阅读说明：本技术 一种利用喷射成形7055铝合金粉末制备棒材的方法 (Method for preparing bar by spray forming 7055 aluminum alloy powder ) 是由 乔勇 张玉 张豪 张捷 于 2021-08-31 设计创作，主要内容包括：本发明提供了一种利用喷射成形7055铝合金粉末制备棒材的方法,包括如下步骤：粉末收集、粉末筛分、包套准备、冷等静压、脱模、热挤压和热处理。本发明的有益之处在于(1)本发明将喷射成形过程中产生的附属粉末挤压成材,在降低能源损耗和生产成本的同时,减少了环境污染；(2)力学性能好,利用该方法制备的7055铝合金棒材T76态抗拉强度达625MPa,远超AMS4336A中7055-T76511状态的力学性能。(The invention provides a method for preparing a bar by using 7055 aluminum alloy powder formed by spraying, which comprises the following steps: powder collection, powder screening, sheath preparation, cold isostatic pressing, demolding, hot extrusion and heat treatment. The invention has the advantages that (1) the accessory powder produced in the spray forming process is extruded into a material, so that the energy consumption and the production cost are reduced, and the environmental pollution is reduced; (2) the 7055 aluminum alloy bar prepared by the method has good mechanical property, the T76-state tensile strength of the 7055 aluminum alloy bar reaches 625MPa, and the mechanical property is far superior to that of the 7055-T76511 state in AMS43 4336A.)

1. A method for preparing a bar by spray forming 7055 aluminum alloy powder is characterized by comprising the following steps:

s1, collecting powder: collecting the powder formed by injection in a storage box under the protection of nitrogen, cooling, and subpackaging and sealing by plastic bags;

s2, powder screening: screening out particles with the particle size of less than 150 mu m by using a rotary vibration sieve;

s3, preparing a wrapping: manufacturing a cylindrical can device, wherein the can device is made of a non-metal material;

s4, cold isostatic pressing: placing the screened powder in a sheath device, vibrating, compacting, sealing, pressurizing to 180-220MPa, and maintaining the pressure for a period of time;

s5, demolding: after the pressure maintaining is finished, releasing the pressure and taking out the ingot blank;

s6, hot extrusion: placing the ingot blank in a heating furnace, heating to 450 +/-10 ℃ along with the furnace, preserving heat for 6-8h, and extruding once to obtain a bar material;

s7, heat treatment: and carrying out heat treatment on the extruded bar stock.

2. The method for preparing a bar by spray forming 7055 aluminum alloy powder according to claim 1, wherein in step S7, the heat treatment is T76 heat treatment;

the T76 heat treatment process comprises the following steps: firstly carrying out solution treatment at 450 +/-5 ℃ for 3 +/-0.2 h, then carrying out solution treatment at 475 +/-5 ℃ for 3 +/-0.2 h, carrying out water quenching to room temperature, finally carrying out aging treatment at 120 +/-5 ℃ for 6 +/-0.2 h, then carrying out aging treatment at 160 +/-5 ℃ for 7 +/-0.2 h, and discharging and air cooling.

3. The method for preparing a bar by spray forming 7055 aluminum alloy powder according to claim 1, wherein in step S6, the die heating temperature of the primary extrusion is 420 ± 10 ℃, the extrusion speed is 0.3mm/S, and the extrusion barrel temperature is 430 ± 10 ℃.

4. The method for preparing a bar by using 7055 aluminum alloy powder formed by spray according to claim 1, wherein in step S1, the powder is attached 7055 aluminum alloy powder generated in the spray process, and the chemical components comprise 2.0-2.6% by mass of Cu, 1.8-2.3% by mass of Mg, 0.08-0.25% by mass of Zr, 7.6-8.4% by mass of Zn, and some inevitable impurities.

5. The method for preparing the bar by using the 7055 aluminum alloy powder spray-formed according to claim 1, wherein in step S4, the powder inside the sheath device is vibrated and compacted by using a vibrating platform, the sheath filled with the powder and tightly sealed is placed in a cylinder of a cold isostatic press, a booster pump is started, the pressure in the cylinder is increased to 200MPa within 15min, and the pressure is maintained for 10min after the pressure is increased.

6. The method for preparing the bar by using the 7055 aluminum alloy powder formed by spraying as claimed in claim 1, wherein in step S2, 7055 aluminum alloy auxiliary powder is sieved into a first type of powder and a second type of powder by using a rotary vibrating sieve provided with a 100-mesh filter screen, the particle size of the first type of powder is less than or equal to 150 μm, and the particle size of the second type of powder is more than 150 μm, and the first type of powder is selected for subsequent production.

7. The method for preparing the bar by using the 7055 aluminum alloy powder spray-formed according to claim 1, wherein in step S3, the material of the wrapping device is rubber, and the specific parameters of the wrapping device are as follows: the inner diameter is 300mm, the wall thickness is 10mm, the height is 600mm, and the upper cover thickness is 60 mm.

8. The method of manufacturing rods using spray forming 7055 aluminum alloy powder according to claim 1, wherein in step S5, the size of the ingot after demolding is Φ 270 x 500 mm.

Technical Field

The invention relates to a method for preparing a bar by spray forming 7055 aluminum alloy powder.

Background

The concept of spray forming was first proposed by Singer, university of Swansea, UK, in 1968 and patented in 1972. The Osprey process was invented as engineering technology since 1974 when Ospreymetals, UK, succeeded in applying Singer's proposal to spray forming for the production of forged blanks. From the whole development process, the foreign spray forming technology goes through the courses of self development and significant improvement of experimental research (1975-1984) on applicable alloy systems, process optimization and atomization deposition mechanism research (1984-1992), atomization technology scale expansion and industrialization (1992-1998) and the like. In recent years, the injection molding technology has become one of the hot spots for the research and industrialization development of the material science and engineering community.

The basic principle of spray forming technology is to atomize metal droplets into fine droplets by means of high-pressure inert gas and make them fly at high speed along the axis of a nozzle, and the droplets are deposited into blanks before they are completely solidified. Has the advantages of fine crystal grains, uniform structure, capability of inhibiting macro segregation and other rapid solidification technologies. The method is not limited by the upper limit of the alloy content, and is a mainstream technology for preparing high-alloying and large-specification materials.

The spray forming process is easy to generate over-sprayed powder in the spraying process due to the problems of multiple parameters, difficult control of the intermediate process and the like. In the process of preparing 7055 aluminum alloy ingot blanks by using a spraying technology, about 20% of accessory powder is generated, on one hand, the accessory powder is difficult to be directly utilized as a terminal product due to wide particle size distribution range, large specific surface area and serious oxidation, and on the other hand, the aluminum powder is large in specific surface area, high in combustion value and unstable compared with common materials, and if the aluminum powder meets a humid environment and reaches a certain concentration in the storage process, explosion is easy to occur, so that certain potential safety hazards exist. At present, the powder is treated by remelting and remelting, so that the solidified and formed powder is remelted into molten aluminum, the problems of environmental pollution, resource waste, low raw material utilization rate and the like are caused, and the production cost is increased. Therefore, there is a strong need for a new process to make rational use of the satellite powder produced during spraying.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a method for preparing a bar by spray forming 7055 aluminum alloy powder.

A method of making bars using spray formed 7055 aluminum alloy powder comprising the steps of:

s1, collecting powder: collecting the powder formed by injection in a storage box under the protection of nitrogen, cooling, and subpackaging and sealing by plastic bags;

s2, powder screening: screening out particles with the particle size of less than 150 mu m by using a rotary vibration sieve;

s3, preparing a wrapping: manufacturing a cylindrical can device, wherein the can device is made of a non-metal material;

s4, cold isostatic pressing: placing the screened powder in a sheath device, vibrating, compacting, sealing, pressurizing to 180-220MPa, and maintaining the pressure for a period of time;

s5, demolding: after the pressure maintaining is finished, releasing the pressure and taking out the ingot blank;

s6, hot extrusion: placing the ingot blank in a heating furnace, heating to 450 +/-10 ℃ along with the furnace, preserving heat for 6-8h, and extruding once to obtain a bar material;

s7, heat treatment: and carrying out heat treatment on the extruded bar stock.

Preferably, in step S7, the heat treatment is T76 heat treatment;

the T76 heat treatment process comprises the following steps: firstly carrying out solution treatment at 450 +/-5 ℃ for 3 +/-0.2 h, then carrying out solution treatment at 475 +/-5 ℃ for 3 +/-0.2 h, carrying out water quenching to room temperature, finally carrying out aging treatment at 120 +/-5 ℃ for 6 +/-0.2 h, then carrying out aging treatment at 160 +/-5 ℃ for 7 +/-0.2 h, and discharging and air cooling.

Preferably, in step S6, the heating temperature of the die for the first extrusion is 420 ± 10 ℃, the extrusion speed is 0.3mm/S, and the temperature of the extrusion cylinder is 430 ± 10 ℃;

preferably, in step S1, the powder is an accessory 7055 aluminum alloy powder generated in the spraying process, and the chemical components include, by mass, 2.0-2.6% of Cu, 1.8-2.3% of Mg, 0.08-0.25% of Zr, 7.6-8.4% of Zn, and some unavoidable impurities.

Preferably, in step S4, the powder inside the sheathing device is vibrated and compacted by using a vibration platform, the tightly sealed sheathing filled with the powder is placed in a cylinder of a cold isostatic press, a booster pump is started to increase the pressure in the cylinder to 200MPa within 15min, and the pressure is maintained for 10min after the pressure is reached.

Preferably, in step S2, the 7055 aluminum alloy auxiliary powder is sieved into a first type of powder and a second type of powder by using a rotary vibrating sieve with a 100-mesh filter screen, the particle size of the first type of powder is less than or equal to 150 μm, the particle size of the second type of powder is greater than 150 μm, and the first type of powder is selected for subsequent production.

Preferably, in step S3, the material of the sheathing device is rubber, and the specific parameters of the sheathing device are as follows: the inner diameter is 300mm, the wall thickness is 10mm, the height is 600mm, and the upper cover thickness is 60 mm.

Preferably, in step S5, the size of the ingot after demolding is Φ 270 × 500 mm.

Has the advantages that:

1. the 7055 aluminum alloy accessory powder produced in the spray forming process is extruded into a material, so that the energy consumption and the production cost are reduced, and the environmental pollution is reduced.

2. The 7055 aluminum alloy bar with certain mechanical properties can be prepared by the method, the tensile strength of the 7055 aluminum alloy bar can reach 625MPa, and the mechanical properties of the 7055-T76511 state in AMS4336A are far better.

Drawings

FIG. 1 is a graph of the screened morphology of 7055 aluminum alloy powder;

FIG. 2 is a particle size distribution diagram of 7055 aluminum alloy powder after screening;

fig. 3 is a metallographic structure of 7055 powder extruded bars.

Detailed Description

For the purpose of enhancing the understanding of the present invention, the present invention will be further described in detail with reference to the following examples and the accompanying drawings, which are only used for explaining the present invention and are not to be construed as limiting the scope of the present invention.

The implementation mode is as follows:

a method for preparing a bar by spray forming 7055 aluminum alloy powder, comprising the steps of:

s1, collecting powder: collecting 7055 aluminum alloy powder generated by atomization in the spray forming process in a storage box under the protection of nitrogen, cooling, subpackaging and sealing by using plastic bags, and placing in an iron bucket and covering for storage to avoid oxidation.

S2, powder screening: the 7055 aluminum alloy auxiliary powder is sieved into first powder and second powder by using a rotary vibration sieve provided with a 100-mesh filter screen, wherein the particle size of the first powder is less than or equal to 150 mu m, and the particle size of the second powder is more than 150 mu m.

S3, preparing a wrapping: a cylindrical sheath device with the inner diameter of 300mm, the wall thickness of 10mm, the height of 600mm and the upper cover thickness of 60mm is manufactured by taking rubber as a raw material.

S4, cold isostatic pressing: the screened 7055 aluminum alloy powder of the first class is filled in a rubber packing sleeve, is vibrated and filled by a vibration platform, and then is covered by an upper cover for sealing; and (3) placing the sheath filled with the powder and tightly sealed in the cylinder body of the cold isostatic press, starting the booster pump to enable the pressure in the cylinder body to rise to 200MPa within 15min, and maintaining the pressure for 10min after the pressure is reached.

S5, demolding: and after the pressure maintaining is finished, the pressure in the cylinder body of the cold isostatic press is removed, the sheath is taken out, and the 7055 aluminum alloy powder cold isostatic press ingot blank is obtained after demolding, wherein the size of the ingot blank is phi 270 x 500 mm.

S6, hot extrusion: and (3) placing the powder ingot blank obtained by cold isostatic pressing into a heating furnace, heating to 450 +/-10 ℃ along with the furnace, preserving the heat for 6-8h, and performing primary extrusion by using a 2000T extruder to obtain a bar material with the diameter of 60mm (double-hole discharging). The extrusion speed is 0.3mm/s, the heating temperature of the die is 420 +/-10 ℃, and the temperature of the extrusion cylinder is 430 +/-10 ℃.

S7, heat treatment: the primary extruded rod obtained by the hot extrusion was subjected to a T76 heat treatment. The T76 heat treatment process comprises the following steps: firstly, carrying out solution treatment at 450 +/-5 ℃ for 3 +/-0.2 h, then carrying out solution treatment at 475 +/-5 ℃ for 3 +/-0.2 h, carrying out water quenching to room temperature, finally carrying out aging treatment at 120 +/-5 ℃ for 6 +/-0.2 h, then carrying out aging treatment at 160 +/-5 ℃ for 7 +/-0.2 h, and discharging and air cooling.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.