A wire spreading device for continuous deposition of interface layer

Abstract

This invention relates to a fiber spreading device for continuous deposition of interface layers. The main functions of the device are debinding and fiber spreading. The working process is as follows: untreated raw SiC fibers are laid out by a fixed support 1, and their horizontal position is constrained by a guide roller 2. They are then sequentially debinded by a heating debinding mechanism 3, over-spread by a pressure fiber spreading mechanism 4, and the degree of fiber spreading is adjusted by a fiber spreading correction mechanism 5. The fibers are then evenly dispersed by an ultrasonic dispersion device 6, and finally the width is constrained by a second width adjustment rod 7 and aligned with the center of the hot zone of the continuous deposition equipment for deposition.

Description

Technical Field

[0001] This invention relates to a fiber preparation technology field for continuous deposition of interface layers using bundled silicon carbide fiber interface layers in the field of ceramic matrix composites. Background Technology

[0002] With the ever-increasing demands for fuel efficiency and thrust-to-weight ratio in aero-engines, there is an urgent need for high-temperature resistant, lightweight structural materials for their hot-section components. Silicon carbide fiber-reinforced silicon carbide (SiC) is a suitable material for this purpose. f The SiC composite material has excellent properties such as high temperature resistance, low density and long service life, making it a promising candidate for application in the field of aero-engines.

[0003] SiC f SiC composites typically consist of three parts: continuous silicon carbide fibers, an interface layer, and a silicon carbide matrix. The interface layer effectively modulates the bonding strength between the SiC fibers and the SiC ceramic matrix, and achieves a toughening effect on the composite through energy release mechanisms such as crack deflection, debonding, and fiber pull-out. Furthermore, the interface layer also acts as a protective layer for oxidation diffusion, protecting the SiC fibers from oxidation. Therefore, improving the stability and uniformity of the interface layer preparation within the fiber bundle is crucial for enhancing the SiC composite matrix. f One of the important directions for improving the properties of SiC composite materials.

[0004] SiC fibers undergo sizing before leaving the factory. The sizing agent forms a protective film on the fiber surface and also has a certain binding effect, causing the fibers to aggregate together. This reduces friction and wear and prevents fuzz formation during subsequent processing and transportation. However, due to limitations in current sizing processes, the coating of the sizing agent on the SiC fiber bundle surface is not uniform along the fiber length, resulting in varying degrees of fiber aggregation at different locations along the length. When such fiber bundles are used to prepare the interface layer using a continuous interface layer deposition process, the quality of the interface layer fluctuates greatly, affecting the properties of the subsequently prepared composite materials. Summary of the Invention

[0005] This invention addresses the shortcomings of the prior art by providing a fiber spreading device for continuous deposition of interface layer. This device improves the uniformity of the interface layer thickness in the circumferential direction of the SiC fiber bundle and the uniformity of the interface layer thickness between different fiber filaments by performing degumming, fiber spreading and width fixing treatment on the fibers. Moreover, the filaments exhibit obvious linear regular arrangement and the original adhesion phenomenon between the fiber filaments does not occur.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] This type of continuous interface layer deposition fiber spreading device operates in a vacuum environment. The device includes a fixed support 1 for an untreated raw fiber cylinder. The fiber bundle drawn from the raw fiber cylinder passes through a guide roller 2. The guide roller 2 has uniformly distributed annular grooves 8 of the same width along its axis. The inner surface of each annular groove 8 has an arc-shaped cross-section along its axial direction. The number of annular grooves 8 corresponds one-to-one with the number of raw fiber cylinders placed on the fixed support 1 and the drawn fiber bundles. The function of the annular grooves 8 is to constrain the horizontal position of the fiber bundle. The arc-shaped inner surface of the annular grooves 8 allows for... To reduce friction between the filament bundle and guide roller 2, damage to the filament bundle is reduced, and the number of fuzzy fibers is decreased. Guide roller 2 can constrain each filament bundle to the same horizontal position, which is beneficial for subsequent processes. Each filament bundle led out by guide roller 2 is degummed by heating and degumming mechanism 3. After heating and degumming, the filament bundle is initially spread by pressure spreading mechanism 4, and the spread width of each filament bundle is greater than the width required by the process. The filament bundle led out by pressure spreading mechanism 4 is then spread and corrected by spreading mechanism 5, which includes a first width adjusting rod and a thickness adjustment rod. The system includes a thickness monitor and a controller. Each filament bundle is constrained in width by a rectangular groove formed by a first width adjustment rod, the number of which is the same as the number of filament bundles. Each filament bundle led out by the filament spreading correction mechanism 5 is uniformly dispersed by an ultrasonic dispersion mechanism 6. Each filament bundle led out by the ultrasonic dispersion mechanism 6 is constrained in width by a rectangular groove formed by a second width adjustment rod 7 to achieve the required width. The number of rectangular grooves formed by the second width adjustment rod 7 is the same as the number of filament bundles. A thickness detector monitors the actual thickness at the center position of the filament bundle passing through the second width adjustment rod 7 and feeds the real-time thickness value back to the controller. The controller fine-tunes the width of the rectangular groove corresponding to the filament bundle on the first width adjustment rod based on the real-time monitored filament bundle width to correct the deviation between the filament bundle width passing through the second width adjustment rod 7 and the required width. The filament bundles passing through the second width adjustment rod 7 are spread to the required width and positioned at the corresponding position on the cross-section of the furnace tube in the hot zone of the continuous deposition equipment, ready to enter the hot zone to begin deposition.

[0008] In addition, the fixed bracket 1 is a crank-connecting rod mechanism and is connected to a preload-adjustable damper to adjust the tension of the filament bundle. Furthermore, the damper connected to the crank-connecting rod mechanism of the fixed bracket 1 can convert the rotation of the paper tube of the bundled fiber into the translation of the damper, so that the damper can play its role. The purpose is twofold: first, to apply a settable tension to the filament bundle during the winding process, so that the filament bundle can fit more closely with the equipment during the subsequent filament spreading and width setting process; second, to make the filament bundle more stable during the hot zone deposition of the continuous deposition equipment.

[0009] In addition, the heating and degumming mechanism 3 has a heating element inside its heating and degumming roller. The heating element is made of alumina to insulate against heat, and its core is hollow to house the resistance wire. During implementation, a temperature monitor monitors the fiber temperature on the surface of the degumming roller. Based on the feedback data from the temperature monitor, the controller controls the power of the resistance wire in the heating element in real time. After the fiber bundle passes through the heating and degumming mechanism, the sizing agent on its surface is decomposed by heating. During implementation, since the sizing agent used is mainly polyvinyl alcohol, which begins to decompose at 200°C, the temperature of the heating and degumming mechanism 3 is set at 250–300°C to achieve complete decomposition of the sizing agent.

[0010] In addition, the pressure spreading mechanism 4 includes extrusion rollers, a distance monitor, a controller, and a lead screw controlled by a vacuum motor. The extrusion rollers are mounted on the lead screw controlled by the vacuum motor, and the roller surfaces are mirror-polished. The extrusion rollers are connected to the support by bearings, with one roller fixed in one position and the other able to change the distance between the two rollers under the control of the lead screw. The spacing between the rollers is set in the controller according to the process requirements, and the spacing is controlled to be less than the thickness calculated from the width required by the process. The reason for this operation is that when the fiber bundle passes through the pressure spreading mechanism 4, the fiber needs to be spread to a width greater than the required width by the process. At this time, the cross-section of the fiber bundle is approximately rectangular. The approximate cross-sectional area of ​​the fiber bundle is calculated using the average diameter of the fiber monofilaments in the fiber bundle and the number of fiber monofilaments in the fiber bundle. Then, the corresponding fiber bundle thickness after spreading is calculated based on the spreading width required by the process, and the spacing between the two extrusion rollers is adjusted to be less than this thickness, so that the width of the fiber after passing through the pressure spreading mechanism is greater than the required width by the process.

[0011] In addition, a rack is connected to each side of the rectangular groove on the first and second width adjusting rods 7. The rack is moved by a vacuum motor through gears to adjust the width of the rectangular groove. In implementation, the surface of the rectangular groove has rounded corners and is mirror-polished to reduce friction, fiber damage, and fuzz.

[0012] In addition, the ultrasonic dispersion mechanism 6 consists of three parts: an ultrasonic generator, a waveguide rod, and a damping support. The waveguide rod is connected to the damping support, and an ultrasonic generator is fixed at one end of the waveguide rod. The surface of the waveguide rod that contacts the filament bundle has a limiting groove, and the edge of the limiting groove is rounded and mirror polished.

[0013] The main functions of the device of this invention are degumming and fiber spreading. In practice, the untreated raw SiC fibers are fed into a bundle by the fixed support 1, and the horizontal position is constrained by the guide roller 2. The fibers are then passed through the heating degumming mechanism 3 for degumming, the pressure fiber spreading mechanism 4 for over-spreading, the fiber spreading correction mechanism 5 for adjusting the degree of spreading, the ultrasonic dispersion device 6 to evenly disperse the fibers, and the second width adjustment rod 7 to finally constrain the width and align it with the center of the hot zone of the continuous deposition equipment for deposition.

[0014] Furthermore, the initial width of the rectangular groove on the first width adjusting rod of the fiber spreading correction mechanism 5 should be the width required by the process. However, the real-time width of the fiber bundle is greater than this width. At this time, the fibers will accumulate at both ends of the rectangular groove. After the fiber bundle passes through the ultrasonic dispersion device 6 and the set limiting groove width is the width required by the process, the cross-section of the fiber bundle after passing through the first width adjusting rod should be approximately rectangular if the fiber spreading width parameter required by the process has been reached due to the ultrasonic dispersion mechanism. Then, the thickness data monitored by the center point thickness monitor should also be the same as the calculated fiber bundle thickness. If the thickness measured by the thickness monitor is greater than the calculated value, it indicates that the fiber is in a state of... If the bundle is in a clustered state and its width is less than the required width, the first width adjusting rod in the filament spreading correction mechanism 5 is constraining the width of the filament bundle too much. At this time, the thickness data is fed back to the controller, which will control the fine-tuning device to expand the width of the rectangular groove on the surface of the first width adjusting rod to reduce the degree of constraint of the first adjusting rod on the filament bundle. If the thickness measured by the thickness monitor is less than the calculated value, it means that the degree of filament spreading is still greater than the required width, and the first width adjusting rod in the filament spreading correction mechanism 5 is not constraining the filament bundle enough. At this time, the thickness data is fed back to the controller, which will control the fine-tuning device to reduce the width of the rectangular groove on the surface of the first width adjusting rod to increase the degree of constraint of the first adjusting rod on the filament bundle. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the device described in this invention.

[0016] Figure 2 This is a schematic diagram of the structure of the fixing bracket in the device described in this invention.

[0017] Figure 3 This is a schematic diagram of the width adjustment mechanism of the first and second width adjustment rods in the device described in this invention.

[0018] Figure 4 The fiber morphology within the rectangular groove of the first width adjustment surface, defined by the fiber spreading correction mechanism 5 in the device of the present invention for different spreading degrees, wherein: a: the spreading degree is greater than the thickness h1 required by the process; b: the spreading degree meets the process requirement h2; c: the spreading degree is less than the process requirement h3.

[0019] Figure 5 The images are SEM images of SiC fibers with a BN interface layer prepared before and after using the device of the present invention, wherein: Figure 5 a represents a SiC fiber bundle with a continuous BN interface layer, prepared using the apparatus and method described in this invention. Figure 5 b represents a SiC fiber bundle with a continuous BN interface layer that was not prepared using the apparatus and method described in this invention.

[0020] Figure 6 These are SEM images of SiC fibers with SiC interface layers prepared before and after using the apparatus of the present invention, wherein: Figure 6 a represents a SiC fiber bundle with a continuous SiC interface layer, prepared using the apparatus and method described in this invention. Figure 6 b represents a SiC fiber bundle with a continuous SiC interface layer that was not prepared using the apparatus and method described in this invention. Detailed Implementation

[0021] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments:

[0022] In the embodiments of the technical solution of the present invention, the wire-spreading device for continuous deposition of the interface layer operates in a vacuum environment, such as... Figure 1As shown, the fiber spreading device operates in a vacuum environment. The device includes a fixed support 1 for an untreated raw fiber cylinder. Fiber bundles drawn from the raw fiber cylinder pass through a guide roller 2. The guide roller 2 has uniformly distributed annular grooves 8 of the same width along its axis. The inner surface of each annular groove 8 has an arc-shaped cross-section along its axial direction. The number of annular grooves 8 corresponds one-to-one with the number of raw fiber cylinders placed on the fixed support 1 and the number of fiber bundles drawn out. Each fiber bundle drawn from the guide roller 2 undergoes degumming via a heating and degumming mechanism 3. After heating and degumming, the fiber bundles undergo preliminary spreading via a pressure spreading mechanism 4, with the spreading width of each fiber bundle exceeding the required process width. The fiber bundles drawn from the pressure spreading mechanism 4 then pass through a spreading correction mechanism 5. The spreading correction mechanism 5 includes a first width adjusting rod, a thickness monitor, and a controller. Each fiber bundle's width is constrained by a rectangular groove formed by the first width adjusting rod. The number of grooves is the same as the number of filament bundles. Each filament bundle led out by the filament spreading and correction mechanism 5 is uniformly dispersed by the ultrasonic dispersion mechanism 6. Each filament bundle led out by the ultrasonic dispersion mechanism 6 passes through a rectangular groove formed by the second width adjustment rod 7 to constrain the width of the filament bundle to meet the process requirements. The number of rectangular grooves formed by the second width adjustment rod 7 is the same as the number of filament bundles. The thickness detector monitors the actual thickness at the center position of the filament bundle passing through the second width adjustment rod 7 and feeds back the real-time thickness value to the controller. The controller fine-tunes the width of the rectangular groove corresponding to the filament bundle on the first width adjustment rod according to the real-time monitored filament bundle width to correct the deviation between the filament bundle width passing through the second width adjustment rod 7 and the process requirements. The filament bundle passing through the second width adjustment rod 7 ends with the filament spreading at the process requirements width and is positioned at the corresponding position of the cross-section of the furnace tube in the hot zone of the continuous deposition equipment, ready to enter the hot zone to begin deposition.

[0023] In addition, the fixed bracket 1 is a crank-connecting rod mechanism and is connected to a preload-adjustable damper to adjust the tension of the filament bundle.

[0024] In addition, the heating and degumming mechanism 3 has a heating element inside the heating and degumming roller. The heating element is made of aluminum oxide to insulate heat, and the core of the heating element is hollow to house the resistance wire.

[0025] In addition, the pressure spreading mechanism 4 includes extrusion rollers, a distance monitor, a controller, and a lead screw controlled by a vacuum motor. The extrusion rollers are mounted on the lead screw controlled by the vacuum motor, and the spacing between the rollers is set according to the width required by the process.

[0026] In addition, a rack is connected to each side of the rectangular groove on the first width adjusting rod and the second width adjusting rod 7. The rack is moved by a vacuum motor through gears to adjust the width of the rectangular groove.

[0027] Furthermore, the rectangular groove surface has rounded corners and a mirror-polished finish to reduce friction, minimize fiber damage, and reduce fuzz.

[0028] In addition, the ultrasonic dispersion mechanism 6 consists of three parts: an ultrasonic generator, a waveguide rod, and a damping support. The waveguide rod is connected to the damping support, and an ultrasonic generator is fixed at one end of the waveguide rod. The surface of the waveguide rod that contacts the filament bundle has a limiting groove, and the edge of the limiting groove is rounded and mirror polished.

[0029] Example 1

[0030] The steps for degumming and spinning SiC fibers using the apparatus of this invention are as follows:

[0031] Step 1: Draw out each SiC fiber bundle supported by the fixed bracket 1 from the wound paper tube;

[0032] Step 2: After the filament bundles are drawn out from the fixed bracket 1, they pass through the guide roller 2, which constrains the horizontal position of each filament bundle.

[0033] Step 3: After the filament bundle is drawn out by the guide roller 2, it passes through the heating and degumming mechanism 3. The heating and degumming mechanism 3 heats the filament bundle, causing the sizing agent on the surface of the filament bundle to decompose due to heat.

[0034] Step 4: After the filament bundle is drawn out by the heating and degumming mechanism 3, it passes through the pressure spreading mechanism 4 and is pressed into a spreading degree greater than the process requirements.

[0035] Step 5: After the filament bundle is drawn out by the pressure spreading mechanism 4, it passes through the spreading correction mechanism 5, which corrects the spreading degree of the filament bundle.

[0036] Step 6: After the filament bundle is drawn out by the filament spreading and correction mechanism 5, it passes through the ultrasonic dispersion mechanism 6. The ultrasonic dispersion mechanism 6 disperses the filament bundle so that the filament bundle is in a uniform state in the subsequent second width adjustment rod 7.

[0037] Step 7: After the filament bundle is led out by the ultrasonic dispersion mechanism 6, it passes through the second width adjustment rod 7. The thickness detector at this point detects the filament spreading effect and feeds the result back to the spreading correction mechanism 5 to further correct the spreading effect in real time and align the filament bundle with the corresponding position in the hot zone furnace tube interface of the deposition equipment.

[0038] In this embodiment, SEM samples were prepared from SiC fibers with a continuous BN interface layer on the surface and SiC fibers with a continuous BN interface layer prepared without using the continuous interface layer deposition fiber spreading device of the present invention. The cross-sectional morphology was observed and the morphological differences between the two types of fibers were compared. Figure 5a represents SiC fibers with a continuous BN interface layer, fabricated using the apparatus described in this invention. Figure 5 b represents SiC fibers with a continuous BN interface layer obtained without using the apparatus described in this invention. It is clearly shown in the figure that the SiC fibers using the apparatus described in this invention exhibit higher uniformity of the interface layer thickness in the circumferential direction and between different fiber filaments compared to fibers without the apparatus described in this invention. Furthermore, the filaments show a clear linear and regular arrangement, and the original adhesion phenomenon between the fiber filaments is not observed.

[0039] Example 2

[0040] The steps of degumming and fiber spreading of SiC fibers using the device of the present invention are the same as those in Example 1. SEM samples were prepared using SiC fibers with a continuous SiC interface layer on the surface obtained in this example and SiC fibers with a continuous SiC interface layer prepared without using the fiber spreading device for continuous deposition of the interface layer in the present invention. The cross-sectional morphology was observed and the morphological differences between the two types of fibers were compared. Figure 6 a represents SiC fibers with a continuous SiC interface layer, fabricated using the apparatus described in this invention. Figure 6 b represents SiC fibers with a continuous SiC interface layer obtained without using the apparatus described in this invention. It is clearly shown in the figure that the SiC fibers using the apparatus described in this invention exhibit higher uniformity of the interface layer thickness in the circumferential direction and between different fiber filaments compared to fibers without the apparatus described in this invention. Furthermore, the filaments show a clear linear and regular arrangement, and the original adhesion phenomenon between the fiber filaments is not observed.

Claims

1. A wire-spreading apparatus for continuous deposition of interface layers, characterized in that: The fiber spreading device operates in a vacuum environment and includes a fixed support (1) for placing untreated raw fiber cylinders; the fiber bundles drawn from the raw fiber cylinders pass through a guide roller (2), the guide roller (2) has annular grooves (8) of the same width evenly distributed along the axial direction, the inner surface of the annular grooves (8) has an arc-shaped cross section along the axial direction, the number of annular grooves (8) is the same as the number of raw fiber cylinders placed on the fixed support (1) and the number of fiber bundles drawn out, and they correspond one-to-one; each fiber bundle drawn out from the guide roller (2) is degummed by a heating degumming mechanism (3), the heating degumming mechanism (3) has a heating element inside the heating degumming roller, the heating element is made of alumina to insulate heat, and the core of the heating element is hollow to place resistance wire; the fiber bundles after heating degumming are initially spread by a pressure fiber spreading mechanism (4), so that the spreading width of each fiber bundle is greater than the width required by the process; The filament bundles drawn out by the pressure spreading mechanism (4) enter the spreading correction mechanism (5), which includes a first width adjusting rod, a thickness monitor, and a controller. Each filament bundle is constrained by a rectangular groove formed by the first width adjusting rod, and the number of rectangular grooves is the same as the number of filament bundles. A rack is connected to each side of the rectangular groove on the first width adjusting rod, and the rack is moved by a vacuum motor through gears to adjust the width of the rectangular groove. Each filament bundle drawn out by the spreading correction mechanism (5) is uniformly dispersed by the ultrasonic dispersion mechanism (6). After ultrasonic dispersion, the filament bundle enters the second width adjustment rod (7). The second width adjustment rod (7) has rectangular grooves with the same number of filament bundles to constrain the width of the filament bundle to the required process value. The rectangular grooves on the second width adjustment rod (7) are also connected to racks on both sides, and the racks are moved by a vacuum motor through gears to adjust the width of the grooves. The thickness monitor in the filament spreading correction mechanism (5) monitors the actual thickness of the filament bundle at the center position after passing through the second width adjustment rod (7) and feeds back the real-time thickness value to the controller. The controller makes a fine adjustment to the width of the rectangular groove on the first width adjustment rod corresponding to the filament bundle based on the real-time monitored filament bundle width to correct the deviation between the width of the filament bundle after passing through the second width adjustment rod (7) and the process requirements. The filaments are spread to the required width by the second width adjustment rod (7), and then positioned at the corresponding position on the cross-section of the furnace tube in the hot zone of the continuous deposition equipment, ready to enter the hot zone to begin deposition.

2. The wire-spreading apparatus for continuous deposition of interface layer according to claim 1, characterized in that, The fixed bracket (1) is a crank-connecting rod mechanism and is connected to a preload-adjustable damper to adjust the tension of the filament bundle.

3. The wire-spreading apparatus for continuous deposition of interface layer according to claim 1, characterized in that, The pressure spreading mechanism (4) includes extrusion rollers, a distance monitor, a controller, and a lead screw controlled by a vacuum motor. The extrusion rollers are set on the lead screw controlled by the vacuum motor, and the spacing between the rollers is set according to the width required by the process.

4. The wire-spreading apparatus for continuous deposition of interface layer according to claim 1, characterized in that, The rectangular grooves on the first and second width adjustment rods (7) have rounded corners and are mirror polished to reduce friction, reduce fiber damage, and reduce fuzz.

5. The wire-spreading apparatus for continuous deposition of interface layer according to claim 1, characterized in that, The ultrasonic dispersion mechanism (6) consists of three parts: an ultrasonic generator, a waveguide rod, and a damping support. The waveguide rod is connected to the damping support. An ultrasonic generator is fixed at one end of the waveguide rod. The surface of the waveguide rod that contacts the wire bundle has a limiting groove. The edge of the limiting groove is rounded and mirror polished.

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