A profiled metal matrix composite preform, a method of manufacture and use thereof

Abstract

The application discloses a method for preparing a special-shaped metal matrix composite preform based on a direct writing forming technology, and comprises the following steps: at room temperature, auxiliary agents containing a solvent, a retarder, a thickening agent, a water-retaining agent and a defoaming agent are fully mixed and dissolved at a certain proportion, then a proper amount of gypsum powder is added for fully stirring to obtain a gypsum slurry; at room temperature, a certain amount of a dispersing agent is dissolved in water, and after the pH value is adjusted, ceramic powder is added and mixed to prepare a reinforced phase slurry; the gypsum slurry and the reinforced phase slurry are installed on two printing heads of a double-head direct writing forming device, printing is carried out based on a preset preform model, and after drying treatment, a metal matrix composite preform with a complex special-shaped structure is obtained. The application adopts the double-head direct writing forming technology to form the preform of the metal matrix composite with a complex shape structure of a sacrificial phase and a reinforced phase, the gypsum is removed after the metal infiltration is completed, and then a complex-shaped metal matrix ceramic composite is obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of profiled metal matrix composites, in particular to a profiled metal matrix composite preform prepared based on direct writing forming technology, a preparation method and application thereof. BACKGROUND

[0002] Metal Matrix Composites (MMCs) are composites with metal or alloy as matrix and particles or fibers of different materials as reinforcement. They combine the properties of the metal matrix and the reinforcement, and have excellent properties such as high heat resistance, strong wear resistance, low density, and high strength. They are widely used in aerospace, transportation, and defense industries.The traditional preparation methods of metal matrix composites include powder metallurgy method

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SUN YP, YAN HG, SUB, et al. Microstructure and Mechanical Properties of Spray Deposition Al / SiCp Composite After Hot Extrusion[J]. Journal of Materials Engineering and Performance, 2011, 20(9): 1697-702.

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[0003] The process of preparing metal matrix composites by liquid infiltration method is as follows Figure 1

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[0004] In view of the above deficiencies existing at present, the application provides a kind of based on direct writing forming technology preparation special-shaped metal matrix composite preform, preparation method and application thereof, the application adopts double-head direct writing forming technology to form the composite structure of sacrificial phase and reinforcing phase, i.e. the preform of complex shape structure metal matrix composite. Among them, the gypsum as the sacrificial phase can be removed after completing the metal infiltration process, and then the complex shape special-shaped component is obtained, and the ceramic powder as the reinforcing phase is retained in the metal and is combined with it. The application solves the problem that the traditional process of metal matrix composite is difficult to prepare complex special-shaped structure metal matrix composite, and overcomes the difficulty that the gypsum slurry is difficult to be directly formed due to short setting time and large bleeding property. The complex special-shaped structure metal matrix composite preform prepared by the application has wide scale range and wide application range, and the control of decimeter level, centimeter level, millimeter level and micron level can be realized simply through needle aperture.

[0005] In order to achieve the above purpose, the application provides a kind of based on direct writing forming technology preparation special-shaped metal matrix composite preform, preparation method and application thereof, the application adopts double-head direct writing forming technology to form the composite structure of sacrificial phase and reinforcing phase, i.e. the preform of complex shape structure metal matrix composite. Among them, the gypsum as the sacrificial phase can be removed after completing the metal infiltration process, and then the complex shape special-shaped component is obtained, and the ceramic powder as the reinforcing phase is retained in the metal and is combined with it. The application solves the problem that the traditional process of metal matrix composite is difficult to prepare complex special-shaped structure metal matrix composite, and overcomes the difficulty that the gypsum slurry is difficult to be directly formed due to short setting time and large bleeding property. The complex special-shaped structure metal matrix composite preform prepared by the application has wide scale range and wide application range, and the control of decimeter level, centimeter level, millimeter level and micron level can be realized simply through needle aperture.

[0006] Step 1: preparation of sacrificial phase slurry:

[0007] At room temperature, the auxiliary agent containing solvent, setting retarder, thickening agent, water retaining agent and defoaming agent is fully mixed and dissolved according to a certain proportion, and then a proper amount of gypsum powder is added for fully stirring to obtain the gypsum slurry;

[0008] Step 2: preparation of reinforcing phase slurry:

[0009] Under room temperature condition, a certain amount of dispersing agent is dissolved in a proper amount of water, and after adjusting the appropriate pH value, ceramic powder is added for stirring and mixing to prepare the reinforcing phase slurry;

[0010] Step 3: direct writing forming of sacrificial phase and reinforcing phase:

[0011] The gypsum slurry and the reinforcing phase slurry are loaded into two needle cylinders, and they are installed on two print heads of the double-head direct writing forming equipment, printing is carried out based on the preform model preset by computer, and after drying treatment, the metal matrix composite preform with complex special-shaped structure is obtained.

[0012] According to one aspect of the application, in step 1, the solid content of the powder in the gypsum slurry is 0.01% to 89%, the adding amount of the setting retarder is 0.001% to 30% of the mass of the powder, the adding amount of the thickening agent is 0.1% to 40% of the mass of the powder; the adding amount of the water retaining agent is 0.01% to 99%; and the adding amount of the defoaming agent is 0.01% to 99% of the mass of the powder.

[0013] According to one aspect of the present application, the ceramic powder comprises any one or more of silicon carbide, silicon nitride, and alumina powder.

[0014] According to one aspect of the present application, in step 2, the solid content of the powder in the reinforcing phase slurry is 0.01% to 99%, the amount of the dispersant added is 0.001% to 10% of the mass of the powder, and the amount of the thickening agent and the defoaming agent added is each 0.001% to 1000% of the mass of the powder.

[0015] According to one aspect of the present application, before step 3, a double-head direct writing pre-treatment is further required for the double-head direct writing device, specifically: the gypsum slurry and the reinforcing phase slurry are stirred and degassed at room temperature.

[0016] According to one aspect of the present application, in step 3, the printing is specifically: the pressure of the needle cylinder installed on the Z-axis is automatically controlled by the computer, the slurry flows out of the needle nozzle and is deposited on the X-Y axis forming platform moving according to the program, so as to obtain a first layer structure; then, the Z-axis is accurately moved upward or rotated to a height determined by the structure scheme, and the second layer forming is performed on the first layer structure; subsequently, the complex special-shaped structure metal matrix composite preform is obtained by means of layer-by-layer stacking.

[0017] According to one aspect of the present application, the drying treatment is oven drying or microwave drying; the humidity of the drying treatment is 20% to 90%, and the temperature is less than 100℃.

[0018] Based on the same inventive concept, the present application further provides a complex special-shaped metal matrix composite preform prepared by the above method.

[0019] Based on the same inventive concept, the present application further provides an application of the complex special-shaped metal matrix composite preform prepared by the above method, comprising the following steps:

[0020] Step 1: immersing a metal liquid into the complex special-shaped metal matrix composite preform, and after solidification, a metal matrix composite containing a sacrificial phase is obtained;

[0021] Step 2: immersing the metal matrix composite containing the sacrificial phase into water, removing the sacrificial phase, and obtaining a complex special-shaped metal matrix composite.

[0022] According to one aspect of the present application, the metal comprises any one of Al, Mg, Cu, Fe, Zn, Ti, and alloys thereof.

[0023] The present application has the following beneficial effects:

[0024] The invention is characterized in that gypsum is used as a sacrificial phase, combined with inorganic materials (ceramic materials) such as silicon carbide, silicon nitride, aluminum oxide, etc. as a reinforcing phase, a corresponding printable slurry is prepared, and a double-head direct writing forming technology is used to prepare a complex-shaped metal matrix composite preform.

[0025] (1) The reinforcing phase slurry is combined with the sacrificial phase slurry, and a metal matrix composite preform with a sacrificial phase is directly prepared by a double-head direct writing forming method;

[0026] (2) The cost of preparing the metal matrix composite preform is low; the prepared inorganic slurry can be discharged according to the printing path;

[0027] (3) The structure of the metal matrix composite preform is controllable, that is, the distribution of the sacrificial phase is controllable;

[0028] (4) After sintering and metal infiltration of the metal matrix composite preform containing the sacrificial phase and the reinforcing phase, the sacrificial phase gypsum is removed, and a metal matrix composite with a complex-shaped structure is obtained;

[0029] (5) The gypsum printing method proposed in the invention can make the gypsum fully undergo hydration reaction, and the obtained gypsum support structure has high strength;

[0030] (6) The three-dimensional periodic structure prepared by the invention has a wide size range, and the decimeter, centimeter, millimeter, micrometer or nanometer level can be easily controlled through the needle aperture. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 A schematic diagram of a liquid infiltration method (gas pressure infiltration) for preparing a metal matrix composite as described in the background art of the invention;

[0032] Figure 2 A schematic diagram of the preparation process of a shaped metal matrix composite as described in the embodiment of the invention;

[0033] Figure 3 Examples of different metal matrix composite preforms containing reinforcing phases and sacrificial phases printed in the embodiment of the invention.

[0034] Explanation of reference signs:

[0035] 1, metal matrix composite preform containing reinforcing phase and sacrificial phase; 2, metal matrix composite containing sacrificial phase; 3, shaped metal matrix composite; 4, reinforcing phase particle; 5, sacrificial phase; 6, metal matrix. DETAILED DESCRIPTION

[0036] In order to make the present application more easily understood, the present application is further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present application and not used to limit the scope of the present application. Obviously, the described examples are only a part of the examples of the present application and not all the examples. Based on the examples in the present application, all the other examples obtained by those skilled in the art without making creative efforts are within the scope of protection of the present application. Unless otherwise defined, the professional terms used below are consistent with the meanings understood by the professionals in the art; unless otherwise specified, the raw materials and reagents involved in the present application can be purchased from the market or prepared by the known methods.

[0037] In order to solve the technical problems in the background art, the present application provides a method for preparing a special-shaped metal matrix composite preform based on a direct writing forming technology, comprising the following steps:

[0038] Step 1: Preparation of a sacrificial phase slurry:

[0039] At room temperature, the auxiliary agents including a solvent, a retarder, a thickening agent, a water retaining agent and a defoaming agent are fully mixed and dissolved in a certain proportion, and then an appropriate amount of gypsum powder is added for fully stirring to obtain a gypsum slurry;

[0040] Preferably, the solid content of the powder in the gypsum slurry is 0.01% to 89%, the addition amount of the retarder is 0.001% to 30% of the mass of the powder, the addition amount of the thickening agent is 0.1% to 40% of the mass of the powder; the addition amount of the water retaining agent is 0.01% to 99%; and the addition amount of the defoaming agent is 0.01% to 99% of the mass of the powder.

[0041] Preferably, the solvent is preferably water; the retarder is preferably any one or more of sodium triphosphate, a protein-based retarder, citric acid and salicylic acid; the thickening agent is methyl cellulose; the water retaining agent is sodium polyacrylate; and the defoaming agent is lauric acid.

[0042] Step 2: Preparation of a reinforcing phase slurry:

[0043] Under room temperature conditions, a certain amount of dispersant is dissolved in an appropriate amount of water, and then a ceramic powder is added for stirring and mixing after adjusting the appropriate pH value to prepare the reinforcing phase slurry.

[0044] Preferably, the ceramic powder includes any one or more of silicon carbide, silicon nitride and alumina powder.

[0045] Preferably, the pH value is 10.

[0046] Preferably, a thickening agent needs to be added after adjusting the pH value.

[0047] Preferably, the solid content of the powder in the reinforcing phase slurry is 0.01% to 99%, the adding amount of the dispersant is 0.001% to 10% of the mass of the powder, and the adding amount of the thickening agent and the defoaming agent is 0.001% to 1000% of the mass of the powder.

[0048] Step 3: Direct writing of the sacrificial phase and the reinforcing phase:

[0049] The gypsum slurry and the reinforcing phase slurry are loaded into two syringes and installed on two print heads of a double-head direct writing device, printing is performed based on a computer preset preform model, and after drying treatment, a metal matrix composite preform with a complex special-shaped structure is obtained.

[0050] Preferably, before step 3, double-head direct writing pretreatment is also required for the double-head direct writing device, specifically: stirring and degassing treatment of the gypsum slurry and the reinforcing phase slurry at room temperature. It should be noted that the stirring and degassing treatment is to ensure that the slurry loaded into the syringe is homogeneous and bubble-free, and can be continuously discharged.

[0051] Preferably, the stirring treatment is to place the syringe in a planetary stirrer for stirring, and the degassing treatment is vacuum degassing at room temperature, and the degassing time is 1 min to 60 min.

[0052] Preferably, the printing specifically refers to: computer automatic control of the pressure of the syringe installed on the Z axis (the pressure range is 1 to 1000 PSI, which is specific to the printing slurry), so that the slurry flows out of the needle nozzle and is deposited on the X-Y axis forming platform moving according to the program (the moving speed is 0.1 to 500 mm / sec, which is specific to the slurry), thereby obtaining a first layer structure; then, the Z axis is accurately moved upward or rotated to a height determined by the structure scheme, and the second layer forming is performed on the first layer structure; subsequently, a complex special-shaped structure metal matrix composite preform is obtained by means of layer-by-layer stacking.

[0053] Preferably, the drying treatment is oven drying or microwave drying; the humidity of the drying treatment is 20% to 90%, and the temperature is less than 100℃.

[0054] The application also discloses a special-shaped metal matrix composite prepared from the special-shaped metal matrix composite preform.

[0055] Step 1: Immersing a metal liquid in the metal matrix composite preform with a complex special-shaped structure, and after solidification, a metal matrix composite containing a sacrificial phase is obtained.

[0056] Step 2: Immersing the metal matrix composite containing the sacrificial phase in water, removing the sacrificial phase (gypsum), and obtaining a metal matrix composite with a complex special-shaped structure.

[0057] Preferably, the metal comprises any one of Al, Mg.

[0058] The principles of the present application are illustrated in Figure 2 The reinforcing phase particles 4 and the sacrificial phase 5 are formed into a metal matrix composite preform 1 containing reinforcing phase and sacrificial phase by multi-head direct writing; the metal matrix composite preform 1 containing reinforcing phase and sacrificial phase is subjected to liquid metal infiltration, and the metal matrix 6 is infiltrated into the gaps between the reinforcing phase particles 4 to obtain a metal matrix composite 2 containing a sacrificial phase; then the sacrificial phase gypsum is removed, and a complex-shaped metal matrix composite 3 is obtained. The present application can overcome the difficulty of directly preparing complex-shaped components in the traditional preparation process, and can save the machining process of the metal matrix composite, thereby realizing the preparation of complex-shaped metal matrix composite components on the basis of a simple process. The multi-head direct writing method is used for multi-material 3D printing, which not only needs to evaluate the rheological properties of a single slurry, but also needs to realize the matching of the shear modulus and yield stress between different kinds of printable slurries. The printing adaptability between the reinforcing phase slurry and the sacrificial phase slurry is realized by adjusting the rheological properties of the slurry and the printing speed, extrusion pressure and other parameters.

[0059] The principles of the present application are illustrated in

[0060] Examples 1-4 are used to prepare gypsum / silicon carbide complex-shaped structure metal matrix composite preforms by using different amounts / kinds of additives.

[0061] Example 1

[0062] At room temperature, first, the retarder (sodium triphosphate, 0.67 g), thickening agent (methyl cellulose, 0.72 g), water retaining agent (sodium polyacrylate, 0.22 g), defoaming agent (lauric acid, 0.45 g) and distilled water (40 g) are mixed and stirred until completely dissolved, then alpha hemihydrate gypsum powder (100 g) is added for sufficient stirring and degassing treatment to obtain a relatively homogeneous gypsum slurry; then the dispersing agent (polyacrylic acid, 0.0192 g) is dissolved in water, the pH value is adjusted to 10, then the silicon carbide powder (40 g) is added for stirring and mixing to obtain a homogeneous and dispersed silicon carbide suspension, and a thickening agent (methyl cellulose, 0.2 g) is added to obtain a homogeneous silicon carbide slurry; finally, the slurry is loaded into the corresponding needle cylinder and stirred for 5 min. The extrusion pressure of the gypsum slurry is set to 35 PSI, and the moving speed is set to 5 mm / s. The extrusion pressure of the silicon carbide slurry is set to 38 PSI, and the moving speed is set to 4 mm / s. After printing, the sample is dried by placing it in a humidity of 30% and a temperature of 60°C for 24 hours to completely dry the sample. The actual photos of the multiple metal matrix composite preforms containing reinforcing phase and sacrificial phase printed out are shown in Figure 3 .

[0063] Example 2

[0064] At room temperature, first, the retarder (protein retarder, 0.75 g), thickening agent (methyl cellulose, 0.72 g), water retaining agent (sodium polyacrylate, 0.22 g), defoaming agent (lauric acid, 0.45 g) and distilled water (42 g) were mixed and stirred until completely dissolved, then alpha-hemihydrate gypsum powder (100 g) was added for sufficient stirring and degassing treatment to obtain a relatively homogeneous gypsum slurry; then by dissolving the dispersing agent (polyethyleneimine, 0.0392 g) in water, adjusting the pH value to 10, adding silicon carbide powder (40 g) for stirring and mixing to obtain a homogeneous and dispersed silicon carbide suspension, and adding a thickening agent (methyl cellulose, 0.25 g) to obtain a homogeneous silicon carbide slurry; finally, the slurry was loaded into the corresponding needle cylinder and stirred for 5 min. The extrusion pressure of the gypsum slurry was set to 32 PSI, and the moving speed was set to 3 mm / s. The extrusion pressure of the silicon carbide slurry was set to 34 PSI, and the moving speed was set to 5 mm / s. After printing, the sample was dried by placing it in a humidity of 30% and a temperature of 60°C for 24 hours to completely dry the sample.

[0065] Example 3

[0066] At room temperature, first, the retarder (citric acid, 0.251 g), thickening agent (methyl cellulose, 0.77 g), water retaining agent (sodium polyacrylate, 0.2 g), defoaming agent (lauric acid, 0.54 g) and distilled water (42 g) were mixed and stirred until completely dissolved, then alpha-hemihydrate gypsum powder (100 g) was added for sufficient stirring and degassing treatment to obtain a relatively homogeneous gypsum slurry; then by dissolving the dispersing agent (polyacrylic acid, 0.02 g) in water, adjusting the pH value to 10, adding silicon carbide powder (50 g) for stirring and mixing to obtain a homogeneous and dispersed silicon carbide suspension, and adding a thickening agent (methyl cellulose, 0.3 g) to obtain a homogeneous silicon carbide slurry; finally, the slurry was loaded into the corresponding needle cylinder and stirred for 5 min. The extrusion pressure of the gypsum slurry was set to 35 PSI, and the moving speed was set to 6 mm / s. The extrusion pressure of the silicon carbide slurry was set to 40 PSI, and the moving speed was set to 3 mm / s. After printing, the sample was dried by placing it in a humidity of 30% and a temperature of 60°C for 24 hours to completely dry the sample.

[0067] Example 4

[0068] At room temperature, first, the retarder (salicylic acid, 0.75 g), thickening agent (methyl cellulose, 0.41 g), water retaining agent (sodium polyacrylate, 0.19 g), defoaming agent (lauric acid, 0.45 g) and distilled water (50 g) were mixed and stirred until completely dissolved, then α-hemihydrate gypsum powder (100 g) was added for sufficient stirring and degassing treatment to obtain a relatively homogeneous gypsum slurry; then by dissolving the dispersant (polyethyleneimine, 0.2 g) in water, adjusting the pH value to 10, adding silicon carbide powder (40 g) for stirring and mixing to obtain a homogeneous and dispersed silicon carbide suspension, and adding a thickening agent (methyl cellulose, 0.4 g) to obtain a homogeneous silicon carbide slurry; finally, the slurry was loaded into the corresponding needle cylinder and stirred for 5 min. The extrusion pressure of the gypsum slurry was set to 35 PSI, and the moving speed was set to 3 mm / s. The extrusion pressure of the silicon carbide slurry was set to 45 PSI, and the moving speed was set to 4 mm / s. After printing, the sample was dried by placing it in a humidity of 30% and a temperature of 60°C for 24 hours to completely dry the sample.

[0069] Examples 5-7 are for preparing gypsum / silicon nitride complex-shaped structure metal matrix composite preforms using different amounts / kinds of additives.

[0070] Example 5

[0071] At room temperature, first, the retarder (protein retarder, 0.75 g), thickening agent (methyl cellulose, 0.72 g), water retaining agent (sodium polyacrylate, 0.22 g), defoaming agent (lauric acid, 0.45 g) and distilled water (42 g) were mixed and stirred until completely dissolved, then α-hemihydrate gypsum powder (100 g) was added for sufficient stirring and degassing treatment to obtain a relatively homogeneous gypsum slurry; then by mixing the dispersant (polyethyleneimine, 0.2 g), solvent (distilled water, 8 g) and silicon nitride powder (30 g) and adjusting the pH value to 10, a homogeneous and dispersed silicon nitride suspension was obtained, and a thickening agent (methyl cellulose, 0.4 g) was added to obtain a homogeneous silicon nitride slurry; finally, the slurry was loaded into the corresponding needle cylinder and stirred for 5 min. The extrusion pressure of the gypsum slurry was set to 32 PSI, and the moving speed was set to 3 mm / s. The extrusion pressure of the silicon nitride slurry was set to 45 PSI, and the moving speed was set to 4 mm / s. After printing, the sample was dried by placing it in a humidity of 30% and a temperature of 60°C for 24 hours to completely dry the sample.

[0072] Example 6

[0073] At room temperature, first, the retarder (sodium tripolyphosphate, 0.67 g), thickening agent (methyl cellulose, 0.72 g), water retaining agent (sodium polyacrylate, 0.22 g), defoaming agent (lauric acid, 0.45 g) and distilled water (40 g) were mixed and stirred until completely dissolved, then a-hemihydrate gypsum powder (100 g) was added for sufficient stirring and degassing treatment to obtain a relatively homogeneous gypsum slurry; then the dispersant (polyethyleneimine, 0.21 g), solvent (distilled water, 10 g) and silicon nitride powder (30 g) were mixed and the pH value was adjusted to 10 to obtain a homogeneous and dispersed silicon carbide suspension, and a thickening agent (methyl cellulose, 0.4 g) was added to obtain a homogeneous silicon nitride slurry; finally, the slurry was loaded into the corresponding needle cylinder and stirred for 5 min. The extrusion pressure of the gypsum slurry was set to 35 PSI, and the moving speed was set to 5 mm / s. The extrusion pressure of the silicon nitride slurry was set to 38 PSI, and the moving speed was set to 4 mm / s. After printing, the sample was dried under the condition of 30% humidity and 60°C temperature for 24 hours to completely dry the sample.

[0074] Example 7

[0075] At room temperature, first, the retarder (citric acid, 0.251 g), thickening agent (methyl cellulose, 0.77 g), water retaining agent (sodium polyacrylate, 0.2 g), defoaming agent (lauric acid, 0.54 g) and distilled water (42 g) were mixed and stirred until completely dissolved, then a-hemihydrate gypsum powder (100 g) was added for sufficient stirring and degassing treatment to obtain a relatively homogeneous gypsum slurry; then the dispersant (tetramethylammonium hydroxide, 0.21 g), solvent (distilled water, 10 g) and silicon nitride powder (30 g) were mixed and the pH value was adjusted to 10 to obtain a homogeneous and dispersed silicon carbide suspension, and a thickening agent (methyl cellulose, 0.4 g) was added to obtain a homogeneous silicon nitride slurry; finally, the slurry was loaded into the corresponding needle cylinder and stirred for 5 min. The extrusion pressure of the gypsum slurry was set to 35 PSI, and the moving speed was set to 6 mm / s. The extrusion pressure of the silicon nitride slurry was set to 38 PSI, and the moving speed was set to 4 mm / s. After printing, the sample was dried under the condition of 30% humidity and 60°C temperature for 24 hours to completely dry the sample.

[0076] Examples 8-10 are for preparing gypsum / alumina complex-shaped structure metal matrix composite preforms using different amounts / kinds of admixtures.

[0077] Example 8

[0078] At room temperature, first the retarder (salicylic acid, 0.75 g), thickening agent (methyl cellulose, 0.41 g), water retaining agent (sodium polyacrylate, 0.19 g), defoaming agent (lauric acid, 0.45 g) and distilled water (50 g) were mixed and stirred until completely dissolved, then α-hemihydrate gypsum powder (100 g) was added for sufficient stirring and degassing treatment to obtain a relatively homogeneous gypsum slurry; then by mixing the dispersant (tetramethylammonium hydroxide, 0.21 g), solvent (distilled water, 10 g) and aluminum oxide powder (30 g) and adjusting the pH value to 10, a homogeneous dispersed aluminum oxide suspension was obtained, and a thickening agent (methyl cellulose, 0.4 g) was added to obtain a homogeneous aluminum oxide slurry; finally, the slurry was loaded into the corresponding needle cylinder and stirred for 5 min. The extrusion pressure of the gypsum slurry was set to 35 PSI, and the moving speed was set to 3 mm / s. The extrusion pressure of the aluminum oxide slurry was set to 40 PSI, and the moving speed was set to 4 mm / s. After printing, the sample was dried under the condition of 30% humidity and 60°C temperature for 24 hours to completely dry the sample.

[0079] Example 9

[0080] At room temperature, first the retarder (salicylic acid, 0.75 g), thickening agent (methyl cellulose, 0.41 g), water retaining agent (sodium polyacrylate, 0.19 g), defoaming agent (lauric acid, 0.45 g) and distilled water (50 g) were mixed and stirred until completely dissolved, then α-hemihydrate gypsum powder (100 g) was added for sufficient stirring and degassing treatment to obtain a relatively homogeneous gypsum slurry; then by mixing the dispersant (tetramethylammonium hydroxide, 0.21 g), solvent (distilled water, 10 g) and aluminum oxide powder (30 g) and adjusting the pH value to 10, a homogeneous dispersed aluminum oxide suspension was obtained, and a thickening agent (methyl cellulose, 0.4 g) was added to obtain a homogeneous aluminum oxide slurry; finally, the slurry was loaded into the corresponding needle cylinder and stirred for 5 min. The extrusion pressure of the gypsum slurry was set to 35 PSI, and the moving speed was set to 3 mm / s. The extrusion pressure of the aluminum oxide slurry was set to 40 PSI, and the moving speed was set to 4 mm / s. After printing, the sample was dried under the condition of 30% humidity and 60°C temperature for 24 hours to completely dry the sample.

[0081] Example 10

[0082] The retarder (protein retarder, 0.75 g), thickening agent (methyl cellulose, 0.72 g), water retaining agent (sodium polyacrylate, 0.22 g), defoaming agent (lauric acid, 0.45 g) and distilled water (42 g) are mixed and stirred at room temperature until completely dissolved, then the α-hemihydrate gypsum powder (100 g) is added for sufficient stirring and degassing treatment to obtain a relatively homogeneous gypsum slurry; then the dispersant (polyvinylpyrrolidone, 0.21 g), solvent (distilled water, 10 g) and aluminum oxide powder (30 g) are mixed and the pH value is adjusted to 10 to obtain a homogeneous dispersed aluminum oxide suspension, and a thickening agent (methyl cellulose, 0.4 g) is added to obtain a homogeneous aluminum oxide slurry; finally, the slurry is loaded into the corresponding needle cylinder and stirred for 5 min. The extrusion pressure of the gypsum slurry is set to 32 PSI, the moving speed is set to 3 mm / s, the extrusion pressure of the aluminum oxide slurry is set to 38 PSI, the moving speed is set to 4 mm / s, and after printing, the sample is dried under the condition of 30% humidity and 60°C for 24 hours to completely dry the sample.

[0083] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the scope of the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for preparing a shaped metal matrix composite preform based on direct-write fabrication technology, characterized in that, The method comprises the following steps: Step 1: preparation of the sacrificial phase slurry At room temperature, auxiliary agents including solvent, retarder, thickening agent, water retaining agent and defoaming agent are mixed and dissolved in a certain proportion, and then a proper amount of gypsum powder is added for fully stirring to obtain a gypsum slurry; wherein the solid content of the powder in the gypsum slurry is 0.01%~89%, the adding amount of the retarder is 0.001%~30% of the mass of the powder, the adding amount of the thickening agent is 0.1%~40% of the mass of the powder, and the adding amount of the defoaming agent is 0.01%~99% of the mass of the powder; Step 2: preparation of the reinforced phase slurry Under room temperature, a certain amount of dispersant is dissolved in a proper amount of water, and then ceramic powder is added for stirring and mixing after adjusting the proper pH value to prepare the reinforced phase slurry; Step 3: direct writing forming of the sacrificial phase and the reinforced phase The gypsum slurry and the reinforced phase slurry are loaded into two needle cylinders, and then the two needle cylinders are installed on two printing heads of a double-head direct writing forming device; printing is performed based on a preform model preset by a computer; after drying treatment, a metal matrix composite preform with a complex special-shaped structure is obtained; wherein the humidity of the drying treatment is 20%~90%, and the temperature is less than 100℃.

2. The method of claim 1, wherein the method is characterized by, The ceramic powder includes any one or more of silicon carbide, silicon nitride and alumina powder.

3. The method of claim 1, wherein the method is characterized by, In step 2, the solid content of the powder in the reinforced phase slurry is 0.01%~99%, the adding amount of the dispersant is 0.001%~10% of the mass of the powder, and the adding amount of the thickening agent and the defoaming agent is both 0.001%~1000% of the mass of the powder.

4. The method of claim 1, wherein the method is characterized by, Before step 3, the double-head direct writing forming device needs to be subjected to a double-head direct writing forming pretreatment, specifically: the gypsum slurry and the reinforced phase slurry are stirred and degassed at room temperature.

5. The method of claim 1, wherein the method is characterized by: In step 3, the printing is specifically: the computer automatically controls the pressure of the needle cylinder installed on the Z axis to make the slurry flow out of the needle nozzle and deposit on an X-Y axis forming platform moving according to the program to obtain a first layer structure; then, the Z axis is accurately moved upward or rotated to a height determined by the structure scheme, and a second layer forming is performed on the first layer structure; subsequently, a complex special-shaped structure metal matrix composite preform is obtained by means of layer-by-layer stacking.

6. The method of claim 1, wherein the method is characterized by: The drying treatment is oven drying or microwave drying.

7. A complex special-shaped metal matrix composite preform prepared by the method of any one of claims 1-6.

8. Use of a shaped metal matrix composite preform prepared according to the method of any one of claims 1 to 6 or of a shaped metal matrix composite preform according to claim 7, characterized in that, The method comprises the following steps: Step 1: immersing a metal liquid into a complex special-shaped structure metal matrix composite preform, and after solidification, a metal matrix composite containing a sacrificial phase is obtained; Step 2: immersing the metal matrix composite containing the sacrificial phase into water to remove the sacrificial phase, and a complex special-shaped structure metal matrix composite is obtained.

9. Use according to claim 8, characterized in that, The metal includes any one of Al, Mg, Cu, Fe, Zn and Ti and an alloy thereof.

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