Spinel type ferrite composite material with high-performance microwave absorption and preparation method thereof

Abstract

The invention provides a spinel type ferrite composite material with high-performance microwave absorption and a preparation method thereof, and relates to the technical field of microwave absorption ferrite materials. According to the composite material, spinel type ferrite such as Ni < 0.4 > Zn < 0.4 > Me < 0.2 > Fe < 1.94 > Cr < 0.01 > O < 4 > (Me = Mg, Co, Ni, Cu and Zn) is used as a substrate material, the substrate material is compounded with a carbon nano tube with the mass fraction of 6.5 wt% to obtain the composite material, and the finally obtained Ni < 0.4 > Zn < 0.4 > Cu < 0.2 > Fe < 1.94 > Cr < 0.01 > O < 4 > / 6.5 wt% CNTs show good microwave absorption performance and have a smaller microwave absorption peak and a thinner impedance matching thickness compared with other microwave absorbents. The preparation method comprises a solid phase method and an ultrasonic method, and is low in cost, simple to operate and short in preparation period. The prepared composite material has good wave-absorbing performance and has a wider application prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of microwave absorbing ferrite materials, and in particular to a spinel ferrite composite material with high-performance microwave absorption and a preparation method thereof. Background Art

[0002] Electronic technology is developing rapidly, and the demand for stealth technology in the military is also increasing. Therefore, the research and development of high-performance absorbing materials is imminent.

[0003] Magnetic materials with mainly magnetic loss and carbon nanotubes (CNTs) materials with mainly dielectric loss are two main absorbing materials that convert electromagnetic energy into thermal energy. Nickel-zinc spinel ferrite is a typical magnetic material. Due to its excellent magnetic properties, low cost and abundant raw materials, it is increasingly favored as an absorbing material. Single spinel ferrite has good magnetic loss characteristics, but its impedance matching effect is not ideal, and its microwave absorption performance is poor, which cannot meet the needs in the real environment. The preparation of spinel ferrite composite materials has become a possibility to improve microwave absorption performance. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a spinel ferrite composite material with high-performance microwave absorption and a preparation method thereof, so as to obtain a composite material with good microwave absorption performance.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented through the following technical solutions:

[0006] A spinel ferrite composite material with high performance microwave absorption, the composite material is Ni 0.4 Zn 0.4 Me 0.2 Fe 1.94 Cr 0.01 O 4 / 6.5wt% CNTs, wherein Me is any one of Mg, Co, Ni, Cu and Zn.

[0007] The preparation method of the above spinel ferrite composite material comprises the following steps:

[0008] S1, according to the chemical formula Ni 0.4 Zn 0.4 Me 0.2 Fe 1.94 Cr 0.01 O 4 Weigh each oxide raw material separately, add distilled water, and place in a ball mill for ball milling to obtain a mixed powder for later use;

[0009] S2, heating the mixed powder to 800-910°C, pre-calcining for 1-10h, and then crushing in a mortar to obtain a pre-made powder;

[0010] S3, adding a binder to the prefabricated powder, heating to 1100°C-1200°C and sintering for 1-10h to obtain spinel ferrite;

[0011] S4, ball-milling the ferrite for 0.5-3h to obtain ferrite powder, dispersing the ferrite powder and carbon nanotubes in a solvent, vibrating the mixture with an ultrasonic oscillator for 0.5-5h, and drying the mixture to obtain a spinel ferrite composite material.

[0012] Preferably, the water-to-material weight ratio of the distilled water added in step S1 is 1.2-1.6.

[0013] Preferably, the ball milling speed in step S1 is 180-300 r / min, and the ball milling time is 1.5-5 h.

[0014] Preferably, the heating rate in step S2 and step S3 is 3-8°C / min.

[0015] Preferably, in step S3, the binder is PVA, and the amount of the binder added is 8-12 wt %.

[0016] Preferably, in step S4, the ferrite powder is sieved through a 80-200 mesh sieve.

[0017] Preferably, the solvent used in step S4 is alcohol.

[0018] Preferably, the drying method in step S4 is drying at a temperature of 60-110° C. for 4-18 hours.

[0019] The present invention provides a spinel ferrite composite material with high-performance microwave absorption and a preparation method thereof, which has the following advantages over the prior art:

[0020] The spinel ferrite composite material prepared by the present invention exhibits good microwave absorption performance, wherein the best material chemical formula is Ni 0.4 Zn 0.4 Cu 0.2 Fe 1.94 Cr 0.01 O 4 / 6.5wt% CNTs, compared with other microwave absorbers, has a smaller microwave absorption peak and thinner impedance matching thickness. The preparation method of the present invention is a solid phase method and an ultrasonic method, which has low cost, simple operation and short preparation cycle. The prepared composite material has good microwave absorption performance and has a wider application prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 XRD diffraction patterns of the composite materials of Examples 1-5 of the present invention;

[0022] Figure 2 This is a SEM image of the composite material of Example 1 of the present invention;

[0023] Figure 3 This is a three-dimensional diagram of the minimum reflection loss of the composite material of Example 1 of the present invention at different thicknesses;

[0024] Figure 4 This is a SEM image of the composite material of Example 2 of the present invention;

[0025] Figure 5 This is a three-dimensional graph of the minimum reflection loss of the composite material of Example 2 of the present invention at different thicknesses;

[0026] Figure 6 This is a SEM image of the composite material of Example 3 of the present invention;

[0027] Figure 7 This is a three-dimensional graph of the minimum reflection loss of the composite material of Example 3 of the present invention at different thicknesses;

[0028] Figure 8 This is a SEM image of the composite material of Example 4 of the present invention;

[0029] Fig. 9 This is a three-dimensional graph of the minimum reflection loss of the composite material of Example 4 of the present invention at different thicknesses;

[0030] Fig.10 This is a SEM image of the composite material of Example 5 of the present invention;

[0031] Fig.11 This is a three-dimensional graph of the minimum reflection loss of the composite material of Example 5 of the present invention at different thicknesses. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention is clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Embodiment 1:

[0034] A spinel ferrite composite material (Ni 0.6 Zn 0.4 Fe 1.94 Cr 0.01 O4 / 6.5wt% CNTs) preparation:

[0035] (1) According to the chemical formula, weigh 46.339g Fe 2 O 3 (99.9%), 13.529g NiO (99%), 9.827gZnO (99%), 0.229g Cr 2 O 3 (99%) mixed powder;

[0036] (2) The mixed powder was placed in a ball mill containing 100 ml of distilled water, the speed of the ball mill was set to 230 rpm, and the ball mill was milled for 3 hours. The powder was taken out and dried to obtain the ball milled raw material;

[0037] (3) placing the ball-milled raw material into a high-temperature sintering furnace, setting the heating rate to 4°C / min, heating the ball-milled raw material to 860°C and keeping the temperature for 6 h to obtain a pre-sintered powder;

[0038] (4) Add 10 wt% PVA to the pre-sintered powder and sinter at 1170°C for 8 hours to obtain Ni 0.6 Zn 0.4 Fe 1.94 Cr 0.01 O 4 Spinel ferrite samples;

[0039] (5) Weigh 7.045 g Ni 0.6 Zn 0.4 Fe 1.94 Cr 0.01 O 4 The spinel ferrite sample and 0.458g of carbon nanotubes were dispersed with alcohol as a dispersant, and then mixed with ferrite powder and vibrated in an ultrasonic vibrator for 1 hour; then placed in a drying oven at 90°C for 12 hours to obtain a composite material Ni 0.6 Zn 0.4 Fe 1.94 Cr 0.01 O 4 / 6.5wt%CNTs.

[0040] For the above composite material Ni 0.6 Zn 0.4 Fe 1.94 Cr 0.01 O 4 / 6.5wt%CNTs for testing:

[0041] Among them through Figure 1 A1 is the XRD diagram of the spinel ferrite composite material obtained in Example 1, indicating that the sample has a single spinel structure;

[0042] Figure 2 This is a SEM image of the spinel ferrite composite material obtained in Example 1, indicating that the spinel ferrite and the carbon nanotubes are mixed uniformly.

[0043] Figure 3 The three-dimensional graph of the minimum reflection loss of the spinel ferrite composite material obtained in Example 1 corresponding to different thicknesses shows that when the matching thickness is 2.5 mm and the frequency is 10.15 GHz, the minimum reflection loss (RL) is -33.73 dB and the effective absorption bandwidth (EAB) is 2.93 GHz.

[0044] Embodiment 2:

[0045] A spinel ferrite composite material (Ni 0.4 Zn 0.4 Co 0.2 Fe 1.94 Cr 0.01 O 4 / 6.5wt% CNTs) preparation method:

[0046] (1) According to the chemical formula, weigh 46.329g Fe 2 O 3 (99.9%), 9.017g NiO (99%), 9.825gZnO (99%), 0.229g Cr 2 O 3 (99%), 3.307 g Co 2 O 3 (99.9%) mixed powder.

[0047] (2) The mixed powder was placed in a ball mill containing 100 ml of distilled water, the speed of the ball mill was set to 230 rpm, and the ball mill was milled for 3 hours. The powder was taken out and dried to obtain the ball milled raw material;

[0048] (3) placing the ball-milled raw material into a high-temperature sintering furnace, setting the heating rate to 4°C / min, heating the ball-milled raw material to 860°C and keeping the temperature for 6 h to obtain a pre-sintered powder;

[0049] (4) Add 10 wt% PVA to the pre-sintered powder and sinter at 1170°C for 8 hours to obtain Ni 0.4 Zn 0.4 Co 0.2 Fe 1.94 Cr 0.01 O 4 Spinel ferrite samples;

[0050] (5) Weigh 7.003gNi 0.4 Zn0.4 Co 0.2 Fe 1.94 Cr 0.01 O 4 The spinel ferrite sample and 0.457g of carbon nanotubes were dispersed with alcohol as a dispersant, and then mixed with the spinel ferrite powder, vibrated in an ultrasonic vibrator for 1 hour, and then placed in a drying oven at 90°C for 12 hours to obtain a composite material Ni 0.4 Zn 0.4 Co 0.2 Fe 1.94 Cr 0.01 O 4 / 6.5wt%CNTs.

[0051] For the above composite material Ni 0.4 Zn 0.4 Co 0.2 Fe 1.94 Cr 0.01 O 4 / 6.5wt%CNTs for testing:

[0052] Figure 1 A2 is the XRD pattern of the spinel ferrite composite material obtained in Example 2, indicating that the sample has a single spinel structure;

[0053] Figure 4 This is a SEM image of the spinel ferrite composite material obtained in Example 2, indicating that the spinel ferrite and the carbon nanotubes are uniformly mixed;

[0054] Figure 5 The three-dimensional graph of the minimum reflection loss of the spinel ferrite composite material obtained in Example 2 corresponding to different thicknesses shows that when the matching thickness is 2.5 mm and the frequency is 10.4 GHz, the minimum reflection loss (RL) is -30.08 dB and the effective absorption bandwidth (EAB) is 3.72 GHz.

[0055] Embodiment 3:

[0056] A spinel ferrite composite material (Ni 0.6 Zn 0.4 Fe 1.94 Cr 0.01 O 4 Preparation of CNTs ( / 6.5wt% CNTs):

[0057] (1) According to the chemical formula, weigh 46.339g Fe 2 O 3 (99.9%), 13.529g NiO (99%), 9.827gZnO (99%), 0.229g Cr2 O 3 (99%) mixed powder;

[0058] (2) The mixed powder was placed in a ball mill containing 100 ml of distilled water, the speed of the ball mill was set to 230 rpm, and the ball mill was milled for 3 hours. The powder was taken out and dried to obtain the ball milled raw material;

[0059] (3) placing the ball-milled raw material into a high-temperature sintering furnace, setting the heating rate to 4°C / min, heating the ball-milled raw material to 860°C and keeping the temperature for 6 h to obtain a pre-sintered powder;

[0060] (4) Add 10 wt% PVA to the pre-sintered powder and sinter at 1170°C for 8 hours to obtain Ni 0.6 Zn 0.4 Fe 1.94 Cr 0.01 O 4 Spinel ferrite samples;

[0061] (5) Weigh 7.045 g Ni 0.6 Zn 0.4 Fe 1.94 Cr 0.01 O 4 The spinel ferrite sample and 0.458g of carbon nanotubes were dispersed with alcohol as a dispersant, and then mixed with ferrite powder, vibrated in an ultrasonic vibrator for 1 hour, and then placed in a drying oven at 90°C for 12 hours to obtain a composite material Ni 0.6 Zn 0.4 Fe 1.94 Cr 0.01 O 4 / 6.5wt%CNTs.

[0062] For the above composite material Ni 0.6 Zn 0.4 Fe 1.94 Cr 0.01 O 4 / 6.5wt%CNTs for testing:

[0063] Figure 1 A3 in FIG. 1 is the XRD diagram of the ferrite composite material obtained in Example 3, indicating that the sample has a single spinel structure.

[0064] Figure 6 This is a SEM image of the spinel ferrite composite material obtained in Example 3, indicating that the spinel ferrite and the carbon nanotubes are mixed uniformly.

[0065] Figure 7The three-dimensional graph of the minimum reflection loss of the spinel ferrite composite material obtained in Example 3 corresponding to different thicknesses shows that when the matching thickness is 2 mm and the frequency is 12.75 GHz, the minimum reflection loss (RL) is -26.79 dB and the effective absorption bandwidth (EAB) is 3.11 GHz.

[0066] Embodiment 4:

[0067] A spinel ferrite composite material (Ni 0.4 Zn 0.4 Cu 0.2 Fe 1.94 Cr 0.01 O 4 Preparation of CNTs ( / 6.5wt%):

[0068] (1) According to the chemical formula, weigh 46.147g Fe 2 O 3 (99.9%), 8.982g NiO (99%), 9.786gZnO (99%), 0.229g Cr 2 O 3 (99%), 4.783g Co 2 O 3 (99%) mixed powder;

[0069] (2) The mixed powder was placed in a ball mill containing 100 ml of distilled water, the speed of the ball mill was set to 230 rpm, and the ball mill was milled for 3 hours. The powder was taken out and dried to obtain the ball milled raw material;

[0070] (3) The ball-milled raw material is placed in a high-temperature sintering furnace and the heating rate is set to 4°C / min. The ball-milled raw material is heated to 860°C and kept at this temperature for 6 hours to obtain a pre-sintered powder;

[0071] (4) Add 10 wt% PVA to the pre-sintered powder and sinter at 1170°C for 8 hours to obtain Ni 0.4 Zn 0.4 Cu 0.2 Fe 1.94 Cr 0.01 O 4 Spinel ferrite samples;

[0072] (5) Weigh 7.014 g Ni 0.4 Zn 0.4 Cu 0.2 Fe 1.94 Cr 0.01 O 4The spinel ferrite sample and 0.456g of carbon nanotubes were dispersed with alcohol as a dispersant, and then mixed with the spinel ferrite powder, vibrated in an ultrasonic vibrator for 1 hour, and then placed in a drying oven at 90°C for 12 hours to obtain a composite material Ni 0.4 Zn 0.4 Cu 0.2 Fe 1.94 Cr 0.01 O 4 / 6.5wt%CNTs.

[0073] For the above composite material Ni 0.4 Zn 0.4 Cu 0.2 Fe 1.94 Cr 0.01 O 4 / 6.5wt%CNTs for testing:

[0074] Figure 1 A4 is the XRD diagram of the spinel ferrite composite material obtained in Example 4, indicating that the sample has a single spinel structure.

[0075] Figure 8 This is a SEM image of the spinel ferrite composite material obtained in Example 4, indicating that the spinel ferrite and the carbon nanotubes are mixed uniformly.

[0076] Fig. 9 The three-dimensional graph of the minimum reflection loss of the spinel ferrite composite material obtained in Example 4 corresponding to different thicknesses shows that when the matching thickness is 1.5 mm and the frequency is 14.95 GHz, the minimum reflection loss (RL) is -46.53 dB and the effective absorption bandwidth (EAB) is 3.55 GHz.

[0077] Embodiment 5:

[0078] A spinel ferrite composite material with microwave absorption (Ni 0.4 Zn 0.6 Fe 1.94 Cr 0.01 O 4 Preparation of CNTs ( / 6.5wt%):

[0079] (1) According to the chemical formula, weigh 46.076g Fe 2 O 3 (99.9%), 8.968g NiO (99%), 14.657gZnO (99%), 0.229g Cr 2 O 3 (99%) mixed powder;

[0080] (2) The mixed powder was placed in a ball mill containing 100 ml of distilled water, the speed of the ball mill was set to 230 rpm, and the ball mill was performed for 3 hours. The mixed powder was taken out and dried to obtain the ball milled raw material;

[0081] (3) placing the ball-milled raw material into a high-temperature sintering furnace, setting the heating rate to 4°C / min, heating the ball-milled raw material to 860°C and keeping the temperature for 6 h to obtain a pre-sintered powder;

[0082] (4) Add 10 wt% PVA to the pre-sintered powder and sinter at 1170°C for 8 hours to obtain Ni 0.4 Zn 0.6 Fe 1.94 Cr 0.01 O 4 Spinel ferrite samples;

[0083] (5) Weigh 7.031gNi 0.4 Zn 0.6 Fe 1.94 Cr 0.01 O 4 The spinel ferrite sample and 0.456g of carbon nanotubes were dispersed with alcohol as a dispersant, and then mixed with ferrite powder, vibrated in an ultrasonic vibrator for 1 hour, and then placed in a drying oven at 90°C for 12 hours to obtain a composite material Ni 0.4 Zn 0.6 Fe 1.94 Cr 0.01 O 4 / 6.5wt%CNTs.

[0084] For the above composite material Ni 0.4 Zn 0.6 Fe 1.94 Cr 0.01 O 4 / 6.5wt%CNTs for testing:

[0085] Figure 1 A5 is the XRD diagram of the spinel ferrite composite material obtained in Example 5, indicating that the sample has a single spinel structure.

[0086] Fig.10 This is a SEM image of the spinel ferrite composite material obtained in Example 5, indicating that the spinel ferrite and the carbon nanotubes are mixed uniformly.

[0087] Fig.11 The three-dimensional graph of the minimum reflection loss of the spinel ferrite composite material obtained in Example 5 corresponding to different thicknesses shows that when the matching thickness is 2.5 mm and the frequency is 10 GHz, the minimum reflection loss (RL) is -26.30 dB and the effective absorption bandwidth (EAB) is 2.34 GHz.

[0088] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A spinel ferrite composite material with high performance microwave absorption, characterized in that: The composite material is Ni 0.4 Zn 0.4 Me 0.2 Fe 1.94 Cr 0.01 O4 / 6.5wt% CNTs, wherein Me is any one of Mg, Co, Ni, Cu and Zn.

2. A method for preparing the composite material according to claim 1, characterized in that: The preparation method comprises the following steps: S1, according to the chemical formula Ni 0.4 Zn 0.4 Me 0.2 Fe 1.94 Cr 0.01 Weigh each oxide raw material separately, add distilled water and place in a ball mill for ball milling to obtain a mixed powder for later use; S2, heating the mixed powder to 800-910°C, pre-calcining for 1-10h, and then crushing in a mortar to obtain a pre-made powder; S3, adding a binder to the prefabricated powder, heating to 1100°C-1200°C and sintering for 1-10h to obtain spinel ferrite; S4, ball-milling the ferrite for 0.5-3h to obtain ferrite powder, dispersing the ferrite powder and carbon nanotubes in a solvent, vibrating the mixture with an ultrasonic oscillator for 0.5-5h, and drying the mixture to obtain a spinel ferrite composite material.

3. The preparation method according to claim 2, characterized in that: The water-to-material weight ratio of the distilled water added in step S1 is 1.2-1.

6.

4. The preparation method according to claim 2, characterized in that: In step S1, the rotation speed of the ball mill is 180-300 r / min, and the ball milling time is 1.5-5 h.

5. The preparation method according to claim 2, characterized in that: The heating rate in step S2 and step S3 is 3-8°C / min.

6. The preparation method according to claim 2, characterized in that: In step S3, the binder is PVA, and the amount of the binder added is 8-12 wt %.

7. The preparation method according to claim 2, characterized in that: In the step S4, the ferrite powder is sieved through a 80-200 mesh sieve.

8. The preparation method according to claim 2, characterized in that: The solvent used in step S4 is alcohol.

9. The preparation method according to claim 2, characterized in that: The drying method in step S4 is drying at a temperature of 60-110° C. for 4-18 hours.

Images