined terminal effect when it damages a target. Used in various weapon systems such as artillery shells, missiles, bombs, and rockets, it determines the final damage effect of the weapon system and therefore holds a crucial position in the research of high-efficiency damage technology. Conventional warheads generally consist of a casing, damage elements, main explosive charge, and fuse. The materials used for the damage elements play a decisive role in the destructive power of the weapon, while the manufacturing process of these materials significantly impacts their application.

[0003] Metallic energetic fragments are currently the most widely used type of energetic damage element in warheads, with zirconium-based alloys being the most typical, possessing moderate density, high strength, and good ignition and incendiary properties. Zr-Cu-Ni-Al amorphous alloys, based on zirconium alloys, further exhibit high strength, high hardness, and good casting processability, making them valuable for applications in energetic fragments and energetic propellant liner construction. However, the preparation of amorphous materials places extremely high demands on raw material purity, compositional uniformity, and cooling rate, resulting in complex and demanding material preparation processes with stringent equipment and process parameters, thus limiting the engineering application of Zr-Cu-Ni-Al amorphous alloys.

[0004] Therefore, a new preparation method is needed for Zr-Cu-Ni-Al energetic alloys, which can greatly simplify the preparation process of energetic materials in this system and meet the industrial production needs of energetic destructive elements for warheads. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a high-frequency induction melting method for preparing energetic alloys, which has the characteristics of simple and reasonable process and short process, and the prepared alloy also has some amorphous characteristics such as high strength and high hardness.

[0006] The technical solution adopted by this invention to solve the above-mentioned technical problems is as follows: a method for preparing energetic alloys by high-frequency induction melting, applicable to Zr-Cu-Ni-Al alloy systems, characterized by including the following steps:

[0007] 1) Raw material selection: The raw materials used are sponge zirconium, copper, nickel and aluminum particles, and the purity of each raw material is not less than 99.9% and the particle size range is 0.5 to 10 mm;

[0008] 2) Raw material placement: Calculate the weight of raw materials according to the energetic alloy composition and crucible capacity. Place 30-70% of the total mass of sponge zirconium at the bottom of the crucible. After the remaining sponge zirconium is mixed evenly with other raw materials, it is filled into the upper part of the crucible.

[0009] 3) Vacuum melting: Place the casting mold as needed, evacuate the high-frequency vacuum induction melting furnace to below 0.1 Pa, then fill it with argon gas to 2000-40000 Pa, turn on the high-frequency induction melting power supply for melting, and adjust the melting power according to the different equipment and crucible capacity, with an adjustment range of 10-50 kW. The total heating time is 60-600 s, of which the heating time after all the raw materials in the crucible have melted is not less than 30 s.

[0010] 4) Casting: Pour the molten alloy into a casting mold and allow it to cool in the furnace.

[0011] 5) After being removed from the furnace, the Zr-Cu-Ni-Al energetic alloy casting is obtained by demolding.

[0012] Furthermore, the chemical composition of the Zr-Cu-Ni-Al energetic alloy, expressed as a percentage by mass, includes, but is not limited to: Zr 40–80, Cu 5–30, Ni 5–20, and Al 1–10.

[0013] Furthermore, the size range of the sponge zirconium particles in step 1) is 0.5 to 5 mm, and the size of the remaining raw material particles is 3 to 10 mm.

[0014] Furthermore, the casting mold in step 3) is a conventional ingot mold or a precision casting mold.

[0015] Furthermore, in step 4), the pouring method involves pouring the material into the casting mold using either a tilting or bottom-drain pouring method.

[0016] Finally, step 5) yields Zr-Cu-Ni-Al energetic alloy castings. These energetic alloys possess high strength, high hardness, and other partially amorphous characteristics, and are used for energetic fragments, energetic shells, or energetic propellant liner components in warheads.

[0017] Compared with the prior art, the advantages of the present invention are as follows:

[0018] 1. By constraining the particle size of raw materials and placing them in a reasonable manner, low-melting-point materials such as copper, nickel, and aluminum in the upper part of the crucible that are easily induction heated first form a small molten pool, which then undergoes an alloying reaction with sponge zirconium. This allows all materials to quickly form a high-temperature molten liquid under high-frequency induction, realizing a short-process and rapid melting and casting of Zr-Cu-Ni-Al energetic alloys, which greatly simplifies the preparation process.

[0019] 2. The prepared alloy has some amorphous characteristics, mainly characterized by high strength, high hardness and excellent casting processability. The strength of its amorphous characteristics is significantly correlated with the amorphous forming ability of the composition and the mechanical properties (strength, ductility and toughness, etc.) of the amorphous state. Moreover, the maximum cross-sectional thickness can reach more than 50 mm, which has good prospects for industrial application.

[0020] The process of this invention is simple and easy to operate, with a short process. High-strength and high-hardness energetic alloy material components with partial amorphous characteristics can be obtained through one-time melting and casting, which greatly simplifies the traditional preparation process. The prepared energetic alloy can be used for components such as energetic fragments of warheads, energetic shells, and energetic propellant liner, and has important practical value. Attached Figure Description

[0021] Figure 1 These are metallographic images of the alloy ingot obtained in Example 1 of this invention;

[0022] Figure 2 This is a photograph of an energetic component obtained in Embodiment 2 of the present invention. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0024] Example 1: Zr64Cu21Ni11Al4

[0025] The preparation process steps are as follows:

[0026] 1. Raw material selection: Sponge zirconium, copper granules, nickel granules and aluminum granules are used. The purity of each raw material is above 99.9%. The particle size range of sponge zirconium is 0.5-5mm, and the particle size of the other raw materials is 3-10mm.

[0027] 2. Raw material placement: Use a ceramic crucible with a single furnace melting capacity of 500g. Place 250g of sponge zirconium at the bottom of the crucible. Mix the remaining sponge zirconium with the other raw materials (250g in total) evenly and fill the upper part of the crucible with the mixture. Then tap and vibrate to compact the mixture.

[0028] 3. Vacuum melting: A small high-frequency vacuum induction melting furnace is used for melting. The casting mold is a graphite mold that has been heated and dried, with an inner cavity diameter of 52mm. The furnace body is evacuated to below 0.1Pa, and then filled with argon gas to 3000Pa. The high-frequency induction melting power supply is turned on for melting. The melting power is 25kW. After heating for 40s, it is observed that all the raw materials in the crucible have melted and the melt is clear. Heating is continued for another 30s.

[0029] 4. Casting: The molten energetic alloy is poured into the graphite mold using a pouring or bottom-drip casting method and cooled in the furnace.

[0030] 5. After being removed from the furnace, the ingot is demolded to obtain a large ingot with a diameter of 52mm and a height of about 40mm.

[0031] The metallographic structure of the alloy ingot prepared in this embodiment is shown in the following image. Figure 1 As shown, energetic alloys have good amorphous forming ability, high strength, high hardness, certain plasticity and good casting processability. They can be melted in one go to obtain large alloy ingots with a diameter of 50 mm and uniform microstructure and properties. Their compressive strength is 1500-1700 MPa, hardness is 50-60 HV, and unnotched impact energy is 3-4 J.

[0032] Example 2: Zr75Cu15Ni5Al5

[0033] The preparation process steps in this embodiment are as follows:

[0034] 1. Raw material selection: Sponge zirconium, copper granules, nickel granules and aluminum granules are used. The purity of each raw material is above 99.9%. The particle size range of sponge zirconium is 0.5-5mm, and the particle size of the other raw materials is 3-10mm.

[0035] 2. Raw material placement: Use a ceramic crucible with a single furnace melting capacity of 600g. Place 300g of sponge zirconium at the bottom of the crucible. Mix the remaining sponge zirconium with the other raw materials (300g in total) evenly and fill the upper part of the crucible with the mixture. Then tap and vibrate to compact the mixture.

[0036] 3. Vacuum melting: A small high-frequency vacuum induction melting furnace is used for melting, and a circular ceramic shell is used for casting mold; the furnace body is evacuated to below 0.1Pa, and then filled with argon to 20000Pa. The high-frequency induction melting power supply is turned on for melting, with a melting power of 30kW. After heating for 50s, it is observed that all the raw materials in the crucible have melted and the melt is clear. Then, heating is continued for another 30s.

[0037] 4. Casting: The molten energetic alloy is poured into the ceramic shell mold using a pouring or bottom-drip casting method, and then cooled in the furnace.

[0038] 5. After being removed from the furnace, the casting is demolded to obtain a circular ring-shaped blank, such as... Figure 2 As shown.

[0039] The energetic alloy prepared in this embodiment exhibits high activity and high strength, and is mainly used for energetic fragments or shell components of warheads. Using this process, it is possible to melt and cast the alloy directly into cylindrical components in a single process, which can then be used directly after cutting.

[0040] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing energetic alloys by high-frequency induction melting, characterized in that... Includes the following steps: 1) Raw material selection: The raw materials used are sponge zirconium, copper granules, nickel granules and aluminum granules. The purity of each raw material is not less than 99.9% and the particle size range is 0.5 to 10 mm. 2) Raw material placement: Calculate the weight of raw materials according to the energetic alloy composition and crucible capacity. Place 30-70% of the total mass of sponge zirconium at the bottom of the crucible. After the remaining sponge zirconium is mixed evenly with other raw materials, it is filled into the upper part of the crucible. 3) Vacuum melting: Place the casting mold as needed, evacuate the high-frequency vacuum induction melting furnace to below 0.1 Pa, then fill it with argon gas to 2000-40000 Pa, turn on the high-frequency induction melting power supply for melting, and adjust the melting power according to the different equipment and crucible capacity, with an adjustment range of 10-50 kW. The total heating time is 60-600 s, of which the heating time after all the raw materials in the crucible have melted is not less than 30 s. 4) Casting: Pour the molten alloy into a casting mold and allow it to cool in the furnace; 5) After being removed from the furnace, the casting is demolded to obtain the energetic alloy casting; The energetic alloy is a Zr-Cu-Ni-Al system, and its chemical composition, in mass percentage, is: Zr 40-80, Cu 5-30, Ni 5-20, and Al 1-10. The Zr-Cu-Ni-Al energetic alloy obtained in step 5) has high strength, high hardness and partial amorphous characteristics, and can be used for energetic fragments of warheads, energetic shells or energetic propellant liner components.

2. The high-frequency induction melting preparation method according to claim 1, characterized in that: The size range of the sponge zirconium particles in step 1) is 0.5-5 mm, and the size range of the other raw material particles is 3-10 mm.

3. The high-frequency induction melting preparation method according to claim 1, characterized in that: The casting mold for step 3) is a conventional ingot mold or a precision casting mold.

4. The high-frequency induction melting preparation method according to claim 1, characterized in that: In step 4), the pouring method involves pouring the material into the casting mold using either a tilting or bottom-drain pouring method.

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