Device and method for preparing high-temperature-resistant high-entropy alloy coating through friction coating

Abstract

The invention discloses a friction coating high-temperature-resistant high-entropy alloy coating preparation device and method, and belongs to the technical field of high-entropy alloy coating preparation. The device comprises a coating friction coating part and a feeding part, the coating friction coating part comprises a discharging barrel, a coating head, a motor, a threaded conveying rod, a material plasticizing device and a cooling protection device, and the feeding part comprises a feeding hopper and a conveying pipe and is connected with the discharging barrel through the conveying pipe. Through integrated design, the device can be used for preparing the high-entropy alloy coating after the preparation steps of device connection inspection, operation stability inspection, feeding and the like. The device can be used for preparing a single high-entropy alloy coating, a component gradient high-entropy alloy coating and a composite high-entropy alloy coating.

Description

Technical Field

[0001] The invention belongs to the technical field of high entropy alloy coating preparation, and specifically relates to a friction-coated high-temperature resistant high entropy alloy coating preparation device and method. Background Art

[0002] With the rapid development of modern industrial technology, various mechanical components have put forward higher requirements for the high temperature resistance, corrosion resistance and wear resistance of the protective coating on the surface of the material, and new high temperature resistant high entropy alloy coatings have gradually attracted attention. High entropy alloys are composed of four or more principal elements. The multi-principal structure gives them high entropy effect, hysteresis diffusion effect, lattice distortion effect and cocktail effect. Among them, the high entropy effect refers to the high entropy of the alloy configuration, which can improve the thermal stability and structural stability of the alloy. The hysteresis diffusion effect refers to the slow diffusion rate between atoms, which helps to keep the microstructure of the alloy stable at high temperatures, thereby maintaining its hardness and strength. The lattice distortion effect refers to the lattice distortion caused by multiple principal elements, which can hinder dislocation movement and improve the strength and hardness of the material. The cocktail effect refers to the cooperation between multiple principal elements to have multiple properties, such as oxidation resistance, corrosion resistance and wear resistance. Therefore, the excellent high temperature performance of high entropy alloys makes them an ideal candidate material for the preparation of high temperature protective coatings.

[0003] The existing high-temperature resistant coating preparation process usually requires heating the coating alloy to a semi-molten or molten state, such as thermal spraying technology, laser cladding, self-propagating high-temperature synthesis technology, etc. However, there are large differences in the melting point, density and atomic radius of the multiple principal elements in the high-entropy alloy, which leads to defects such as component segregation, cracks and holes during the cooling and solidification process after the coating is prepared, which seriously affects the high-temperature oxidation resistance, corrosion resistance and wear resistance of the high-entropy alloy coating. In addition, traditional high-temperature coatings usually require post-processing processes such as heat treatment and mechanical polishing after preparation, resulting in problems such as long coating preparation process, high cost and difficulty in ensuring coating quality. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a friction coating high temperature resistant high entropy alloy coating preparation device and method to solve the defects of high temperature resistant high entropy alloy coating composition segregation, cracks and holes in the existing preparation process, long process flow, high cost, and difficult to ensure coating quality.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A friction coating high temperature resistant high entropy alloy coating preparation device comprises a discharge barrel, the inside of the discharge barrel is provided with a cavity along the axial direction, a coaxial threaded feed rod is arranged in the cavity, and a feed thread is arranged on the outer wall of the threaded feed rod; A motor is provided at the upper end of the discharging cylinder, and the power output end of the motor is connected to the upper end of the threaded feeding rod; a hopper is provided on the side wall of the discharging cylinder, and the discharging port of the hopper is connected to the cavity; The material plasticizing device and the cooling protection device are arranged outside the discharging barrel, the feeding hopper is above the material plasticizing device, and the material plasticizing device is at the upper end of the cooling protection device; a heating resistance wire is arranged inside the material plasticizing device, and a medium pipeline is arranged around the discharging barrel in the cooling protection device; The lower end of the threaded feeding rod is detachably connected with a coating head, and the upper end surface of the coating head is rotatably connected to the lower end of the discharge barrel; A plurality of hollow through holes are arranged inside the coating head, the upper ends of the hollow through holes are connected to the cavity, and the lower ends of the hollow through holes are connected to the outside world; a central friction convex head is arranged at the center position of the bottom of the coating head, and a plurality of spiral convex heads are arranged around the central friction convex head at the bottom of the coating head, and the hollow through hole is arranged between the central friction convex head and the spiral convex head, and the spiral convex head is in the shape of an arc, and the bending direction of the arc is opposite to the rotation direction of the coating head; a coaxial annular groove is arranged at the bottom of the coating head, and the spiral convex head is in the inner circle of the annular groove.

[0006] A further improvement of the present invention is: Preferably, the central friction protrusion is a hemispherical protrusion or a truncated cone-shaped protrusion; The bottom end diameter of the central friction protrusion is D1≤D (D is the diameter of the threaded feed rod), and the height is 0.6 times the target thickness of the coating.

[0007] Preferably, the hollow through holes are equally divided around the circumference of the central friction convex head, and the diameter D2 of the circumscribed circle of the lower end outlet of the hollow through holes is greater than twice the diameter D1 of the bottom end of the central friction convex head; The spiral convex head is arranged in equal parts around the circumference of the central friction convex head, and the spiral convex head is composed of a long arc side, a short straight side, a short arc side and a short straight side connected end to end; the vertices of the short straight side on the near-center side of the spiral convex head are distributed on a circle with a diameter D3 coaxial with the central friction convex head, and D3 is greater than 3D1; the vertices of the short straight side on the far-center side of the spiral convex head are distributed on a circle with a diameter D4 coaxial with the central friction convex head, and D4 is greater than 6D1; the extension line of the short arc side is tangent to the outlet edge of the lower end of the hollow through hole; The long arc side and the short arc side of the spiral convex head have an radian of 1.5D2, the short straight side is perpendicular to the long arc side and the short arc side, the length of the short straight side is 0.5D1, and the height of the spiral convex head is 0.6 times the target thickness of the coating layer.

[0008] Preferably, a connecting boss protruding upward is provided at the center of the coating head, and the connecting boss and the lower end of the threaded feeding rod are detachably connected; An annular boss protruding upward is circumferentially arranged on the edge of the upper end surface of the coating head, and the annular boss is connected to the bottom of the discharge barrel through a double bearing.

[0009] Preferably, the material plasticizing device comprises a shell, the shell is arranged on the cooling protection device, the heating resistance wire is arranged between the shell and the threaded feeding rod, each heating motor group is arranged vertically, all the heating resistance wires are arranged at equal intervals around the circumference of the discharge barrel, and each heating resistance wire is provided with a terminal head at the end; The heating resistor wire is divided into three parts, which are respectively: heating resistor wire 1, heating resistor wire 2 and heating resistor wire 3 from top to bottom vertically. Temperature sensor 1 is provided at the upper end of heating resistor wire 1, temperature sensor 2 is provided vertically between heating resistor wire 1 and heating resistor wire 2, temperature sensor 3 is provided vertically between heating resistor wire 2 and heating resistor wire 3, and temperature sensor 4 is provided vertically at the lower end of heating resistor wire 3. The temperature signal collected by the temperature sensor is transmitted back to the main control end, and the main control end adjusts the heat output of each part of the heating resistor wire according to the PID control algorithm. This multi-stage feedback control temperature system can control the heating process more accurately, ensure the temperature uniformity of the entire heating area, and avoid overheating and energy waste.

[0010] The heating resistance wire is a zigzag structure, a wave structure or a serpentine structure.

[0011] Preferably, the calculation formula for the number of heating resistance wires to be set is: f=3πd⁄4, wherein f is the number of heating resistance wires to be set, and d is the outer diameter of the discharge barrel.

[0012] Preferably, the cavity in the discharge barrel is divided into an upper cavity and a lower cavity, the inner diameter of the upper cavity is a fixed value, and the inner diameter of the lower cavity gradually decreases from top to bottom. The calculation formula of the inner diameter of the lower cavity is: d2= (1) —The angle between the gradient slope and the axis, the optimal range is 5-25°, and the calculation formula is: ; —The friction coefficient between the plasticized material and the inner wall of the discharge barrel is affected by the plasticized material system, the material of the inner wall of the discharge barrel and the temperature; d1—fixed diameter of the upper cavity of the discharge barrel, in mm; —Total height of the inner wall of the variable diameter discharge barrel, in mm.

[0013] Preferably, the threaded feed rod is arranged in the upper part of the cavity, and the outer wall is provided with a feed thread.

[0014] Preferably, the hollow through holes are equally divided around the center of the coating head, and the lateral radius of the hollow through holes gradually decreases.

[0015] A method for preparing a friction-coated high-temperature resistant high-entropy alloy coating based on the above device comprises the following steps: Step 1, connecting the coating head and the discharge barrel; Step 2, moving the coating head to the initial position of the workpiece, setting the rotation speed, forward speed and forward route of the threaded feed rod; Step 3, adding the coating raw material into the feeding hopper, and starting the motor, the material plasticizing device and the cooling protection device in sequence; the coating raw material moves downward in the cavity of the discharge barrel under the action of the threaded feeding rod, and is discharged from the hollow through hole of the coating head, and is stirred evenly by the central friction convex head and the spiral convex head. While stirring, the coating raw material is coated on the surface of the workpiece; Step 4: After the coating head reaches the end position, the material plasticizing device (10), the cooling protection device and the motor are turned off in sequence.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The invention discloses a friction coating high temperature resistant high entropy alloy coating preparation device, the device comprises a coating friction coating part and a feeding part, the coating friction coating part comprises a discharge barrel, a coating head, a motor, a threaded feeding rod, a material plasticizing device and a cooling protection device, the feeding part comprises a feeding hopper and a feeding pipe, and is connected to the discharge barrel through the feeding pipe. The device is designed to be integrated, and can prepare a high entropy alloy coating after the preparation steps such as the connection of the inspection device, the operation stability and the feeding. The device can prepare a single high entropy alloy coating, a composition gradient high entropy alloy coating and a composite high entropy alloy coating. The device adds raw materials into the discharge barrel through the feeding device, and the threaded feeding rod inside the discharge barrel transmits the raw materials downward and provides downward extrusion pressure. The raw materials transported downward pass through the material plasticizing device in turn to complete the plasticization of the material body. The material plasticizing device accurately controls the plasticization state of the material through a multi-stage feedback control temperature system. The cooling protection device can be fed with different cooling media such as liquid and gas to avoid the plasticizing device from heating and damaging the lower coating head. The discharge barrel is divided into a fixed inner diameter section and a gradient variable inner diameter section. The fixed inner diameter section is conducive to the downward conveying of the raw material by the feeding thread rod. The gradient variable inner diameter section can evenly distribute the pressure of the plasticized material during the downward extrusion process and control the flow speed and direction of the plasticized material; in addition, the uniformly distributed pressure in the gradient variable inner diameter hole and the low material flow rate help to reduce the wear of the inner wall of the discharge barrel and extend its service life. The stable plasticized material body enters the lower coating head through the gradient variable inner diameter discharge barrel and is extruded from the hollow through hole of the coating head under the downward pressure of the threaded feeding rod. The extruded plasticized material is coated under the friction of the coating head. The friction coating part enables the high entropy alloy coating to complete the coating in a semi-solid state. The process temperature below the melting point solves the problem of easy component segregation, cracks and hole defects in the high entropy alloy coating. The end face of the coating head of the friction coating part is provided with a spiral convex head, which rotates and rubs with the coating layer and undergoes severe plastic deformation, thereby further refining, densifying, and homogenizing the coating structure and obtaining excellent coating surface quality. The coating prepared by this method has a smooth surface, dense structure, uniform composition and excellent performance. In addition, the device is an automated system composed of a feeding part and a friction coating part, which can realize integrated forming from feeding to coating preparation. The device has a simple structure and a high degree of automation. It can reduce manpower and material costs in material preparation, and especially avoid the problems of large pollution and long time consumption of traditional preparation technology.

[0017] The present invention also discloses a method for preparing a friction-coated high-temperature resistant high-entropy alloy coating, which first feeds the material through a feeding device, controls the parameters of a heating device and a cooling protection device, obtains a semi-solid coating pre-deposition body through heating through a plasticizing device and a cooling protection device of the material preparation main body, and friction-coates the pre-deposition body in the feeding cylinder, thereby realizing coating preparation. In the present invention, the high-entropy alloy coating refines, densifies, and homogenizes the surface coating structure through friction coating, which can improve the high-temperature oxidation resistance, corrosion resistance, and wear resistance of the coating. The device is simple to operate and has a short process flow. By adjusting the type, speed, and sequence of feeding powder, single alloy coating, composition gradient coating, and composite coating preparation can be realized. The coating prepared by this method has a smooth surface, dense structure, uniform composition, and excellent performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic structural diagram of a friction-coated high-temperature-resistant high-entropy alloy coating preparation device of the present invention; Figure 2 is a cross-sectional view of the inner wall of a fixed diameter discharge barrel of the present invention; Figure 3 It is a cross-sectional view of the inner wall of the variable diameter discharge barrel of the present invention; Figure 4 It is a schematic diagram of the material delivery conduit of the present invention; Figure 5 This is a schematic diagram of the threaded feed rod of the present invention; Figure 6 is a schematic diagram of the wedge thread of the present invention; Figure 7 This is a schematic diagram of the multi-stage feedback temperature control structure of the plasticizing device of the present invention. Figure 8 1 is a schematic diagram of a coating head of the present invention; Fig. 9 is a second schematic diagram of the coating head of the present invention; Fig.10 It is a schematic diagram of a spiral convex head of the present invention.

[0019] Among them, 1-feeding hopper; 1-1 feed splash guard; 2-first valve; 3-L-type feed pipe; 3-1-L-type feed pipe short tube; 3-2-L-type feed pipe long tube; 4-feeding port; 5-motor; 6-fixed housing; 7-discharging barrel; 7-1-discharging barrel outer wall; 7-2-fixed diameter discharging barrel inner wall; 7-3 variable diameter discharging barrel inner wall; 7-4-upper part cavity; 7-5-lower part cavity; 8-threaded feed rod; 9-feeding thread; 9-1-wedge-shaped thread flat top; 9-2-wedge-shaped thread bevel; 10-material plasticizing device; 10-1-connection head; 10-2-heating resistance wire; 10-21-heating resistance wire one; 10-22-heating resistance wire two; 10-23-heating resistance wire three; 10-3-outer Shell; 10-4-temperature sensor; 10-41-temperature sensor one; 10-42-temperature sensor two; 10-43-temperature sensor three; 10-44-temperature sensor four; 10-5-main control end; 11-cooling protection device; 11-1-medium pipeline; 11-2-medium transmission pipeline; 12-second valve; 13-coating head; 13-1-connecting boss; 13-2-annular boss; 13-3-annular groove; 13-4-spiral boss; 13-41-long arc edge; 13-42-short arc edge; 13-43-short straight edge; 13-5-hemispherical boss; 13-6-circular discharge hole; 13-7-truncated cone boss; 13-8-elliptical discharge port; 13-9-hollow through hole. DETAILED DESCRIPTION

[0020] The present invention is further described in detail below in conjunction with the accompanying drawings: In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention; the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance; in addition, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal connection of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] See also Figure 1The present invention discloses a friction coating high temperature resistant high entropy alloy coating preparation device, which includes a feeding part and a coating part, and the feeding part is arranged on the coating part. The feeding part includes a feeding hopper 1 and an L-shaped feeding pipe 3. The main structure of the feeding hopper 1 is inverted cone shape. The upper edge of the feeding hopper 1 is provided with a feeding splash-proof edge 1-1. The lower end of the feeding hopper is connected to the L-shaped feeding pipe 3, and the L-shaped feeding pipe 3 is provided with a first valve 2. The coating part includes a discharge barrel 7, a threaded feeding rod 8, a material plasticizing device 10, a cooling protection device 11 and a coating head 13. The upper end of the discharge barrel 7 is connected to a fixed housing 6, and a feed port 4 is arranged on the outer side of the discharge barrel 7 at the lower part of the fixed housing 6, and the feed port 4 is connected to the lower end of the L-shaped feeding pipe 3; the outer side of the discharge barrel 7 is sequentially provided with a material plasticizing device 10 and a cooling protection device 11; the feed port 4 is above the material plasticizing device 10, and the material plasticizing device 10 is at the upper end of the cooling protection device 11. A threaded feeding rod 8 is coaxially arranged inside the discharge barrel 7 , and a coaxial motor 5 is connected to the upper end of the threaded feeding rod 8 . The motor 5 is arranged in a fixed housing 6 , and a coating head 13 is threadedly connected to the lower end of the threaded feeding rod 8 .

[0022] As a preferred solution, the feed port 4 is split-connected to the L-shaped feed pipe 3. The L-shaped feed pipe 3 is an integrated complex-shaped pipe, including an L-shaped feed pipe short pipe 3-1 and an L-shaped feed pipe long pipe 3-2. The L-shaped feed pipe short pipe 3-1 is vertically arranged, and the angle between the L-shaped feed pipe short pipe 3-1 and the L-shaped feed pipe long pipe 3-2 is 100-150°. The end of the L-shaped feed pipe short pipe 3-1 is connected to the first valve 2, and the end of the L-shaped feed pipe long pipe 3-2 is connected to the feed port 4.

[0023] As a preferred solution, the discharge barrel 7 is a variable inner diameter barrel, and a cavity for placing the threaded feed rod 8 and the feed thread 9 is provided inside the discharge barrel 7-1 along the length direction. The diameter of the outer wall 7-1 of the discharge barrel is a fixed value, and the cavity is divided into an upper cavity 7-4 and a lower cavity 7-5. The upper cavity 7-4 is the cavity between the upper end of the discharge barrel 7 and the horizontal height of the bottom end of the material plasticizing device 10, and the inner diameter is a fixed value, which is d1; the cavity from the horizontal height of the bottom end of the material plasticizing device 10 to the bottom of the discharge barrel 7 is the lower cavity 7-5, and the inner diameter of the lower cavity 7-5 gradually decreases from top to bottom, which is a variable diameter d2. The gradient variable inner diameter section can evenly plasticize the pressure of the material during the downward extrusion process and control the flow speed and direction of the plasticized material; in addition, the uniformly distributed pressure and low material flow rate in the gradient variable inner diameter hole help reduce the wear of the inner wall of the discharge barrel and extend its service life. Therefore, the angle θ between the inclined surface of the inner wall of the lower cavity 7-5 and the axis should satisfy the following relationship. The gradient change of the inner diameter can ensure the smooth flow of the material and avoid excessive pressure and wear of the discharge barrel.

[0024]

[0025]

[0026] Simplify to get

[0027] m—mass of plasticized material, unit: g; —The friction coefficient between the plasticized material and the inner wall of the discharge barrel is affected by the plasticized material system, the material of the inner wall of the discharge barrel and the temperature; —The angle between the gradient slope and the axis, the optimal range is recommended to be 5-25°; The calculation formula of the variable diameter d2 of the discharge barrel is: d2= (1) d1—fixed diameter of the upper cavity 7-4 of the discharge barrel, in mm; —Total height of the inner wall 7-3 of the variable diameter discharge barrel, in mm.

[0028] The fixed diameter discharge barrel inner wall 7-2 facilitates the material transmission by the feeding screw, and the variable diameter discharge barrel inner wall 7-3 can slow down the material flow rate, which is beneficial to improving the flow state of the material and filling the pores to obtain a dense and uniform plasticized material body; the evenly distributed plasticized material pressure and low plasticized material flow rate help to reduce the wear of the inner wall of the discharge barrel and extend its service life.

[0029] See also Figure 1 and Figure 2 The material plasticizing device 10 includes a shell 10-3, which is arranged on the cooling protection device 11. The shell 10-3 is composed of an outer arc surface, an upper annular surface and a lower annular surface, and is sealed from top to bottom and from the outside. The shell body material is composed of ceramic fiber, refractory brick, vermiculite, mineral wool multi-layer insulation layer and stainless steel shell, which has good thermal insulation performance to ensure rapid temperature rise and avoid energy dissipation; the heating resistance wire 10-2 is arranged between the shell 10-3 and the discharge barrel 7, and a plurality of heating resistance wires 10-2 are arranged around the discharge barrel 7. The length direction of the heating resistance wire 10-2 is parallel to the axial direction of the discharge barrel 7, and is arranged at equal intervals along the outer wall of the discharge barrel 7. The upper end of each heating resistance wire 10 is provided with a terminal 10-1, and the terminal 10-1 is used to connect to an external power supply.

[0030] The heating resistor wire is divided into three parts, which are respectively: heating resistor wire 1 10-21, heating resistor wire 2 10-22 and heating resistor wire 3 10-23 from top to bottom in vertical direction. A temperature sensor 1 10-41 is provided at the vertical upper end of the heating resistor wire 10-21, a temperature sensor 2 10-42 is provided vertically between the heating resistor wire 10-21 and the heating resistor wire 2 10-22, a temperature sensor 3 10-43 is provided vertically between the heating resistor wire 2 10-22 and the heating resistor wire 3 10-23, and a temperature sensor 4 10-44 is provided vertically at the lower end of the heating resistor wire 3 10-23. The temperature signal collected by the temperature sensor 10-4 is transmitted back to the main control end 10-5, and the main control end 10-5 adjusts the heat output of each part of the heating resistor wire 10-2 according to the PID control algorithm. This multi-stage feedback control temperature system can control the heating process more accurately, ensure the temperature uniformity of the entire heating area, and avoid overheating and energy waste.

[0031] As a preferred solution, each heating resistance wire 2 has a zigzag structure, a wave structure or a serpentine structure, which extends the stroke length of the heating resistance wire 2 in the space, so that the heating resistance wire 2 can not only fully heat the side wall of the discharge barrel 7, but also fully heat the air in the space, reducing the heat dissipation of the heating resistance wire 2.

[0032] As a preferred solution, the number f of the heating resistance wires 10-2 can be changed according to the diameter d of the discharge barrel 7, and the relationship is: f=3πd⁄4, the temperature of the material plasticizing device 10 can be set, and the heating temperature T r The calculation formula is: (2) k-empirical coefficient, 0.5-0.7; a-principal number of high entropy alloy elements; c i — represents the atomic percentage of the 𝑖th component in the alloy system; (T m ) i — represents the melting point of the 𝑖th element in the alloy system.

[0033] See also Figure 1 and Figure 3 The cooling protection device 11 includes a medium transmission pipeline 11-2, a medium pipeline 11-1 and a second valve 12. The medium pipeline 11-1 is threadedly wrapped around the outer wall of the discharge barrel 7 and connected to the medium transmission pipeline 11-2. The second valve 12 is arranged on the medium transmission pipeline 11-2.

[0034] The cooling protection device 11 is provided with a medium pipeline 11-1 arranged around the outer wall of the discharge barrel 7, the vertical section of the medium pipeline 11-1 is semicircular, and the radius of the section is r; the two ends of the medium pipeline 11-1 are respectively connected with a medium transmission pipeline 11-2, and the two medium transmission pipelines 11-2 are respectively arranged on the upper end face and the lower end face of the cooling protection device 11, and the two medium transmission pipelines 11-2 are arranged horizontally, and the axis is in the horizontal direction, and the angle between the two medium transmission pipelines 11-2 is 180°, that is, they are respectively arranged on both sides of the discharge barrel 7, and each end of the medium transmission pipeline 11-2 is connected to the external medium input port and the medium output port, and each outer end of the medium transmission pipeline 11-2 is provided with a second valve 12; the cooling protection device 11 can be passed through different constant temperature media such as liquid and gas, and the cooling rate can be controlled by changing the type and flow rate of the medium. The purpose of the cooling protection device 11 is to avoid the heat generation of the plasticizing device from damaging the lower end coating head. In addition, the selection of the medium should ensure that the plasticized state of the material can achieve uniform coating of the coating.

[0035] As a preferred solution, the end of each medium transmission pipeline 11 - 2 protrudes from the plane of its end surface to facilitate communication with an external medium pipeline.

[0036] It should be noted that one of the two medium transmission pipelines 11 - 2 is an input pipeline and the other is an output pipeline, and which one can be specifically adjusted according to actual application requirements.

[0037] Different from traditional alloy materials, high entropy alloys have multiple main elements, and the atomic diameters, diffusion capabilities, interactions between elements and melting points of each element are very different, which easily leads to segregation and defects. It is necessary to adopt a multi-stage plasticizing device 10 with a feedback control temperature system to ensure the uniformity of the plasticized material. The inner wall 7-3 of the variable diameter discharge barrel obtains a uniform and dense plasticized material body under the combined action of the plasticized material's own gravity and the extrusion of the feeding screw 9.

[0038] See also Figure 1 and Figure 5 The threaded feed rod 8 is located inside the discharge barrel 7 and is arranged along the length direction of the discharge barrel 7. The threaded feed rod 8 and the discharge barrel 7 are coaxial. The upper end of the threaded feed rod 8 is connected to the power output end of the motor 5, and the lower end of the threaded feed rod 8 is connected to the coating head 13. The feed thread 9 is distributed outside the feed rod 8. The upper end of the feed thread 9 is higher than the feed port 4 by a pitch h, and the lower end of the feed thread 9 is flush with the lower end height of the material plasticizing device 10. The rotation speed of the threaded feed rod 8 is 0-2000 rpm, and the axial top pressure is 0-100 kN.

[0039] As a preferred solution, see Figure 5 and Figure 6The diameter of the threaded feed rod 8 is D (1.5D=d1), the thread shape of the feed thread 9 is a wedge thread, the cross section of the wedge thread is a trapezoid, including an outer wedge thread flat top 9-1, the two sides of the wedge thread flat top 9-1 are respectively connected to the ends of the wedge thread bevel 9-2, and the other end of the wedge thread bevel 9-2 is connected to the outer side of the threaded feed rod 8. The wedge surface slope γ is 30°, the thread is a clockwise thread, the thread pitch h is 0.5-1.5D, and the feed thread 9 has a diameter of 2D.

[0040] See also Figure 1 and Figure 8 The bottom of the threaded feed rod 8 is connected to the coating head 13. The coating head 13 is provided with a vertical hollow through hole 13-9 around its central axis. The hollow through hole 13-9 penetrates the upper and lower end surfaces of the coating head 13 and is used for extruding the plasticized material. During the extrusion, a dense and smooth coating is applied through the rotational friction at the bottom of the coating head 13. The central part of the coating head 13 is provided with an upwardly protruding connecting boss 13-1. The connecting boss 13-1 is coaxial with the threaded feed rod 8. The connection method between the connecting boss 13-1 and the threaded feed rod 8 includes but is not limited to a threaded connection 13-1, a key connection and a pin connection. As a preferred solution, the side wall of the connecting boss 13-1 is provided with a threaded structure, which can be inserted into the threaded feed rod 3 from the bottom for easy disassembly, so that the coating head 13 can be threadedly connected to the bottom of the threaded feed rod 8 to achieve power transmission. An upwardly protruding annular boss 13-2 is provided around the circumference of the upper end surface of the coating head 13. The annular boss 13-2 is connected to the bottom of the discharge barrel 7 through a double bearing, thereby ensuring the airtightness of the lower end of the discharge barrel to prevent the plasticized material from overflowing.

[0041] As a preferred solution, the longitudinal cross-section of each hollow through hole 13-9 is trapezoidal, and the transverse radius of the hollow through hole 13-9 gradually decreases from top to bottom to facilitate the extrusion of the plasticized material.

[0042] As a preferred solution, the hole type of each hollow through hole 13-9 includes but is not limited to a circular discharge hole 13-6 and an elliptical discharge hole 13-8, and the size and number of the discharge holes can be customized according to the discharge volume required by actual working conditions.

[0043] In some embodiments of the present invention, an annular groove 13-3 with the same center is provided on the lower end surface of the coating head 13, the inner diameter of the annular groove 13-3 is 3 / 5d3 (d3 is the coating head diameter, unit: mm), the outer diameter range is 7 / 10-9 / 10d3, and the groove depth is 2 mm. The inner diameter of the annular groove 13-3 should be larger than the outer diameter of the spiral convex head 13-4, the outer diameter range should be smaller than the coating head 13 diameter, and the depth and width are selected with the goal of changing the material flow state and forming an excellent coating surface quality. The function of the annular groove 13-3 is to transform the flow state of the plasticized material extruded along the circumferential direction of the coating head 13 into a downward flow. The change in the material flow state can eliminate the defects in the coating thickness direction and increase the bonding strength between the coating and the coated workpiece.

[0044] A central friction convex head is provided at the center of the lower end face of the coating head 13, and the shapes include but are not limited to a hemispherical convex head 13-5 and a truncated cone convex head 13-7; the diameter of the end face of the hemispherical convex head 13-5 in contact with the coating head 13 is D1, and the height is 0.6 times the required coating thickness; the diameter of the truncated cone convex head 13-7 in contact with the coating head 13 is D1, the outermost end face diameter is 0.6D1, and the height is 0.6 times the required coating thickness. The function of the central friction convex head is to densify and homogenize the coating at the center of the coating head 13 to prevent the material extruded from the discharge port from accumulating in the center of the coating.

[0045] See also Fig.10 The spiral convex head 13-4 is equally divided around the circumference of the central friction convex head 13-5, and the spiral convex head is composed of a long arc side 13-41, a short arc side 13-42 and two short straight sides 13-43; the vertices of the short straight sides 13-43 on the near-center side of the spiral convex head 13-4 are distributed on the circumference of the circle with the same center diameter D3 as the central friction convex head 13-5, and D3 should be greater than 3D1; the vertices of the short straight sides 13-43 on the far-center side of the spiral convex head 13-4 are distributed on the circumference of the circle with the same center diameter D3 as the central friction convex head 13-5, and D3 should be greater than 3D1; The head 13-5 is on the circumference of the circle with the center diameter D4, and D4 should be greater than 6D1; the extension line of the short arc edge 13-42 is inscribed with the lower end outlet edge of the hollow through hole 13-9; the arc of the long arc segment 13-41 and the short arc segment 13-42 of the spiral convex head is 1.5D2, the short straight side 13-43 is perpendicular to the long arc segment 13-41 and the short arc segment 13-42, the length of the short straight side 13-43 is 0.5D1, and the height of the spiral convex head 13-4 is 0.6 times the target thickness of the coating layer. The arc bending direction of the spiral convex head 13-4 is opposite to the rotation direction of the coating head 13. The opposite arc direction is conducive to guiding the material to flow rapidly in the circumferential direction and avoid clogging the discharge port 13-6, and is conducive to densification and uniformity of the coating material. The spiral convex head can change the material flow direction and accelerate the flow of the extruded material at the discharge port, thereby avoiding clogging of the discharge port.

[0046] The raw materials added to the friction coating high temperature resistant high entropy alloy coating preparation device include but are not limited to high entropy alloy powder, particles, and debris.

[0047] Through the above device, the coating preparation method of the friction coating high temperature resistant high entropy alloy coating preparation device comprises the following steps: Step 1, install the coating head 13, then start the motor 5, the material plasticizing device 10 and the cooling protection device 11 in sequence, and check whether the device operates stably. After checking that the operation is normal, turn off the material plasticizing device 10, the cooling protection device 11 and the motor 5 in sequence; Step 2, install the workpiece to be coated, program in the processing equipment system, set the rotation speed, forward speed and forward route of the threaded feed rod 8 and other related parameters, the staff manually controls the moving handle to further control the processing process, move the coating head 13 to the initial position of the processing, obtain the rough coordinates of the starting position of the processing, and input the precise processing starting position into the program through the judgment of the engineer, and determine the end point according to the requirements, adjust the lower end position of the coating head 13 to the predetermined position on the surface of the coating workpiece to be prepared, and the height from the surface of the plate is the predetermined coating thickness; Step 3, add coating raw materials into the feeding hopper 1; start the motor 5, the material plasticizing device 10, the cooling protection device 11 and the first valve 2 in sequence, and when the plasticized coating raw materials are stably extruded from the lower end of the coating head 13, the coating is applied according to a predetermined rotation speed, forward speed and path; in this process, the motor 5 is started to drive the threaded feed rod 8 to rotate, and the coating raw materials gradually move downward under the action of the feed threads on the threaded feed rod 8. When it moves to the material plasticizing device 10, the coating raw materials are evenly heated and have better fluidity. After the coating raw materials flow out through the coating head 13, they reach the surface of the workpiece and are evenly stirred by the central friction convex head and the spiral convex head 13-4 on the surface of the workpiece.

[0048] Step 4, when the coating head 13 reaches the end position, the first valve 2, the material plasticizing device 10, the cooling protection device 11 and the motor 5 are closed in sequence; The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A friction coating high temperature resistant high entropy alloy coating preparation device, characterized in that: The material discharging cylinder (7) comprises a cavity formed inside the material discharging cylinder (7) along the axial direction, a coaxial threaded material feeding rod (8) is arranged inside the cavity, and a material feeding thread (9) is arranged on the outer wall of the threaded material feeding rod (8); A motor (5) is disposed at the upper end of the discharge barrel (7), and a power output end of the motor (5) is connected to the upper end of the threaded feed rod (8); a feeding hopper (1) is disposed on the side wall of the discharge barrel (7), and a discharge port of the feeding hopper (1) is connected to the cavity; The material plasticizing device (10) and the cooling protection device (11) are arranged outside the discharge barrel (7); the feeding hopper (1) is above the material plasticizing device (10), and the material plasticizing device (10) is at the upper end of the cooling protection device (11); a heating resistance wire (10-2) is arranged inside the material plasticizing device (10), and a medium pipeline (11-1) is arranged in the cooling protection device (11) around the discharge barrel (7); The lower end of the threaded feed rod (8) is detachably connected to a coating head (13), and the upper end surface of the coating head (13) is rotatably connected to the lower end of the discharge barrel (7); The coating head (13) is provided with a plurality of hollow through holes (13-9) inside, the upper end of the hollow through hole (13-9) is connected to the cavity, and the lower end of the hollow through hole (13-9) is connected to the outside; a central friction convex head is provided at the center position of the bottom of the coating head (13), and a plurality of spiral convex heads (13-4) are provided around the central friction convex head at the bottom of the coating head (13); the hollow through hole (13-9) is provided between the central friction convex head and the spiral convex head (13-4), and the spiral convex head (13-4) is in the shape of an arc, and the bending direction of the arc is opposite to the rotation direction of the coating head (13); a coaxial annular groove (13-3) is provided at the bottom of the coating head (13), and the spiral convex head (13-4) is in the inner circle of the annular groove (13-3).

2. The friction coating high temperature resistant high entropy alloy coating preparation device according to claim 1 is characterized in that: The central friction protrusion is a hemispherical protrusion (13-5) or a truncated cone-shaped protrusion (13); The bottom end diameter D1 of the central friction protrusion is ≤D (D is the diameter of the threaded feed rod), and the height is 0.6 times the target thickness of the coating.

3. The friction coating high temperature resistant high entropy alloy coating preparation device according to claim 1 is characterized in that: The hollow through holes (13-9) are equally divided around the circumference of the central friction convex head (13-5), and the diameter D2 of the circumscribed circle of the lower end outlet of the hollow through holes (13-9) is greater than twice the diameter D1 of the bottom end of the central friction convex head (13-5); The spiral convex head (13-4) is arranged in equal parts around the circumference of the central friction convex head (13-5), and the spiral convex head (13-4) is composed of a long arc side (13-41), a short straight side (13-43), a short arc side (13-42) and a short straight side (13-43) connected end to end; the vertices of the short straight side (13-43) on the near-center side of the spiral convex head (13-4) are distributed on a circumference with a diameter D3 co-centered with the central friction convex head (13-5), and D3 is greater than 3D1; the vertices of the short straight side (13-43) on the far-center side of the spiral convex head (13-4) are distributed on a circumference with a diameter D4 co-centered with the central friction convex head (13-5), and D4 is greater than 6D1; the extension line of the short arc side (13-42) is tangent to the outlet edge of the lower end of the hollow through hole (13-9); The long arc side (13-41) and the short arc side (13-42) of the spiral convex head both have an arc angle of 1.5D2, the short straight side (13-43) is perpendicular to the long arc side (13-41) and the short arc side (13-42), the length of the short straight side (13-43) is 0.5D1, and the height of the spiral convex head (13-4) is 0.6 times the target thickness of the coating layer.

4. The friction coating high temperature resistant high entropy alloy coating preparation device according to claim 1 is characterized in that: A connecting boss (13) protruding upward is provided at the center of the coating head (13), and the connecting boss (13) and the lower end of the threaded feed rod (8) are detachably connected; An upwardly protruding annular boss (13-2) is circumferentially arranged on the edge of the upper end surface of the coating head (13); the annular boss (13-2) is connected to the bottom of the discharge barrel (7) via a double bearing.

5. The friction coating high temperature resistant high entropy alloy coating preparation device according to claim 1, characterized in that: The material plasticizing device (10) comprises a shell (10-3), the shell (10-3) is arranged on the cooling protection device (11), a plurality of rows of heating resistance wires (10-2) are arranged between the shell (10-3) and the threaded feeding rod (8), each row of heating resistance wires (10-2) is arranged vertically, all the heating resistance wires (10-2) are arranged at equal intervals around the circumference of the discharge barrel (7), and a terminal head (10-1) is arranged at the end of each row of heating resistance wires (10); Each row of heating resistance wires (10) is divided into three parts, which are arranged vertically from top to bottom: heating resistance wire one (10-21), heating resistance wire two (10-22) and heating resistance wire three (10-23); a temperature sensor one (10-41) is arranged at the vertical upper end of heating resistance wire one (10-21); a temperature sensor two (10-42) is arranged vertically between heating resistance wire one (10-21) and heating resistance wire two (10-22); a temperature sensor three (10-43) is arranged vertically between heating resistance wire two (10-22) and heating resistance wire three (10-23); a temperature sensor four (10-44) is arranged at the vertical lower end of heating resistance wire three (10-23); all temperature sensors are connected to a main control terminal (10-5); The heating resistance wire (2) has a zigzag structure, a wave structure or a serpentine structure.

6. The friction coating high temperature resistant high entropy alloy coating preparation device according to claim 5, characterized in that: The calculation formula for the number of heating resistance wires (2) is: f=3πd⁄4, wherein f is the number of heating resistance wires (2) and d is the outer diameter of the discharge barrel (7).

7. The friction coating high temperature resistant high entropy alloy coating preparation device according to claim 1 is characterized in that: The cavity in the discharge barrel (7) is divided into an upper cavity (7-4) and a lower cavity (7-5). The inner diameter of the upper cavity (7-5) is a fixed value, and the inner diameter of the lower cavity (7-5) gradually decreases from top to bottom. The calculation formula of the inner diameter of the lower cavity (7-5) is: d2= （1） —The angle between the gradient slope and the axis, the optimal range is 5-25°, and the calculation formula is: ; —The friction coefficient between the plasticized material and the inner wall of the discharge barrel is affected by the plasticized material system, the material of the inner wall of the discharge barrel and the temperature; d1—fixed diameter of the upper cavity (7-4) of the discharge barrel, in mm; —Total height of the inner wall (7-3) of the variable diameter discharge barrel, in mm.

8. The friction coating high temperature resistant high entropy alloy coating preparation device according to claim 7, characterized in that: The threaded material feeding rod (8) is arranged in the upper part of the cavity (7-5), and the outer wall is provided with a material feeding thread (9).

9. The friction coating high temperature resistant high entropy alloy coating preparation device according to claim 1, characterized in that: The hollow through holes (13-9) are equally divided around the center of the coating head (13), and the lateral radius of the hollow through holes (13-9) gradually decreases.

10. A method for preparing a friction-coated high-temperature resistant high-entropy alloy coating based on the device of claim 1, characterized in that: The following steps are involved: Step 1, connecting the coating head (13) and the discharge barrel (7); Step 2, moving the coating head (13) to the initial position of the workpiece, and setting the rotation speed, forward speed and forward route of the threaded feed rod (8); Step 3, adding the coating raw material into the feeding hopper (1), and starting the motor (5), the material plasticizing device (10) and the cooling protection device (11) in sequence; the coating raw material moves downward in the cavity of the discharge barrel (7) under the action of the threaded feed rod (8), is discharged from the hollow through hole (13-9) of the coating head (13), and is stirred evenly by the central friction convex head and the spiral convex head (13-4), and while stirring, the coating raw material is coated on the surface of the workpiece; Step 4: After the belt coating head (13) reaches the end position, the material plasticizing device (10), the cooling protection device (11) and the motor (5) are turned off in sequence.

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