Detailed Description
The present invention is further illustrated by the following examples, but is not limited to the details of the description.
Example 1
An iron-nickel fiber reinforced cement-based electromagnetic wave absorbing material, wherein the weight ratio of water to cement is 1: 2; the weight percentage of the sand is 200 percent based on the total mass of the water and the cement; the weight percentage of the iron-nickel alloy fiber is 30 percent based on the total mass of the water and the cement. Wherein the nickel content of the iron-nickel alloy fiber is 76 wt%, the iron content is 23 wt%, and the chromium content is 1 wt%. The length-diameter ratio of the iron-nickel alloy fiber is 600, and the diameter of the iron-nickel alloy fiber is 12 mu m.
The preparation method of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material comprises the following steps:
1) weighing cement and sand according to the proportion, and performing dry mixing, wherein in the dry mixing process, the iron-nickel alloy fiber is divided into 4 batches, and 1/4 batches are fed;
2) adding water into the dry stirring materials in 2 batches of 1/2, and uniformly stirring to obtain a stirring material of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material;
3) and adopting a mould to pour and prepare a plate-shaped or cuboid sample.
And testing the electromagnetic wave absorption performance of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material plate with the thickness of 6mm according to the GJB 2038A-2011 radar wave absorption material reflectivity test method. The results show that the minimum reflectivity is-21.0 dB and the effective bandwidth (reflectivity less than-10 dB) is 9.2GHz-15.8GHz in the X-band of 8GHz-18 GHz.
The crack resistance of the electromagnetic wave absorbing material plate was tested according to CECS38-2004 fibrous concrete structure technical specification appendix D. The total crack area of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material plate in 24 hours of the experiment is 79.2mm2。
The compressive strength and the flexural strength (a cuboid sample with the size of 40mm multiplied by 160mm) of the material are tested according to the GB/T17671 cement mortar strength test method (ISO method), and after 28 days of curing, the compressive strength is 12.3MPa, the flexural strength is 4.2MPa, and the flexural ratio is 2.93.
Example 2
An iron-nickel fiber reinforced cement-based electromagnetic wave absorbing material, wherein the weight ratio of water to cement is 1: 2; the weight percentage of the sand is 150 percent based on the total mass of the water and the cement; the weight percentage of the iron-nickel alloy fiber is 30 percent based on the total mass of the water and the cement. Wherein the nickel content of the iron-nickel alloy fiber is 76 wt%, the iron content is 23 wt%, and the chromium content is 1 wt%. The length-diameter ratio of the iron-nickel alloy fiber is 600, and the diameter of the iron-nickel alloy fiber is 12 mu m.
The preparation method of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material comprises the following steps:
1) weighing cement and sand according to the proportion, and performing dry mixing, wherein in the dry mixing process, the iron-nickel alloy fiber is divided into 4 batches, and 1/4 batches are fed;
2) adding water into the dry stirring materials in 2 batches of 1/2, and uniformly stirring to obtain a stirring material of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material;
3) and adopting a mould to pour and prepare a plate-shaped or cuboid sample.
And testing the electromagnetic wave absorption performance of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material plate with the thickness of 6mm according to the GJB 2038A-2011 radar wave absorption material reflectivity test method. The results show that the minimum reflectivity is-22.0 dB and the effective bandwidth (reflectivity less than-10 dB) is 9.1GHz-16.0GHz in the X-band of 8GHz-18 GHz.
The crack resistance of the electromagnetic wave absorbing material plate was tested according to CECS38-2004 fibrous concrete structure technical specification appendix D. The total crack area of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material plate in 24 hours of the experiment is 89.6mm2。
The compressive strength and the flexural strength (a cuboid sample with the size of 40mm multiplied by 160mm) of the material are tested according to the GB/T17671 cement mortar strength test method (ISO method), and after 28 days of curing, the compressive strength is 12.8MPa, the flexural strength is 4.7MPa, and the flexural ratio is 2.72.
Example 3
An iron-nickel fiber reinforced cement-based electromagnetic wave absorbing material, wherein the weight ratio of water to cement is 1: 2; the weight percentage of the sand is 200 percent based on the total mass of the water and the cement; the weight percentage of the iron-nickel alloy fiber is 20 percent based on the total mass of the water and the cement. Wherein the nickel content of the iron-nickel alloy fiber is 70 wt%, the iron content is 29 wt%, and the chromium content is 1 wt%. The length-diameter ratio of the iron-nickel alloy fiber is 600, and the diameter of the iron-nickel alloy fiber is 12 mu m.
The preparation method of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material comprises the following steps:
1) weighing cement and sand according to the proportion, and performing dry mixing, wherein in the dry mixing process, the iron-nickel alloy fiber is divided into 4 batches, and 1/4 batches are fed;
2) adding water into the dry stirring materials in 2 batches of 1/2, and uniformly stirring to obtain a stirring material of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material;
3) and adopting a mould to pour and prepare a plate-shaped or cuboid sample.
And testing the electromagnetic wave absorption performance of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material plate with the thickness of 6mm according to the GJB 2038A-2011 radar wave absorption material reflectivity test method. The results show that the minimum reflectivity is-16.7 dB and the effective bandwidth (reflectivity less than-10 dB) is 9.7GHz-15.1GHz in the X-band of 8GHz-18 GHz.
The crack resistance of the electromagnetic wave absorbing material plate was tested according to CECS38-2004 fibrous concrete structure technical specification appendix D. The total crack area of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material plate in 24 hours of the experiment is 128.3mm2。
The compressive strength and the flexural strength (a cuboid sample with the size of 40mm multiplied by 160mm) of the material are tested according to the GB/T17671 cement mortar strength test method (ISO method), and after 28 days of curing, the compressive strength is 12.2MPa, the flexural strength is 3.8MPa, and the flexural ratio is 3.21.
Example 4
An iron-nickel fiber reinforced cement-based electromagnetic wave absorbing material, wherein the weight ratio of water to cement is 1: 2; the weight percentage of the sand is 200 percent based on the total mass of the water and the cement; the weight percentage of the iron-nickel alloy fiber is 30 percent based on the total mass of the water and the cement. Wherein the nickel content of the iron-nickel alloy fiber is 76 wt%, the iron content is 23 wt%, and the chromium content is 1 wt%. The length-diameter ratio of the iron-nickel alloy fiber is 900, and the diameter is 20 mu m.
The preparation method of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material comprises the following steps:
1) weighing cement and sand according to the proportion, and performing dry mixing, wherein in the dry mixing process, the iron-nickel alloy fiber is divided into 4 batches, and 1/4 batches are fed;
2) adding water into the dry stirring materials in 2 batches of 1/2, and uniformly stirring to obtain a stirring material of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material;
3) and adopting a mould to pour and prepare a plate-shaped or cuboid sample.
And testing the electromagnetic wave absorption performance of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material plate with the thickness of 6mm according to the GJB 2038A-2011 radar wave absorption material reflectivity test method. The results show a minimum reflectivity of-15.0 dB and an effective bandwidth (reflectivity less than-10 dB) of 11.3GHz-14.9GHz at the X-band of 8GHz-18 GHz.
The crack resistance of the electromagnetic wave absorbing material plate was tested according to CECS38-2004 fibrous concrete structure technical specification appendix D. The total crack area of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material plate in 24 hours of the experiment is 149.7mm2。
The compressive strength and the flexural strength (a cuboid sample with the size of 40mm multiplied by 160mm) of the material are tested according to the GB/T17671 cement mortar strength test method (ISO method), and after 28 days of curing, the compressive strength is 12.3MPa, the flexural strength is 4.1MPa, and the flexural ratio is 3.0.
Comparative example 1
A cementitious material, wherein the weight ratio of water to cement is 1: 2; the weight percentage of the sand is 200 percent based on the total mass of the water and the cement.
The preparation method of the cement-based material comprises the following steps:
1) according to the proportion, firstly weighing cement and sand and carrying out dry mixing;
2) dividing the dry stirring materials into 2 batches, adding water into each batch of 1/2, and uniformly stirring to obtain a cement-based material stirring material;
3) and adopting a mould to pour and prepare a plate-shaped or cuboid sample.
And testing the electromagnetic wave absorption performance of the cement-based material plate with the thickness of 6mm according to the GJB 2038A-2011 radar electromagnetic wave absorption material reflectivity test method. The results show a minimum reflectivity of-0.2 dB at the X-band of 8GHz-18 GHz.
The crack resistance of the cement-based material boards was tested according to CECS38-2004 technical specification annex D of the fiber concrete structure. The total crack area of the cement-based material plate in the experiment 24h is 874mm2。
The compressive strength and the flexural strength (the sample size is 40mm multiplied by 160mm) of the material are tested according to the GB/T17671 cement mortar strength test method (ISO method), and after 28 days of curing, the compressive strength is 12MPa, the flexural strength is 3.1MPa, and the flexural ratio is 3.87.
Comparative example 2
An iron-nickel alloy powder reinforced cement-based electromagnetic wave absorbing material, wherein the weight ratio of water to cement is 1: 2; the weight percentage of the sand is 200 percent based on the total mass of the water and the cement; the weight percentage of the iron-nickel alloy powder is 30 percent based on the total mass of the water and the cement. Wherein the iron-nickel alloy powder has a nickel content of 76 wt%, an iron content of 23 wt% and a chromium content of 1 wt%. The mesh number of the iron-nickel alloy powder is 300.
The preparation method of the iron-nickel alloy powder reinforced cement-based electromagnetic wave absorption material comprises the following steps:
1) weighing cement and sand according to the proportion, and carrying out dry mixing, wherein in the dry mixing process, the iron-nickel alloy powder is divided into 4 batches, and 1/4 batches are fed;
2) adding water into the dry stirring materials in 2 batches of 1/2, and uniformly stirring to obtain a stirring material of the iron-nickel alloy powder reinforced cement-based electromagnetic wave absorption material;
3) and adopting a mould to pour and prepare a plate-shaped or cuboid sample.
And testing the electromagnetic wave absorption performance of the iron-nickel alloy powder reinforced cement-based electromagnetic wave absorption material plate with the thickness of 6mm according to the GJB 2038A-2011 radar wave absorption material reflectivity test method. The results show a minimum reflectivity of-2.1 dB at the X-band of 8GHz-18 GHz.
The crack resistance of the electromagnetic wave absorbing material plate was tested according to CECS38-2004 fibrous concrete structure technical specification appendix D. The total crack area of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material plate in the experiment for 24 hours is 654.8mm2。
The compressive strength and the flexural strength (a cuboid sample with the size of 40mm multiplied by 160mm) of the material are tested according to the GB/T17671 cement mortar strength test method (ISO method), and after 28 days of curing, the compressive strength is 12.1MPa, the flexural strength is 3.1MPa, and the flexural ratio is 3.90.
Comparative example 3
An iron-nickel fiber reinforced cement-based electromagnetic wave absorbing material, wherein the weight ratio of water to cement is 1: 2; the weight percentage of the sand is 400 percent based on the total mass of the water and the cement; the weight percentage of the iron-nickel alloy fiber is 30 percent based on the total mass of the water and the cement. Wherein the nickel content of the iron-nickel alloy fiber is 76 wt%, the iron content is 23 wt%, and the chromium content is 1 wt%. The length-diameter ratio of the iron-nickel alloy fiber is 600, and the diameter of the iron-nickel alloy fiber is 12 mu m.
The preparation method of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material comprises the following steps:
1) weighing cement and sand according to the proportion, and performing dry mixing, wherein in the dry mixing process, the iron-nickel alloy fiber is divided into 4 batches, and 1/4 batches are fed;
2) adding water into the dry stirring materials in 2 batches of 1/2, and uniformly stirring to obtain a stirring material of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material;
3) and adopting a mould to pour and prepare a plate-shaped or cuboid sample.
And testing the electromagnetic wave absorption performance of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material plate with the thickness of 6mm according to the GJB 2038A-2011 radar wave absorption material reflectivity test method. The results show a minimum reflectivity of-12.1 dB and an effective bandwidth (reflectivity less than-10 dB) of 11.3GHz-14.2GHz at the X-band of 8GHz-18 GHz.
The crack resistance of the electromagnetic wave absorbing material plate was tested according to CECS38-2004 fibrous concrete structure technical specification appendix D. The total crack area of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material plate in 24 hours of the experiment is 132.1mm2。
The compressive strength and the flexural strength (a cuboid sample with the size of 40mm multiplied by 160mm) of the material are tested according to the GB/T17671 cement mortar strength test method (ISO method), and after 28 days of curing, the compressive strength is 12.20MPa, the flexural strength is 3.7MPa, and the flexural ratio is 3.30.
Comparative example 4
An iron-nickel fiber reinforced cement-based electromagnetic wave absorbing material, wherein the weight ratio of water to cement is 1: 2; the weight percentage of the sand is 200 percent based on the total mass of the water and the cement; the weight percentage of the iron-nickel alloy fiber is 50 percent based on the total mass of the water and the cement. Wherein the nickel content of the iron-nickel alloy fiber is 76 wt%, the iron content is 23 wt%, and the chromium content is 1 wt%. The length-diameter ratio of the iron-nickel alloy fiber is 600, and the diameter of the iron-nickel alloy fiber is 12 mu m.
The preparation method of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material comprises the following steps:
1) weighing cement and sand according to the proportion, and performing dry mixing, wherein in the dry mixing process, the iron-nickel alloy fiber is divided into 4 batches, and 1/4 batches are fed;
2) adding water into the dry stirring materials in 2 batches of 1/2, and uniformly stirring to obtain a stirring material of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material;
3) and adopting a mould to pour and prepare a plate-shaped or cuboid sample.
And testing the electromagnetic wave absorption performance of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material plate with the thickness of 6mm according to the GJB 2038A-2011 radar wave absorption material reflectivity test method. The results show a minimum reflectivity of-5.2 dB at the X-band of 8GHz-18 GHz.
The crack resistance of the electromagnetic wave absorbing material plate was tested according to CECS38-2004 fibrous concrete structure technical specification appendix D. The total crack area of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material plate in 24 hours of the experiment is 68.3mm2。
The compressive strength and the flexural strength (a cuboid sample with the size of 40mm multiplied by 160mm) of the material are tested according to the GB/T17671 cement mortar strength test method (ISO method), and after 28 days of curing, the compressive strength is 12.5MPa, the flexural strength is 4.5MPa, and the flexural ratio is 2.78.
Comparative example 5
An iron-nickel fiber reinforced cement-based electromagnetic wave absorbing material, wherein the weight ratio of water to cement is 1: 2; the weight percentage of the sand is 200 percent based on the total mass of the water and the cement; the weight percentage of the iron-nickel alloy fiber is 30 percent based on the total mass of the water and the cement. Wherein the nickel content of the iron-nickel alloy fiber is 76 wt%, the iron content is 23 wt%, and the chromium content is 1 wt%. The length-diameter ratio of the iron-nickel alloy fiber is 1200, and the diameter of the iron-nickel alloy fiber is 30 micrometers.
The preparation method of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material comprises the following steps:
1) weighing cement and sand according to the proportion, and performing dry mixing, wherein in the dry mixing process, the iron-nickel alloy fiber is divided into 4 batches, and 1/4 batches are fed;
2) adding water into the dry stirring materials in 2 batches of 1/2, and uniformly stirring to obtain a stirring material of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material;
3) and adopting a mould to pour and prepare a plate-shaped or cuboid sample.
And testing the electromagnetic wave absorption performance of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material plate with the thickness of 6mm according to the GJB 2038A-2011 radar wave absorption material reflectivity test method. The results show a minimum reflectivity of-8.2 dB at the X-band of 8GHz-18 GHz.
The crack resistance of the electromagnetic wave absorbing material plate was tested according to CECS38-2004 fibrous concrete structure technical specification appendix D. The total crack area of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material plate in 24 hours of the experiment is 178.3mm2。
The compressive strength and the flexural strength (a cuboid sample with the size of 40mm multiplied by 160mm) of the material are tested according to the GB/T17671 cement mortar strength test method (ISO method), and after 28 days of curing, the compressive strength is 11.3MPa, the flexural strength is 3.0MPa, and the flexural ratio is 3.77.
Comparative example 6
The iron-nickel alloy fibers had a nickel content of 65 wt%, an iron content of 33 wt%, and a chromium content of 2 wt%, and the rest was the same as in example 1.
And testing the electromagnetic wave absorption performance of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material plate with the thickness of 6mm according to the GJB 2038A-2011 radar wave absorption material reflectivity test method. The results show a minimum reflectivity of-13 dB and an effective bandwidth (reflectivity less than-10 dB) of 11.3GHz-13.5GHz at the X-band of 8GHz-18 GHz.
The crack resistance of the electromagnetic wave absorbing material plate was tested according to CECS38-2004 fibrous concrete structure technical specification appendix D. The total crack area of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material plate in 24 hours of the experiment is 80.3mm2。
The compressive strength and the flexural strength (a cuboid sample with the size of 40mm multiplied by 160mm) of the material are tested according to the GB/T17671 cement mortar strength test method (ISO method), and after 28 days of curing, the compressive strength is 12.3MPa, the flexural strength is 4.3MPa, and the flexural ratio is 2.86.
Comparative example 7
The iron-nickel alloy fibers had a nickel content of 85 wt%, an iron content of 14 wt%, and a chromium content of 1 wt%, and the rest was the same as in example 1.
And testing the electromagnetic wave absorption performance of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material plate with the thickness of 6mm according to the GJB 2038A-2011 radar wave absorption material reflectivity test method. The results show a minimum reflectivity of-12 dB and an effective bandwidth (reflectivity less than-10 dB) of 11.5GHz-13.7GHz at the X-band of 8GHz-18 GHz.
The crack resistance of the electromagnetic wave absorbing material plate was tested according to CECS38-2004 fibrous concrete structure technical specification appendix D. The total crack area of the iron-nickel fiber reinforced cement-based electromagnetic wave absorption material plate in 24 hours of the experiment is 78.8mm2。
The compressive strength and the flexural strength (a cuboid sample with the size of 40mm multiplied by 160mm) of the material are tested according to the GB/T17671 cement mortar strength test method (ISO method), and after 28 days of curing, the compressive strength is 12.3MPa, the flexural strength is 4.2MPa, and the flexural ratio is 2.93.
As can be seen from the above examples and comparative examples, the material of the present application was imparted with remarkable electromagnetic wave absorption properties as compared with comparative example 1 in which the iron-nickel alloy fiber was not incorporated, indicating that the formulation of the present invention can impart electromagnetic wave absorption properties to the cement-based material. Compared with the comparative example 2 in which 300-mesh iron-nickel alloy powder with the same mass is doped, the electromagnetic wave absorption performance of the example 1 is obviously higher than that of the comparative example 2, and the crack resistance and the fracture resistance of the example 1 are both higher than those of the comparative example 2, which shows that the electromagnetic wave absorption performance, the crack resistance and the fracture resistance of the material are more effectively improved by doping the iron-nickel alloy fiber than by doping the iron-nickel alloy powder. Example 1 compared with comparative example 3 in which the weight percentage of sand is 400% based on the total mass of water and cement, the electromagnetic wave absorption performance, crack resistance performance and fracture resistance performance of the material are improved to a limited extent since the relative content of cement and iron-nickel alloy fiber is reduced due to the excessive amount of sand used in comparative example 3. Compared with the comparative example 4 in which the weight percentage of the iron-nickel fibers is 60% based on the total mass of the water and the cement, in the comparative example 4, the iron-nickel fibers are excessively doped, the fibers are mutually contacted to form a communicated conductive network, the electromagnetic wave is reflected, the absorption performance is reduced, and after the doping is excessively large, the condition of uneven dispersion occurs, so that the mechanical property is not improved along with the doping amount and is proportionally improved. Compared with the comparative example 5 in which the length-diameter ratio of the iron-nickel fiber is 1200 and the diameter of the iron-nickel fiber is 12 micrometers, the iron-nickel fiber in the comparative example 5 is too long, the dispersion is not uniform, the mechanical property is not improved, and the compression resistance is reduced due to the formation of stress concentration points in the material. Example 1 is different from comparative examples 6 to 7 in that the content of iron and nickel in the incorporated iron-nickel fiber is different, and example 1 in which the content of nickel is 76 wt%, the content of iron is 23 wt%, and the content of chromium is 1 wt% is an excellent process for iron-nickel fiber, and the fiber having this composition has an excellent electromagnetic wave absorption effect compared with the fibers in comparative examples 6 to 7. But the change of the composition has little influence on the mechanical property of the fiber, and when the fiber mixing amount is the same and the cement-based material components are the same, the mechanical properties of the materials are similar.
It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. Not all embodiments are exhaustive. All obvious changes and modifications which are obvious to the technical scheme of the invention are covered by the protection scope of the invention.