CN114054722B - High overload resistant foamed zinc-aluminum eutectoid alloy/aluminum alloy composite material and preparation method thereof - Google Patents

Abstract

The invention relates to a high overload resistant zinc-aluminum eutectoid alloy/aluminum alloy composite material and a preparation method thereof. The method comprises the steps of firstly forming a prefabricated composite body by an aluminum alloy pipe and NaCl pore-forming agent particles in a seepage mould, then pouring a zinc-aluminum eutectoid alloy melt into the preheated seepage mould, enabling the zinc-aluminum eutectoid alloy melt to seep into pores of the NaCl pore-forming agent particles under the pressure of filled air, and obtaining the high overload-resistant foamed zinc-aluminum eutectoid alloy/aluminum alloy composite material after completely dissolving the NaCl pore-forming agent particles in water and cutting off foamed zinc-aluminum eutectoid alloy at the upper end, the lower end and the periphery of the aluminum alloy pipe. The composite material obtained by the invention has a series of advantages of good and stable interface connection effect, high load shedding rate, strong damping capacity and energy absorbing capacity, small compression displacement and the like, and has simple process, high production efficiency, outstanding product quality and convenient mass production.

Description

A kind of anti-high overload foam zinc-aluminum eutectoid alloy/aluminum alloy composite material and preparation method thereof

technical field

The technical solution of the invention relates to the technical field of composite materials, in particular to a high overload resistant zinc-aluminum eutectoid alloy/aluminum alloy composite material and a preparation method thereof.

Background technique

The rapid development and application of information technology has promoted the exploration of high-speed launch technology all over the world. The precision electronic components and sensitive components carried by various types of high ^- speed launching smart devices will be subjected to instantaneous and high-energy strong impacts during the high-speed launching process. In some special processes (such as penetration), the impact acceleration is more likely to be as high as 10 ⁵ g. Under the action of such a high acceleration, these precision electronic components and sensitive components will bear huge pressure, so they are very likely to be damaged and fail in the high overload environment of high-speed launch. At present, anti-high overload technology has become one of the main bottlenecks restricting the development of my country's informatization and national defense and military forces.

One of the main methods to improve the high overload resistance of precision devices is to add load shedding components (materials) to them, and use the energy storage and energy consumption mechanism of the load shedding components (materials) to effectively reduce the peak impact acceleration, thereby significantly reducing the high overload. Environmental effects on precision devices. Currently commonly used load shedding components (materials) can be mainly divided into metals and rubbers. Among them, rubber materials are light in weight, large in damping, and strong in buffering effect, but their load capacity is weak, and they are prone to aging and failure in high and low temperature environments; metal materials mainly include disc springs and foamed aluminum. Among them, the disc spring can bear a large impact load and has a strong vibration absorption ability, but its disadvantage is that its mass is too large, which does not meet the lightweight requirements of high-speed launch devices. Aluminum foam has a sponge-like structure. Due to the layer-by-layer collapse of cells or the mechanism of overall distortion and collapse during compression deformation, there will be a long stress plateau in the stress-strain curve, so it can be maintained at a constant stress level. It absorbs a large amount of impact energy under high load conditions, so that precision devices are protected from damage in high overload environments. Therefore, it is expected to be widely used in the field of high-speed transmission. However, the compressive mechanical properties of aluminum foam commonly used at present are relatively low. At the same time, because aluminum itself does not have high damping characteristics, although it has the effect of cell effect on damping enhancement, its overall damping ability is still limited. This will lead to limited energy absorption ability and serious vibration of the protected precision devices during the high-speed launch process, so it is still difficult to obtain wide promotion and application in the field of high-speed launch.

Contents of the invention

The technical problem to be solved by the present invention is: a kind of anti-high overload foamed zinc-aluminum eutectoid alloy/aluminum alloy composite material and its preparation method. In the method, the aluminum alloy tube and NaCl pore-forming agent particles that have been roughened on the inner wall are firstly placed in the The prefabricated composite is formed in the infiltration mold, and then the zinc-aluminum eutectoid alloy melt is poured into the preheated infiltration mold, and the zinc-aluminum eutectoid alloy melt is infiltrated into NaCl to make pores under the pressure of the filled air In the pores of the agent particles, after all the NaCl pore-forming agent particles are dissolved in water and the foamed zinc-aluminum eutectoid alloy at the upper and lower ends of the aluminum alloy tube is cut off, a high-overload-resistant foamed zinc-aluminum eutectoid alloy is obtained / Aluminum alloy composite material. The composite material prepared by the present invention has a series of advantages such as good and stable interface connection effect, high load shedding rate, strong damping ability and energy absorption ability, and small compression displacement, and the process involved is simple, high production efficiency, and high product quality. Prominent and convenient for large-scale production.

Technical scheme of the present invention is:

A high overload resistant foam zinc-aluminum eutectoid alloy/aluminum alloy composite material is composed of an inner core and an outer layer; wherein, the inner core is a columnar foam zinc alloy, and the outer layer is an aluminum alloy tube.

The foamed zinc alloy is preferably a foamed zinc-aluminum eutectoid alloy; the strength of the aluminum alloy tube is greater than that of the inner core material, preferably 6061 aluminum alloy or 7075 aluminum alloy;

The inner diameter of the aluminum alloy tube is 0.8 to 0.9 times the outer diameter;

The average pore diameter of the foam alloy is 0.3mm-0.9mm.

The outer diameter of the aluminum alloy tube is preferably 10-30 mm.

The zinc-aluminum eutectoid alloy is a zinc-aluminum alloy with a specific composition, that is, a zinc-based alloy with an aluminum mass percentage of 22%.

The preparation method of the anti-high overload foam zinc-aluminum eutectoid alloy/aluminum alloy composite material, the specific steps are as follows:

The first step, pretreatment of NaCl pore-forming agent particles:

Put the NaCl pore-forming agent particles into the resistance furnace, heat it up to 430-460°C and keep it warm for 3-4 hours, then sieve the NaCl pore-forming agent particles with a particle size of 0.3-0.9mm for use;

The second step, the preparation and preheating treatment of the percolation mold:

Heat the steel seepage mold to 450-470°C and keep it warm; the steel seepage mold is provided with an upper cover and a lower cover, the upper cover is provided with an air inlet, and the lower cover is provided with an air outlet; the middle and lower parts of the steel seepage mold It is a vertically distributed aluminum alloy tube, and the inside, upper, lower and surrounding parts of the aluminum alloy tube are all compacted NaCl pore-forming agent particles; the height of the aluminum alloy tube is 30-40% of the depth of the percolation mold;

The particle size range of the NaCl pore-forming agent particles is 0.3 mm to 0.9 mm; the number of aluminum alloy tubes in the steel percolation mold is 1 to 30;

The inner wall of the aluminum alloy tube is roughened by steel wire brushing for 3-5 minutes.

The thickness of the NaCl pore-forming agent particles in the lower part of the aluminum alloy tube is 5-7% of the depth of the steel percolation mold; the thickness of the NaCl pore-forming agent particles in the upper part of the aluminum alloy tube is 4-6% of the depth of the steel percolation mold ;

The third step, seepage casting:

After the steel infiltration mold is kept warm for 5-9 minutes, start to melt the zinc-aluminum eutectoid alloy, and then pour the zinc-aluminum eutectoid alloy melt at 650-670°C and hold for 20-25 minutes from the upper part into the infiltration mold, and then cover the infiltration mold Put the upper cover, and fill the infiltration mold with air from the vent hole of the upper cover. After the air pressure in the infiltration mold reaches 0.2-0.3MPa, keep the pressure for 40-60s. After the pressure is released, put the infiltration mold into water at room temperature for cooling , after the mold is cooled to room temperature, the obtained composite is taken out from the percolation mold and set aside;

The fourth step is to prepare foamed zinc-aluminum eutectoid alloy/aluminum alloy composite product:

After the composite body obtained in the previous step is ultrasonically cleaned to remove the NaCl pore-forming agent particles, the zinc-aluminum foam eutectoid alloy at the upper and lower ends of the aluminum alloy tube and the surroundings are cut and removed to obtain a zinc-aluminum foam eutectoid alloy/aluminum alloy composite material. That is, the anti-high overload foam zinc-aluminum eutectoid alloy/aluminum alloy composite material.

The NaCl pore former particles are commercially available.

The beneficial effects of the present invention are: the present invention has the following prominent substantive features:

(1) The present invention adopts air pressure seepage integrated molding casting technology, which can realize the integral molding of foam zinc-aluminum eutectoid alloy and aluminum alloy tube, and has the advantages of convenient material selection, simple process, and high quality of bonding of foam core material and tube wall.

(2) In the technology of the present invention, before infiltration casting, the inner wall of the aluminum alloy tube is polished and roughened with a fine strip steel wire brush, so that the zinc-aluminum eutectoid alloy melt fills the concave area of the rough surface during the infiltration process. After the melt is solidified, the foam core and the tube wall will form a good mechanical engagement, which further improves the bonding strength of the interface, thereby ensuring good load transfer between the alloy tube and the foam, and greatly enhancing the resistance of the composite material obtained. Impact stability and energy absorption, load reduction and vibration reduction effects. Compared with the existing CN109175374A published and Zhu Xiang et al. (Zhu Xiang, Yin Yao, Wang Rui, Kang Miao, Research on Energy Absorption Performance of Foam Aluminum Filled Thin-walled Aluminum Alloy Multicellular Components and Unit Cell Components, Engineering Mechanics, 2021 , 38 (5): 247-256), the preparation method of directly filling the foam core into the hollow tube, the air pressure seepage integrated molding technology of the present invention, not only has high production efficiency, but also because the hollow tube and the foam are synchronized Forming, the connection effect of the interface is good, and the stability is high, which can ensure the good comprehensive performance of the obtained composite material.

(3) In the technology of the present invention, the infiltration mold is quenched immediately after infiltration casting. This ingenious treatment can not only make the foamed zinc-aluminum eutectoid alloy/aluminum alloy composite easier and faster to demould, but more importantly, it can finally make the foamed zinc-aluminum alloy by reducing the β phase of the core foamed zinc-aluminum eutectoid alloy Obtain enough stable lamellar eutectoid structures to improve the mechanical and damping properties of composite materials. This is also a method that has never been involved in the preparation technology of foamed metal materials through the infiltration casting process. This creative technology provides a new idea for the preparation of high-performance zinc-aluminum alloy materials.

(4) The present invention adopts the air pressure seepage integrated forming casting process, and a large number of alloy pipes can be placed inside the mold at the same time (the size of the seepage mold can be adjusted arbitrarily), which improves the production efficiency of the material to a certain extent. For example, the composite material prepared by the air pressure seepage integrated molding casting process of the present invention can be directly used after being cut into the required size, while the prior art needs to cut the foam alloy and the filling tube material separately, so the required construction period It will at least double or even longer; in addition, when using the existing technology to cut separately, it is necessary to consider the size matching between the foam core and the filling tube. If the matching accuracy is not enough, the foam sample needs to be polished or even re-cut, which will increase The construction period is long, and the interface matching degree of the obtained filling pipe composite material is difficult to compare with the interface of the composite material prepared by the air pressure seepage integrated molding casting process of the present invention. If the technology of the present invention and the prior art are used to prepare the same amount of filling pipe composite materials with the same working efficiency, the technology of the present invention can save at least half of the construction period conservatively.

(5) The air pressure seepage integrated molding casting process adopted in the present invention has strong controllability to the preparation of composite materials of different types and with different compressive mechanical performance parameters. Aluminum alloy tubes can also be put into several alloy tubes of different materials at the same time.

(6) The composite material prepared by adopting the technology of the present invention not only significantly increases the compressive mechanical properties due to the existence of the dense aluminum alloy tube, but also has a significantly higher damping capacity than the foamed aluminum material (shown according to the internal friction meter measurement results, the foamed zinc The damping of aluminum eutectoid alloy at room temperature (Q ^-1 ≈ 0.025 ~ 0.03) is about 5 to 6 times that of foamed aluminum (Q - 1 ≈ 0.004 ~ 0.006), and this difference will increase with the temperature expand further). This makes the composite material prepared by the technology of the present invention not only have excellent load shedding performance but also have higher energy absorption ability than aluminum foam in high overload environment, and can play a better role in protecting precision devices. The vibration reduction effect makes it more able to give full play to its functional characteristics. In addition, due to the strong energy-absorbing ability of the composite material, it can successfully protect precision devices from damage in a high-overload environment, and at the same time, the displacement will be smaller. The need for lightweight The cabin space of high-speed launchers is often very limited. By forming high-damping foam material and light weight, high-strength thin-walled aluminum alloy tube into a composite material with high energy absorption, high damping, high unloading rate, and low compression displacement, there is no report yet. This technology originated from the invention of the inventor creative labor.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Fig. 1 is the schematic diagram of the percolation mold adopted by the technology of the present invention and the macroscopic and microscopic appearance diagrams of the produced product, wherein, Fig. 1 (a) is the schematic diagram of the percolation mold adopted by the technology of the present invention; Fig. 1 (b ) is the macroscopic morphology of the foamed zinc-aluminum eutectoid alloy prepared in Example 1 of the present invention (the cutting height is 10 mm). Fig. 1 (c) is the macro-morphology (cutting height is 10mm) of the foam zinc-aluminum eutectoid alloy/6061 aluminum alloy composite material that the embodiment of the present invention 2 makes; Fig. 1 (d) makes for the embodiment of the present invention 3 The macroscopic morphology of the foamed zinc-aluminum eutectoid alloy/6061 aluminum alloy composite material (cutting height is 10mm); Fig. 1 (e) is the foamed zinc-aluminum eutectoid alloy/6061 aluminum alloy composite material obtained in Example 3 of the present invention sectional view (cutting height is 10mm); Fig. 1 (f) is the macroscopic morphology (cutting height is 10mm) of the zinc-aluminum eutectoid foam/6061 aluminum alloy composite material that the embodiment of the present invention 4 and 5 make; 1(g)～figure (i) are the SEM images of the core foam of the zinc-aluminum eutectoid foam/6061 aluminum alloy composite material obtained in Examples 3, 4 and 5 of the present invention respectively; The macroscopic appearance of the foamed zinc-aluminum eutectoid alloy/6061 aluminum alloy composite material that embodiment 6 makes (cutting height is 10mm); Fig. 1 (k) is the foamed zinc-aluminum eutectoid alloy/6061 that the embodiment of the present invention makes Macroscopic morphology of 6061 aluminum alloy composite material (cutting height is 10mm);

Fig. 2 is the energy absorption capacity curves of the foamed zinc-aluminum eutectoid alloy and the foamed zinc-aluminum eutectoid alloy/6061 aluminum alloy composite material prepared in Examples 1-7 (corresponding to sample numbers 1-7#) of the present invention.

Fig. 3 is the damping-temperature diagram of the foamed zinc-aluminum eutectoid alloy prepared in Example 1 of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Example 1:

This embodiment is comparative example:

The first step, pretreatment of NaCl pore-forming agent particles:

Put the NaCl pore-forming agent particles into the resistance furnace, heat it up to 450°C and keep it warm for 3.5 hours to remove its crystallization water and adsorption water, and prevent it from producing gas or bursting during the infiltration casting process, and then sieve it through a standard sieve , to obtain a particle diameter of nearly spherical NaCl pore-forming agent particles of 0.3mm, stand-by;

The second step, the preparation and preheating treatment of the percolation mold:

Pour the NaCl pore-forming agent particles pretreated in the first step into a steel infiltration mold with an inner diameter of 30 mm and a depth of 210 mm, and the bottom cover has four symmetrically distributed round holes with a diameter of 1 mm. When the NaCl pore-forming agent particles After pouring in completely, use a stick with a flat end to press the surface for compaction treatment, and finally put the percolation mold into the crucible resistance furnace, heat it up to 460°C, and keep it for use;

The third step, seepage casting:

After the percolation mold is kept warm for 7 minutes, put the zinc-aluminum eutectoid alloy bar with a mass ratio of 1:3.2 to NaCl particles into a graphite crucible and put it into another crucible resistance furnace and heat it up to 660°C. After the alloy is melted, keep it warm 25 minutes, within this time, evenly spread a layer of soft mud mixed with tap water and clay on the inner edge of the upper cover of the seepage mold, and scrape it flat. Take it out from the furnace, then pour the zinc-aluminum eutectoid alloy melt into the percolation mold, then cover the percolation mold upper cover, and use an air compressor to fill the percolation mold with air from the vent hole of the upper cover, and wait for the percolation mold. After the air pressure reaches 0.25MPa, keep the pressure for 50s. After the pressure is released, put the infiltration mold into water at room temperature for cooling. After the mold is cooled to room temperature, take out the obtained composite from the infiltration mold for use;

The fourth step is to prepare foamed zinc-aluminum eutectoid alloy products:

The composite obtained in the three steps was cleaned in an ultrasonic cleaner for 5.5 hours, and the water was changed every 1 hour to completely dissolve the NaCl pore-forming agent particles to obtain a foamed zinc-aluminum eutectoid alloy material. The obtained foam material was put into a vacuum drying oven and dried at 60° C. for 3.5 hours, that is, a foam zinc-aluminum eutectoid product with an average pore diameter of 0.3 mm was finally obtained.

Example 2:

The first step, pretreatment of NaCl pore-forming agent particles:

Put the NaCl pore-forming agent particles into the resistance furnace, heat it up to 430°C and keep it warm for 4 hours to remove its crystallization water and adsorption water, and prevent it from producing gas or bursting during the percolation casting process, and then sieve it through a standard sieve. Obtaining particle diameter is the nearly spherical NaCl pore-forming agent particle of 0.3mm, stand-by;

The second step, the preparation and preheating treatment of the percolation mold:

Pour the NaCl pore-forming agent particles pretreated in the first step into a steel infiltration mold with an inner diameter of 30 mm and a depth of 210 mm, and the bottom cover has four symmetrically distributed round holes with a diameter of 1 mm. When the NaCl pore-forming agent particles Stop when the height is 10.5mm, press the surface with a rod with a flat end surface for pre-compacting treatment, then polish the inner wall with a wire brush for 3 minutes, with an inner diameter of 8mm, an outer diameter of 10mm, and a height of 63mm. 3 pieces of 6061 Insert the aluminum alloy tube vertically into the percolation mold, and then continue to pour the NaCl pore-forming agent particles. When the NaCl pore-forming agent particles completely cover the aluminum alloy tube and exceed 8.4mm, stop pouring, and then press it with the above-mentioned rod with a flat end surface. The surface is compacted, and finally the infiltration mold is put into the crucible resistance furnace, and it is kept warm after heating up to 450°C for use;

The third step, seepage casting:

After the infiltration mold is kept warm for 5 minutes, put the zinc-aluminum eutectoid alloy rod with a mass ratio of 1:3.2 to NaCl particles into a graphite crucible and put it into another crucible resistance furnace and heat it up to 650°C. After the alloy is melted, keep it warm 25 minutes, within this time, evenly apply a layer of soft mud mixed with sodium silicate aqueous solution and clay on the inner edge of the upper cover of the seepage mold, and scrape it flat. After the zinc-aluminum eutectoid alloy melt is kept warm, the seepage mold Take it out from the crucible resistance furnace, then pour the zinc-aluminum eutectoid alloy melt into the percolation mold, then cover the percolation mold upper cover, and use an air compressor to fill the percolation mold with air from the vent hole of the upper cover, and wait for percolation After the air pressure in the mold reaches 0.2MPa, keep the pressure for 60s. After the pressure is released, put the percolation mold into water at room temperature for cooling. After the mold is cooled to room temperature, take the obtained composite out of the percolation mold for use;

The fourth step is to prepare foamed zinc-aluminum eutectoid alloy/6061 aluminum alloy composite product:

The composite obtained in the three steps was cleaned in an ultrasonic cleaner for 5 hours, and the water was changed every 1 hour to completely dissolve the NaCl pore-forming agent particles. The foamed zinc-aluminum eutectoid alloy at the upper and lower ends of the 6061 aluminum alloy tube and the surroundings are removed to obtain 3 foamed zinc-aluminum eutectoid alloy/6061 aluminum alloy composite materials, and then the composite materials are put into a vacuum drying oven at 50°C to dry After drying for 4 hours, the foamed zinc-aluminum eutectoid alloy/6061 aluminum alloy composite material product is finally obtained, wherein the average pore diameter of the foamed zinc-aluminum eutectoid is 0.3mm, and the wall thickness of the 6061 aluminum alloy tube is 1.0mm.

Example 3:

The first step, pretreatment of NaCl pore-forming agent particles:

Put the NaCl pore-forming agent particles into the resistance furnace, heat it up to 450°C and keep it warm for 3.5 hours to remove its crystallization water and adsorption water, and prevent it from producing gas or bursting during the infiltration casting process, and then sieve it through a standard sieve , to obtain a particle diameter of nearly spherical NaCl pore-forming agent particles of 0.3mm, stand-by;

The second step, the preparation and preheating treatment of the percolation mold:

Pour the NaCl pore-forming agent particles pretreated in the first step into a steel infiltration mold with an inner diameter of 30 mm and a depth of 210 mm, and the bottom cover has four symmetrically distributed round holes with a diameter of 1 mm. When the NaCl pore-forming agent particles Stop when the height is 12mm, press the surface with a rod with a flat end surface for pre-compacting treatment, and then polish the inner wall with a wire brush for 4 minutes, with an inner diameter of 9mm, an outer diameter of 10mm, and a height of 70mm. Three pieces of 6061 aluminum Insert the alloy tube vertically into the percolation mold, then continue to pour NaCl pore-forming agent particles, stop pouring when the NaCl pore-forming agent particles completely cover the aluminum alloy tube and exceed 10mm, and then press the surface with a flat-end rod to make Compaction treatment, and finally put the infiltration mold into the crucible resistance furnace, heat it up to 460°C, and keep it for use;

The third step, seepage casting:

After the percolation mold is kept warm for 7 minutes, put the zinc-aluminum eutectoid alloy bar with a mass ratio of 1:3.2 to NaCl particles into a graphite crucible and put it into another crucible resistance furnace and heat it up to 660°C. After the alloy is melted, keep it warm 25 minutes, within this time, evenly apply a layer of soft mud mixed with sodium silicate aqueous solution and clay on the inner edge of the upper cover of the seepage mold, and scrape it flat. After the zinc-aluminum eutectoid alloy melt is kept warm, the seepage mold Take it out from the crucible resistance furnace, then pour the zinc-aluminum eutectoid alloy melt into the percolation mold, then cover the percolation mold upper cover, and use an air compressor to fill the percolation mold with air from the vent hole of the upper cover, and wait for percolation After the air pressure in the mold reaches 0.25MPa, keep the pressure for 50s. After the pressure is released, put the percolation mold vertically into the water at room temperature for cooling. After the mold is cooled to room temperature, take out the obtained composite from the percolation mold for use;

The fourth step is to prepare foamed zinc-aluminum eutectoid alloy/6061 aluminum alloy composite product:

The composite obtained in the three steps was cleaned in an ultrasonic cleaner for 5.5 hours, and the water was changed every 1 hour to completely dissolve the NaCl pore-forming agent particles. Cut off the zinc-aluminum foam eutectoid alloy at the upper and lower ends of the 6061 aluminum alloy tube and the surroundings to obtain 3 foam zinc-aluminum eutectoid alloy/6061 aluminum alloy composite materials, and then put the obtained composite materials in a vacuum drying oven at 60°C After drying for 3.5 hours, the foamed zinc-aluminum eutectoid/6061 aluminum alloy composite material product is finally obtained, wherein the average pore diameter of the foamed zinc-aluminum eutectoid is 0.3mm, and the wall thickness of the 6061 aluminum alloy tube is 0.5mm.

Example 4:

In this example, except that the nearly spherical NaCl pore-forming agent particles with a particle size of 0.6 mm are obtained by sieving through a standard sieve in the first step, other steps are the same as in Example 3. In the analysis alloy/6061 aluminum alloy composite material product, the average pore diameter of the foamed zinc-aluminum eutectoid alloy is 0.6mm, and the wall thickness of the 6061 aluminum alloy tube is 0.5mm.

Example 5:

In this example, except that the nearly spherical NaCl pore-forming agent particles with a particle size of 0.9 mm are obtained by screening with a standard sieve in the first step, other steps are the same as in Example 3, and the zinc-aluminum foam finally prepared in this example In the analysis alloy/6061 aluminum alloy composite material product, the average pore diameter of the foamed zinc-aluminum eutectoid alloy is 0.9mm, and the wall thickness of the 6061 aluminum alloy tube is 0.5mm.

Embodiment 6:

In this embodiment, three 6061 aluminum alloy tubes with an inner wall of 8 mm in diameter, 10 mm in outer diameter and a height of 70 mm are vertically inserted into the percolation mold in the second step, and the other steps are the same as in embodiment 3. , in the foamed zinc-aluminum eutectoid alloy/6061 aluminum alloy composite material product finally prepared in this embodiment, the average pore diameter of the foamed zinc-aluminum eutectoid is 0.3 mm, and the wall thickness of the 6061 aluminum alloy tube is 1 mm.

Embodiment 7:

The first step, pretreatment of NaCl pore-forming agent particles:

Put the NaCl pore-forming agent particles into the resistance furnace, heat it up to 460°C and keep it warm for 3 hours to remove its crystallization water and adsorption water, and prevent it from generating gas or bursting during the percolation casting process, and then sieve it through a standard sieve. Obtaining particle diameter is the nearly spherical NaCl pore-forming agent particle of 0.3mm, stand-by;

The second step, the preparation and preheating treatment of the percolation mold:

Pour the NaCl pore-forming agent particles pretreated in the first step into a steel infiltration mold with an inner diameter of 30 mm and a depth of 210 mm, and the bottom cover has four symmetrically distributed round holes with a diameter of 1 mm. When the NaCl pore-forming agent particles Stop when the pouring height is 14.7mm, press the surface with a rod with a flat end surface for pre-compacting treatment, and then polish the inner wall with a wire brush for 5 minutes, with an inner diameter of 9mm, an outer diameter of 10mm, and a height of 84mm. Three pieces of 6061 Insert the aluminum alloy tube vertically into the percolation mold, and then continue to pour the NaCl pore-forming agent particles. When the NaCl pore-forming agent particles completely cover the aluminum alloy tube and exceed 12.6mm, stop pouring, and then press it with a rod with a flat end. The surface is compacted, and finally the percolation mold is put into the crucible resistance furnace, and the temperature is raised to 470°C, and then kept for use;

The third step, seepage casting:

After the infiltration mold is kept warm for 9 minutes, put the zinc-aluminum eutectoid alloy bar with a mass ratio of 1:3.2 to NaCl particles into a graphite crucible and put it into another crucible resistance furnace and raise the temperature to 670°C, and keep it warm after the alloy is melted 20 minutes, within this time, evenly apply a layer of soft mud mixed with sodium silicate aqueous solution and clay on the inner edge of the upper cover of the percolation mold, and scrape it flat. Take it out from the crucible resistance furnace, then pour the zinc-aluminum eutectoid alloy melt into the percolation mold, then cover the percolation mold upper cover, and use an air compressor to fill the percolation mold with air from the vent hole of the upper cover, and wait for percolation After the air pressure in the mold reaches 0.3MPa, keep the pressure for 40s, then put the infiltration mold vertically into the water at room temperature for cooling, and after the mold is cooled to room temperature, take out the obtained composite from the infiltration mold for use;

The fourth step is to prepare foamed zinc-aluminum eutectoid alloy/6061 aluminum alloy composite product:

The composite obtained in the three steps was cleaned in an ultrasonic cleaner for 6 hours, and the water was changed every 1 hour to completely dissolve the NaCl pore-forming agent particles. The foamed zinc-aluminum eutectoid alloy at the upper and lower ends of the 6061 aluminum alloy tube and the surrounding areas are cut off to obtain 3 foamed zinc-aluminum eutectoid alloy/6061 aluminum alloy composite materials, and then the composite materials obtained are put into a vacuum drying oven and dried at 70°C After drying for 3 hours, the foamed zinc-aluminum eutectoid alloy/6061 aluminum alloy composite material product is finally obtained, wherein the average pore diameter of the foamed zinc-aluminum eutectoid alloy is 0.3 mm, and the wall thickness of the 6061 aluminum alloy tube is 0.5 mm.

The numbers of the samples prepared in the above-mentioned Examples 1-7 are 1-7#, that is, the numbers of the examples correspond to the numbers of the samples.

Fig. 1 (a) shows the schematic diagram of the percolation mold adopted by the technology of the present invention. The composite material finished product prepared by adopting the technology of the present invention is cylindrical (as shown in Fig. 1 (c, d, f, j, k)). Figure 1(e) shows the cross-sectional view of the foamed zinc-aluminum eutectoid alloy/6061 aluminum alloy composite material obtained in Example 3. It can be seen from the figure that the core foam and the thin-walled aluminum alloy tube present a good mechanical engagement state, and the interface The combination is tight, which guarantees the smooth transmission of stress between the two. Figure 1 (g-i) shows the SEM images of the core foam of the zinc-aluminum eutectoid foam/6061 aluminum alloy composite material obtained in Examples 3-5, and it can be seen from the figure that the core of the composite material is evenly distributed in pores The open-cell foam zinc-aluminum eutectoid alloy has a strong connection between the cell walls and no obvious seepage casting defects. All of the composites shown in Figure 1 share the high-quality properties of the composites described above.

Fig. 2 shows the energy absorption capacity curves of the composite products prepared in Examples 1-7. It can be seen from the figure that the foamed zinc-aluminum eutectoid alloy/6061 aluminum alloy composite material has significantly improved energy absorption capacity (up to about 19MJ/m ³ ) compared with the foamed zinc-aluminum eutectoid alloy. In addition, the energy-absorbing capacity of the composite material will increase with the increase of the wall thickness of the aluminum alloy tube and the increase of the pore size of the foam. The high strength and high energy absorption capacity of the composite material prepared by the technology of the present invention can be attributed not only to the synergistic effect of the core foam and the aluminum alloy tube, but also to the good interface formed between the two.

Figure 3 shows the damping-temperature diagram of the foamed zinc-aluminum eutectoid alloy. It can be seen that the foamed zinc-aluminum eutectoid alloy has ultra-high damping capacity. It is precisely because of the high damping characteristic of the core foam of the composite material that the foam zinc-aluminum eutectoid alloy/6061 aluminum alloy composite material prepared by the technology of the present invention also has high damping ability.

从而说明采用本发明技术制备的锌铝共析合金/6061铝合金复合材料具有优良的应力减载效果。结合图2、图3同时可知，采用本发明技术制备的锌铝共析合金/6061铝合金复合材料亦具有高的吸能本领和阻尼本领，因此本发明技术所制备的锌铝共析合金/6061铝合金复合材料在抗高过载的军事工程领域极具应用价值。Table 1 shows the stress in the dynamic compression process of the foamed zinc-aluminum eutectoid alloy and the foamed zinc-aluminum eutectoid alloy/6061 aluminum alloy composite material prepared in Examples 1-7 (corresponding to sample numbers 1-7#) of the present invention Load shedding performance (using split Hopkinson pressure bar test). It can be seen from the table that the stress unloading rate of all samples has reached more than 89%.

This shows that the zinc-aluminum eutectoid alloy/6061 aluminum alloy composite material prepared by the technology of the present invention has excellent stress relief effect. In conjunction with Fig. 2 and Fig. 3, it can be seen that the zinc-aluminum eutectoid alloy/6061 aluminum alloy composite material prepared by the technology of the present invention also has high energy absorption capacity and damping capacity, so the zinc-aluminum eutectoid alloy/6061 aluminum alloy composite material prepared by the technology of the present invention The 6061 aluminum alloy composite material has great application value in the military engineering field of high overload resistance.

In summary, the composite material prepared by the technology of the present invention makes up for the fact that the foamed zinc-aluminum eutectoid alloy can withstand small loads, be easily unstable and collapse, and have weak energy absorption capacity when used alone, while the 6061 aluminum alloy thin-walled tube is non-axial. The bearing capacity is poor, the failure process is difficult to control, and the damping load reduction ability is poor. This kind of composite material has outstanding advantages such as high bearing capacity, strong energy absorption ability and damping ability, high load shedding efficiency, high stability, and service in extreme environments. It is very suitable for precision devices in high overload environments during high-speed launching. protection. The composite material can not only effectively reduce the load of precision devices with a small compression displacement as a load reduction material, but also protect the precision devices from vibration, so that their functional characteristics can be fully exerted.

Table 1 shows the stress in the dynamic compression process of the foamed zinc-aluminum eutectoid alloy and the foamed zinc-aluminum eutectoid alloy/6061 aluminum alloy composite material prepared in Examples 1-7 (corresponding to sample numbers 1-7#) of the present invention Load shedding performance (using split Hopkinson pressure bar test).

Table 1

serial number Input stress peak value/MPa Input stress duration/μs Output stress peak value/MPa Output stress duration/μs Stress unloading rate/% 1# 449 177 19.8 173 95.6 2# 406 164 41.0 155 89.9 3# 437 161 26.6 165 93.9 4# 439 163 28.5 156 93.5 5# 431 161 29.3 160 93.2 6# 413 163 42.9 158 89.6 7# 421 162 25.8 166 93.9

Matters not covered in the present invention are known technologies.

Claims (6)

1. A high overload resistant foamed zinc-aluminum eutectoid alloy/aluminum alloy composite material is characterized in that the material comprises an inner core and an outer layer; wherein the inner core is columnar foam zinc-aluminum eutectoid alloy, and the outer layer is an aluminum alloy pipe; the strength of the aluminum alloy pipe is greater than that of the inner core material;

the preparation method of the high overload-resistant foamed zinc-aluminum eutectoid alloy/aluminum alloy composite material comprises the following steps:

firstly, pretreatment of NaCl pore-forming agent particles:

placing NaCl pore-forming agent particles into a resistance furnace, keeping the temperature for 3-4 hours after the temperature is raised to 430-460 ℃, and then screening the NaCl pore-forming agent particles with the particle size of 0.3-0.9 mm for later use;

secondly, preparing and preheating a seepage die:

heating the steel seepage die to 450-470 ℃ and then preserving heat; the steel seepage die is provided with an upper cover and a lower cover, the upper cover is provided with an air inlet, and the lower cover is provided with an air outlet; the middle lower part in the steel seepage die is an aluminum alloy pipe which is vertically distributed, and the inside, the upper part, the lower part and the periphery of the aluminum alloy pipe are compacted NaCl pore-forming agent particles; the height of the aluminum alloy pipe is 30-40% of the depth of the seepage die;

the particle size range of the NaCl pore-forming agent particles is 0.3 mm-0.9 mm; the number of the aluminum alloy pipes in the steel seepage die is 1-30;

thirdly, seepage casting:

after the steel seepage mould is kept warm for 5-9 min, smelting zinc-aluminum eutectoid alloy, pouring the zinc-aluminum eutectoid alloy melt which is 650-670 ℃ and kept warm for 20-25 min into the seepage mould from the upper part, covering an upper cover of the seepage mould, filling air into the seepage mould from an air inlet of the upper cover, keeping the pressure for 40-60 s after the air pressure in the seepage mould reaches 0.2-0.3 MPa, putting the seepage mould into water at room temperature for cooling after the pressure is released, and taking out the obtained composite from the seepage mould after the mould is cooled to the room temperature for standby;

fourthly, preparing a foamed zinc-aluminum eutectoid alloy/aluminum alloy composite material product:

and (3) removing NaCl pore-forming agent particles from the composite body obtained in the previous step through ultrasonic cleaning, and then cutting to remove the foam zinc-aluminum eutectoid alloy at the upper end, the lower end and the periphery of the aluminum alloy pipe, thereby obtaining the foam zinc-aluminum eutectoid alloy/aluminum alloy composite material, namely the high overload resistant foam zinc-aluminum eutectoid alloy/aluminum alloy composite material.

2. The high overload resistant zinc aluminum eutectoid alloy/aluminum alloy composite material according to claim 1, wherein the aluminum alloy tube is made of 6061 aluminum alloy or 7075 aluminum alloy.

3. The high overload resistant foamed zinc-aluminum eutectoid alloy/aluminum alloy composite material according to claim 1, wherein the inner diameter of the aluminum alloy pipe is 0.8-0.9 times of the outer diameter; the outer diameter of the aluminum alloy pipe is 10-30 mm;

the average pore diameter of the foamed zinc-aluminum eutectoid alloy is 0.3 mm-0.9 mm.

4. The high overload-resistant foamed zinc-aluminum eutectoid alloy/aluminum alloy composite material according to claim 1, which is characterized in that in the preparation method, the thickness of NaCl pore-forming agent particles at the lower part of an aluminum alloy pipe is 5-7% of the depth of a steel seepage die; the thickness of NaCl pore-forming agent particles at the upper part of the aluminum alloy pipe is 4-6% of the depth of the steel seepage die.

5. The high overload-resistant foamed zinc-aluminum eutectoid alloy/aluminum alloy composite material according to claim 1, which is characterized in that in the preparation method, the inner wall of the aluminum alloy pipe is subjected to rough treatment of grinding for 3-5 min by a wire brush.

6. The preparation method of the high overload resistant foamed zinc-aluminum eutectoid alloy/aluminum alloy composite material is characterized by comprising the following steps:

firstly, pretreatment of NaCl pore-forming agent particles:

placing NaCl pore-forming agent particles into a resistance furnace, keeping the temperature for 3-4 hours after the temperature is raised to 430-460 ℃, and then screening the NaCl pore-forming agent particles with the particle size of 0.3-0.9 mm for later use;

secondly, preparing and preheating a seepage die:

heating the steel seepage die to 450-470 ℃ and then preserving heat; the steel seepage die is provided with an upper cover and a lower cover, the upper cover is provided with an air inlet, and the lower cover is provided with an air outlet; the middle lower part in the steel seepage die is an aluminum alloy pipe which is vertically distributed, and the inside, the upper part, the lower part and the periphery of the aluminum alloy pipe are compacted NaCl pore-forming agent particles; the height of the aluminum alloy pipe is 30-40% of the depth of the seepage die;

the particle size range of the NaCl pore-forming agent particles is 0.3 mm-0.9 mm; the number of the aluminum alloy pipes in the steel seepage die is 1-30;

thirdly, seepage casting:

after the steel seepage mould is kept warm for 5-9 min, smelting zinc-aluminum eutectoid alloy, pouring the zinc-aluminum eutectoid alloy melt which is 650-670 ℃ and kept warm for 20-25 min into the seepage mould from the upper part, covering an upper cover of the seepage mould, filling air into the seepage mould from an air inlet of the upper cover, keeping the pressure for 40-60 s after the air pressure in the seepage mould reaches 0.2-0.3 MPa, putting the seepage mould into water at room temperature for cooling after the pressure is released, and taking out the obtained composite from the seepage mould after the mould is cooled to the room temperature for standby;

fourthly, preparing a foamed zinc-aluminum eutectoid alloy/aluminum alloy composite material product:

removing NaCl pore-forming agent particles from the composite body obtained in the previous step through ultrasonic cleaning, and then cutting to remove foamed zinc-aluminum eutectoid alloy at the upper end, the lower end and the periphery of the aluminum alloy pipe to obtain a foamed zinc-aluminum eutectoid alloy/aluminum alloy composite material, namely a high overload resistant foamed zinc-aluminum eutectoid alloy/aluminum alloy composite material;

the composition of the material comprises an inner core and an outer layer; wherein the inner core is columnar foam zinc-aluminum eutectoid alloy, and the outer layer is an aluminum alloy pipe; the strength of the aluminum alloy pipe is greater than that of the inner core material.

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