Gradient silicon nitride reinforced metal matrix composite material, and preparation method and application thereof

Abstract

The application belongs to the technical field of composite materials, and particularly relates to a gradient silicon nitride reinforced metal matrix composite material, a preparation method thereof and application thereof. The gradient silicon nitride reinforced metal matrix composite material provided by the application has a silicon nitride layer, a first transition layer, a second transition layer and a metal layer, the components of silicon nitride and metal between the layers are in gradient distribution, and after calcination, the layers form an integral structure, the layers cooperate with each other, the obtained gradient silicon nitride reinforced metal matrix composite material has high strength, good wear resistance and excellent overall mechanical properties. The gradient silicon nitride reinforced metal matrix composite material provided by the application is used in the fields of aerospace, machinery and building, and is particularly suitable for places with special requirements for strength and wear resistance, has a long service life and good safety.

Description

A gradient silicon nitride reinforced metal matrix composite material, its preparation method and application Technical Field

[0001] This invention belongs to the field of composite material technology, specifically relating to a gradient silicon nitride reinforced metal matrix composite material, its preparation method, and its application. Background Technology

[0002] Silicon nitride is a newly developed structural engineering ceramic in recent years. It has good chemical stability, high temperature resistance, high strength and high hardness, good thermal shock resistance, low high-temperature creep, and good wear resistance. It is widely used in aerospace, machinery, chemical and other fields.

[0003] Chinese patent CN107188596A discloses a method for preparing porous gradient silicon nitride-silicon carbide composite ceramics for electromagnetic wave absorption. The ceramics form a continuous gradient silicon carbide distribution inside, which can effectively reduce the reflection of electromagnetic waves on the surface of the porous silicon nitride-silicon carbide composite ceramics, while ensuring the absorption effect of electromagnetic waves inside the porous silicon nitride-silicon carbide composite ceramics, thus significantly improving the electromagnetic wave absorption performance of porous silicon nitride-silicon carbide composite ceramics.

[0004] Chinese patent CN104311114A discloses a method for preparing gradient porous silicon nitride ceramic materials, which yields gradient porous silicon nitride ceramic materials with high porosity and abundant pore size.

[0005] However, the silicon nitride composite materials prepared by the above-mentioned patents generally suffer from low strength and poor wear resistance. Summary of the Invention

[0006] The purpose of this invention is to provide a gradient silicon nitride reinforced metal matrix composite material, its preparation method and application. The gradient silicon nitride reinforced metal matrix composite material provided by this invention has high strength and good wear resistance.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] This invention provides a gradient silicon nitride reinforced metal matrix composite material, comprising, from top to bottom, a silicon nitride layer, a first transition layer, a second transition layer, and a metal layer bonded together sequentially;

[0009] The raw materials for the silicon nitride layer include 80-90 wt% silicon nitride, 8-15 wt% aluminum, and 2-5 wt% manganese;

[0010] The raw materials for the first transition layer include 55-70 wt% silicon nitride, 20-40 wt% aluminum, and 5-10 wt% manganese;

[0011] The raw materials for the second transition layer include 20-40 wt% silicon nitride, 50-70 wt% aluminum, and 8-18 wt% manganese;

[0012] The raw materials for the metal layer include 5-15 wt% silicon nitride, 75-85 wt% aluminum, and 10-20 wt% manganese.

[0013] Preferably, the silicon nitride layer comprises 83-87 wt% silicon nitride, 10-13 wt% aluminum, and 4-5 wt% manganese.

[0014] The raw materials for the first transition layer include 60-65 wt% silicon nitride, 27-34 wt% aluminum, and 7-9 wt% manganese;

[0015] The raw materials for the second transition layer include 26-38.5 wt% silicon nitride, 55-65 wt% aluminum, and 10-15 wt% manganese;

[0016] The raw materials for the metal layer include 8-12 wt% silicon nitride, 79-82 wt% aluminum, and 14-18 wt% manganese.

[0017] Preferably, the thickness ratio of the silicon nitride layer to the first transition layer is 5-25:10-32;

[0018] The thickness ratio of the silicon nitride layer to the second transition layer is 5-25:10-32;

[0019] The thickness ratio of the silicon nitride layer to the metal layer is 10–32:35–60.

[0020] Preferably, the pore size of the gradient silicon nitride reinforced metal matrix composite material is 0.1 to 200 μm.

[0021] Preferably, the thickness of the gradient silicon nitride reinforced metal matrix composite material is 1 to 10 mm.

[0022] The present invention also provides a method for preparing the gradient silicon nitride reinforced metal matrix composite material described above, comprising the following steps:

[0023] (1) According to the formula, silicon nitride, aluminum, manganese and sintering aid are mixed and pressed into shape to obtain silicon nitride layer;

[0024] (2) According to the formula, silicon nitride, aluminum, manganese and sintering aid are mixed and pressed into shape to obtain the first transition layer;

[0025] (3) According to the formula, silicon nitride, aluminum, manganese and sintering aid are mixed and pressed into shape to obtain the second transition layer;

[0026] (4) According to the formula, silicon nitride, aluminum, manganese and sintering aid are mixed and pressed into shape to obtain a metal layer;

[0027] (5) The silicon nitride layer, the first transition layer, the second transition layer and the metal layer are stacked from top to bottom and then pressed, pre-oxidized and calcined in sequence to obtain a gradient silicon nitride reinforced metal matrix composite material.

[0028] There is no requirement for the time order of steps (1) to (4).

[0029] Preferably, the pressing pressure is 100-300 MPa, and the holding time is 3-10 min.

[0030] Preferably, the pre-oxidation temperature is 800–1400°C, and the holding time is 3–10 hours.

[0031] Preferably, the calcination temperature is 2000–2400℃, and the holding time is 3–8 hours.

[0032] The present invention also provides the application of the gradient silicon nitride reinforced metal matrix composite material described in the above-described scheme or the gradient silicon nitride reinforced metal matrix composite material obtained by the preparation method described in the above-described scheme in aerospace, machinery and construction.

[0033] This invention provides a gradient silicon nitride reinforced metal matrix composite material. The gradient silicon nitride reinforced metal matrix composite material provided by this invention comprises a silicon nitride layer, a first transition layer, a second transition layer, and a metal layer. The silicon nitride and metal components are distributed in a gradient between the layers. After calcination, the layers form an integral structure, with some porous structures penetrating each layer. The columnar structures within the porous structure exhibit higher strength. The layers work together to obtain a gradient silicon nitride reinforced metal matrix composite material with high strength, good wear resistance, and excellent overall mechanical properties.

[0034] This invention also provides a method for preparing the gradient silicon nitride reinforced metal matrix composite material described above. The preparation method provided by this invention is simple in steps, convenient in operation, highly feasible, and low in cost.

[0035] This invention also provides applications of the gradient silicon nitride reinforced metal matrix composites described in the above-described schemes or the gradient silicon nitride reinforced metal matrix composites prepared by the above-described methods in aerospace, machinery, and construction. The gradient silicon nitride reinforced metal matrix composites provided by this invention are used in aerospace, machinery, and construction fields, and are particularly suitable for applications with special requirements for strength and wear resistance, offering long service life and good safety. Detailed Implementation

[0036] This invention provides a gradient silicon nitride reinforced metal matrix composite material, comprising, from top to bottom, a silicon nitride layer, a first transition layer, a second transition layer, and a metal layer bonded together sequentially;

[0037] The raw materials for the silicon nitride layer include 80-90 wt% silicon nitride, 8-15 wt% aluminum, and 2-5 wt% manganese;

[0038] The raw materials for the first transition layer include 55-70 wt% silicon nitride, 20-40 wt% aluminum, and 5-10 wt% manganese;

[0039] The raw materials for the second transition layer include 20-40 wt% silicon nitride, 50-70 wt% aluminum, and 8-18 wt% manganese;

[0040] The raw materials for the metal layer include 5-15 wt% silicon nitride, 75-85 wt% aluminum, and 10-20 wt% manganese.

[0041] The gradient silicon nitride reinforced metal matrix composite material provided by the present invention includes a silicon nitride layer; the raw material of the silicon nitride layer includes 80-90 wt% silicon nitride, preferably 83-87 wt%, more preferably 84-86 wt%, and even more preferably 85 wt%; the raw material of the silicon nitride layer includes 8-15 wt% aluminum, preferably 9-14 wt%, more preferably 10-13 wt%, and even more preferably 11-12 wt%; the raw material of the silicon nitride layer includes 2-5 wt% manganese, preferably 3-5 wt%, and even more preferably 4-5 wt%.

[0042] The gradient silicon nitride reinforced metal matrix composite material provided by the present invention includes a first transition layer; the raw material of the first transition layer includes 55-70 wt% silicon nitride, preferably 58-68 wt%, more preferably 60-66 wt%, and even more preferably 62-64 wt%; the raw material of the first transition layer includes 20-40 wt% aluminum, preferably 22-38 wt%, more preferably 25-35 wt%, and even more preferably 27-34 wt%; the raw material of the first transition layer includes 5-10 wt% manganese, preferably 6-10 wt%, more preferably 7-9 wt%, and even more preferably 8 wt%.

[0043] The gradient silicon nitride reinforced metal matrix composite material provided by the present invention includes a second transition layer; the raw material of the second transition layer includes 20-40 wt% silicon nitride, preferably 26-38.5 wt%, more preferably 29-36 wt%, and even more preferably 32-34 wt%; the raw material of the second transition layer includes 50-70 wt% aluminum, preferably 55-65 wt%, more preferably 57-64 wt%, and even more preferably 60-62 wt%; the raw material of the second transition layer includes 8-18 wt% manganese, preferably 10-15 wt%, and even more preferably 12-14 wt%.

[0044] The gradient silicon nitride reinforced metal matrix composite material provided by the present invention includes a metal layer; the raw material of the metal layer includes 5-15 wt% silicon nitride, preferably 8-12 wt%, more preferably 9-11 wt%, and even more preferably 10 wt%; the raw material of the metal layer includes 75-85 wt% aluminum, preferably 79-82 wt%, and even more preferably 80 wt%; the raw material of the metal layer includes 10-20 wt% manganese, preferably 14-18 wt%, and even more preferably 16 wt%.

[0045] In this invention, the thickness ratio of the silicon nitride layer to the first transition layer is preferably 5-25:10-32, more preferably 9-21:13-28, and even more preferably 14-17:18-22.

[0046] In this invention, the thickness ratio of the silicon nitride layer to the second transition layer is preferably 5-25:10-32, more preferably 10-20:18-27, and even more preferably 14-16:22-24.

[0047] In this invention, the thickness ratio of the silicon nitride layer to the metal layer is preferably 10-32:35-60, more preferably 15-25:40-55, and even more preferably 18-22:45-50.

[0048] In this invention, the pore size of the gradient silicon nitride reinforced metal matrix composite material is preferably 0.1 to 200 μm, more preferably 1 to 150 μm.

[0049] In this invention, the thickness of the gradient silicon nitride reinforced metal matrix composite material is preferably 1 to 10 mm, more preferably 3 to 8 mm, and even more preferably 5 to 7 mm.

[0050] The present invention also provides a method for preparing the gradient silicon nitride reinforced metal matrix composite material described above, comprising the following steps:

[0051] (1) According to the formula, silicon nitride, aluminum, manganese and sintering aid are mixed and pressed into shape to obtain silicon nitride layer;

[0052] (2) According to the formula, silicon nitride, aluminum, manganese and sintering aid are mixed and pressed into shape to obtain the first transition layer;

[0053] (3) According to the formula, silicon nitride, aluminum, manganese and sintering aid are mixed and pressed into shape to obtain the second transition layer;

[0054] (4) According to the formula, silicon nitride, aluminum, manganese and sintering aid are mixed and pressed into shape to obtain a metal layer;

[0055] (5) The silicon nitride layer, the first transition layer, the second transition layer and the metal layer are stacked from top to bottom and then pressed, pre-oxidized and calcined in sequence to obtain a gradient silicon nitride reinforced metal matrix composite material.

[0056] There is no requirement for the time order of steps (1) to (4).

[0057] According to the formula, silicon nitride, aluminum, manganese, and sintering aids are mixed (referred to as the first mixture) and then pressed into shape (referred to as the first pressing) to obtain a silicon nitride layer. In this invention, the first mixture is preferably stirred or ball-milled; the pressure of the first pressing is preferably 50-90 MPa, more preferably 60-80 MPa, and even more preferably 70 MPa; the holding time is preferably 3-5 min, more preferably 4 min.

[0058] In this invention, the mass ratio of the sintering aid to the total mass of silicon nitride, aluminum and manganese is preferably 2 to 15:100, more preferably 4 to 12:100, and even more preferably 6 to 10:100.

[0059] According to the formula, silicon nitride, aluminum, manganese, and sintering aids are mixed (referred to as the second mixture) and then pressed into shape (referred to as the second pressing) to obtain a first transition layer. In this invention, the second mixture is preferably the same as the first mixture, and will not be described again here; the second pressing is preferably the same as the first pressing, and will not be described again here.

[0060] In this invention, the mass ratio of the sintering aid to the total mass of silicon nitride, aluminum and manganese is preferably 5 to 18:100, more preferably 7 to 16:100, and even more preferably 9 to 13:100.

[0061] According to the formula, silicon nitride, aluminum, manganese, and sintering aids are mixed (referred to as the third mixture) and then pressed into shape (referred to as the third pressing) to obtain a second transition layer. In this invention, the third mixture is preferably the same as the first mixture, and will not be described again here; the third pressing is preferably the same as the first pressing, and will not be described again here.

[0062] In this invention, the mass ratio of the sintering aid to the total mass of silicon nitride, aluminum and manganese is preferably 8 to 20:100, more preferably 10 to 17:100, and even more preferably 13 to 15:100.

[0063] According to the formula, silicon nitride, aluminum, manganese, and sintering aids are mixed (referred to as the fourth mixture) and then pressed into shape (referred to as the fourth pressing) to obtain a metal layer. In this invention, the fourth mixture is preferably the same as the first mixture, and will not be described again here; the fourth pressing is preferably the same as the first pressing, and will not be described again here.

[0064] In this invention, the mass ratio of the sintering aid to the total mass of silicon nitride, aluminum and manganese is preferably 8 to 25:100, more preferably 12 to 22:100, and even more preferably 15 to 17:100.

[0065] After obtaining the silicon nitride layer, the first transition layer, the second transition layer, and the metal layer, the present invention stacks the silicon nitride layer, the first transition layer, the second transition layer, and the metal layer sequentially from top to bottom, and then sequentially presses, pre-oxidizes, and calcines them to obtain a gradient silicon nitride reinforced metal matrix composite material. In the present invention, the stacking is preferably performed with the silicon nitride layer, the first transition layer, the second transition layer, and the metal layer aligned vertically.

[0066] In this invention, the pressing pressure is preferably 100-300 MPa, more preferably 150-270 MPa, and even more preferably 200-240 MPa, and the holding time is preferably 3-10 min, more preferably 5-8 min, and even more preferably 6-7 min.

[0067] In this invention, the pre-oxidation temperature is preferably 800-1400℃, more preferably 900-1200℃, and even more preferably 1000-1100℃, and the heat preservation time is preferably 3-10h, more preferably 5-8h, and even more preferably 6-7h.

[0068] In this invention, the calcination temperature is preferably 2000-2400℃, more preferably 2100-2300℃, and even more preferably 2250℃, and the holding time is preferably 3-8h, more preferably 4-7h, and even more preferably 5-6h.

[0069] The present invention also provides the application of the gradient silicon nitride reinforced metal matrix composite material described in the above-described scheme or the gradient silicon nitride reinforced metal matrix composite material obtained by the preparation method described in the above-described scheme in aerospace, machinery and construction.

[0070] The gradient silicon nitride reinforced metal matrix composite material provided by this invention can be used in aerospace, machinery and construction fields, and is especially suitable for applications with special requirements for strength and wear resistance. It has a long service life and good safety.

[0071] To further illustrate the present invention, the following detailed description of the embodiments is provided in conjunction with the present invention, but these descriptions should not be construed as limiting the scope of protection of the present invention.

[0072] Example 1

[0073] This embodiment provides a gradient silicon nitride reinforced metal matrix composite material, which includes, from top to bottom, a silicon nitride layer, a first transition layer, a second transition layer and a metal layer bonded together in sequence;

[0074] The raw materials for the silicon nitride layer include 80 wt% silicon nitride, 15 wt% aluminum, and 5 wt% manganese;

[0075] The raw materials for the first transition layer include 55 wt% silicon nitride, 40 wt% aluminum, and 5 wt% manganese;

[0076] The raw materials for the second transition layer include 20 wt% silicon nitride, 70 wt% aluminum, and 10 wt% manganese;

[0077] The raw materials for the metal layer include 5 wt% silicon nitride, 75 wt% aluminum, and 20 wt% manganese;

[0078] The thickness ratio of the silicon nitride layer to the first transition layer is 5:32;

[0079] The thickness ratio of the silicon nitride layer to the second transition layer is 5:10;

[0080] The thickness ratio of the silicon nitride layer to the metal layer is 10:35;

[0081] The pore size of the gradient silicon nitride reinforced metal matrix composite material is 0.1–200 μm;

[0082] The thickness of the gradient silicon nitride reinforced metal matrix composite material is 5 mm.

[0083] The preparation method of the gradient silicon nitride reinforced metal matrix composite material in this embodiment includes the following steps:

[0084] (1) According to the formula, silicon nitride, aluminum, manganese and sintering aid are stirred and mixed, and then pressure is maintained at 50MPa for 5min to obtain silicon nitride layer;

[0085] (2) According to the formula, silicon nitride, aluminum, manganese and sintering aid are stirred and mixed, and then pressure is maintained at 50MPa for 5min to obtain the first transition layer;

[0086] (3) According to the formula, silicon nitride, aluminum, manganese and sintering aid are stirred and mixed, and then pressure is maintained at 90MPa for 3min to obtain the second transition layer;

[0087] (4) According to the formula, silicon nitride, aluminum, manganese and sintering aid are stirred and mixed, and then pressure is maintained at 90MPa for 3min to obtain a metal layer;

[0088] (5) The silicon nitride layer, the first transition layer, the second transition layer and the metal layer are stacked from top to bottom, pressed at 100MPa for 10min, pre-oxidized at 800℃ for 10h, and calcined at 2000℃ for 8h to obtain a gradient silicon nitride reinforced metal matrix composite material.

[0089] There is no requirement for the time order of steps (1) to (4).

[0090] Example 2

[0091] This embodiment provides a gradient silicon nitride reinforced metal matrix composite material, which includes, from top to bottom, a silicon nitride layer, a first transition layer, a second transition layer and a metal layer bonded together in sequence;

[0092] The raw materials for the silicon nitride layer include 90 wt% silicon nitride, 8 wt% aluminum, and 2 wt% manganese;

[0093] The raw materials for the first transition layer include 70 wt% silicon nitride, 20 wt% aluminum, and 10 wt% manganese;

[0094] The raw materials for the second transition layer include 40 wt% silicon nitride, 50 wt% aluminum, and 10 wt% manganese;

[0095] The raw materials for the metal layer include 5 wt% silicon nitride, 75 wt% aluminum, and 20 wt% manganese;

[0096] The thickness ratio of the silicon nitride layer to the first transition layer is 25:10;

[0097] The thickness ratio of the silicon nitride layer to the second transition layer is 25:10;

[0098] The thickness ratio of the silicon nitride layer to the metal layer is 32:60;

[0099] The pore size of the gradient silicon nitride reinforced metal matrix composite material is 0.1–200 μm;

[0100] The thickness of the gradient silicon nitride reinforced metal matrix composite material is 10 mm.

[0101] The preparation method of the gradient silicon nitride reinforced metal matrix composite material in this embodiment includes the following steps:

[0102] (1) According to the formula, silicon nitride, aluminum, manganese and sintering aid are stirred and mixed, and then pressure is maintained at 90MPa for 3min to obtain silicon nitride layer;

[0103] (2) According to the formula, silicon nitride, aluminum, manganese and sintering aid are stirred and mixed, and then pressure is maintained at 90MPa for 3min to obtain the first transition layer;

[0104] (3) According to the formula, silicon nitride, aluminum, manganese and sintering aid are stirred and mixed, and then pressure is maintained at 50MPa for 5min to obtain the second transition layer;

[0105] (4) According to the formula, silicon nitride, aluminum, manganese and sintering aid are stirred and mixed, and then pressure is maintained at 50MPa for 5min to obtain a metal layer;

[0106] (5) The silicon nitride layer, the first transition layer, the second transition layer and the metal layer are stacked from top to bottom, pressed at 300MPa for 3min, pre-oxidized at 1400℃ for 3h, and calcined at 2400℃ for 3h to obtain a gradient silicon nitride reinforced metal matrix composite material.

[0107] There is no requirement for the time order of steps (1) to (4).

[0108] Example 3

[0109] This embodiment provides a gradient silicon nitride reinforced metal matrix composite material, which includes, from top to bottom, a silicon nitride layer, a first transition layer, a second transition layer and a metal layer bonded together in sequence;

[0110] The raw materials for the silicon nitride layer include 85 wt% silicon nitride, 12 wt% aluminum, and 3 wt% manganese;

[0111] The raw materials for the first transition layer include 60 wt% silicon nitride, 30 wt% aluminum, and 10 wt% manganese;

[0112] The raw materials for the second transition layer include 32 wt% silicon nitride, 50 wt% aluminum, and 18 wt% manganese;

[0113] The raw materials for the metal layer include 5 wt% silicon nitride, 75 wt% aluminum, and 20 wt% manganese;

[0114] The thickness ratio of the silicon nitride layer to the first transition layer is 15:22;

[0115] The thickness ratio of the silicon nitride layer to the second transition layer is 15:22;

[0116] The thickness ratio of the silicon nitride layer to the metal layer is 32:55;

[0117] The pore size of the gradient silicon nitride reinforced metal matrix composite material is 0.1–200 μm;

[0118] The thickness of the gradient silicon nitride reinforced metal matrix composite material is 1 mm.

[0119] The preparation method of the gradient silicon nitride reinforced metal matrix composite material in this embodiment includes the following steps:

[0120] (1) According to the formula, silicon nitride, aluminum, manganese and sintering aid are stirred and mixed, and then pressure is maintained at 80MPa for 4min to obtain silicon nitride layer;

[0121] (2) According to the formula, silicon nitride, aluminum, manganese and sintering aid are stirred and mixed, and then pressure is maintained at 80MPa for 4min to obtain the first transition layer;

[0122] (3) According to the formula, silicon nitride, aluminum, manganese and sintering aid are stirred and mixed, and then pressure is maintained at 80MPa for 4min to obtain the second transition layer;

[0123] (4) According to the formula, silicon nitride, aluminum, manganese and sintering aid are stirred and mixed, and then pressure is maintained at 70MPa for 4min to obtain a metal layer;

[0124] (5) The silicon nitride layer, the first transition layer, the second transition layer and the metal layer are stacked from top to bottom, pressed at 200MPa for 6min, pre-oxidized at 1200℃ for 7h, and calcined at 2200℃ for 6h to obtain a gradient silicon nitride reinforced metal matrix composite material.

[0125] There is no requirement for the time order of steps (1) to (4).

[0126] Example 4

[0127] This embodiment provides a gradient silicon nitride reinforced metal matrix composite material, which includes, from top to bottom, a silicon nitride layer, a first transition layer, a second transition layer and a metal layer bonded together in sequence;

[0128] The raw materials for the silicon nitride layer include 82 wt% silicon nitride, 13 wt% aluminum, and 5 wt% manganese;

[0129] The raw materials for the first transition layer include 65 wt% silicon nitride, 30 wt% aluminum, and 5 wt% manganese;

[0130] The raw materials for the second transition layer include 40 wt% silicon nitride, 52 wt% aluminum, and 8 wt% manganese;

[0131] The raw materials for the metal layer include 15 wt% silicon nitride, 75 wt% aluminum, and 10 wt% manganese;

[0132] The thickness ratio of the silicon nitride layer to the first transition layer is 5:32;

[0133] The thickness ratio of the silicon nitride layer to the second transition layer is 5:32;

[0134] The thickness ratio of the silicon nitride layer to the metal layer is 32:35;

[0135] The pore size of the gradient silicon nitride reinforced metal matrix composite material is 0.1–200 μm;

[0136] The thickness of the gradient silicon nitride reinforced metal matrix composite material is 8 mm.

[0137] The preparation method of the gradient silicon nitride reinforced metal matrix composite material in this embodiment includes the following steps:

[0138] (1) According to the formula, silicon nitride, aluminum, manganese and sintering aid are stirred and mixed, and then pressed at 60MPa for 5min to obtain silicon nitride layer;

[0139] (2) According to the formula, silicon nitride, aluminum, manganese and sintering aid are stirred and mixed, and then pressure is maintained at 60MPa for 5min to obtain the first transition layer;

[0140] (3) According to the formula, silicon nitride, aluminum, manganese and sintering aid are stirred and mixed, and then pressure is maintained at 60MPa for 5min to obtain the second transition layer;

[0141] (4) According to the formula, silicon nitride, aluminum, manganese and sintering aid are stirred and mixed, and then pressure is maintained at 60MPa for 5min to obtain a metal layer;

[0142] (5) The silicon nitride layer, the first transition layer, the second transition layer and the metal layer are stacked from top to bottom, pressed at 250MPa for 5min, pre-oxidized at 1000℃ for 7h, and calcined at 2200℃ for 7h to obtain a gradient silicon nitride reinforced metal matrix composite material.

[0143] There is no requirement for the time order of steps (1) to (4).

[0144] Example 5

[0145] This embodiment provides a gradient silicon nitride reinforced metal matrix composite material, which includes, from top to bottom, a silicon nitride layer, a first transition layer, a second transition layer and a metal layer bonded together in sequence;

[0146] The raw materials for the silicon nitride layer include 88 wt% silicon nitride, 10 wt% aluminum, and 2 wt% manganese;

[0147] The raw materials for the first transition layer include 65 wt% silicon nitride, 25 wt% aluminum, and 10 wt% manganese;

[0148] The raw materials for the second transition layer include 28 wt% silicon nitride, 60 wt% aluminum, and 12 wt% manganese;

[0149] The raw materials for the metal layer include 10 wt% silicon nitride, 75 wt% aluminum, and 15 wt% manganese;

[0150] The thickness ratio of the silicon nitride layer to the first transition layer is 25:32;

[0151] The thickness ratio of the silicon nitride layer to the second transition layer is 25:32;

[0152] The thickness ratio of the silicon nitride layer to the metal layer is 32:35;

[0153] The pore size of the gradient silicon nitride reinforced metal matrix composite material is 0.1–200 μm;

[0154] The thickness of the gradient silicon nitride reinforced metal matrix composite material is 3 mm.

[0155] The preparation method of the gradient silicon nitride reinforced metal matrix composite material in this embodiment includes the following steps:

[0156] (1) According to the formula, silicon nitride, aluminum, manganese and sintering aid are stirred and mixed, and then pressed at 60MPa for 5min to obtain silicon nitride layer;

[0157] (2) According to the formula, silicon nitride, aluminum, manganese and sintering aid are stirred and mixed, and then pressure is maintained at 60MPa for 5min to obtain the first transition layer;

[0158] (3) According to the formula, silicon nitride, aluminum, manganese and sintering aid are stirred and mixed, and then pressure is maintained at 90MPa for 3min to obtain the second transition layer;

[0159] (4) According to the formula, silicon nitride, aluminum, manganese and sintering aid are stirred and mixed, and then pressure is maintained at 70MPa for 4min to obtain a metal layer;

[0160] (5) The silicon nitride layer, the first transition layer, the second transition layer and the metal layer are stacked from top to bottom, pressed at 150MPa for 10min, pre-oxidized at 1000℃ for 9h, and calcined at 2100℃ for 7h to obtain a gradient silicon nitride reinforced metal matrix composite material.

[0161] There is no requirement for the time order of steps (1) to (4).

[0162] The mechanical properties of the gradient silicon nitride reinforced metal matrix composites of Examples 1 to 5 of the present invention were tested, and the results are shown in Table 1.

[0163] Table 1. Mechanical property data of graded silicon nitride reinforced metal matrix composites in Examples 1-5

[0164] Example Flexural strength (MPa) Wear rate (10) -6 mm 3 / Nm) Example 1 2077.4116 Example 2 2197.6124 Example 3 2012.9112 Example 4 2155.4130 Example 5 2181.1122 surface

[0165] As shown in Table 1, the gradient silicon nitride reinforced metal matrix composite material provided by the present invention has excellent strength and wear resistance.

[0166] As can be seen from the above embodiments, the gradient silicon nitride reinforced metal matrix composite material provided by the present invention has high strength, good wear resistance, and excellent overall mechanical properties, and can be used in aerospace and other fields with high requirements for material mechanical properties.

[0167] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. Other embodiments can be obtained based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A gradient silicon nitride reinforced metal matrix composite material, characterized in that, The composite material comprises, from top to bottom, a silicon nitride layer, a first transition layer, a second transition layer, and a metal layer, bonded together sequentially. The silicon nitride layer is made of 90 wt% silicon nitride, 8 wt% aluminum, and 2 wt% manganese. The first transition layer is made of 70 wt% silicon nitride, 20 wt% aluminum, and 10 wt% manganese. The second transition layer is made of 40 wt% silicon nitride, 50 wt% aluminum, and 10 wt% manganese. The metal layer is made of 5 wt% silicon nitride, 75 wt% aluminum, and 20 wt% manganese. The thickness ratio of the silicon nitride layer to the first transition layer is 25:

10. The thickness ratio of the silicon nitride layer to the second transition layer is 25:

10. The thickness ratio of the silicon nitride layer to the metal layer is 32:

60. The pore size of the gradient silicon nitride-reinforced metal matrix composite material is 0.1–200 μm. The thickness of the gradient silicon nitride-reinforced metal matrix composite material is 1–10 mm.

2. The method for preparing the gradient silicon nitride reinforced metal matrix composite material according to claim 1, characterized in that, Includes the following steps: (1) According to the formula, silicon nitride, aluminum, manganese and sintering aid are mixed and pressed into shape to obtain silicon nitride layer; (2) According to the formula, silicon nitride, aluminum, manganese and sintering aid are mixed and pressed to obtain the first transition layer; (3) According to the formula, silicon nitride, aluminum, manganese and sintering aid are mixed and pressed to obtain the second transition layer; (4) According to the formula, silicon nitride, aluminum, manganese and sintering aid are mixed and pressed to obtain the metal layer; (5) The silicon nitride layer, the first transition layer, the second transition layer and the metal layer are stacked from top to bottom and then pressed, pre-oxidized and calcined in sequence to obtain the gradient silicon nitride reinforced metal matrix composite material; the time order of the steps (1) to (4) is not required.

3. The preparation method according to claim 2, characterized in that, The pressing pressure is 100-300 MPa, and the holding time is 3-10 min.

4. The preparation method according to claim 2, characterized in that, The pre-oxidation temperature is 800–1400℃, and the holding time is 3–10 hours.

5. The preparation method according to claim 2, characterized in that, The calcination temperature is 2000–2400℃, and the holding time is 3–8 hours.

6. The application of the gradient silicon nitride reinforced metal matrix composite material according to claim 1 or the gradient silicon nitride reinforced metal matrix composite material obtained by any one of claims 2 to 5 in aerospace, machinery and construction.