Method and device for preparing alumina fiber reinforced composite material by dynamic response ultrasonic method

Abstract

The invention discloses a method and a device for preparing an alumina fiber reinforced composite material by a dynamic response ultrasonic method. The device comprises a wire unwinding device, a degumming heating furnace, an aluminum melting heating furnace, a wire winding platform and a wire winding device which are sequentially arranged in the horizontal direction. The molten aluminum heating furnace contains aluminum melt, and the ultrasonic vibration device is inserted into the aluminum melt through the upper surface of the molten aluminum heating furnace. The ultrasonic vibration device is an ultrasonic vibration head in the aluminum melting heating furnace, and an ultrasonic vibration head scrubbing device is arranged at the bottom of the ultrasonic vibration head; the ultrasonic vibration device is further provided with an ultrasonic cooling system and a lifting platform outside the aluminum melting heating furnace. The invention further provides a preparation method implemented through the device, and according to the method, the mechanical strength of the composite material is greatly improved while the continuous production stability is guaranteed by controlling technological parameters among all the steps and controlling real-time alternation of the ultrasonic vibration heads through the dynamic response range.

Description

TECHNICAL FIELD

[0001] The application relates to a preparation method of an alumina fiber reinforced composite material, in particular to a method for preparing an alumina fiber reinforced composite material by a dynamic response ultrasonic method and a device thereof, and belongs to the technical field of material science. BACKGROUND

[0002] Metal matrix composites have been paid great attention due to their high specific strength, specific stiffness and performance design and other characteristics. The development of the aerospace industry and the automobile industry greatly promotes the research and application of metal matrix composites, and metal matrix composites show strong vitality.

[0003] At present, the research on continuous fiber reinforced aluminum matrix composites mainly focuses on carbon fibers and silicon carbide fibers as reinforcing phases, but the free C element will react with the aluminum alloy matrix to generate harmful phases such as Al4C3, which affects the comprehensive performance of the composite material.

[0004] Alumina fiber (Al2O3f) is a new type of high-performance ceramic crystal fiber, which has the characteristics of high-temperature oxidation resistance, high strength and modulus, corrosion resistance, ablation resistance, high-temperature insulation and heat insulation, low thermal expansion and the like, and is widely used in the fields of aerospace, rail transportation, petrochemical smelting and the like. And there is no excess harmful phase between alumina fiber and aluminum matrix, and the performance of alumina fiber reinforced aluminum matrix composite is better than that of other ceramic fiber reinforced aluminum matrix composite.

[0005] However, there is a certain wettability problem between alumina fiber and aluminum matrix, which will cause defects in the bonding interface between alumina fiber and aluminum matrix to a certain extent, and there are problems such as poor combination of fiber and matrix and uneven dispersion in the preparation process, which affects the overall performance of the material. Therefore, how to improve the bonding strength and dispersion uniformity of alumina fiber and aluminum matrix has become a technical problem to be solved. At present, it is a common method to add ultrasonic equipment in the aluminum alloy melt to improve the wettability between the ceramic fiber and the aluminum matrix to improve the quality of the bonding interface. However, since the ultrasonic vibration rod is mainly made of Ti alloy material, long-time work in the aluminum melt will cause the reaction between the ultrasonic vibration rod and the aluminum, reducing the ultrasonic efficiency. How to avoid or weaken this phenomenon is the key to ensure the continuous production of alumina fiber reinforced aluminum matrix composite material. SUMMARY

[0006] In view of the problems in the prior art, a first object of the present application is to provide a device for dynamically responding ultrasonic method for preparing alumina fiber reinforced composite material. The device is based on the synergy between the components, while ensuring the high bonding interface quality between the alumina and the reinforcing fibers in the composite material, the working state of the ultrasonic vibration head is adjusted in real time through the PLC integrated control system, effectively solving the problem of the occurrence of side reactions between the ultrasonic vibration device and the composite material matrix due to long-term continuous production in the prior art, while reducing the cost of continuous production, the mechanical properties of the composite material are also greatly improved.

[0007] A second object of the present application is to provide a method for dynamically responding ultrasonic method for preparing alumina fiber reinforced composite material. The method is a continuous preparation method, by controlling the process parameters between each step, the mechanical strength of the composite material is controlled; the method uses dynamic response range to control the real-time alternation of the ultrasonic vibration head, so as to ensure the ultrasonic stability of long-term production, through testing, the tensile strength of the alumina fiber reinforced aluminum matrix composite material obtained by the method provided by the present application is increased by about 30% compared with the aluminum matrix composite material obtained by the prior art, which can reach 1100MPa.

[0008] In order to achieve the above technical purposes, the present application provides a device for dynamically responding ultrasonic method for preparing alumina fiber reinforced composite material, which comprises a wire laying device (1), a glue removing heating furnace (4), a molten aluminum heating furnace (5), a wire collecting platform (7) and a wire collecting device (2) arranged in the horizontal direction in sequence; the molten aluminum heating furnace (5) contains an aluminum melt (6), and an ultrasonic vibration device is inserted into the aluminum melt through the upper surface of the molten aluminum heating furnace;

[0009] The ultrasonic vibration device in the molten aluminum heating furnace is an ultrasonic vibration head I (10) and an ultrasonic vibration head II (14), and the bottom of the ultrasonic vibration head I and II is respectively provided with an ultrasonic vibration head scrubbing device I (11) and an ultrasonic vibration head scrubbing device II (15); the ultrasonic vibration device outside the molten aluminum heating furnace is also provided with an ultrasonic cooling system I (9), an ultrasonic cooling system II (13), a lifting platform I (8) and a lifting platform II (12), and the lifting platform controls the immersion depth of the ultrasonic vibration head in the aluminum melt.

[0010] The key of the present application is to control the frequency stability of the composite process by the alternative ultrasonic replacement head, and the stability of the ultrasonic frequency directly affects the wetting reaction behavior between the alumina fiber and the aluminum melt. When the ultrasonic frequency fluctuates too much, the acoustic cavitation effect and acoustic flow intensity in the aluminum melt will be significantly uneven, which will cause the following adverse effects:

[0011] (1) The interface bonding quality is reduced: when the frequency is too low, the acoustic energy density is insufficient, the flowability and wettability of the melt are reduced, and air holes or unwetted areas are easily formed at the interface between the fiber and the matrix;

[0012] (2) Fiber breakage or uneven distribution: When the frequency is too high, the cavitation bubbles collapse violently, generating excessive local impact force, which can cause surface damage or breakage of the alumina fiber, resulting in uneven distribution of the fiber;

[0013] (3) Fluctuation of composite structure: The instability of the sound pressure field causes local aggregation of particles or fibers, leading to segregation of the matrix structure and increase of the porosity;

[0014] (4) Shortened life of ultrasonic head: The frequency mismatch causes abnormal thermal-mechanical coupling between the vibration head and the melt, which can easily exacerbate surface reaction and wear. Therefore, by setting the dynamic response range (1-3%) of the ultrasonic frequency through the PLC system and automatically switching the ultrasonic vibration head when the frequency deviates from the range, the melt acoustic energy density can be kept stable, the interface reaction can be controlled, and the consistency of the composite quality can be achieved under continuous production conditions, thereby ensuring the high strength and high reliability of the alumina fiber reinforced aluminum matrix composite material.

[0015] It should be noted that the device provided by the present application not only realizes the preparation of alumina fiber reinforced composite material, but also is suitable for the preparation of other ceramic fiber materials, especially high-strength and high-toughness fiber materials such as nitrogen carbide, silicon carbide and carbon fiber, which can realize uniform distribution and continuity of fiber density during preparation.

[0016] As a preferred scheme, the molten aluminum heating furnace (5) is further provided with an ultrasonic frequency detection device (16) inserted into the aluminum melt, and the ultrasonic data is transmitted to the PLC integrated control system (17) outside the molten aluminum heating furnace.

[0017] As a preferred scheme, the PLC integrated control system is further connected with the lifting platform to control the ultrasonic vibration head to alternately immerse into the aluminum melt.

[0018] The present application also provides a method for preparing alumina fiber reinforced composite material by dynamic response ultrasonic method, which is implemented by the device of any one of the above.

[0019] As a preferred scheme, the method for preparing alumina fiber reinforced composite material comprises the following steps:

[0020] Step S1, the alumina fiber roll is placed on the fiber placing device, and sequentially passes through the degumming heating furnace, the molten aluminum heating furnace, the fiber collecting platform and the fiber collecting device;

[0021] Step S2, aluminum blocks and aluminum-magnesium alloy are added to the molten aluminum heating furnace, all ultrasonic vibration heads are raised to the highest position, and the molten aluminum heating furnace is started;

[0022] Step S3, start the take-up and release device, start a single ultrasonic vibration head immersed in the aluminum melt, and set the ultrasonic frequency dynamic response range, detect the ultrasonic vibration head frequency through the ultrasonic frequency detection device, when the ultrasonic frequency drops out of the dynamic response range, replace another ultrasonic vibration head, and remove the surface of the replaced ultrasonic vibration head by the ultrasonic vibration head scrubbing device.

[0023] Step S4, repeat step S3 until the entire use of the alumina fiber roll is completed, and the alumina fiber roll is obtained.

[0024] As a preferred scheme, the diameter of the alumina fiber is 10-20 μm.

[0025] When the fiber diameter deviates from the design range of 10-20 μm, the following adverse effects will occur:

[0026] 1) When the fiber is too thin (<10 μm), the single fiber strength is high but the overall toughness is low, and it is easy to break during the take-up and release process due to tension fluctuation or melt disturbance, resulting in damage to the fiber continuity, and thus causing local fiber-poor areas or interface defects in the composite material.

[0027] 2) When the fiber is too thick (>20 μm), the flexibility decreases, making it difficult to pass through the take-up port and the guide wheel, and causing blockage or curling, affecting continuous production; at the same time, the thicker fiber is difficult to disperse in the ultrasonic field, causing uneven wetting or poor interface bonding;

[0028] 3) Uneven diameter distribution also causes local fluctuations in the fiber volume fraction, resulting in a decrease in the interface stress transfer efficiency of the composite material and unstable tensile properties. Therefore, the present application limits the diameter of the alumina fiber to 10-20 μm, which can ensure that the fiber has sufficient strength and flexibility while ensuring good wettability and uniform dispersion during continuous fiber release and ultrasonic compounding, thereby obtaining a composite material with stable mechanical properties and reliable interface bonding.

[0029] As a preferred scheme, the start-up process of the aluminum melting furnace is to heat the furnace temperature to 650-800℃ and maintain for 2h.

[0030] As a preferred scheme, the surface oxide film of the aluminum melt in the aluminum melting furnace needs to be removed before the ultrasonic vibration head is immersed in the aluminum melt.

[0031] As a preferred scheme, the ultrasonic frequency of the ultrasonic vibration head is 18-22 KHz.

[0032] As a preferred scheme, the ultrasonic frequency dynamic response range is 1-3%.

[0033] Through the foregoing description, the ultrasonic frequency is too high or too low to realize the high-quality continuous production of the composite material, and the ultrasonic process plays an important role in promoting the interface wetting, enhancing the combination and uniformly dispersing of the aluminum melt and the aluminum oxide fiber in the preparation of the composite material. The mechanism mainly includes cavitation effect and acoustic streaming effect, and the interface quality is improved by breaking the oxide film, promoting the melt to infiltrate into the fiber gap and discharging the gas. When the ultrasonic frequency is too low, the acoustic energy density is insufficient, and the wetting and degassing effect is weakened; when the frequency is too high, the cavitation is too violent, and the aluminum oxide fiber is easily eroded or broken, resulting in uneven distribution of the fiber and increase of the interface defects. Therefore, the ultrasonic frequency is controlled at 18-22 kHz, and the dynamic response range is set to 1-3%, the vibration head is automatically switched by the PLC system when the frequency deviates from the range, so as to maintain the stability of the acoustic field, realize the continuous and uniform cavitation and acoustic streaming effect in the melt, and ensure the interface quality of the composite material and the stability of the continuous production.

[0034] As a preferred scheme, the speed of collecting and releasing the wire is 0.05-0.2 m / min.

[0035] As a preferred scheme, the tensile strength of the composite material at room temperature is 1000-1200 MPa.

[0036] As a preferred scheme, the ultrasonic frequency of the ultrasonic vibration head is 20 kHz.

[0037] As a preferred scheme, the dynamic response range of the ultrasonic frequency is 2%.

[0038] Compared with the prior art, the technical scheme of the present application has the following beneficial technical effects:

[0039] (1) The device provided by the present application is based on the synergistic effect between the components, and can ensure the high bonding interface quality between the aluminum oxide and the reinforcing fiber in the composite material, and through the PLC integrated control system, the working state of the ultrasonic vibration head can be adjusted in real time, so that the occurrence of the side reaction between the ultrasonic vibration device and the composite material matrix caused by long-term continuous production in the prior art can be effectively solved, the cost of continuous production can be reduced, and the mechanical properties of the composite material can be greatly improved.

[0040] (2) The preparation method provided by the present application is a continuous preparation method, and the mechanical strength of the composite material can be controlled by controlling the process parameters between the steps; the real-time alternation of the ultrasonic vibration head is controlled by using the dynamic response range, so that the ultrasonic stability of long-term production can be ensured, and through testing, the tensile strength of the aluminum oxide fiber reinforced aluminum matrix composite material obtained by using the method provided by the present application is increased by about 30% compared with the aluminum matrix composite material obtained by using the prior art, and can reach 1100 MPa. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to make the technical solution in the embodiments of the present application clearer, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0042] Figure 1 A schematic diagram of the device for preparing the dynamic response ultrasonic method alumina fiber reinforced composite material provided in embodiment 1 of the present application is shown in the figure.

[0043] In the figure, 1 is a wire feeding device, 2 is a wire collecting device, 3 is an alumina fiber bundle, 4 is a degumming heating furnace, 5 is an aluminum melting heating furnace, 6 is an aluminum melt, 7 is a wire collecting platform, 8 is a lifting platform I, 9 is an ultrasonic cooling system I, 10 is an ultrasonic vibration head I, 11 is an ultrasonic vibration head scrubbing device I, 12 is a lifting platform II, 13 is an ultrasonic cooling system II, 14 is an ultrasonic vibration head II, 15 is an ultrasonic vibration head scrubbing device II, 16 is an ultrasonic frequency detection device, and 17 is a PLC integrated control system.

[0044] Figure 2 A tensile mechanical property diagram of the alumina fiber reinforced composite material provided in embodiment 1 of the present application is shown in the figure.

[0045] Figure 3 An SEM cross-section diagram of the alumina fiber reinforced composite material provided in embodiment 1 of the present application is shown in the figure. DETAILED DESCRIPTION

[0046] In order to make the technical solution in the embodiments of the present application clearer, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0047] The endpoints of the ranges and any values in the ranges disclosed herein are not limited to the precise values recited as implicitly split into the endpoint values unless the context clearly dictates otherwise. For values that are ostensibly continuous within a range, smaller values can be derived between the endpoints, between the endpoints and the individual values, and between the individual values, and these smaller values are to be considered as being specifically disclosed herein.

[0048] Embodiment 1

[0049] The embodiment provides a device for preparing a dynamic response ultrasonic method alumina fiber reinforced composite material, which comprises, in the horizontal direction, a wire feeding device 1, a degumming heating furnace 4, an aluminum melting heating furnace 5, a wire collecting platform 7, and a wire collecting device 2 arranged in sequence; the aluminum melting heating furnace 5 contains an aluminum melt 6, and an ultrasonic vibration device is inserted into the aluminum melt through the upper surface of the aluminum melting heating furnace;

[0050] The ultrasonic vibration device is provided with ultrasonic vibration head I 10 and ultrasonic vibration head II 14 inside the molten aluminum heating furnace, and is provided with ultrasonic vibration head scrubbing device I 11 and ultrasonic vibration head scrubbing device II 15 at the bottom of the ultrasonic vibration head; the ultrasonic vibration device is also provided with ultrasonic cooling system I 9, ultrasonic cooling system II 13, lifting platform I 8 and lifting platform II 12 outside the molten aluminum heating furnace, and the lifting platform controls the immersion depth of the ultrasonic vibration head in the aluminum melt; the molten aluminum heating furnace 5 is also provided with an ultrasonic frequency detection device 16 that penetrates into the aluminum melt, and the ultrasonic data is transmitted to the PLC integrated control system 17 outside the molten aluminum heating furnace.

[0051] Through the above device, the embodiment also provides a method for dynamically responding to the ultrasonic method for preparing alumina fiber reinforced composite materials, and the process is as follows:

[0052] Step S1, first place the alumina fiber roll on the yarn placing device 1, pass the alumina fiber bundle 3 through the glue removing heating furnace 4, the molten aluminum heating furnace 5, the yarn collecting platform 7, and place the alumina fiber bundle 3 on the yarn collecting device 2.

[0053] Step S2, place 5000g of aluminum blocks and 500g of aluminum-magnesium alloy blocks in the crucible in the molten aluminum heating furnace 5, start the heating device to 750 DEG C and keep for 2h, and then remove the surface alumina film, at this time, the ultrasonic vibration heads 10 and 15 are at the highest position of the lifting platform and are not immersed in the aluminum melt 6.

[0054] Step S3, start the yarn collecting and placing equipment at a speed of 0.1m / min, simultaneously immerse in the aluminum melt 6, set the ultrasonic frequency to 20KHz, and set the dynamic response range of the ultrasonic frequency to 2%.

[0055] Step S4, the PLC control integrated system 17 monitors the ultrasonic frequency to decrease to 19.6 KHz through the ultrasonic frequency detection device 16 after 45 minutes, the PLC control integrated system 17 controls the lifting platform I 8 to move the ultrasonic cooling system I 9 and the ultrasonic vibration head I 10 to the specified position, at this time, the ultrasonic vibration head I 10 removes the residual aluminum on the surface through the ultrasonic vibration head scrubbing device I 11, and the PLC control integrated system 17 controls the lifting platform II 12 to move the ultrasonic cooling system II 13 and the ultrasonic vibration head II 14 to the specified height to immerse in the aluminum melt 6, and continue the ultrasonic work.

[0056] In step S5, after working for another 45 minutes, the PLC control integrated system 17 monitors the ultrasonic frequency through the ultrasonic frequency detection device 16 and finds that the ultrasonic frequency has dropped to 19.6 kHz. The PLC control integrated system 17 then controls the lifting platform II 12 to move the ultrasonic cooling system II 13 and the ultrasonic vibrating head II 14 to the designated position. At this time, the ultrasonic vibrating head II 14 passes through the ultrasonic vibrating head cleaning device II 15 to remove the residual aluminum on the surface. At the same time, the PLC control integrated system 17 controls the lifting platform I 8 to move the ultrasonic cooling system I 9 and the ultrasonic vibrating head I 10 to the designated height to immerse them in the aluminum melt 6 and continue ultrasonic work.

[0057] Step S6, repeat steps S4 and S5 until all the fiber rolls on the unwinding device 1 are used up. The PLC control integrated system 17 controls lifting platform I 8 and lifting platform II 12, causing ultrasonic cooling system I 9, ultrasonic vibrating head I 10, ultrasonic cooling system II 13, and ultrasonic vibrating head II 14 to move to their highest positions. The heating furnace is then turned off, and the alumina fiber-reinforced aluminum matrix composite material prepared by the winding device 2 is removed. The resulting aluminum matrix composite material is designated as sample 2, and its tensile mechanical properties are as follows: Figure 2 As shown, it is 1100MPa.

[0058] Comparative Example 1

[0059] The preparation process of this comparative example is exactly the same as that of Example 1, except that in step S2, the heating device is started and held at 700°C for 2 hours. The resulting aluminum-based composite material is designated as Sample 1, and its tensile mechanical properties are as follows: Figure 2 As shown, it is 900 MPa.

[0060] Comparative Example 2

[0061] The preparation process of this comparative example is exactly the same as that of Example 1, except that in step S2, the heating device is started and held at 800°C for 2 hours. The resulting aluminum-based composite material is designated as sample 3, and its tensile mechanical properties are as follows: Figure 2 As shown, it is 850 MPa.

Claims

1. An apparatus for preparing alumina fiber-reinforced composite materials using a dynamic response ultrasonic method, characterized in that: It includes a wire feeding device (1), a de-adhesive heating furnace (4), an aluminum melting heating furnace (5), a wire taking platform (7), and a wire taking device (2) arranged in a horizontal direction; the aluminum melting heating furnace (5) contains molten aluminum (6), and an ultrasonic vibration device is inserted into the molten aluminum through the upper surface of the aluminum melting heating furnace; The ultrasonic vibration device inside the aluminum melting furnace consists of ultrasonic vibration head I (10) and ultrasonic vibration head II (14). Ultrasonic vibration head cleaning device I (11) and ultrasonic vibration head cleaning device II (15) are respectively provided at the bottom of ultrasonic vibration head I and II. The ultrasonic vibration device outside the aluminum melting furnace is also provided with ultrasonic cooling system I (9), ultrasonic cooling system II (13), lifting platform I (8) and lifting platform II (12). The lifting platform controls the immersion depth of the ultrasonic vibration head in the aluminum melt.

2. The apparatus for preparing alumina fiber-reinforced composite materials by dynamic response ultrasonic method according to claim 1, characterized in that: The aluminum melting furnace (5) is also equipped with an ultrasonic frequency detection device (16) that probes into the molten aluminum, and collects ultrasonic data and transmits it to the PLC integrated control system (17) outside the aluminum melting furnace.

3. The apparatus for preparing alumina fiber-reinforced composite materials by dynamic response ultrasonic method according to claim 2, characterized in that: The PLC integrated control system is also connected to the lifting platform to control the ultrasonic vibrating head to alternately immerse in the molten aluminum.

4. A method for preparing alumina fiber-reinforced composite materials using a dynamic response ultrasonic method, characterized in that: The alumina fiber reinforced composite material is implemented by any one of the apparatuses described in claims 1 to 3; the alumina fiber reinforced composite material comprises the following components by mass percentage: 65-75% alumina fiber, 25-30% Al, and 1-3% Mg.

5. The method for preparing alumina fiber-reinforced composite materials by dynamic response ultrasonication according to claim 4, characterized in that, Includes the following steps: Step S1: Place the alumina fiber roll on the feeding device and pass it sequentially through the degumming heating furnace, the aluminum melting heating furnace, the winding platform, and the winding device; Step S2: Add the aluminum block and aluminum-magnesium alloy into the aluminum melting furnace, raise all ultrasonic vibration heads to the highest position, and start the aluminum melting furnace; Step S3: Start the take-up and unwrap device, start a single ultrasonic vibrating head to immerse in the aluminum melt, and set the ultrasonic frequency dynamic response range. Detect and monitor the frequency of the ultrasonic vibrating head through the ultrasonic frequency detection device. When the ultrasonic frequency drops beyond the dynamic response range, replace and start another ultrasonic vibrating head, and remove the residual aluminum on the surface of the replaced ultrasonic vibrating head through the ultrasonic vibrating head cleaning device. Step S4: Repeat step S3 until all the alumina fiber rolls on the feeding filaments are used up, and the desired result is obtained.

6. The method for preparing alumina fiber-reinforced composite materials by dynamic response ultrasonication according to claim 5, characterized in that: The diameter of the alumina fiber is 10~20μm; the start-up process of the aluminum melting furnace is as follows: the temperature inside the furnace is raised to 650~800℃ and held for 2 hours.

7. The method for preparing alumina fiber-reinforced composite materials by dynamic response ultrasonication according to claim 5, characterized in that: Before the ultrasonic vibrating head is immersed in the molten aluminum, the surface oxide film of the molten aluminum in the heating furnace needs to be removed.

8. The method for preparing alumina fiber-reinforced composite materials by dynamic response ultrasonication according to claim 5, characterized in that: The ultrasonic frequency of the ultrasonic vibrating head is 18~22KHz; the dynamic response range of the ultrasonic frequency is 1~3%.

9. The method for preparing alumina fiber-reinforced composite materials by dynamic response ultrasonication according to claim 5, characterized in that: The winding and unwinding rates are 0.05~0.2 m / min; the room temperature tensile strength of the composite material is 1000~1200 MPa.

Images