CN101737574B - Preparation method of thin-wall tubular product of particle-reinforced aluminum-based composite material - Google Patents

Abstract

The invention relates to a method for preparing a particle-reinforced aluminum-based composite material thin-walled pipe, comprising (1) preparing a pipe blank by adopting a stirring casting process and a powder metallurgy process; Compression deformation experiment to obtain deformation conditions suitable for processing; (3) Carry out spinning finite element numerical simulation on the tube blank, optimize process parameters, and carry out hot spinning and warm spinning; (4) Perform solid solution treatment on the obtained pipe, After water quenching at room temperature, aging. The pipe material prepared by the invention has a large ratio of diameter to wall thickness, the inner and outer surfaces of the pipe material are smooth and free of defects, the wall thickness of the pipe material is uniform, and the interface between the reinforcement particles and the matrix of the thin-walled pipe material is well bonded. The method has the advantages of short flow, labor-saving processing, energy saving and environmental protection, simple process, low cost of raw materials, suitable for large-scale production, can be widely used in the preparation of high-strength and light-weight pipe fittings in the fields of aerospace, automobiles, advanced weapons and the like, and has good promotion value.

Description

Preparation method of particle-reinforced aluminum matrix composite thin-walled pipe

technical field

The invention relates to a method for preparing thin-walled pipes of particle-reinforced aluminum-based composite materials, which belongs to the field of preparation of thin-walled pipes of difficult-to-form materials.

Background technique

Particle-reinforced aluminum matrix composites have the advantages of high specific strength, high specific modulus, good wear resistance and dimensional stability, and are widely used in aerospace, automobile manufacturing, advanced equipment and other fields. Particle-reinforced aluminum matrix composite pipe fittings are lightweight, high-strength, high-modulus components, which can further reduce the weight of aerospace equipment, and are urgently needed in advanced weapons. After searching the existing technical literature, it is found that Chinese patents have not yet publicly reported the preparation method of the particle-reinforced aluminum matrix composite thin-walled pipe.

The thin-walled composite pipes prepared by hot and strong spinning methods have a large diameter-to-wall-thickness ratio, which is difficult to achieve by single processing methods such as casting, extrusion, and rolling. Thin-walled composite pipes can also be prepared by casting and powder metallurgy ingot + back extrusion + spinning, but the process is long and requires a large extruder, resulting in high production costs.

Contents of the invention

The purpose of the present invention is to overcome the technical bottleneck in the processing of difficult-to-form material pipes, and provide a short-process preparation method for thin-walled pipes of particle-reinforced aluminum-based composite materials.

To achieve the above object, the present invention takes the following technical solutions:

A method for preparing a particle-reinforced aluminum matrix composite material thin-walled pipe, comprising the steps of:

(1) Prepare the tube blank of particle reinforced aluminum matrix composite material by stirring casting process or powder metallurgy process;

(2) Homogenize the tube blank, turn and peel off the skin, carry out high-temperature compression deformation experiments, study thermal deformation behavior, and select deformation conditions suitable for processing;

(3) performing spinning finite element numerical simulation on the tube blank, optimizing process parameters, and performing hot spinning and warm spinning to obtain a particle-reinforced aluminum matrix composite material tube;

(4) The particle-reinforced aluminum-matrix composite pipe obtained in step (3) is subjected to solution treatment, quenched in water at room temperature, and aged to obtain a particle-reinforced aluminum-matrix composite thin-walled pipe.

A preferred technical solution is characterized in that: in the particle-reinforced aluminum-based composite material, the reinforcing particles are mainly Al ₂ O ₃ or SiC, the volume fraction of the reinforcing particles is 5-20%, and the average size of the reinforcing particles is 0.5μm～10μm, the matrix alloy is 2××× series and 6××× series.

A preferred technical solution is characterized in that: the homogenization treatment described in step (2) is a two-stage homogenization treatment or a single-stage homogenization treatment, and the two-stage homogenization treatment is: the first-stage heating temperature is 410 ~ 480°C, heat preservation for 6-12 hours; second-stage heating temperature is 500-540°C, heat preservation for 6-12 hours; heating temperature for single-stage homogenization treatment is 500-540°C, heat preservation for 12-24 hours.

A preferred technical solution, characterized in that: in the high-temperature compression deformation test described in step (2), the temperature range is 300-550°C, the temperature interval is 50°C, and the strain rate range is 0.001-10s ^-1 , using The Kumar model establishes the constitutive relationship of the composite material, and combines the microstructure under different deformation conditions to obtain the deformation conditions suitable for the processing of the composite material. The temperature range for the thermal processing of the composite material is 400-550 °C.

A preferred technical solution is characterized in that: the optimized process parameters described in step (3) are that the selectable process window of hot spinning and warm spinning of composite materials is relatively narrow, and the more suitable pass thinning rate It is 15-35%, and the more suitable feed ratio is 0.5-2mm/r.

A preferred technical solution, characterized in that: the spinning temperature of the hot spinning described in step (3) is 450-540°C, the spinning working angle is 20-25°, and the mold is preheated at 300-350°C , and use an oxygen-acetylene flame spray gun to supplement heat, and the feed ratio is 0.5~1.5mm/r.

A preferred technical solution, characterized in that: the spinning temperature of the warm spinning described in step (3) is 200-350°C, the spinning working angle is 20-25°, and the mold is preheated at 200-300°C , and use an oxygen-acetylene flame spray gun to supplement heat, and the feed ratio is 1-2mm/r.

A preferred technical solution is characterized in that: after the warm spinning, annealing, the annealing temperature is 250°C, heat preservation for 60 minutes, and cooling with the furnace; in order to ensure the quality of the inner and outer surfaces, warm spinning is performed after lowering the temperature , The warm spinning temperature is 150°C, the spinning working angle is 25°, and the oxygen-acetylene flame spray gun is used to supplement heat intermittently for a short time, and the feed ratio is 1.5mm/r.

A preferred technical solution is characterized in that: the solution treatment temperature described in step (4) is 500-545°C, and the holding time is 50-150min; the aging temperature is 140-185°C, and the heat preservation time is 8-150min. 36h.

The diameter-to-wall-thickness ratio of the particle-reinforced aluminum matrix composite material thin-walled pipe prepared by the invention is greater than 50:1.

Microstructural analysis by transmission electron microscope (TEM) or scanning electron microscope (SEM), no cracks were found in the reinforcement particles in the thin-walled pipe, and no microscopic defects such as cracks were found at the interface between the reinforcement particles and the matrix. The interface is well integrated.

The advantages of the present invention are:

The preparation method of the present invention solves the problem of the preparation of thin-walled aluminum-based composite pipes reinforced by particles of difficult-to-form materials. Because the existence of the reinforcement particle ceramic phase reduces the plasticity of the material, the spinning of the pipes is quite difficult, and the compression test is used to obtain composite pipes. The material is suitable for deformation conditions for processing. Three-dimensional numerical simulation of composite material pipe spinning optimizes process parameters, effectively controls deformation temperature and feed rate, and realizes that the temperature of the deformation zone during spinning is within the range of temperature and strain rate suitable for deformation, avoiding reinforcement The occurrence of microscopic defects such as particle breakage and interface cracking. Problems such as cracking of reinforcement particles and cracking at the interface during spinning of composite materials are solved.

Composite tube blanks are prepared by stirring casting process and powder metallurgy process. The raw materials are cheap and the production process is simple. Tube blanks of different specifications and diameters can be prepared. This patent has a short preparation process and does not require large-scale extrusion equipment. It is a labor-saving forming method. Energy saving and environmental protection; the prepared composite thin-walled composite pipe has good interface bonding between the thin-walled pipe particles and the matrix, good surface quality, uniform wall thickness, high dimensional accuracy, good mechanical properties, and is suitable for large-scale production. It can be widely used in the preparation of high-strength and light-weight pipe fittings in the fields of aerospace, automobiles, advanced weapons, etc., and has good promotion value.

The present invention will be further described below through specific embodiments, but it does not mean to limit the protection scope of the present invention.

Detailed ways

Example 1

Preparation of Al ₂ O ₃ /6061 composite tube billet by stirring casting method: add 6061 aluminum alloy into the crucible, heat it under the protection of argon to melt the aluminum alloy ingot, raise the temperature to 680-1000°C, and mix the 6061 aluminum alloy with Prefabricated blocks with Al ₂ O ₃ particle volume ratio of 5 to 2:1 are preheated to 500 to 700°C, added to the aluminum alloy solution, and mechanically stirred, and hexachloroethane is added to the melt to degas, and cast The temperature is 650-780°C, and then poured into the mold to form a tube blank; the specification of the tube blank is: Ф120mm×15mm×400mm. In Al ₂ O ₃ /6061 composites, the volume fraction of Al ₂ O ₃ reinforcing particles is 8%, and the average size is 7μm. The tube blank is subjected to double-stage homogenization treatment at 420°C×6h+500°C×6h, turned and skinned, and then subjected to a thermal compression test. The constitutive relationship of composite materials was established by Kumar model, the temperature range was 300-550℃, the temperature interval was 50℃, and the strain rate range was 0.001-10s ^-1 .

Using a dynamic material model, using Matlab software to write a program, establish a processing map, use a scanning electron microscope and a metallographic microscope to observe the microstructure under different deformation conditions, and determine the dynamics of the matrix alloy. The deformation condition is to obtain the deformation condition suitable for processing of the composite material, and the temperature range of the composite material suitable for thermal processing is 400-550°C. Commercial finite element software was used to establish a three-dimensional spinning model, and an 8-node hexahedral grid was used to analyze the effects of spinning temperature, spinning feed ratio, spinning working angle, and thinning rate on the uniformity of material deformation during spinning. Influence, optimize the spinning process parameters, the hot spinning temperature is 500°C, the spinning working angle is 25°, the tool and mold are preheated at 300°C, and the oxygen-acetylene flame spray gun is used to supplement the heat, and the feed ratio is 0.7mm/r. The pass thinning rate is 25%. The warm spinning temperature is 250°C, the spinning working angle is 25°, the tool and mold are preheated at 200°C, and the oxygen-acetylene flame spray gun is used to supplement the heat, the feed ratio is 1mm/r, and the pass thinning rate is 25%. Spinning 7 times. The solid solution temperature is 510°C, heat preservation for 60min, water quenching at room temperature, and then aging treatment at 165°C×28h. The specifications of the obtained Al ₂ O ₃ /6061Al composite thin-walled pipe are: diameter 942 mm, wall thickness 2 mm, length 3.4 m, volume fraction of Al ₂ O ₃ particles 8%.

Example 2

The preparation process of the composite material, the preparation of the tube blank, the uniform treatment, and the processing process of hot spinning are the same as in Example 1. The temperature of the warm spinning is 250°C, the working angle of the spinning is 25°, the tool and mold are preheated at 250°C, and the Oxygen-acetylene flame spray gun heat supplement, the feed ratio is 1mm/r, the pass thinning rate is 25%, and the spinning is 3 passes. The annealing temperature is 250°C, the temperature is kept for 60 minutes, and the furnace is cooled. In order to ensure the quality of the inner and outer surfaces, the spinning temperature is lowered to 150°C, the working angle of spinning is 25°, and the oxygen-acetylene flame spray gun is used to replenish heat intermittently for a short time, the feed ratio is 1.5mm/r, and the number of passes is reduced. Thinness rate is 30%; solid solution temperature is 510°C, heat preservation for 50min, water quenching at room temperature, and then aging treatment at 165°C×24h. The specifications of the obtained Al ₂ O ₃ /6061Al composite thin-walled pipe are: diameter 100 mm, wall thickness 1 mm, length 3 m, volume fraction of Al ₂ O ₃ particles 8%.

Example 3

The Al ₂ O ₃ /2124 composite tube blank is prepared by powder metallurgy, and the specification of the tube blank is Ф300mm×40mm×200mm. In Al ₂ O ₃ /2124 composites, the volume fraction of Al ₂ O ₃ reinforcing particles is 10%, and the average size is 0.5 μm. The tube blank is subjected to double-stage homogenization treatment at 480°C×6h+540°C×6h, turned and skinned, and then subjected to a thermal compression test. The temperature range suitable for thermal processing of composite materials is 400-550°C. The Kumar model is used to establish the constitutive relationship of the composite material. The temperature range is 300-550°C, the temperature interval is 50°C, and the strain rate range is 0.001-10s ^-1 . Combined with the microstructure under different deformation conditions, the deformation suitable for processing of the composite material is obtained. condition. Using finite element numerical simulation to optimize the spinning process parameters, the hot spinning temperature is 540°C, the spinning working angle is 25°, the tool and mold are preheated at 350°C, and the oxygen-acetylene flame spray gun is used to supplement the heat, and the feed ratio is 0.7mm /r, the pass thinning rate is 20%. The warm spinning temperature is 300°C, the spinning working angle is 25°, the tool and mold are preheated at 300°C, and the heat is supplemented by an oxygen-acetylene flame spray gun, the feed ratio is 1mm/r, and the pass thinning rate is 25%. The solid solution temperature is 540°C, heat preservation for 60min, water quenching at room temperature, and then aging treatment at 165°C×12h. The specifications of the obtained Al ₂ O ₃ /2124Al composite thin-walled pipe are: diameter 230 mm, wall thickness 5 mm, length 2 m, volume fraction of Al ₂ O ₃ particles 10%.

Example 4

The powder metallurgy method is used to prepare the SiC/2124 composite tube blank, and the specification of the tube blank is Ф150mm×20mm×300mm. In SiC/2124 composites, the volume fraction of SiC reinforcing particles is 8%, and the average size is 10μm. ;Put the tube billet into 520℃×12h for homogenization treatment, turn and peel off the skin, and then conduct a thermal compression test. The temperature range suitable for thermal processing of composite materials is 400-550℃. The Kumar model is used to establish the constitutive relationship of the composite material. The temperature range is 300-550°C, the temperature interval is 50°C, and the strain rate range is 0.001-10s ^-1 . Combined with the microstructure under different deformation conditions, the deformation suitable for processing of the composite material is obtained. condition. Using finite element numerical simulation to optimize the spinning process parameters, the hot spinning temperature is 520°C, the spinning working angle is 25°, the tool and mold are preheated at 350°C, and the oxygen-acetylene flame spray gun is used to supplement the heat, and the feed ratio is 0.7mm /r, the pass thinning rate is 20%. The warm spinning temperature is 350°C, the spinning working angle is 25°, the tool and mold are preheated at 300°C, and the heat is supplemented by an oxygen-acetylene flame spray gun, the feed ratio is 1mm/r, and the pass thinning rate is 25%. The solid solution temperature is 545°C, heat preservation for 60min, water quenching at room temperature, and then aging treatment at 185°C×8h. The specifications of the obtained SiC/2124Al composite thin-walled pipe are: diameter 114mm, wall thickness 2mm, length 4m, volume fraction of SiC particles 8%.

Transmission electron microscope (TEM) or scanning electron microscope (SEM) microstructure analysis shows that in the thin-walled pipes prepared in Examples 1-4, no cracks are found in the reinforcement particles, and no cracks and other microstructures are found at the interface between the reinforcement particles and the matrix Al. Defects, interfacial bonding between particles and matrix is good. The thin-walled pipes of particle-reinforced aluminum-based composite materials prepared in Examples 1-4 have a large diameter-to-wall thickness ratio, smooth inner and outer surfaces without defects, and uniform wall thicknesses.

Claims (9)

1. the preparation method of a thin-wall tubular product of particle-reinforced aluminum-based composite material comprises the steps:

(1) adopt stirring casting technology or powder metallurgical technique to prepare the pipe of particle enhanced aluminum-based composite material;

(2) described pipe is carried out homogenization and handle, turning strips off the skin, and carries out the high temperature compression experiment, obtains the texturizing condition of suitable processing;

(3) described pipe is carried out the spinning finite element numerical simulation, optimize process parameter, and carry out hot spinning and warm spinning, obtain particle enhanced aluminum-based composite material tubing;

(4) the particle enhanced aluminum-based composite material tubing with step (3) gained carries out solution treatment, and after the room temperature shrend, timeliness obtains thin-wall tubular product of particle-reinforced aluminum-based composite material.

2. the preparation method of thin-wall tubular product of particle-reinforced aluminum-based composite material according to claim 1, it is characterized in that: in the described particle enhanced aluminum-based composite material, enhanced granule is Al ₂O ₃Or SiC, the volume fraction of enhanced granule is 5～20%, the average-size of enhanced granule is 0.5 μ m～10 μ m, matrix alloy is 2 * * * be with 6 * * * be.

3. the preparation method of thin-wall tubular product of particle-reinforced aluminum-based composite material according to claim 1, it is characterized in that: the homogenization described in the step (2) is treated to the processing of twin-stage homogenization or the single-stage homogenization is handled, the twin-stage homogenization is treated to: first order heating-up temperature is 410～480 ℃, insulation 6～12h; Second level heating-up temperature is 500～540 ℃, insulation 6～12h; The heating-up temperature that the single-stage homogenization is handled is 500～540 ℃, insulation 12～24h.

4. the preparation method of thin-wall tubular product of particle-reinforced aluminum-based composite material according to claim 1, it is characterized in that: in the high temperature compression test described in the step (2), temperature range is 300～550 ℃, and the temperature interval is 50 ℃, and the strain rate scope is 0.001～10s ^-1The texturizing condition of described suitable processing is 400～550 ℃ for the hot processing temperature scope.

5. the preparation method of thin-wall tubular product of particle-reinforced aluminum-based composite material according to claim 1, it is characterized in that: the passage reduction of hot spinning described in the step (3) and warm spinning is 15～35%, feed ratio is 0.5～2mm/r.

6. the preparation method of thin-wall tubular product of particle-reinforced aluminum-based composite material according to claim 1, it is characterized in that: the spinning temperature of the hot spinning described in the step (3) is 450～540 ℃, the spinning operating angle is 20～25 °, 300～350 ℃ of tool and mould preheatings, and adopting the concurrent heating of oxy-acetylene flame spray gun, feed ratio is 0.5～1.5mm/r.

7. the preparation method of thin-wall tubular product of particle-reinforced aluminum-based composite material according to claim 1, it is characterized in that: the spinning temperature of the warm spinning described in the step (3) is 200～350 ℃, the spinning operating angle is 20～25 °, 200～300 ℃ of tool and mould preheatings, and adopting the concurrent heating of oxy-acetylene flame spray gun, feed ratio is 1～2mm/r.

8. the preparation method of thin-wall tubular product of particle-reinforced aluminum-based composite material according to claim 7 is characterized in that: after described temperature spinning, and annealing, annealing temperature is 250 ℃, insulation 60min; Carry out warm spinning again, warm spinning temperature is 150 ℃, and the spinning operating angle is 25 °, and adopts the discontinuity concurrent heating of oxy-acetylene flame spray gun short time, and feed ratio is 1.5mm/r.

9. the preparation method of thin-wall tubular product of particle-reinforced aluminum-based composite material according to claim 1, it is characterized in that: the temperature of the solution treatment described in the step (4) is 500～545 ℃, holding time 50～150min; Described aging temp is 140～185 ℃, insulation 8～36h.