TWI458837B - Method for making magnesium matrix composite material - Google Patents

Description

Preparation method of magnesium matrix composite material

The invention relates to a preparation method of a composite material, in particular to a preparation method of a magnesium matrix composite material.

One of the most abundant elements in the magnesium crust, accounting for about 25% of the crust composition, is rich in resources. Magnesium alloy is the lightest of the modern structural metal materials. It is known as small specific gravity, high specific strength, good shock absorption, and also has excellent casting properties, cutting performance, thermal conductivity and electromagnetic shielding performance. The 21st century era metal has a wide range of applications in 3C products, automobiles, and aerospace. In addition, since magnesium is more competitive in price than aluminum, the development and application of magnesium alloys has been further expanded.

One of the hotspots in the field of magnesium alloys is magnesium-based composites, especially magnesium-based composites containing nano-scale reinforcements. The magnesium-based composite material containing the nano-scale reinforcement can effectively improve the toughness and wear resistance of the magnesium alloy while ensuring the above advantages of the magnesium alloy. However, the preparation of such magnesium-based composite materials in the prior art is often carried out by powder metallurgy, melt infiltration, stirred casting, and the like. The magnesium-based composite material formed by the above methods disperses the nano-scale reinforcement in the molten state of the magnesium alloy, which tends to cause agglomeration of the nano-scale reinforcement, resulting in uneven dispersion. Due to the uneven dispersion of the nano-scale reinforcement in the magnesium-based material, the strength and toughness of the magnesium-based composite material are poor.

In order to solve the above problems, CS Goh et al. have developed another method for preparing magnesium-based composite materials (see, Development of novel carbon nanotube reinforced magnesium nanocomposites using the powder metallurgy technique, CS Goh et al., Nanotechnology, vol 17, p7). (2006)), the method comprises mixing a magnesium-based material powder having a purity of 98.5% and a carbon nanotube particle by a V-blender for 10 hours; and extruding the magnesium-based material powder and the carbon nanotube particles at a high pressure. The mixture is obtained to obtain a micron-sized magnesium-based composite billet; under the protection of argon, the above-mentioned micron-sized billet is sintered in a furnace into a magnesium-based composite semi-solid material having a thixotropic structure. Although the method for preparing the magnesium-based composite material can relatively improve the problem of uneven dispersion of the carbon nanotube particles in the magnesium-based material, the powdery carbon nanotube particles are easily aggregated, causing agglomeration of the carbon nanotubes. Therefore, the problem that the carbon nanotubes still have uneven dispersion in the magnesium-based material causes the strength and toughness of the magnesium-based composite material to be relatively poor.

In view of the above, it is necessary to provide a method for preparing a magnesium-based composite material, which can uniformly disperse a nano-scale reinforcement in a magnesium-based material, so that the magnesium-based composite material prepared by the method has better performance. Strength and toughness.

A method for preparing a magnesium-based composite material, comprising the steps of: providing a magnesium-based material melt; providing a plurality of nano-scale reinforcements to be melt-mixed with the above-mentioned magnesium-based material; and ultrasonically treating the magnesium-based material and the nano-scale a mixture of reinforcements; and spray-forming a mixture of the above-described magnesium-based material and a nano-scale reinforcement to obtain the magnesium-based composite material.

A method for preparing a magnesium-based composite material, comprising the steps of: placing a magnesium-based material melt in a furnace under a protective gas atmosphere; and adding a plurality of nano-scale reinforcements to the furnace by using a gas carrying device While using a stirrer to mix the above magnesium a base material and a nano-scale reinforcement; treating the mixture of the magnesium-based material and the nano-scale reinforcement by using at least one ultrasonic device; and spraying the mixture of the magnesium-based material and the nano-scale reinforcement by spray coating, The magnesium-based composite material was obtained.

Compared with the prior art, the above preparation method of the magnesium-based composite material has the following advantages: First, ultrasonic treatment of the mixture of the magnesium-based material and the nano-scale reinforcement enables the nano-scale reinforcement to be uniformly dispersed in the magnesium-based material. . Next, a method of forming a mixture of the ultrasonically treated magnesium-based material and the nano-scale reinforcement by spray coating is used to more uniformly disperse the nano-scale reinforcement in the magnesium-based material. Therefore, the present technical solution can uniformly disperse the nano-scale reinforcement in the magnesium-based material, so that the magnesium-based composite material prepared by the technical solution has the advantages of high strength and good toughness.

110‧‧‧furnace

120‧‧‧Intake pipe

130‧‧‧Agitator

140‧‧‧ gas carrier

150‧‧‧Mine-based material melt

210;312‧‧‧Mixed mixture of magnesium-based materials and nano-scale reinforcements

220‧‧‧ ultrasonic device

314‧‧‧Magnesium-based composite materials

320‧‧‧ pump

330‧‧‧Spray forming device

331‧‧‧Intake pipe

332‧‧‧ funnel

334‧‧‧Atomization room

336‧‧‧ nozzle

338‧‧‧Collection board

339‧‧‧Connecting tube

FIG. 1 is a flow chart of a method for preparing a magnesium-based composite material provided by the technical solution.

2 is a schematic structural view of an apparatus for mechanically stirring a magnesium-based material melt and a nano-scale reinforcement according to an embodiment of the present technical solution.

FIG. 3 is a schematic structural view of an apparatus for ultrasonically treating a mixture of a magnesium-based material and a nano-scale reinforcement according to an embodiment of the present technical solution.

4 is a schematic structural view of an apparatus for spray-molding a mixed melt of a magnesium-based material and a nano-scale reinforcement according to an embodiment of the present technical solution.

A method for preparing a magnesium-based composite material provided by the present technical solution will be further described in detail below with reference to the accompanying drawings and specific embodiments.

Referring to FIG. 1 , the preparation method of the magnesium-based composite material provided by the technical solution mainly includes the following steps:

Step 1: Provide a melt of magnesium-based material.

The method for preparing the magnesium-based material melt comprises the following steps: First, a magnesium-based material is provided. The magnesium-based material is pure magnesium or a magnesium alloy. The magnesium alloy component contains, in addition to magnesium, one or more of other metal elements such as zinc, manganese, aluminum, zirconium, hafnium, lithium, silver, and calcium. Among them, magnesium accounts for more than 80% of the total mass of magnesium alloy, and other metal elements account for less than 20% of the total mass of magnesium alloy. In this embodiment, the preferred magnesium-based material is pure magnesium.

Next, the above magnesium-based material is heated and melted in a protective gas atmosphere to obtain a melt of the magnesium-based material. Among them, the heating temperature is related to the melting point of the magnesium-based material. Preferably, the heating temperature ranges from 630 to 670 °C. In the present embodiment, the preferred heating temperature is 650 °C. The shielding gas is a mixed gas of nitrogen, nitrogen and sulfur hexafluoride (SF ₆ ) or a mixed gas of sulfur dioxide and dry air. In this embodiment, the shielding gas is preferably nitrogen. The protective gas acts to form a protective film on the surface of the melt of the magnesium-based material to isolate the melt from the air to prevent oxidative combustion of the magnesium-based material.

Finally, the heating is stopped, the temperature is maintained and the above protective gas atmosphere is maintained. The heat retention means a temperature at which the magnesium-based material is kept molten.

It will be appreciated that the magnesium based material melt can also be prepared by other methods.

Step 2: providing a plurality of nano-scale reinforcements, which are mixed with the above-mentioned magnesium-based material melt.

The method of mixing a magnesium-based material with a nano-scale reinforcement specifically includes the following steps: First, a plurality of nano-scale reinforcements are provided. The material of the nano-scale reinforcement is one or more of a carbon nanotube, a tantalum carbide, an alumina, and a titanium carbide. In this embodiment, The material of the nano-scale reinforcement is a carbon nanotube. The nano-sized reinforcement has a particle diameter of from 1 to 100 nm. In this embodiment, the particle size of the nano-sized reinforcement is preferably 20-30 nm. The nano-scale reinforcement functions to enhance the strength and toughness of the magnesium-based material.

It can be understood that the material of the nano-scale reinforcement in the technical solution is not limited to one or several kinds of carbon nanotubes, tantalum carbide, aluminum oxide and titanium carbide, and any other reinforcement material, such as fiber material, It can achieve the same reinforcing and toughening effect on the magnesium-based material as the above-mentioned reinforcement, and is within the protection scope of the present technical solution.

Next, the above-mentioned nano-sized reinforcement is melt-mixed with the above-mentioned magnesium-based material.

Specifically, the method of melt mixing the above-mentioned nano-scale reinforcement with the above-mentioned magnesium-based material comprises the steps of: adding the nano-scale reinforcement to the gas in a gas-carrying manner under the protective gas atmosphere; In the melt of the magnesium-based material; mechanically stirring the melt of the magnesium-based material. Wherein, in the above mixing process, the magnesium-based material melt should be maintained in a molten state. The molten state temperature of the magnesium-based material is related to the material composition of the magnesium-based material itself. In this embodiment, the temperature of the magnesium-based material during the above mixing process is maintained at 670-680 ° C, which serves to reduce the viscosity of the magnesium-based material and prevent the viscosity of the magnesium-based material from being too high to avoid the nanometer. The agglomeration of the graded reinforcement; and preventing the excessive temperature from damaging the protective film formed on the surface of the melt of the magnesium-based material by the protective gas, thereby oxidizing and burning the magnesium-based material.

The specific process of the gas carrying mode includes the steps of: blowing a nano-scale reinforcement by a carrier gas; and adding the nano-scale reinforcement to the melt of the magnesium-based material by the flow of the carrier gas . The carrier gas is a mixed gas of argon gas, nitrogen gas, argon gas and nitrogen gas or a mixed gas of sulfur dioxide and nitrogen gas. In this embodiment, the carrier gas is preferably argon. The nano-scale reinforcement in the above magnesium-based composite The mass percentage in the material is from 0.01 to 10%. In this embodiment, the content of the nano-scale reinforcement in the above-mentioned magnesium-based composite material is preferably 5% by mass. The manner of mechanical agitation includes forward rotation, reverse rotation, or both. In this embodiment, the manner of mechanical agitation is preferably forward rotation. The combination of the gas-carrying nano-reinforcing body and the mechanically-saturated magnesium-based material melt enables the nano-scale reinforcement to be continuously added to the magnesium-based material melt in a small amount, and can be gradually dispersed in the magnesium-based material. In the material melt, the problem that the nano-level reinforcement is lifted up due to a large specific surface is avoided after the one-time addition of the nano-scale reinforcement.

Step 3: Ultrasonic treatment of the above magnesium-based material and nano-scale reinforcement.

Specifically, the method for ultrasonically treating a mixture of the above magnesium-based material and a nano-scale reinforcement comprises the steps of: oscillating the magnesium-based material with a nano-level enhancement using ultrasonic waves of at least one frequency in a protective gas atmosphere; The mixture of bodies is a total of 1-10 minutes; the ultrasonic vibration is stopped. Wherein, in order to maintain the mixture of the magnesium-based material and the nano-scale reinforcement in a molten state, the nano-scale reinforcement agglomeration and the oxidative combustion of the mixture of the magnesium-based material and the nano-scale reinforcement are avoided. The molten state temperature of the mixture of the magnesium-based material and the nano-scale reinforcement is related to the specific material composition of the magnesium-based material and the nano-scale reinforcement mixture. In this embodiment, the temperature of the mixture of the magnesium-based material and the nano-scale reinforcement should be maintained at 670-680 °C.

The shielding gas is a mixed gas of nitrogen, nitrogen and sulfur hexafluoride (SF ₆ ) or a mixed gas of sulfur dioxide and dry air. In this embodiment, the shielding gas is preferably nitrogen. The manner of the ultrasonic treatment includes intermittent and uninterrupted. Preferably, the manner of the ultrasonic treatment is intermittent. The ultrasonic waves have a frequency in the range of 15-20 kHz. In this embodiment, the frequency of the ultrasonic waves is preferably two, which are 15 kHz and 20 kHz, respectively. When the frequency of the ultrasonic wave exceeds 20 kHz, the oscillation speed is fast, but the range of action is relatively narrow, and the dispersion effect on the nano-scale reinforcement is not obvious; when the frequency of the ultrasonic wave is lower than 15 kHz, it is harmful to the human ear, industrially. Ultrasonic waves below 15 kHz are generally not used. The ultrasonic treatment can make the nano-scale reinforcement more uniformly dispersed in the magnesium-based material. In this embodiment, the process of ultrasonically oscillating the mixture of the magnesium-based material and the nano-scale reinforcement by using two ultrasonic frequencies of 15 kHz and 20 kHz includes the following steps: in the environment of shielding gas, first adopting 15 kHz Ultrasonic vibration of the mixture of the magnesium-based material and the nano-scale reinforcement, and then ultrasonic vibration of the mixture of the magnesium-based material and the nano-scale reinforcement by 15 kHz, the ultrasonic oscillation time is 1-10 minutes; Stop the ultrasonic shock.

Step 4: Spraying a mixture of the above magnesium-based material and a nano-scale reinforcement to form the magnesium-based composite material.

The method for spray-molding a mixture of the above magnesium-based material and a nano-scale reinforcement specifically comprises the steps of: mixing a mixture of the above-mentioned magnesium-based material having a certain temperature and a nano-scale reinforcement by using an inert gas under a certain pressure. High speed spraying onto a substrate to obtain a magnesium-based composite material. Wherein the pressure is from 0.5 to 0.9 MPa, preferably 0.8 MPa. The inert gas is a mixed gas of argon gas, nitrogen gas, argon gas and nitrogen gas or a mixed gas of sulfur dioxide and nitrogen gas. The inert gas is preferably nitrogen. The high-speed spraying of the mixed melt of the magnesium-based material and the nano-scale reinforcement onto a substrate by using an inert gas specifically includes: the inert gas firstly adding the magnesium-based material to the nano-scale reinforcement The mixture is atomized into fine droplets, which are then sprayed onto a substrate at a high speed to form a magnesium-based composite on the substrate. Wherein the mixture of the magnesium-based material and the nano-scale reinforcement in the step is a mixture of the ultrasonic-treated magnesium-based material and the nano-scale reinforcement. In order to make the magnesium-based material and nano-scale During the spray molding of the mixture of the reinforcement, the nano-scale reinforcement is more uniform and the dispersion effect is better, and the temperature of the mixture of the magnesium-based material and the nano-scale reinforcement should be relatively high, so that The viscosity is relatively small. However, the mixture of the magnesium-based material and the nano-scale reinforcement is easily oxidatively burned at a high temperature, so the temperature of the mixture of the magnesium-based material and the nano-scale reinforcement is not too high. The temperature of the mixture of the magnesium-based material and the nano-scale reinforcement should be maintained at 680-730 °C. In this embodiment, the temperature of the mixture of the magnesium-based material and the nano-scale reinforcement ranges from 690 to 710 °C. The temperature of the process is higher than the temperature of the magnesium-based material and the nano-scale reinforcement mixture during the ultrasonic treatment because the mixture of the magnesium-based material and the nano-scale reinforcement is not in the process of the spray coating. It is required to oscillate, and the protective film formed on the surface of the magnesium-based material melt is not easily damaged, so that the mixture of the magnesium-based material and the nano-scale reinforcement is not oxidatively burned at 680-730 °C.

In addition, in the technical solution, the method for preparing the magnesium-based composite material further includes the steps of: melting the magnesium-based composite material; and spray-molding the molten magnesium-based composite material. Among them, the above steps can be looped multiple times. The above steps and the purpose of the multiple loops are to spray the magnesium-based composite material into fine droplets by spray coating technology, so that the above-mentioned nano-scale reinforcement is more uniformly dispersed in the magnesium-based material, thereby improving magnesium. The strength and toughness of the matrix composite.

Further, the above-mentioned magnesium-based composite material may be further subjected to a calendering treatment to obtain a magnesium plate sheet having a predetermined thickness. The step of calendering comprises passing the above-described magnesium-based material through a nip between rolls of relatively rotating, leveling. Among them, by controlling the above nip, a magnesium sheet having a predetermined thickness is obtained. It can be understood that the step of the subsequent calendering process can be selected according to actual conditions.

Referring to FIG. 2 to FIG. 4 together, the embodiment of the technical solution further provides an application. A method for preparing a magnesium-based composite material by a specific device, which mainly comprises the following steps:

Step 1: In a protective gas atmosphere, the magnesium-based material is placed in the furnace 110 and melted.

The shielding gas is introduced into the closed furnace 110 through the intake pipe 120; in the protective gas environment, the magnesium-based material is placed in the furnace 110 for heating, and heated to melt the magnesium-based material to obtain a magnesium-based material melt 150. ; stop heating. The magnesium-based material is pure magnesium or a magnesium alloy. In this embodiment, the magnesium-based material is preferably pure magnesium. The heating temperature is 630-670 ° C, preferably the heating temperature is 650 ° C. The shielding gas is a mixed gas of nitrogen, nitrogen and sulfur hexafluoride (SF ₆ ) or a mixed gas of sulfur dioxide and dry air. In this embodiment, the shielding gas is preferably nitrogen. The flow rate of the shielding gas preferably ranges from 1 to 20 ml/min.

Step 2: a nano-scale reinforcement is added to the furnace 110 by using the gas carrying device 140, and the magnesium-based material and the nano-scale reinforcement are mixed by using the agitator 130 to obtain a mixture of the magnesium-based material and the nano-scale reinforcement. (As shown in Figure 3).

Specifically, the method for mixing a magnesium-based material and a nano-scale reinforcement specifically includes the steps of: placing a nano-scale reinforcement in a gas carrying device 140, and carrying a gas to blow the nano-scale reinforcement, The nano-scale reinforcement is continuously added to the furnace 110 under the action of a carrier gas, and the temperature in the furnace 110 is 670-680 ° C, while the agitator 130 applies magnesium to the furnace 110 at a rotational speed of 20-60 rpm. The base material melt 150 is mechanically stirred; after the addition of the nano-scale reinforcement, the agitator 130 stops mechanical agitation to obtain a mixture 210 of the magnesium-based material and the nano-scale reinforcement; and the gas carrying device 140 and the agitator 130 is removed from the furnace 110.

The material of the nano-scale reinforcement is carbon nanotube, tantalum carbide, aluminum oxide and titanium carbide One or several of them. In this embodiment, the material of the nano-scale reinforcement is preferably a carbon nanotube. The nano-sized reinforcement has a particle diameter of from 1 to 100 nm. In this embodiment, the particle size of the nano-sized reinforcement is preferably 20-30 nm. The nano-scale reinforcement has a mass percentage of 0.01 to 10% in the above-mentioned magnesium-based composite material. In this embodiment, the content of the nano-scale reinforcement in the above-mentioned magnesium-based composite material is preferably 5% by mass. The carrier gas is a mixed gas of argon gas, nitrogen gas, argon gas and nitrogen gas or a mixed gas of sulfur dioxide and nitrogen gas. In this embodiment, the carrier gas is preferably argon. The manner of mechanical agitation includes forward rotation, reverse rotation, or both. In this embodiment, the manner of mechanical agitation is preferably forward rotation.

Step 3: The mixture 210 of the above magnesium-based material and the nano-scale reinforcement is treated with at least one ultrasonic device 220.

Specifically, the shielding gas is introduced into the furnace 110 through the intake pipe 120, the temperature in the furnace 110 is maintained at 670-680 ° C, and at least one ultrasonic device 220 is inserted into the mixture of the magnesium-based material and the nano-scale reinforcement. In 210, ultrasonic vibration is performed for 1-10 minutes; and ultrasonic vibration is stopped to obtain a mixture 312 of the magnesium-based material and the nano-scale reinforcement (as shown in Fig. 4). In the present embodiment, the number of the ultrasonic devices is preferably two to prevent the nano-scale reinforcement from being more uniformly dispersed in the magnesium-based material due to the limited oscillation range of the ultrasonic waves. The ultrasonic device ultrasonic treatment method comprises first fluctuating a wide range of the mixture 210 of the magnesium-based material and the nano-scale reinforcement by using 15 kHz; and then using the 20 kHz for the magnesium-based material and the nano-scale The mixture 210 of reinforcements undergoes rapid oscillation. By this method, the nano-scale reinforcement can be sufficiently uniformly dispersed in the magnesium-based material. The manner of the ultrasonic treatment includes intermittent and uninterrupted. In this embodiment, the manner of the ultrasonic oscillation is preferably intermittent.

Step 4: Spraying the mixture 312 of the magnesium-based material and the nano-scale reinforcement by spray coating device 330 to obtain the magnesium-based composite material 314.

The spray forming device 330 includes at least a funnel 332, a connecting pipe 339, an intake pipe 331, a nozzle 336, and a spray chamber 334. The connecting pipe 339 connects the funnel 332 and the atomizing chamber 334, and the air inlet pipe 331 The connecting tube 339 is connected, and the nozzle 336 is located at one end of the connecting tube 339 near the atomizing chamber 334. The atomizing chamber 334 is provided with at least one collecting plate 338, and the collecting plate 338 is disposed opposite to the above-mentioned nozzle 336.

The method of spray forming the mixture 312 of the magnesium-based material and the nano-scale reinforcement by the spray coating device 330 includes the following steps: mixing the magnesium-based material in the furnace 110 with the nano-scale reinforcement by the pump 320 312 is injected into the funnel 332 having a certain temperature in the spray molding apparatus 330; the inert gas is introduced into the connecting pipe 339 through the intake pipe 331, and the mixture 312 is placed in the connecting pipe 339 at a pressure of 0.5-0.9 MPa. The inert gas is atomized into fine droplets; and the fine droplets are sprayed at high speed through the nozzle 336 onto the collecting plate 338 in the atomizing chamber 334 to obtain a magnesium-based composite material 314. In this embodiment, the temperature in the funnel 332 ranges from 680 to 730 °C. In this embodiment, the temperature in the funnel 332 is preferably 660-670 ° C, and the pressure is preferably 0.8 MPa. The inert gas is a mixed gas of argon gas, nitrogen gas, argon gas and nitrogen gas or a mixed gas of sulfur dioxide and nitrogen gas. In this embodiment, the inert gas is preferably nitrogen. The distance from the nozzle 336 to the collecting plate 338 is 200-700 mm. In this embodiment, the distance from the nozzle 336 to the collecting plate 338 is preferably 300 mm. The collection plate 338 can be fixed or mobile. In this embodiment, the collection plate 338 is preferably mobile.

In addition, the method for preparing the magnesium-based composite material further includes the following steps: The above-mentioned magnesium-based composite material 314 is melted in the melting furnace 110; and the molten magnesium-based composite material 314 is spray-molded by the spray molding apparatus 330 to obtain a magnesium-based composite material in which a nano-sized reinforcing body is more uniformly dispersed. It can be understood that this step can repeat the loop to melt the magnesium-based composite material in a furnace, and spray-form the above-mentioned molten magnesium-based composite material by a spray molding apparatus.

Further, the above-mentioned magnesium-based composite material may be further subjected to calendering treatment by a calender to obtain a magnesium sheet sheet having a predetermined thickness. Among them, a magnesium plate sheet having a predetermined thickness can be obtained by controlling the size of the nip in the above calender.

The method for preparing a magnesium-based composite material provided by the embodiments of the present technical solution has the following advantages: first, while the stirrer mechanically stirs the melt of the magnesium-based material, the nano-scale reinforcement is added through the gas carrying device, so that The rice grade reinforcement is continuously added to the melt of the magnesium-based material in a small amount, so that the nano-scale reinforcement can be gradually dispersed in the melt of the magnesium-based material, thereby avoiding the larger specific surface after the nano-scale reinforcement is added at one time. Causes the problem of assembly floating up. Secondly, after the nano-scale reinforcement and the magnesium-based material melt are mechanically stirred and mixed, the ultrasonic vibration device is used for ultrasonic vibration treatment, so that the nano-scale reinforcement is uniformly dispersed in the magnesium-based material. Thirdly, the spray-forming technology is used to spray the inert gas at a high speed to atomize the mixture into droplets to achieve further dispersion of the nano-scale reinforcement in the magnesium-based material, and the nano-scale reinforcement is applied by multiple spray forming techniques. More uniform dispersion in magnesium based materials. Therefore, the present technical solution enables the nano-scale reinforcement to be uniformly dispersed in the magnesium-based material, so that the magnesium-based composite material prepared by the embodiment of the present technical solution has the advantages of high strength and good toughness.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Anyone who is familiar with the skill of this case will be assisted by the essence of the invention. Equivalent modifications or variations made by God are to be covered by the following patents.

Claims (18)

A method for preparing a magnesium-based composite material, comprising the steps of: providing a magnesium-based material melt; providing a plurality of nano-scale reinforcements to be melt-mixed with the above-mentioned magnesium-based material; and ultrasonically treating the magnesium-based material and the nano-scale a mixture of reinforcements; and spray-forming a mixture of the above-mentioned magnesium-based material and a nano-scale reinforcement to obtain the magnesium-based composite material, the improvement being that the spray-molding mixture of the above-mentioned magnesium-based material and a nano-scale reinforcement The method comprises the steps of: maintaining a temperature of a mixture of the above magnesium-based material and a nano-scale reinforcement at 680-730 ° C; and using a inert gas to treat the magnesium-based material with a nanometer at a pressure of 0.5-0.9 MPa The mixture of graded reinforcements is sprayed onto a substrate at high speed. The method for producing a magnesium-based composite material according to claim 1, wherein the magnesium-based material is pure magnesium or a magnesium alloy. The method for preparing a magnesium-based composite material according to claim 1, wherein the material of the nano-scale reinforcement is one or more of a carbon nanotube, a tantalum carbide, an alumina, and a titanium carbide. The method for producing a magnesium-based composite material according to claim 1, wherein the nano-sized reinforcing body has a particle diameter of from 1 to 100 nm. The method for producing a magnesium-based composite material according to claim 1, wherein the nano-scale reinforcement has a mass percentage of 0.01 to 10% in the magnesium-based composite material. The method for producing a magnesium-based composite material according to claim 1, wherein the method of mixing a magnesium-based material melt with a nano-scale reinforcement comprises the steps of: enhancing the nano-scale in a protective gas atmosphere The body is added to the melt of the magnesium-based material by gas-carrying; and the magnesium-based material melt is mechanically stirred. The method for producing a magnesium-based composite material according to claim 6, wherein the shielding gas comprises a mixed gas of nitrogen, nitrogen and sulfur hexafluoride or a mixed gas of sulfur dioxide and dry air. The method for preparing a magnesium-based composite material according to claim 6, wherein the specific process of the gas carrying mode comprises the steps of: carrying a gas-blown nano-scale reinforcement; and passing the gas-carrying Flowing the nanoscale reinforcement into the melt of the magnesium based material. The method for producing a magnesium-based composite material according to claim 8, wherein the carrier gas is a mixed gas of argon gas, nitrogen gas, argon gas and nitrogen gas or a mixed gas of sulfur dioxide and nitrogen gas. The method for preparing a magnesium-based composite material according to claim 1, wherein the ultrasonically treating the mixture of the magnesium-based material and the nano-scale reinforcement comprises ultrasonically oscillating the magnesium-based material in a protective gas atmosphere A step of a mixture of nanoscale reinforcements for 1-10 minutes. The method for producing a magnesium-based composite material according to claim 10, wherein the ultrasonic wave has a frequency in the range of 15 to 20 kHz. The method for producing a magnesium-based composite material according to claim 1, wherein the inert gas is a mixed gas of argon gas, nitrogen gas, argon gas and nitrogen gas or a mixed gas of sulfur dioxide and nitrogen gas. The method for preparing a magnesium-based composite material according to claim 1, wherein the method for preparing the magnesium-based composite material further comprises the steps of: melting the magnesium-based composite material; and spray-molding the molten magnesium-based composite material material. The method for producing a magnesium-based composite material according to claim 1, further comprising subjecting the magnesium-based composite material to a calendering treatment to obtain a magnesium plate sheet having a predetermined thickness. A method for preparing a magnesium-based composite material, comprising the steps of: placing a magnesium-based material in a furnace under a protective gas atmosphere and melting; adding a plurality of nano-scale reinforcements to the furnace by using a gas carrying device Wherein, the magnesium-based material and the nano-scale reinforcement are mixed by a stirrer; the mixture of the magnesium-based material and the nano-scale reinforcement is treated by at least one ultrasonic device; and the magnesium-based material is spray-formed by a spray coating device. A mixture of a material and a nano-scale reinforcement to obtain the magnesium-based composite material, wherein the method for spray-molding a mixture of the above-mentioned magnesium-based material and a nano-scale reinforcement by a spray coating apparatus comprises the following steps: The above magnesium-based material and nano-scale reinforcement The mixture is injected into the funnel of the spray molding apparatus; maintaining the temperature of the mixture of the above magnesium-based material and the nano-scale reinforcement at 680-730 ° C; and passing the inert gas through the intake pipe at a pressure of 0.5-0.9 MPa The connecting tube is inserted into the connecting tube, and the mixture of the above magnesium-based material and the nano-level reinforcing body is atomized into fine droplets in the connecting tube, and the fine droplets are sprayed at high speed through the nozzle to the collecting plate in the atomization chamber. The method for preparing a magnesium-based composite material according to claim 15, wherein the spray molding apparatus comprises at least a funnel, a connecting pipe, an intake pipe, a nozzle and a spray chamber, wherein the connecting pipe is connected to the above a funnel and a spray chamber, wherein the intake pipe is connected to the connecting pipe, the nozzle is located at an end of the connecting pipe near the atomizing chamber, and the atomizing chamber is provided with at least one collecting plate, and the collecting plate is opposite to the nozzle Settings. The method for producing a magnesium-based composite material according to claim 15, wherein the nozzle has a certain distance from the collecting plate, and the distance ranges from 200 to 700 mm. The method for producing a magnesium-based composite material according to claim 15, further comprising calendering the magnesium-based composite material to obtain a magnesium plate sheet having a predetermined thickness.