CN114653906A - A kind of preparation method and system device of metal matrix composite plate - Google Patents

Abstract

The invention provides a preparation method and a system device for a metal matrix composite sheet. The preparation method comprises the steps of cooling the metal matrix melt to a semi-solid slurry, mixing it with reinforcing particles, and performing electromagnetic vibration and casting and rolling to obtain crystal grains. Small metal matrix composite sheet, the preparation method can improve the mechanical properties of the metal matrix composite sheet, reduce the grain size of the composite sheet, and improve the tensile strength and elongation at break; the system device used for the preparation method includes a mixing device , an outlet channel arranged on one side of the lower part of the mixing device, and an electromagnetic vibration device and a casting and rolling device connected with the outlet channel in sequence, the device has a simple structure and high efficiency.

Description

A kind of preparation method and system device of metal matrix composite plate

technical field

The invention relates to the technical field of material forming, in particular to a preparation method and a system device of a metal matrix composite plate.

Background technique

Continuous casting and rolling of metal alloys refers to the process in which metal alloy melts undergo rolling deformation at the same time as continuous casting and solidification. The liquid metal alloy is directly poured into the roll gap, and the roll not only acts as a mold, but also presses and deforms the metal at the same time. This process is also called liquid rolling or ingotless rolling. The distance from the front edge of the feeding nozzle to the center line of the casting roll becomes the casting area. When the liquid metal enters the casting area through the feeding nozzle, it immediately meets the two rotating casting rolls, and the heat of the liquid metal continuously flows from the vertical direction. It is transmitted to the casting roll in the direction of the casting roll surface, and the temperature of the liquid metal adhering to the casting roll surface is rapidly lowered, so that the liquid metal is cooled, crystallized, and solidified on the casting roll surface. With the continuous rotation of the casting roll, the heat of the liquid metal continues to be transferred to the casting and rolling, and is continuously taken away by the cooling water in the casting roll, the crystals continue to grow into the liquid, and the solidified layer thickens accordingly. The liquid metal is in contact with the two casting rolls at the same time and crystallizes at the same time. The crystallization process and conditions are the same, and the speed and thickness of the solidified layer are the same. When the center lines of the rolls meet below, the casting process is completed, and then the two casting rolls are subjected to the rolling action of the solidified structure of the two casting rolls, and a certain rolling processing rate is given. This is the basic principle of continuous casting and rolling.

The particle-reinforced metal matrix composite material is a metal matrix composite material comprising a metal or alloy matrix reinforced with particles such as carbides, nitrides, and graphite. The base metal and reinforcing particles can be selected according to the working conditions. The commonly used particles are silicon carbide, titanium carbide, boron carbide, tungsten carbide, aluminum oxide, silicon nitride, titanium boride, boron nitride and graphite. The size of the powder is generally 3.5 to 10 μm, and there are also particles of <3.5 μm and 30 μm, and the content ranges from 5% to 75%, depending on the needs. Metal substrates include aluminum, magnesium, titanium, copper, iron, etc. and their alloys. Manufacturing methods include powder metallurgy, casting, vacuum pressure impregnation and co-spray deposition. It can be directly made into parts, or it can be made into ingots for hot extrusion, forging, rolling, etc.

CN105312520B discloses a continuous casting and rolling method for manufacturing silicon carbide particle reinforced aluminum-based composite profiles. The mechanical stirring method is used to prepare silicon carbide particle-reinforced aluminum base material composite slurry, and the slurry is continuously and uniformly injected into two castings through a flow distribution component. In the casting and rolling molten pool composed of roll units, the continuous casting and rolling of silicon carbide particles reinforced aluminum substrate composite profiles is realized, but the grains of metal alloys are coarse, and the mechanical properties of metal alloy cast-rolled sheets are poor.

CN110935852A discloses a continuous fiber reinforced metal matrix composite material strip preparation equipment and method. The manufacturing equipment includes a fiber wire feeding mechanism, a pouring front box, a casting and rolling mechanism, and a cooling system. The fiber wire feeding mechanism is provided with a front pressure plate, The rear pressing plate and the fiber protection gas circulation system have the functions of fiber gas protection and tension, but the grains of the metal alloy are coarse, and the mechanical properties of the metal alloy cast-rolled sheet are poor.

CN1325197C discloses a double-roll ultra-high-speed continuous casting machine for magnesium sheet and strip. The double-roll continuous casting machine is composed of solidification rolls, forming rolls and an integrated front box overflow nozzle. In the continuous casting machine, the solidification and forming of the magnesium sheet and strip are completed at different positions on the solidification roll and the forming roll, but the grains of the metal alloy are coarse, and the mechanical properties of the metal alloy cast and rolled sheet are poor.

Therefore, it is necessary to develop a method that can prepare a fine-grained metal matrix composite sheet to improve the mechanical properties of the metal matrix composite sheet.

SUMMARY OF THE INVENTION

In view of the problems existing in the prior art, the present invention provides a method for preparing a metal matrix composite sheet, which is achieved by mixing semi-solid slurry and reinforcing particles, and then casting and rolling after electromagnetic vibration to obtain small crystal grains. The metal matrix composite sheet, the system device used for the preparation method includes a mixing device, an outlet channel, an electromagnetic vibration device and a casting and rolling device, thereby improving the mechanical properties of the metal matrix composite sheet, reducing the grain size of the composite sheet, and improving the tensile strength and tensile strength. Elongation at break.

For this purpose, the present invention adopts the following technical solutions:

In a first aspect, the present invention provides a preparation method of a metal matrix composite sheet, the preparation method comprising the following steps:

(1) cooling the metal-based melt to a semi-solid state to obtain a semi-solid slurry;

(2) mixing the semi-solid slurry and reinforcing particles to obtain a semi-solid slurry containing a reinforcing phase;

(3) The semi-solid slurry containing the reinforcing phase is cast and rolled after electromagnetic vibration to obtain a metal matrix composite plate.

The invention cools the metal-based melt to a semi-solid state to obtain a semi-solid slurry. At this time, the temperature is located above the solid-liquid two-phase region in the phase diagram, and the semi-solid slurry still has good fluidity; the semi-solid slurry is mixed with Reinforcing the particle body to obtain a semi-solid slurry containing a reinforcing phase. At this time, the semi-solid slurry containing a reinforcing phase contains liquid metal, primary metal matrix phase and solid reinforcing particles. To the effect of heterogeneous nucleation, the nucleation position of the metal matrix is increased, and the grain refinement is promoted; the semi-solid slurry containing the reinforcing phase is electromagnetically vibrated, so that mechanical waves or mechanical disturbances are loaded on the slurry to be solidified. The effect of crushing the thixotropic crystal grains to further refine the grains, and then casting and rolling, the obtained metal matrix composite sheet has small grain size, near-net shape, and improves tensile strength and elongation at break. , the mechanical properties are improved.

Preferably, the semi-solid slurry in step (1) contains liquid metal and primary metal matrix phase.

Preferably, the metal in step (1) includes any one or a combination of at least two of aluminum alloy, magnesium alloy, titanium alloy, copper alloy or iron alloy, wherein a typical but non-limiting combination is: aluminum alloy and magnesium Combinations of alloys, combinations of titanium alloys and copper alloys, combinations of titanium alloys, copper alloys and iron alloys, etc.

The metal-based melts of the present invention include pure metal melts or metal alloy melts. The metal alloy melts are not limited to only contain metals, but may also contain non-metallic substances, as long as the alloy melts are mainly composed of metal elements. It is sufficient to use the alloy, for example, the alloy can be AZ91D magnesium alloy, AZ31D magnesium alloy or 7075 aluminum alloy.

Preferably, the melted metal-based melt is kept warm before the cooling.

In the present invention, the melted metal-based melt is kept warm before the temperature is lowered, in order to promote the uniformity of the melt composition and to stabilize the melt state in the liquid phase region.

Preferably, the incubation time is 15-25 min, such as 15 min, 16 min, 17 min, 18 min, 19 min, 20 min, 21 min, 22 min, 23 min, 24 min or 25 min, etc.

Preferably, the mixing in step (2) is performed under stirring.

Preferably, the stirring time is 1～120min, for example, it can be 1min, 10min, 20min, 30min, 40min, 50min, 60min, 70min, 80min, 90min, 100min, 110min or 120min, etc., preferably 5～60min.

Preferably, the stirring includes mechanical stirring and/or ultrasonic stirring.

Preferably, the rotational speed of the mechanical stirring is 1-3000r/min, for example, it can be 1r/min, 10r/min, 100r/min, 300r/min, 500r/min, 800r/min, 1000r/min, 1500r/min , 2000r/min, 2500r/min or 3000r/min, etc., preferably 5-200r/min.

Preferably, the frequency of the ultrasonic stirring is 20-130 kHz, such as 20 kHz, 30 kHz, 40 kHz, 50 kHz, 60 kHz, 70 kHz, 80 kHz, 90 kHz, 100 kHz, 110 kHz, 120 kHz or 130 kHz.

Preferably, the reinforcing particles include any one or a combination of at least two of carbides, nitrides, oxides, carbon fibers, glass fibers, graphene, carbon nanotubes or graphite, among which typical but non-limiting The combination is: the combination of carbide and nitride, the combination of oxide and carbon fiber, the combination of oxide and graphite, the combination of glass fiber, graphene and carbon nanotube, etc.

The carbide in the present invention can be either a single carbide or a mixture of multiple carbides, which is not particularly limited here.

In the present invention, the nitride can be either a single carbide or a mixture of multiple nitrides, which is not particularly limited here.

In the present invention, the oxide can be either a single carbide or a mixture of multiple oxides, which is not particularly limited here.

Preferably, the carbide includes silicon carbide, titanium carbide, boron carbide or tungsten carbide.

Preferably, the nitride comprises boron nitride, phosphorus nitride, silicon nitride, titanium nitride, magnesium nitride, aluminum nitride, manganese nitride or zirconium nitride.

Preferably, the oxide comprises titanium oxide, silicon oxide, magnesium oxide, aluminum oxide, ceria, zirconium oxide, lanthanum oxide or tungsten oxide.

Preferably, the particle size of the reinforcing particles is 0.1 to 200 μm, for example, 0.1 μm, 1 μm, 10 μm, 30 μm, 50 μm, 80 μm, 100 μm, 130 μm, 150 μm, 180 μm or 200 μm, preferably 5 to 100 μm.

Preferably, the mass ratio of the semi-solid slurry to the reinforcing particles is (200-1.5):1, for example, 200:1, 180:1, 150:1, 130:1, 100:1, 50:1 1, 25:1, 20:1, 15:1, 10:1, 5:1, 3:1, 2:1 or 1.5:1, etc., preferably (20-4):1.

In the present invention, the mass ratio of the semi-solid slurry to the reinforced particles is (200-1.5): 1, which can not only ensure that the metal matrix composite plate has sufficient volume fraction of the particle reinforced phase, but also avoid the low fluidity of the mixed slurry. Difficulty in casting.

Preferably, the volume solid ratio of the semi-solid slurry is 1-80%, for example, it can be 1%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70% or 80%, etc., preferably 12 to 30%.

In the present invention, the volume solid ratio of the semi-solid slurry is 1-80%, which can not only ensure the thixotropic forming characteristics of the semi-solid slurry, but also avoid the difficulty in forming the cast-rolled sheet due to the poor fluidity of the slurry.

Preferably, the amplitude of the electromagnetic vibration in step (3) is 0.5-50 mm, such as 0.5 mm, 1 mm, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm or 50 mm.

Preferably, the frequency of the electromagnetic vibration is 0.1-1000 Hz, such as 0.1 Hz, 1 Hz, 10 Hz, 100 Hz, 200 Hz, 400 Hz, 500 Hz, 600 Hz, 700 Hz, 800 Hz or 1000 Hz, etc., preferably 5-100 Hz.

Preferably, the reinforcing phase-containing semi-solid slurry is driven by the pressure of the gas, and is cast and rolled after being subjected to electromagnetic vibration.

Preferably, the gas comprises any one or a combination of at least two of argon, carbon dioxide, nitrogen dioxide, sulfur hexafluoride, nitrogen or helium, wherein a typical but non-limiting combination is: argon and Combination of carbon dioxide, combination of nitrogen dioxide and sulfur hexafluoride, combination of sulfur hexafluoride, nitrogen and helium, etc.

Preferably, the pressure of the gas is 0.1-70 MPa, such as 0.1 MPa, 0.2 MPa, 0.5 MPa, 1 MPa, 10 MPa, 20 MPa, 30 MPa, 40 MPa, 50 MPa, 60 MPa or 70 MPa, etc., preferably 0.2-10 MPa.

Preferably, the casting includes eccentric twin roll casting or non-eccentric twin roll casting, preferably eccentric twin roll casting.

In the present invention, the eccentric double-roller casting and rolling can be used to effectively increase the area of the casting and rolling solidification zone and improve the stability of the casting and rolling process.

Preferably, the rotation speed of the lower roll during casting and rolling is 1-3000r/min, for example, it can be 1r/min, 10r/min, 100r/min, 200r/min, 500r/min, 800r/min, 1000r/min, 1500r/min, 2000r/min, 2500r/min or 3000r/min, etc., preferably 50-1000r/min.

Preferably, the rotation speed of the upper roll in the casting and rolling is 1-3000r/min, such as 1r/min, 10r/min, 100r/min, 200r/min, 500r/min, 800r/min, 1000r/min, 1500r/min, 2000r/min, 2500r/min or 3000r/min, etc., preferably 50-1000r/min.

In eccentric twin-roll casting, the lower roll has a cooling function and the upper roll has a deformation function. In non-eccentric twin-roll casting, both the lower roll and the upper roll have both a cooling function and a deformation function.

As the preferred technical solution of the present invention, the preparation method comprises the following steps:

(1) after the molten metal-based melt is kept warm for 15 to 25 minutes, the temperature is lowered to a semi-solid state to obtain a semi-solid slurry;

(2) Mix the semi-solid slurry with a mass ratio of (200～1.5):1 under mechanical stirring and/or ultrasonic stirring and the reinforced particles with a particle size of 0.1～200 μm for 1～120min, wherein the rotational speed of the mechanical stirring is 1 to 3000 r/min, the frequency of ultrasonic stirring is 20 to 130 kHz, and a semi-solid slurry containing a reinforcing phase with a volume solid phase ratio of 1 to 80% is obtained;

(3) The gas with the pressure of 0.1-70MPa is used to drive the flow of the semi-solid slurry containing the reinforcing phase, and it is cast and rolled after the electromagnetic vibration with the amplitude of 0.5-50mm and the frequency of 0.1-1000Hz. Rolling or eccentric twin-roll casting, the rotating speed of the lower roll is 1-3000 r/min and the rotating speed of the upper roll is 1-3000 r/min in the casting and rolling to obtain a metal matrix composite plate.

In a second aspect, the present invention provides a system device for preparing a metal matrix composite plate, the system device is used for the preparation method of a metal matrix composite plate according to the first aspect; the system device includes a mixing device, which is arranged in the mixing device The outlet channel on one side of the lower part, and the electromagnetic vibration device and the casting and rolling device connected with the outlet channel in sequence.

The metal-based melt is cooled in the mixing device to form a semi-solid state, and the reinforcing particles are added to the mixing device, so that the semi-solid slurry and the reinforcing particles are mixed, and the heterogeneous nucleation effect increases the nucleation position of the metal matrix and promotes the grain size. Refinement to obtain a semi-solid slurry containing a reinforcing phase. After the semi-solid slurry containing a reinforcing phase passes through the outlet channel, it is subjected to electromagnetic vibration by an electromagnetic vibration device, and the crystal grains to be thixotropic are broken by the action of mechanical shear waves. To achieve the effect of further refinement of grains, casting and rolling are carried out through a casting and rolling device to obtain a metal matrix composite plate.

Preferably, the system device further comprises a gas release device.

Preferably, the gas release device is arranged at the front end of the mixing device.

In the present invention, the gas releasing device fills the high-pressure gas into the mixing device, so that the semi-solid slurry containing the reinforcing phase flows under the pressure of the gas and flows out from the outlet channel.

Preferably, the mixing device includes a mixing tank.

Preferably, the mixing box is provided with a heating device.

In the present invention, the mixing box is provided with a heating device, and the melted metal-based melt is heated during heat preservation before cooling, so as to ensure that the metal in the mixing box is kept in a liquid state.

Preferably, a stirring device is provided in the mixing box.

Preferably, the stirring device includes a mechanical stirring device and/or an ultrasonic stirring device.

Preferably, a temperature measuring device is provided in the mixing box.

The present invention has no limitation on the temperature measuring device, and any instrument known to those skilled in the art that can be used to measure temperature can be used, and a resistance heating system that can digitally control temperature can also be used, which is not particularly limited here.

Preferably, a solid adding device is provided in the mixing box.

The present invention does not limit the device for adding solids, and any device known to those skilled in the art that can be used for adding solids can be used, and no particular limitation is made here.

Preferably, a heating device is provided on the outlet channel.

In the present invention, a heating device is arranged on the outlet channel to ensure that the semi-solid slurry containing the reinforcing phase will not solidify into a full solid state after flowing out from the outlet, and the fluidity of the semi-solid slurry containing the reinforcing phase is maintained.

Preferably, the casting and rolling device comprises an eccentric twin-roll casting and rolling device or a non-eccentric twin-roll casting and rolling device.

Preferably, the casting and rolling device includes a lower roll and an upper roll.

Preferably, the ratio of the diameters of the lower roll to the upper roll is 1 to 3, for example, 1, 1.3, 1.5, 1.8, 2, 2.3, 2.5, 2.8 or 3, etc.

In the present invention, the diameters of the lower roll and the upper roll can be equal or unequal. When the diameters of the lower roll and the upper roll are not equal, asynchronous rolling can be achieved to optimize the texture distribution of the cast and rolled sheet.

Preferably, the roll gap width between the lower roll and the upper roll is 0.1-20mm, for example, 0.1mm, 0.5mm, 1mm, 5mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm or 20mm.

In the present invention, a method for preparing a metal matrix composite plate by using a system device for preparing a metal matrix composite plate, the method comprises the following steps:

(1) Turn on the heating device in the mixing box, keep the melted metal-based melt in the mixing box of the mixing device for 15-25 minutes, close the heating device in the mixing box, observe the temperature measuring device in the mixing box, put the The metal-based melt is cooled to a semi-solid state to obtain a semi-solid slurry;

(2) Add reinforced particles with a particle size of 0.1 to 200 μm into the mixing box through a solid adding device, and use a mechanical stirring device and/or an ultrasonic stirring device to stir and mix a semi-solid with a mass ratio of (200 to 1.5):1. Slurry and reinforced particles for 1 to 120 minutes, wherein the rotational speed of mechanical stirring is 1 to 3000 r/min, and the frequency of ultrasonic stirring is 20 to 130 kHz to obtain a semi-solid slurry containing a reinforcing phase with a volume solid phase rate of 1 to 80% ;

(3) The gas with a pressure of 0.1 to 70 MPa is released by the gas release device, and the semi-solid slurry containing the reinforcing phase flows through the electromagnetic vibration device with an amplitude of 0.5 to 50 mm and a frequency of 0.1 to 1000 Hz for electromagnetic vibration. In the casting and rolling device For casting and rolling, the rotation speed of the lower roll in the casting and rolling device is 1~3000r/min, the rotation speed of the upper roll is 1~3000r/min, the ratio of the diameter of the lower roll and the upper roll is 1~3, and the difference between the lower roll and the upper roll is 1~3. The width of the roll gap is 0.1-20 mm to obtain a metal matrix composite sheet.

Compared with the prior art, the present invention at least has the following beneficial effects:

(1) The preparation method of the metal matrix composite plate provided by the present invention, by mixing semi-solid slurry and reinforcing particles, and electromagnetic vibration, the prepared metal matrix composite plate has fine grains, and the grain size is ≤100.5 μm, and the preferred condition is , the grain size is less than or equal to 50.9 μm;

(2) According to the preparation method of the metal matrix composite sheet provided by the present invention, the obtained metal matrix composite sheet has uniform structure, excellent mechanical properties, tensile strength≥168MPa, elongation at break≥1.2%, and under optimal conditions, tensile strength≥190MPa , elongation at break ≥ 2.3%;

(3) The preparation method of the metal matrix composite sheet provided by the present invention belongs to the near-net-shape technology and has high efficiency;

(4) The system device for preparing a metal matrix composite plate provided by the present invention has a simple structure and a short process, and can reduce the preparation cost of the metal matrix composite plate.

Description of drawings

FIG. 1 is a system device for preparing a metal matrix composite plate applied in Example 1 of the present invention.

In the figure: 1-mixing box; 2-stirring device; 3-temperature measuring device; 4-solid adding device; 5-gas releasing device; 6-electromagnetic vibration device; 7-lower roller; 8-upper roller.

Detailed ways

The technical solutions of the present invention are further described below with reference to the accompanying drawings and through specific embodiments.

The present invention will be described in further detail below. However, the following examples are only simple examples of the present invention, and do not represent or limit the protection scope of the present invention. The protection scope of the present invention is subject to the claims.

1. Example

Example 1

This embodiment provides a system device for preparing metal matrix composite plates. As shown in FIG. 1 , the system device includes a mixing device, and the mixing device includes a mixing box 1. The mixing box 1 is provided with a heating device. 1 is provided with a stirring device 2, a temperature measuring device 3 and a solid adding device 4, and the stirring device 2 adopts a mechanical stirring device; a gas release device 5 is provided at the front end of the mixing device, and an outlet channel is provided on the lower side of the mixing device, and the outlet channel A heating device is provided, as well as an electromagnetic vibration device 6 and a casting and rolling device that are connected to the outlet channel and arranged in sequence, wherein the casting and rolling device adopts an eccentric double-roll casting and rolling device. The casting and rolling device includes a lower roll 7 and an upper roll 8. The lower roll 7 The ratio to the diameter of the upper roll 8 is 1.5, and the roll gap width between the lower roll 7 and the upper roll 8 is 7 mm.

This embodiment also provides a method for preparing a metal matrix composite sheet, the preparation method is performed in the system device provided in this embodiment, and includes the following steps:

(1) Turn on the heating device in the mixing box 1, keep the melted AZ91D magnesium alloy melt in the mixing box 1 of the mixing device at 720°C for 20 minutes, close the heating device in the mixing box 1, and observe the mixing box. The temperature measuring device 3 in 1 cools the AZ91D magnesium alloy melt to a semi-solid state of 590°C to obtain a semi-solid slurry;

(2) Add silicon carbide with a particle size of 5 μm into the mixing box 1 through the solid adding device 4 in the mixing box 1, and mechanically stir and mix the semi-solid slurry and silicon carbide with a mass ratio of 15:1 for 50 minutes. The stirring speed is 150 r/min to obtain a semi-solid slurry containing a reinforcing phase with a volume solid phase ratio of 16%;

(3) The argon gas with a pressure of 0.2 MPa is released from the gas release device 5 to drive the flow of the semi-solid slurry containing the reinforcing phase, and the electromagnetic vibration is carried out by the electromagnetic vibration device 6 with an amplitude of 50 mm and a frequency of 5 Hz, and is carried out in the casting and rolling device. For casting and rolling, the rotational speed of the lower roll 7 in the casting and rolling device is 100 r/min, and the rotational speed of the upper roll 8 is 100 r/min to obtain a metal matrix composite plate.

Example 2

This embodiment provides a system device for preparing a metal matrix composite sheet. The difference between the system device and the embodiment 1 is that the ratio of the diameters of the lower roll and the upper roll is 1, and the roll gap width between the lower roll and the upper roll is 0.1 mm. , and the rest are the same as in Example 1.

This embodiment also provides a method for preparing a metal matrix composite sheet, the preparation method is performed in the system device provided in this embodiment, and includes the following steps:

(1) Turn on the heating device in the mixing box, keep the melted AZ31D magnesium alloy melt in the mixing box of the mixing device at 710°C for 25 minutes, turn off the heating device in the mixing box, and observe the temperature measuring device in the mixing box. Cool the AZ31D magnesium alloy melt to a semi-solid state of 575°C to obtain a semi-solid slurry;

(2) The carbon fiber with a particle size of 8 μm is added to the mixing box through the solid adding device in the mixing box, and the mass ratio of the semi-solid slurry and carbon fiber is 10:1 by mechanical stirring, and the rotating speed of the mechanical stirring is 200r/min. , to obtain a semi-solid slurry containing a reinforcing phase with a volume solid ratio of 12%;

(3) The argon gas with the pressure of 1MPa is released by the gas release device to drive the flow of the semi-solid slurry containing the reinforcing phase, and the electromagnetic vibration is carried out by the electromagnetic vibration device with the amplitude of 4mm and the frequency of 20Hz, and the casting and rolling are carried out in the casting and rolling device. In the casting and rolling device, the rotational speed of the lower roll is 50 r/min, and the rotational speed of the upper roll is 50 r/min to obtain a metal matrix composite plate.

Example 3

This embodiment provides a system device for preparing a metal matrix composite sheet. The difference between the system device and the embodiment 1 is that the ratio of the diameters of the lower roll and the upper roll is 3, and the roll gap width between the lower roll and the upper roll is 1.5mm. , and the rest are the same as in Example 1.

This embodiment also provides a method for preparing a metal matrix composite sheet, the preparation method is performed in the system device provided in this embodiment, and includes the following steps:

(1) Turn on the heating device in the mixing box, keep the melted 7075 aluminum alloy melt in the mixing box of the mixing device at 650°C for 15 minutes, close the heating device in the mixing box, and observe the temperature measuring device in the mixing box. Cool the 7075 aluminum alloy melt to 610 ℃ semi-solid to obtain semi-solid slurry;

(2) Add alumina particles with a particle size of 20 μm into the mixing box through the solid adding device in the mixing box, and mechanically stir and mix the semi-solid slurry with a mass ratio of 5:1 and the alumina particles for 60 minutes. The rotating speed is 5r/min, and the semi-solid slurry containing the reinforcing phase with the volume solid phase ratio of 21% is obtained;

(3) The helium gas with a pressure of 5Mpa is released by the gas release device to drive the flow of the semi-solid slurry containing the reinforcing phase, and the electromagnetic vibration is carried out by an electromagnetic vibration device with an amplitude of 1mm and a frequency of 50Hz, and casting and rolling are carried out in the casting and rolling device. In the casting and rolling device, the rotational speed of the lower roll is 200 r/min, and the rotational speed of the upper roll is 200 r/min to obtain a metal matrix composite plate.

Example 4

This embodiment provides a system device for preparing a metal matrix composite sheet. The difference between the system device and the embodiment 1 is that the stirring device adopts an ultrasonic stirring device. 1 is the same.

This embodiment also provides a method for preparing a metal matrix composite sheet, the preparation method is performed in the system device provided in this embodiment, and includes the following steps:

(1) Turn on the heating device in the mixing box, keep the melted 7075 aluminum alloy melt in the mixing box of the mixing device at 650°C for 15 minutes, close the heating device in the mixing box, and observe the temperature measuring device in the mixing box. Cool the 7075 aluminum alloy melt to 610 ℃ semi-solid to obtain semi-solid slurry;

(2) Add silicon carbide with a particle size of 50 μm into the mixing box through the solid adding device in the mixing box, and ultrasonically stir and mix the semi-solid slurry and silicon carbide with a mass ratio of 4:1 for 60 minutes, wherein the frequency of ultrasonic stirring is 20 Hz to obtain a semi-solid slurry containing a reinforcing phase with a volume solid ratio of 15%;

(3) The nitrogen dioxide with a pressure of 10 MPa is released by the gas release device to drive the flow of the semi-solid slurry containing the reinforcing phase, and the electromagnetic vibration is carried out by an electromagnetic vibration device with an amplitude of 0.5 mm and a frequency of 100 Hz, and casting is carried out in the casting and rolling device. Rolling, the rotational speed of the lower roll in the casting and rolling device is 600 r/min, and the rotational speed of the upper roll is 600 r/min to obtain a metal matrix composite plate.

Example 5

This embodiment provides a system device for preparing a metal matrix composite sheet. The difference between the system device and the embodiment 1 is that the stirring device adopts an ultrasonic stirring device. 1 is the same.

This embodiment also provides a method for preparing a metal matrix composite sheet, the preparation method is performed in the system device provided in this embodiment, and includes the following steps:

(1) Turn on the heating device in the mixing box, keep the molten copper-iron 10 alloy melt in the mixing box of the mixing device at 1100°C for 15 minutes, turn off the heating device in the mixing box, and observe the temperature measuring device in the mixing box , cooling the copper-iron 10 alloy melt to 850 ℃ semi-solid to obtain semi-solid slurry;

(2) Add silicon nitride with a particle size of 100 μm into the mixing box through the solid adding device in the mixing box, and ultrasonically stir and mix the semi-solid slurry and silicon nitride with a mass ratio of 15:1 for 50 minutes. The frequency is 130 Hz to obtain a semi-solid slurry containing a reinforcing phase with a volume solid phase rate of 30%;

(3) The semi-solid slurry containing the reinforcing phase is driven to flow by nitrogen gas with a pressure of 5 MPa released by the gas release device, electromagnetic vibration is carried out by an electromagnetic vibration device with an amplitude of 0.5 mm and a frequency of 100 Hz, and casting and rolling are carried out in the casting and rolling device, In the casting and rolling device, the rotational speed of the lower roll is 1000 r/min, and the rotational speed of the upper roll is 1000 r/min to obtain a metal matrix composite plate.

Example 6

This embodiment provides a method for preparing a metal matrix composite sheet. The difference between the method and the embodiment 1 is only that the mass ratio of the semi-solid slurry and silicon nitride in step (2) is controlled to be 20:1, so as to obtain the volume The semi-solid slurry containing the reinforcing phase with a solid phase ratio of 12% is the same as in Example 1.

Example 7

This embodiment provides a method for preparing a metal matrix composite sheet. The difference between the method and the embodiment 1 is only that the mass ratio of the semi-solid slurry and silicon nitride in step (2) is controlled to be 4:1, so as to obtain the volume The semi-solid slurry containing the reinforcing phase with a solid phase ratio of 30%, and the rest are the same as in Example 1.

Example 8

This embodiment provides a method for preparing a metal matrix composite sheet. The difference between the method and the embodiment 1 is that the mass ratio of the semi-solid slurry and silicon nitride in step (2) is controlled to be 200:1 to obtain the volume The semi-solid slurry containing the reinforcing phase with a solid phase ratio of 1%, and the rest are the same as those in Example 1.

Example 9

This embodiment provides a method for preparing a metal matrix composite sheet. The difference between the method and the embodiment 1 is that the mass ratio of the semi-solid slurry and silicon nitride in step (2) is controlled to be 1.5:1 to obtain the volume The semi-solid slurry containing the reinforcing phase with a solid phase ratio of 80%, and the rest are the same as in Example 1.

2. Comparative ratio

Comparative Example 1

This comparative example provides a method for preparing a metal matrix composite sheet. The difference between the method and Example 1 is that step (1) does not perform cooling to a semi-solid slurry, and the rest are the same as those in Example 1.

Comparative Example 2

This comparative example provides a preparation method of a metal matrix composite sheet, the difference between the method and Example 1 is only that no silicon carbide is added in step (2), and the rest are the same as those of Example 1.

Comparative Example 3

This comparative example provides a preparation method of a metal matrix composite plate, the difference between the method and the embodiment 1 is that the electromagnetic vibration is not performed in step (3), and the rest are the same as those of the embodiment 1.

3. Tests and Results

Test Method for Grain Size of Metal Matrix Composite Sheets: Measured according to ASTM E112-1996.

Test Method for Tensile Strength of Metal Matrix Composite Sheets: Measured according to ASTM D 3552-96(07).

Test Method for Elongation at Break of Metal Matrix Composite Sheets: Measured according to ASTM D 3552-96(07).

The test results of the above examples and comparative examples are shown in Table 1.

Table 1

Grain size (μm) Tensile strength (MPa) Elongation at break (%) Example 1 41.2 220 3.1 Example 2 50.9 190 2.4 Example 3 35.6 421 5.7 Example 4 41.2 409 4.8 Example 5 100.5 310 10.7 Example 6 45.6 204 5.4 Example 7 35.2 246 2.3 Example 8 69.2 171 2.5 Example 9 50.2 168 1.2 Comparative Example 1 80.2 163 2.8 Comparative Example 2 102.1 125 4.8 Comparative Example 3 76.4 162 2.0

The following points can be seen from Table 1:

(1) The present invention provides a preparation method of a metal matrix composite sheet, the preparation method obtains a metal matrix composite sheet with small crystal grains by mixing semi-solid slurry and reinforcing particles, and then casting and rolling after electromagnetic vibration. Improve the mechanical properties of the metal matrix composite sheet, improve the tensile strength and elongation at break, specifically, in Examples 1 to 9, the grain size is ≤ 100.5 μm, the tensile strength is ≥ 168MPa, and the elongation at break is ≥ 1.2%, preferably Under the conditions, the grain size is ≤50.9μm, the tensile strength is ≥190MPa, and the elongation at break is ≥2.3%;

(2) Combining Example 1 and Examples 6-9, it can be seen that the mass ratios of the semi-solid slurry and silicon nitride in Example 1 and Examples 6-7 are controlled to be 15:1, 20:1 and 4:1 respectively , correspondingly, the volume solid ratios of the semi-solid slurry containing the reinforcing phase were 16%, 12% and 30%, respectively, compared with the mass ratios of the semi-solid slurry and silicon nitride in Examples 8 to 9, respectively. Controlled as 200:1 and 1.5:1, correspondingly, the volume solid ratio of the semi-solid slurry containing the reinforcing phase is 1% and 80%, respectively, the metal matrix composite in Example 1 and Examples 6-7 The grain sizes of the plates are 41.2 μm, 45.6 μm and 35.2 μm, respectively, the tensile strengths are 220 MPa, 204 MPa and 246 MPa, and the elongation at break are 3.1%, 5.4% and 2.3%, respectively. The grain size of the plate is 69.2 μm and 50.2 m, respectively, the tensile strength is 171 MPa and 168 MPa, and the elongation at break is 2.5% and 1.2%, respectively. It can be seen that the mass ratio of the semi-solid slurry and the reinforced particle in the present invention is It is controlled within the range of (20-4):1, and the volume solid phase ratio of the corresponding semi-solid slurry containing reinforcing phase is controlled within the range of 12-30%, which can reduce the grain size of the metal matrix composite sheet and improve the Tensile strength and elongation at break;

(3) Combining Example 1 and Comparative Example 1, it can be seen that step (1) in Example 1 is cooled to a semi-solid slurry, compared to the step (1) in Comparative Example 1 that is not cooled to a semi-solid slurry. , the grain size of the metal matrix composite sheet in Example 1 is 41.2 μm, the tensile strength is 220 MPa, and the elongation at break is 3.1%. In Comparative Example 1, the grain size of the metal matrix composite sheet is 80.2 μm, and the tensile strength is 163 MPa. The elongation at break is 2.8%, it can be seen that in the present invention, the temperature is lowered to the semi-solid slurry in step (1), which can reduce the grain size of the metal matrix composite sheet and improve the tensile strength and elongation at break;

(4) Combining Example 1 and Comparative Example 2, it can be seen that silicon carbide is added in step (2) in Example 1. Compared with step (2) in Comparative Example 2, where silicon carbide is not added, the metal matrix composite in Example 1 The grain size of the sheet is 41.2 μm, and the tensile strength is 220 MPa. In Comparative Example 2, the grain size of the metal matrix composite sheet is 102.1 μm, and the tensile strength is 125 MPa. It can be seen that the present invention adds reinforcing particles in step (2). It can not only meet the requirements of the elongation at break of the metal matrix composite sheet, but also reduce the grain size of the metal matrix composite sheet and improve the tensile strength;

(5) Combining Example 1 and Comparative Example 3, it can be seen that step (3) in Example 1 performs electromagnetic vibration. Compared with step (3) in Comparative Example 3, where electromagnetic vibration is not performed, the metal matrix composite in Example 1 The grain size of the sheet is 41.2 μm, the tensile strength is 220 MPa, and the elongation at break is 3.1%. It can be seen that the present invention performs electromagnetic vibration in step (3), which can reduce the grain size of the metal matrix composite sheet and improve the tensile strength and elongation at break.

To sum up, the preparation method of the metal matrix composite sheet provided by the present invention, the preparation method obtains the metal matrix composite sheet with small crystal grains by mixing the semi-solid slurry and reinforcing particles, and then casting and rolling after electromagnetic vibration. Thereby improving the mechanical properties of the metal matrix composite sheet, increasing the tensile strength and elongation at break, the grain size ≤ 100.5μm, the tensile strength ≥ 168MPa, the elongation at break ≥ 1.2%, under optimal conditions, the grain size ≤ 50.9μm, tensile strength ≥190MPa, elongation at break ≥2.3%.

The applicant declares that the present invention illustrates the detailed structural features of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed structural features, that is, it does not mean that the present invention must rely on the above-mentioned detailed structural features to be implemented. Those skilled in the art should understand that any improvement to the present invention, the equivalent replacement of the selected components of the present invention, the addition of auxiliary components, the selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims (10)

1. a preparation method of metal matrix composite plate, is characterized in that, described preparation method comprises the following steps: (1) cooling the metal-based melt to a semi-solid state to obtain a semi-solid slurry; (2) mixing the semi-solid slurry and reinforcing particles to obtain a semi-solid slurry containing a reinforcing phase; (3) The semi-solid slurry containing the reinforcing phase is cast and rolled after electromagnetic vibration to obtain a metal matrix composite plate. 2. The preparation method according to claim 1, wherein the metal in step (1) comprises any one or a combination of at least two in aluminum alloy, magnesium alloy, titanium alloy, copper alloy or iron alloy; Preferably, the molten metal-based melt is kept warm before the cooling; Preferably, the incubation time is 15-25 min. 3. preparation method according to claim 1 and 2 is characterized in that, the described mixing of step (2) is carried out under stirring; Preferably, the stirring time is 1-120 min; Preferably, the stirring includes mechanical stirring and/or ultrasonic stirring; Preferably, the rotational speed of the mechanical stirring is 1-3000 r/min; Preferably, the frequency of the ultrasonic stirring is 20-130 kHz. 4. The preparation method according to any one of claims 1 to 3, wherein the reinforcing particles comprise carbides, nitrides, oxides, carbon fibers, glass fibers, graphene, carbon nanotubes or graphite. any one or a combination of at least two; Preferably, the carbide comprises silicon carbide, titanium carbide, boron carbide or tungsten carbide; Preferably, the nitride comprises boron nitride, phosphorus nitride, silicon nitride, titanium nitride, magnesium nitride, aluminum nitride, manganese nitride or zirconium nitride; Preferably, the oxide comprises titanium oxide, silicon oxide, magnesium oxide, aluminum oxide, ceria, zirconium oxide, lanthanum oxide or tungsten oxide; Preferably, the particle size of the reinforcing particles is 0.1-200 μm; Preferably, the mass ratio of the semi-solid slurry to the reinforcing particles is (200-1.5):1; Preferably, the volume solid phase ratio of the reinforcing phase-containing semi-solid slurry is 1-80%, preferably 12-30%. 5. The preparation method according to any one of claims 1 to 4, wherein the amplitude of the electromagnetic vibration in step (3) is 0.5 to 50 mm; Preferably, the frequency of the electromagnetic vibration is 0.1-1000 Hz; Preferably, the semi-solid slurry containing the reinforcing phase flows under the pressure of gas, and is cast and rolled after being subjected to electromagnetic vibration; Preferably, the gas comprises any one or a combination of at least two of argon, carbon dioxide, nitrogen dioxide, sulfur hexafluoride, nitrogen or helium; Preferably, the pressure of the gas is 0.1-70 MPa; Preferably, the casting includes eccentric twin-roll casting or non-eccentric twin-roll casting, preferably eccentric twin-roll casting; Preferably, the rotational speed of the middle and lower rolls in the casting and rolling is 1-3000 r/min; Preferably, the rotational speed of the upper roll in the casting and rolling is 1-3000 r/min. 6. A system device for preparing a metal matrix composite sheet, wherein the system device is used for the preparation method of a metal matrix composite sheet according to any one of claims 1 to 5; The system device includes a mixing device, an outlet channel arranged on one side of the lower part of the mixing device, and an electromagnetic vibration device and a casting and rolling device connected with the outlet channel and arranged in sequence. 7. The system device of claim 6, wherein the system device further comprises a gas release device; Preferably, the gas release device is arranged at the front end of the mixing device. 8. The system device according to claim 6 or 7, wherein the mixing device comprises a mixing tank; Preferably, the mixing box is provided with a heating device; Preferably, a stirring device is provided in the mixing box; Preferably, the stirring device includes a mechanical stirring device and/or an ultrasonic stirring device; Preferably, a temperature measuring device is provided in the mixing box; Preferably, a solid adding device is provided in the mixing box. 9 . The system device according to claim 6 , wherein a heating device is provided on the outlet channel. 10 . The system device according to any one of claims 6 to 9, wherein the casting and rolling device comprises an eccentric twin-roll casting and rolling device or a non-eccentric twin-roll casting and rolling device; Preferably, the casting and rolling device includes a lower roll and an upper roll; Preferably, the ratio of the diameters of the lower roll to the upper roll is 1-3; Preferably, the width of the roll gap between the lower roll and the upper roll is 0.1-20 mm.

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