The present application relates to the technical field of vacuum coating, and more particularly, relates to a vacuum coating device for uniformly distributing a metal steam by using a guide plate type structure.
Physical vapor deposition (PVD) refers to a process technique that a plated metal is heated under vacuum conditions, so that it is deposited in a gaseous state onto a substrate to form a coating, and depending on different heating modes, it is classified as (resistive or inductive) electric heating, electron beam gun heating (EBPVD), or the like. Vacuum coating, serving as a surface modification and coating process, has been widely applied in electronic, glass, plastic, and other industries, and the vacuum coating technology has main advantages that it is environmental, has good coating performance, and achieves a diversity in plated materials. The key to the use of the vacuum coating technology for continuous strip steel lies in several aspects such as continuous coating production, large-scale production, high-rate production, mass production, etc. Since the 1980s, much research has been conducted on the technology by respective steel companies in the world. The technology is receiving unprecedented attention and is considered to be an innovative surface coating process as the hot galvanizing technology and the electro galvanizing technology become mature.
A key point in vacuum coating is how to obtain a coating with a uniform thickness by arranging the nozzle. The documents disclosed abroad at present mainly involve the following aspects.
1) An Integrated Evaporation Crucible and Flow Distribution Nozzle Structure
The European patents BE1009321A6 and BE1009317A61 respectively disclose crucible nozzle structures as shown in
The patents JPS59177370A and U.S. Pat. No. 4,552,092A also disclose related evaporation crucible and nozzle structure.
2) A Separated Evaporation Crucible and Flow Distribution Nozzle Structure
The patent WO2018/020311A1 discloses a separated crucible nozzle structure, as shown in
The patent CN103249860A discloses a separated flow distributor and nozzle structure. As shown in
The patent CN101175866A discloses a form of a metal steam flow distributor and nozzle.
These patents are all related to specific forms of the nozzles in the coating process, but cannot indicate that these nozzles can achieve uniform coating. The coating uniformity of the surface of a steel plate is a key factor for a subsequent process such as bending and punching.
In view of the above-mentioned defects existing in the prior art, an objective of the present application is to provide a vacuum coating device for uniformly distributing a metal steam by using a guide plate type structure, wherein the metal steam is uniformly distributed and guided by guide plates on a core rod, is subjected to a secondary buffered distribution by a pressure stabilizing plate, and then is sprayed from a coating nozzle to finally form a uniform coating on a surface of a steel plate.
To achieve the above objective, the present application employs the following technical solutions. A vacuum coating device for uniformly distributing a metal steam by using a guide plate type structure comprises a crucible, wherein an induction heater for heating a molten metal in the crucible to form metal steam is arranged outside the crucible; a top of the crucible is connected to a flow distribution tank body by a metal steam pipeline; a core rod and a pressure stabilizing plate, which extend in a horizontal direction, are arranged inside the flow distribution tank body; the core rod is located below the pressure stabilizing plate; a coating nozzle is arranged on top of the flow distribution tank body; an induction coil is arranged outside the flow distribution tank body; and a pressure regulating valve is arranged on the metal steam pipeline.
One or more heating holes extending in an axial direction of the core rod are formed inside the core rod; an resistance wire is arranged inside each heating hole; a primary guide plate, a secondary guide plate and a tertiary guide plate are arranged on a surface of the core rod; the primary guide plate is arranged towards the metal steam pipeline; the secondary guide plate is arranged on an outer side of the primary guide plate; and the tertiary guide plate is arranged on an outer side the secondary guide plate.
A buffer groove is formed in an inner wall of the flow distribution tank body, and the buffer groove corresponds to the core rod in position.
Optionally, the buffer groove is arranged opposite to the core rod in the horizontal direction such that the buffer groove corresponds to the core rod in position.
Optionally, the outer side of the primary guide plate is a side of the primary guide plate facing away from an orifice of the metal steam pipeline in a circumferential direction of the core rod; and the outer side of the secondary guide plate is a side of the secondary guide plate facing away from the orifice of the metal steam pipeline in the circumferential direction of the core rod.
Preferably, the core rod has a circular, elliptical, trapezoidal or rectangular cross section.
Preferably, a length of the primary guide plate is less than a length of the secondary guide plate; and the length of the secondary guide plate is less than a length of the tertiary guide plate.
Preferably, the secondary guide plate and the tertiary guide plate are both provided with opening holes arranged at equal intervals.
Preferably, an angle between the primary guide plate and the secondary guide plate is 15°-45°, and an angle between the secondary guide plate and the tertiary guide plate is 20°-45°.
Preferably, a length L1 of the primary guide plate, a length L2 of the secondary guide plate, a length L3 of the tertiary guide plate, a length h of each opening hole in the secondary guide plate or a length h of each opening hole in the tertiary guide plate, a distance d between the adjacent opening holes in the secondary guide plate or a distance d between the adjacent opening holes in the tertiary guide plate, a power of the resistance wire and a pressure of the metal steam in the metal steam pipeline satisfy the following relationship: when the pressure of the metal steam in the metal steam pipeline is 1000-100000 Pa, L1/L3=0.2-0.4, L2/L3=0.4-0.7, h=2-6 mm, d=8-15 mm, and the power of the resistance wire is 8-20 KW/m2.
Optionally, as the pressure of the metal steam in the metal steam pipeline is increased, a value of L1/L3 is increased, a value of L2/L3 is increased, a value of h is reduced, a value of d is increased, and the power of the resistance wire is increased.
Optionally, when the pressure of the metal steam in the metal steam pipeline is 50000-100000 Pa, L1/L3=0.3-0.4, L2/L3=0.6-0.7, h=2-4 mm, d=12-15 mm, and the power of the resistance wire is 15-20 KW/m2;
Preferably, the pressure stabilizing plate is set to be of a porous structure, a ratio of a total hole area Stotal hole area of the pressure stabilizing plate to an airflow channel area Soutlet at an outlet of the coating nozzle is greater than or equal to 0.1, i.e., Stotal hole area/Soutlet≥0.1.
Preferably, the holes in the pressure stabilizing plate are circular, square or triangular.
Preferably, the holes in the pressure stabilizing plate extend in a straight or curved line.
Preferably, the outlet of the coating nozzle is set to be of a slit type or a porous type. The airflow channel area at the outlet of the coating nozzle is Soutlet, and an airflow channel area at an interface of the top of the crucible and the metal steam pipeline is Sinlet, wherein a ratio of Soutlet to Sinlet is greater than or equal to 0.05-5, i.e., Soutlet/Sinlet≥0.05-5.
Preferably, the coating nozzle is of the slit type, and has a straight or curved profile; or, the coating nozzle is of the porous type, and has a rectangular, circular, or trapezoidal profile.
Preferably, the core rod is connected to the flow distribution tank body by means of threads or inlaying.
According to the vacuum coating device for uniformly distributing a metal steam by using a guide plate type structure provided by the present application, the metal steam is obtained by melting and evaporating the molten metal in the crucible by induction heating of the induction heater; the metal steam enters the flow distribution tank body through the metal steam pipeline; the induction coil is arranged outside the flow distribution tank body for heating, and the core rod with the guide plates is arranged inside the flow distribution tank body; the core rod is fixed inside the flow distribution tank body by means of threads or inlaying, and the axial heating holes are formed in the core rod are heated by the resistance wires. According to the evaporating temperature of the metal steam, and after the nozzle and the core rod are heated to the desired temperature, the pressure regulating valve is opened, and the metal steam enters the flow distribution tank body and impacts onto the surface of the core rod. The guide plates on the surface of the core rod are formed by protruding structures with distributing and guiding functions, and distribute the flow in cooperation with the interior of the flow distribution tank body, thereby achieving the function of distributing the metal steam uniformly into the flow distribution tank body. The pressure stabilizing plate is arranged in the flow distribution tank body for the secondary buffered distribution of the metal steam entering a distribution cavity. Then the metal steam is sprayed out from the coating nozzle and contacts a preprocessed metal plate at high velocity, thereby forming a uniform metal coating.
The technical solutions of embodiments of the present application are further described below in connection with the accompanying drawings.
Referring now to
One or more heating holes 24 are formed inside the core rod 19. In an example as shown in
The heating holes 24 extend in an axial direction of the core rod 19 (a direction perpendicular to the paper surface of
That is, the secondary guide plates 26 are located on outer sides of the primary guide plates 25, and the tertiary guide plates 27 are located on outer sides of the secondary guide plates 26. That is, in the circumferential direction of the core rod 19, the secondary guide plates 26 are located on the sides of the primary guide plates 25 facing away from an orifice 17a of the metal steam pipeline 17, and the tertiary guide plates 27 are located on the sides of the secondary guide plates 26 facing away from the orifice 17a of the metal steam pipeline 17. By the above arrangement, in the circumferential direction of the core rod 19, the primary guide plates 25, the secondary guide plates 26, and the tertiary guide plates 27 have sequentially increasing distances from the orifice 17a of the metal steam pipeline 17.
Across section of the core rod 19 may be circular, elliptical, trapezoidal, rectangular or be in other shapes. The core rod 19 is mainly used for buffered distribution of the metal steam 15 entering the flow distribution tank body 18 from the metal steam pipeline 17, and then the metal steam 15 flows along the surface of the core rod 19.
A length L1 of the primary guide plate 25 is less than a length L2 of the secondary guide plate 26, and the length L2 of the secondary guide plate 26 is less than a length L3 of the tertiary guide plate 27.
The secondary guide plate 26 and the tertiary guide plate 27 are both provided with opening holes arranged at equal intervals and shaped to be rectangular or trapezoidal.
An angle A1 between the primary guide plate 25 and the secondary guide plate 26 is set to be 15°-45°, and an angle A2 between the secondary guide plate 26 and the tertiary guide plate 27 is set to be 20°-45°.
A buffer groove 28 is formed in an inner wall of the flow distribution tank body 18, and corresponds to the core rod 19 in position. Exemplarily, the buffer groove 28 is arranged opposite to the core rod 19 in the horizontal direction such that the buffer groove 28 corresponds to the core rod 19 in position.
The workflow of the vacuum coating device of the present application is as follows:
The molten metal 14 may include metals such as zinc, magnesium, aluminum, tin, nickel, copper and iron, and in addition, may also include low-melting-point (less than 2000° C.) oxides of these elements.
A preprocessed metal plate 27 is cleaned by a plasma device or other devices before the vacuum coating, and its preheating temperature reaches 80-300° C.
Referring again to
In some embodiments, as the pressure of the metal steam 15 in the metal steam pipeline 17 is increased, a value of L1/L3 is increased, a value of L2/L3 is increased, a value of h is reduced, a value of d is increased, and the power of the resistance wires is increased.
Optionally, in some embodiments, when the pressure of the metal steam 15 in the metal steam pipeline 17 is 50000-100000 Pa, L1/L3=0.3-0.4, L2/L3=0.6-0.7, h=2-4 mm, d=12-15 mm, and the power of the resistance wires is 15-20 KW/m2;
Please refer to
The holes in the pressure stabilizing plate 20 (the porous structure) are circular, square, triangular or are of other shapes.
The holes in the pressure stabilizing plate 20 (the porous structure) extend in various forms, such as a straight line, a curved line, or a multi-layer structure.
The outlet of the coating nozzle 21 is set to be of a slit type or a porous type. The airflow channel area at the outlet of the coating nozzle 21 is Soutlet, and an airflow channel area at an interface of the top of the crucible 13 and the metal steam pipeline 17 is Sinlet, wherein a ratio of Soutlet to Sinlet is greater than or equal to 0.05-5, i.e., Soutlet/Sinlet≥0.05-5.
When being set to be of the slit type, the coating nozzle 21 has a straight or curved profile; or, when being set to be of the porous type, the coating nozzle 21 has a rectangular, circular, or trapezoidal profile or other profiles.
The coating nozzle 21 may be made of graphite, ceramic, or metal, or other materials that can be processed.
Zinc evaporation coating on the surface of a steel plate 28 is adopted. The steel plate 28 has a width of 1200 mm, and the steel plate 28 is heated to 150° C. after washed and dried. The crucible 13 is heated with the induction heater 16 to evaporate zinc. The pressure of zinc steam in the crucible 13 reaches 60000 Pa by controlling the power, and at the moment, the pressure regulating valve 23 is in the closed state. When the pressure of the steam in the crucible 13 reaches 60000 Pa, the pressure regulating valve 23 is opened and the metal steam 15 enters the flow distribution tank body 18, in which the core rod 19 and the pressure stabilizing plate 20 are arranged, through the metal steam pipeline 17.
The core rod 19 is set to be cylindrical (i.e., the core rod 19 has a circular cross section), and is provided with guide plates on the surface thereof. The angle A1 between the primary guide plate 25 and the secondary guide plate 26 is set to be 20°, and the angle A2 between the secondary guide plate 26 and the tertiary guide plate 27 is set to be 25°. A length ratio of the primary guide plate 25 to the tertiary guide plate 27 is L1/L3=0.35, and a length ratio of the secondary guide plate 26 to the tertiary guide plate 27 is L2/L3=0.65. The opening hole 26a in the secondary guide plate 26 has a length h=3 mm, and the opening hole 27a in the tertiary guide plate 27 has a length h=3 mm. The adjacent opening holes 26a in the secondary guide plate 26 have a distance d=13 mm, and the adjacent opening holes 27a in the tertiary guide plate 27 have a distance d=13 mm. The power of the resistance wires is set to be 18 KW/m2, as shown in
The pressure stabilizing plate 20 has a porous structure, and Stotal hole area/Soutlet=2.8.
The working pressure inside the coating nozzle 21 is 55000 Pa. The coating nozzle 21 is made of graphite, and the outlet of the coating nozzle 21 is of the slit type and is rectangular, wherein Soutlet/Sinlet=0.93.
Those of ordinary skill in the art should realize that the above embodiments are merely used for illustrating the present application and not intended to limit the present application. Variations and modifications made to the above embodiments are intended to fall within the scope of the claims of the present application as long as they fall within the spirit of the present application.
Number | Date | Country | Kind |
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202010702080.0 | Jul 2020 | CN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/CN2021/107674 | 7/21/2021 | WO |