ZrB2 coated zirconium powder as well as preparation method and application thereof

Abstract

The invention provides ZrB2-coated zirconium powder and a preparation method and application thereof, the ZrB2-coated zirconium powder comprises zirconium powder and a ZrB2 coating layer coating the zirconium powder, the particle size D90 of the zirconium powder is less than or equal to 50 [mu] m, and the thickness of the coating layer is 0.1-3 [mu] m; the mass percentage of ZrB2 is 1-60%, and the preparation method comprises the following steps: taking zirconium powder and boron powder, uniformly mixing the zirconium powder and the boron powder in a ball milling manner, putting the mixed material into a vacuum tube furnace, and carrying out high-temperature sintering to obtain the ZrB2-coated zirconium powder, the purity of the zirconium powder is greater than or equal to 95%, and the particle size D90 is less than or equal to 50 microns; the boron powder comprises amorphous boron powder and crystal boron, and the granularity is less than or equal to 1 micron; the mass ratio of the zirconium powder to the boron powder is (10: 1)-(100: 1). The product is high in calorific value, the density and energy of the solid propellant can be improved, meanwhile, the preparation mode is simple, experimental results are controllable, and batch preparation is easy to achieve.

Description

Technical Field

[0001] The present invention generally relates to the technical field of energetic materials, and in particular to a ZrB 2 Coated zirconium powder and preparation method and application thereof. Background Art

[0002] The main components of solid propellants are binders, oxidizers and metal fuels. The addition of metal fuels is one of the important ways to increase the energy of solid propellants, not only because the metal fuel has a high density and releases a large amount of heat per unit volume, but also because the heat of vaporization of metal oxides is high, which can provide a lot of energy to solid propellants and inhibit the instability of propellant combustion. The metal fuels in solid propellants mainly include Al, Mg, Zr, and Ti. Among them, aluminum powder and magnesium powder have been put into practical use, and the remaining metal powders are still in the research stage. Compared with aluminum and magnesium, zirconium powder has a high density, a large volume calorific value, and excellent combustion performance. Studies have shown that the burning rate of zirconium powder of 40 to 70 μm is equivalent to that of aluminum powder of 10 μm, and the content of 3 μm zirconium particles has a similar effect on the burning rate of propellants as nano-aluminum particles. Therefore, the use of zirconium powder is a favorable choice for preparing high energy density solid propellants.

[0003] However, zirconium powder, as a metal fuel with high density and high volumetric heat of combustion, is limited in its use in solid propellants due to its high electrostatic sensitivity and potential safety hazards. When the average particle size of zirconium powder is less than 10 μm and it is in a suspended state, it will spontaneously combust or even explode. Therefore, zirconium powder must be modified before it can be used in solid propellants. The literature currently displayed shows that the use of terminal hydroxybutadiene (HTPB, 0.96 g cm -3 , 43.10 kJ·cm -3 ), glycidyl azide (GAP, 1.3 g cm -3 , 26.67 kJ·cm -3 )), polymethyl methacrylate (PMMA, 1.29 g·cm -3 ), nitrocellulose azide (NC, 1.66 g cm -3 ), aluminum oxide (Al 2 O 3 , 3.5 g cm -3 ), zinc oxide (ZnO, 5.6 g·cm -3 ), polyimide (PI, 1.59 g·cm -3 ), nanocarbon film (C, 2.26 g·cm -3 , 74.04 kJ·cm -3 ) etc. to modify the zirconium powder. However, these coating materials have low volume calorific value and lose zirconium powder (Zr, 6.49g·cm -3 , 78.28 kJ·cm -3)Original advantages of high density and high volume calorific value.

[0004] It is very important to find a high calorific value material to modify the metal zirconium powder. Zirconium boride, as an inorganic ceramic phase material, is insulating and has high density and volume calorific value (ZrB 2 , 6.09 g·cm -3 , 110.61 kJ·cm -3 ), and the reaction between B and Zr is relatively simple. Therefore, coating the surface of zirconium powder with inorganic ceramic phase zirconium boride is the key to preparing high calorific value zirconium powder composite fuel. Summary of the invention

[0005] In order to overcome the technical defect of low volume calorific value of composite zirconium powder in the prior art, the present invention provides a ZrB 2 Coated zirconium powder and preparation method and application thereof, wherein the zirconium powder is coated with ZrB 2 The coating layer ensures the high density of zirconium powder while ensuring that its volume calorific value is not lost.

[0006] The technical solution of the present invention is that a ZrB 2 Coated zirconium powder, including zirconium powder and ZrB coated outside the zirconium powder 2 The particle size of the zirconium powder is D 90 ≤50μm, the thickness of the coating layer is 0.1μm-3μm; the ZrB 2 The mass percentage is: 1%-60%.

[0007] The present invention also provides the above-mentioned ZrB 2 The preparation method of the coated zirconium powder comprises taking zirconium powder and boron powder, mixing them evenly by ball milling, and then placing the mixed materials into a vacuum tube furnace for high temperature sintering to obtain the ZrB 2 Coated zirconium powder.

[0008] Furthermore, the purity of the zirconium powder is ≥95%, and the particle size D 90 ≤50μm.

[0009] Furthermore, the above-mentioned boron powder includes amorphous boron powder and crystalline boron, and the particle size is ≤1 micron.

[0010] Furthermore, the mass ratio of the zirconium powder to the boron powder is 10:1-100:1.

[0011] Furthermore, the ball milling method includes planetary ball milling or horizontal ball milling, the ball milling speed is 200 rpm to 400 rpm, and the ball milling time is 1 h to 6 h.

[0012] Furthermore, the high temperature sintering temperature is 700° C. to 1200° C., and the holding time is 30 min to 300 min.

[0013] Furthermore, the vacuum tube furnace is filled with argon or helium.

[0014] The present invention also provides the above-mentioned ZrB 2 Application of coated zirconium powder in solid propellant components.

[0015] The beneficial effects of the present invention are: the ZrB disclosed in the present invention 2 The coated zirconium powder has a high calorific value, which is beneficial to improving the density and energy of solid propellants. At the same time, the preparation method is simple, the experimental results are controllable, and batch preparation is easy to achieve. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] These and / or other aspects and advantages of the present invention will become more clear and easier to understand from the following detailed description of the embodiments of the present invention in conjunction with the accompanying drawings, in which:

[0017] Figure 1 The XRD patterns of the zirconium powder raw materials and the products obtained in Examples 1-5 in the present invention;

[0018] Figure 2 The XRD diagram of the product obtained in Examples 6-11 of the present invention;

[0019] Figure 3 These are SEM images of the products obtained in Examples 1-11 of the present invention, wherein (a)-(b) correspond to the products of Examples 1-2, respectively, and (c) corresponds to the product of Example 9. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0021] Embodiment 1:

[0022] Weigh zirconium powder (D 90 ≤50μm, the same in the following embodiments) and boron powder (particle size ≤1μm, the same in the following embodiments), and then ball milled at 300rpm for 3h. The ball-milled sample was placed in a vacuum tube furnace, and kept at 700℃ for 90min under argon or helium atmosphere to obtain ZrB 2 The coated zirconium powder composite material is marked as No. 1#. The XRD diagram of the raw zirconium powder and the XRD diagram of the obtained product in this embodiment are shown in Figure 1 As shown: Zirconium powder contains ZrB 2 The generation of ZrB 2 The content is 4.37%; the SEM picture of the product obtained in this example is as follows Figure 3As shown in the figure, the sample coating thickness is 0.68 μm. The sample volume calorific value is increased from 68.98 kJ·cm -3 Increased to 70.25 kJ·cm -3 .

[0023] Embodiment 2:

[0024] Weigh zirconium powder and boron powder in a mass ratio of 10:1, and then ball-mill at 300 rpm for 3 hours. Put the ball-milled sample into a vacuum tube furnace and keep it at 800℃ for 90 minutes under argon or helium atmosphere to obtain ZrB 2 The coated zirconium powder composite material is marked as No. 2#. The XRD pattern of the product prepared in this example is as follows Figure 1 As shown: Zirconium powder contains ZrB 2 The generation of ZrB 2 The content is 18.08%. The SEM picture of this example is as follows Figure 3 As shown in the figure, the sample coating thickness is 0.92 μm. The sample volume calorific value is increased from 68.98 kJ·cm -3 Increased to 76.30 kJ·cm -3 .

[0025] Embodiment 3:

[0026] Weigh zirconium powder and boron powder in a mass ratio of 10:1, and then ball-mill at 300 rpm for 3 hours. The ball-milled sample is placed in a vacuum tube furnace and kept at 900°C for 90 minutes under an argon or helium atmosphere to obtain ZrB 2 The coated zirconium powder composite material is marked as No. 3#. The XRD pattern of the product prepared in this embodiment is as follows Figure 1 As shown: Zirconium powder contains ZrB 2 The generation of ZrB 2 The content is 35.25%. The sample coating layer thickness is 1.82μm, and the volume calorific value is 77.55kJ·cm -3 .

[0027] Embodiment 4:

[0028] Zirconium powder and boron powder were weighed in a mass ratio of 10:1, and then ball-milled at 300 rpm for 3 h. The ball-milled sample was placed in a vacuum tube furnace and kept at 1200 °C for 90 min under an argon or helium atmosphere to obtain ZrB 2 The coated zirconium powder composite material is marked as No. 4#. The XRD pattern of the product prepared in this embodiment is as follows Figure 1 As shown: Zirconium powder contains ZrB 2 The generation of ZrB 2 The content is 59.33%. The sample coating layer thickness is 2.14μm, and the volume calorific value is 81.06kJ·cm-3 .

[0029] Embodiment 5:

[0030] Weigh zirconium powder and boron powder in a mass ratio of 10:1, and then ball-mill at 300 rpm for 3 hours. The ball-milled sample is placed in a vacuum tube furnace and kept at 900°C for 30 minutes under an argon or helium atmosphere to obtain ZrB 2 The coated zirconium powder composite material is numbered 5#. The XRD pattern of the product prepared in this example is as follows Figure 1 As shown: Zirconium powder contains ZrB 2 The generation of ZrB 2 The content is 22.65%. The sample coating layer thickness is 1.16μm, and the volume calorific value is 76.98kJ·cm -3 .

[0031] Embodiment 6:

[0032] Weigh zirconium powder and boron powder in a mass ratio of 10:1, and then ball-mill at 300 rpm for 3 hours. Put the ball-milled sample into a vacuum tube furnace and keep it at 900℃ for 150 minutes under argon or helium atmosphere to obtain ZrB 2 The coated zirconium powder composite material is marked as No. 6#. The XRD pattern of the product prepared in this embodiment is as follows Figure 2 As shown: Zirconium powder contains ZrB 2 The generation of ZrB 2 The content is 41.29%. The sample coating layer thickness is 1.95 μm, and the volume calorific value is 79.80 kJ·cm -3 .

[0033] Embodiment 7:

[0034] Weigh zirconium powder and boron powder in a mass ratio of 10:1, and then ball-mill at 300 rpm for 3 hours. Put the ball-milled sample into a vacuum tube furnace and keep it at 900℃ for 300 minutes under argon or helium atmosphere to obtain ZrB 2 The coated zirconium powder composite material is numbered 7#. The XRD pattern of the product prepared in this example is as follows Figure 2 As shown: Zirconium powder contains ZrB 2 The generation of ZrB 2 The content is 43.83%. The sample coating thickness is 2.03 μm and the volume calorific value is 80.58 kJ·cm -3 .

[0035] Embodiment 8:

[0036] Zirconium powder and boron powder were weighed in a mass ratio of 20:1, and then ball-milled at 300 rpm for 3 h. The ball-milled sample was placed in a vacuum tube furnace and kept at 900 °C for 90 min under an argon or helium atmosphere to obtain ZrB 2 The coated zirconium powder composite material is numbered 8#. The XRD pattern of the product prepared in this example is as follows Figure 2 As shown: Zirconium powder contains ZrB 2 The generation of ZrB 2 The content is 19.70%. The sample coating thickness is 1.03 μm and the volume calorific value is 76.31 kJ·cm -3 .

[0037] Embodiment 9:

[0038] Weigh zirconium powder and boron powder according to a mass ratio of 100:1, and then ball mill at 300 rpm for 3 hours. The ball-milled sample is placed in a vacuum tube furnace and kept at 900°C for 90 minutes under an argon or helium atmosphere to obtain ZrB 2 The coated zirconium powder composite material is numbered 9#. The XRD pattern of the product prepared in this example is as follows Figure 2 As shown: Zirconium powder contains ZrB 2 The generation of ZrB 2 The content is 10.46%. The SEM picture of this example is as follows Figure 3 As shown in the figure, the sample coating thickness is 1.71 μm, and the surface is dotted. The volume calorific value of the sample is 72.99 kJ·cm -3 .

[0039] Embodiment 10:

[0040] Weigh zirconium powder and boron powder in a mass ratio of 10:1, and then ball-mill at 400 rpm for 1 hour. The ball-milled sample is placed in a vacuum tube furnace and kept at 900°C for 90 minutes under an argon or helium atmosphere to obtain ZrB 2 The coated zirconium powder composite material is numbered 10#. The XRD pattern of the product prepared in this example is as follows Figure 2 As shown: Zirconium powder contains ZrB 2 The generation of ZrB 2 The content is 36.78%. The sample coating thickness is 1.87 μm and the volume calorific value is 78.13 kJ·cm -3 .

[0041] Embodiment 11:

[0042] Weigh zirconium powder and boron powder in a mass ratio of 10:1, and then ball-mill at 200 rpm for 6 hours. Put the ball-milled sample into a vacuum tube furnace and keep it at 900℃ for 90 minutes under argon or helium atmosphere to obtain ZrB 2The coated zirconium powder composite material is numbered 11#. The XRD pattern of the product prepared in this example is as follows Figure 2 As shown: Zirconium powder contains ZrB 2 The generation of ZrB 2 The content is 33.21%. The sample coating layer thickness is 1.55 μm, and the volume calorific value is 77.53 kJ·cm -3 .

[0043] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. Therefore, the scope of protection of the present invention should be subject to the scope of protection of the claims.

Claims

1. A ZrB2-coated zirconium powder, characterized in that: The invention comprises zirconium powder and a ZrB2 coating layer coated on the outside of the zirconium powder, wherein the particle size of the zirconium powder is D 90 ≤50μm, the thickness of the coating layer is 0.1μm-3μm; the mass percentage of ZrB2 is: 1%-60%.

2. A method for preparing ZrB2-coated zirconium powder according to claim 1, characterized in that: Zirconium powder and boron powder are taken and mixed evenly by ball milling. The mixed materials are then placed in a vacuum tube furnace for high-temperature sintering to obtain the ZrB2-coated zirconium powder.

3. The method for preparing ZrB2-coated zirconium powder according to claim 2, characterized in that: The purity of the zirconium powder is ≥95%, and the particle size D90 is ≤50 μm.

4. The method for preparing ZrB2-coated zirconium powder according to claim 2, characterized in that: The boron powder includes amorphous boron powder and crystalline boron, and the particle size is ≤1 micron.

5. The method for preparing ZrB2-coated zirconium powder according to claim 2, characterized in that: The mass ratio of zirconium powder to boron powder is 10:1-100:

1.

6. The method for preparing ZrB2-coated zirconium powder according to claim 2, characterized in that: The ball milling method includes planetary ball milling or horizontal ball milling, the ball milling speed is 200 rpm to 400 rpm, and the ball milling time is 1 h to 6 h.

7. The method for preparing ZrB2-coated zirconium powder according to claim 2, characterized in that: The high temperature sintering temperature is 700°C to 1200°C, and the holding time is 30min to 300min.

8. The method for preparing ZrB2-coated zirconium powder according to claim 2, characterized in that: The vacuum tube furnace is filled with argon or helium.

9. An application of the ZrB2-coated zirconium powder according to claim 1, characterized in that: Used in solid propellant components.

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