阅读说明：本技术 Pvd厚度控制 (PVD thickness control ) 是由 L·库梅尔 T·道贝 于 2020-04-22 设计创作，主要内容包括：本发明涉及一种用于在带材涂层设备(1)中利用金属基材(12)对金属带材(10)进行涂层的方法,其中,所述涂层根据物理气相沉积(PVD)的原理进行并且通过带材速度和雾化速率的参数调整涂层厚度。根据本发明规定,在金属带材(10)的涂层厚度变化和/或宽度变化的情况下,雾化速率和带材速度同时发生改变,从而能够独立于热雾化过程直接实施所述涂层厚度变化。(The invention relates to a method for coating a metal strip (10) with a metal base material (12) in a strip coating installation (1), wherein the coating is carried out according to the principle of Physical Vapor Deposition (PVD) and the thickness of the coating is adjusted by means of the parameters of strip speed and atomization rate. According to the invention, the atomization rate and the strip speed are simultaneously varied in the case of a change in the thickness and/or a change in the width of the coating of the metal strip (10), so that the coating thickness change can be carried out directly independently of the thermal atomization process.)

1. A method for coating a metal strip (10) with a metal base material (12) in a strip coating installation (1), wherein the coating is carried out according to the principle of Physical Vapor Deposition (PVD) and the coating thickness is adjusted by means of parameters of strip speed and atomization rate,

it is characterized in that the preparation method is characterized in that,

in the case of a change in the thickness and/or width of the coating of the metal strip (10), the atomization rate and the strip speed are simultaneously varied, so that the coating thickness change can be carried out directly independently of the thermal atomization process.

2. The method of claim 1, wherein the atomization rate and the ribbon velocity are varied over a fixed time interval.

3. Method according to claim 1 or 2, wherein the coating thickness variation and/or the width variation of the metal strip (10) is carried out by numerical pairing of the atomization rate and the strip speed per time interval.

4. The method of claim 3, wherein the numerical pairing is based on historical data and/or model relationships.

5. The method according to any one of the preceding claims, wherein the metal strip (10) comprises a steel strip and the metal substrate (12) comprises zinc.

6. Method according to any of the preceding claims, wherein the variation in coating thickness and/or the variation in width of the metal strip (10) is at least 10%, preferably 15%, more preferably 20%, and most preferably 25%.

7. Method according to any one of the preceding claims, wherein a coating thickness measurer (20) is used for determining the coating thickness.

8. An apparatus (1) for coating a metal strip (10) with a metal substrate (12),

comprising a continuous processing line (2) in which the metal strip (10) is moved in a direction of movement (3), wherein a coating device (16) is provided in the processing line (2), in which coating device the metal strip (10) can be coated at least on one side with the metal base material (12) according to the principle of Physical Vapor Deposition (PVD) and the coating thickness can be adjusted by means of the parameters of the strip speed and the atomization rate,

it is characterized in that the preparation method is characterized in that,

a control unit (18) which, in the event of a change in the coating thickness and/or a change in the width of the metal strip (10), simultaneously varies the atomization rate and the strip speed, so that the coating thickness change can be carried out directly independently of the thermal atomization process.

9. Apparatus (1) according to claim 8, wherein a coating thickness measurer (20) is provided downstream of the coating device (16).

Technical Field

The invention relates to a method for coating a metal strip with a metal substrate, in particular zinc, in a strip coating installation, wherein the coating is carried out according to the principle of Physical Vapor Deposition (PVD) and the thickness of the coating is adjusted by means of parameters of the strip speed and the atomization rate, and to an installation for coating a metal strip with a metal substrate.

Background

Methods for applying a passivation layer to a metal strip are known in principle from the prior art.

For example, document JPS6296669 discloses a method for coating a steel strip with a zinc layer, wherein the temperature of the steel strip is adjusted to a specific temperature range before coating.

Document JPS63128168 discloses a method for coating a steel strip with a zinc layer, which has a better deep drawability.

A control unit for a vapour phase deposition apparatus is known from document JPH05287528 to improve the quality of the deposited layer. The thickness of the deposited coating is determined continuously by a coating thickness detector and the strip speed is determined continuously by a speed detector and sent to a control unit. For example, if the coating thickness set point is exceeded or not reached, the speed of the strip is adjusted accordingly by the control unit so that the deposited coating thickness remains constant.

From the document JPS6320448 a method is known for coating a steel strip with aluminum, in which the formation of an aluminum-iron alloy layer is prevented by a previously formed AlN (aluminum nitride) layer. The coating thickness of the AlN layer is adjusted here by adjusting the strip speed.

Document DE1521573 discloses a control device for a vacuum continuous strip coating method, in which metal vapor is deposited on the strip surface as a function of the strip speed, in order to achieve a uniform coating thickness.

Document EP0176852 discloses a vacuum coating device for continuously coating a metal strip, wherein a control device is provided for varying the width of the metal vapor channel, so that metal strips of different widths can be coated with a uniform coating thickness.

In PVD coating processes, the desired metal substrate is atomized and deposited on the metal surface, wherein the atomization is usually carried out in vacuum using known techniques. The atomized metal substrate is then deposited on the surface of the metal strip.

Since the atomization process is a thermal process, in the case of process variations, such as variations in the thickness and/or width of the coating of the metal strip, the atomization rate can only be adjusted slowly, so that the sections formed on the metal strip do not have the desired coating thickness and are therefore not of satisfactory quality.

Disclosure of Invention

It is therefore the object of the present invention to provide a method and an apparatus which overcome the disadvantages of the prior art.

This object is achieved by a method having the features of claim 1 and by an apparatus having the features of claim 8.

The dependent claims relate respectively to preferred or further embodiments of the invention, the individual features of which can be freely combined with one another within technically expedient scope, if necessary also across the category limits of the individual claims.

The method is provided for coating a metal strip with a metal substrate in a strip coating installation, wherein the coating is carried out according to the principle of Physical Vapor Deposition (PVD) and the coating thickness is adjusted by means of parameters of the strip speed and the atomization rate. According to the invention, it is provided that, in the case of a change in the coating thickness and/or a change in the width of the metal strip, the atomization rate and the strip speed are simultaneously varied, so that the coating thickness change can be carried out directly independently of the thermal atomization process. In other words, in the case of coating thickness variations, the atomization rate can be adjusted in advance.

The coating can be carried out on one side or preferably on both sides, that is to say both the upper side and the lower side of the metal strip are coated.

The invention likewise provides an apparatus for coating a metal strip with a metal substrate, comprising a continuous processing line in which the metal strip is moved in a direction of movement, wherein a coating device is provided in the processing line, in which coating device the metal strip can be coated at least on one side with the metal substrate according to the principle of Physical Vapor Deposition (PVD), and wherein the thickness of the coating can be adjusted by means of parameters of the strip speed and the atomization rate. According to the invention, the device comprises a control unit which, in the event of a change in the coating thickness and/or a change in the width of the metal strip, simultaneously varies the atomization rate and the strip speed, so that the change in the coating thickness can be carried out directly independently of the thermal atomization process.

The invention is based on the basic knowledge that the coating thickness variation can be adjusted directly on the metal strip by means of superimposed speed adjustment independently of the slow heat transfer process. Thus, the formation of larger sections of metal strip which do not yet have the desired newly adjusted coating thickness can be effectively circumvented. Furthermore, the adjustment of the atomization rate is advantageous for a process or a plant which is operated at an optimum production speed.

By the expression "and/or", a person skilled in the art realizes that different embodiment variants can be realized with the method according to the invention or with the device according to the invention.

For example, if a new coating thickness is to be applied on the metal strip to be coated or on a subsequent metal strip, the atomization rate is adjusted accordingly. In the case of a decrease in the thickness of the coating, the atomization rate decreases, and in the case of an increase in the thickness of the coating, the atomization rate increases. The slow decrease or increase in the atomization rate lasts for several minutes, at which stage it is compensated by a continuous adjustment in the form of an increase or decrease in the strip speed, so that the thickness of the coating deposited on the subsequent metal strip immediately corresponds to the desired target coating thickness.

For example, if a subsequent metal strip is wider or narrower than the preceding metal strip, to be coated with the same coating thickness, the atomization rate is adjusted accordingly. If the subsequent strip is narrower, the rate of atomization is reduced. If the subsequent strip is wider, the rate of atomization is increased. The slow decrease or increase in the atomization rate lasts for several minutes, at which stage it is compensated by a continuous adjustment in the form of an increase or decrease in the strip speed, so that the thickness of the coating deposited on the subsequent strip immediately corresponds to the desired target coating thickness.

In a further embodiment variant according to the invention, the subsequent strip can be made wider than the preceding metal strip, wherein the coating thickness on the subsequent strip is greater than on the preceding metal strip. In this case, the atomization rate will increase accordingly and the strip speed will decrease. The slow increase in the atomization rate lasted for several minutes, at which stage it was compensated by a continuous decrease in the strip speed, so that the thickness of the coating deposited on the subsequent strip immediately corresponded to the desired target coating thickness.

In a further embodiment variant according to the invention, the subsequent strip can be made wider than the preceding metal strip, wherein the coating thickness on the subsequent strip is smaller than on the preceding metal strip. In this case, the variation in the atomization rate and the ribbon speed is dependent on the width variation of the subsequent ribbon and the target coating thickness. For example, if in this configuration the atomization rate and the strip speed are kept constant, the coating thickness is automatically adjusted to a smaller value due to the larger area to be coated on the subsequent strip. For example, if only the strip speed is reduced, the coating thickness will still automatically adjust to a smaller value due to the larger area to be coated on subsequent strips. In principle, however, the atomization rate and the strip speed are simultaneously varied according to the desired target specification in such a way that the coating thickness deposited on the subsequent strip immediately corresponds to the desired target coating thickness.

In a further embodiment variant according to the invention, the subsequent strip can be made narrower than the preceding metal strip, wherein the coating thickness on the subsequent strip is greater than on the preceding metal strip. The atomization rate and the strip speed are simultaneously varied according to the specification in such a way that the thickness of the coating deposited on the subsequent strip immediately corresponds to the desired target coating thickness.

Finally, in a further embodiment variant according to the invention, the subsequent strip can be made narrower than the preceding metal strip, wherein the coating thickness on the subsequent strip is smaller than on the preceding metal strip. The atomization rate and the strip speed are simultaneously varied as a function of said parameters in such a way that the thickness of the coating deposited on the subsequent strip immediately corresponds to the desired target coating thickness.

In a preferred embodiment, the atomization rate and the strip speed are changed together at fixed time intervals, so that the two parameters can be adjusted to one another in a particularly fine manner. In principle, the shorter the time interval selected, the more precisely the coating thickness variation and/or the width variation of the metal strip can be implemented.

Preferably, the coating thickness variation and/or the width variation of the metal strip are carried out by numerical pairing of the atomization rate and the strip speed per time interval, which are particularly preferably based on historical data and/or model relationships. Given the change in the area to be coated and/or in the thickness of the coating to be coated, the speed regulation can be correspondingly pre-controlled in each time unit in order to achieve an instantaneous regulation.

The metal strip is preferably a steel strip. The metal substrate preferably comprises zinc, so that a pure zinc layer is formed as the resulting coating.

In a further preferred embodiment variant, the metal substrate can further have a composition of magnesium, aluminum, iron or silicon, so that a zinc alloy layer is formed as the resulting coating.

In a particularly preferred embodiment, the variation in the thickness of the coating and/or the variation in the width of the metal strip is at least 10%, more preferably 15%, still more preferably 20%, and most preferably 25%.

For determining the coating thickness, a coating thickness measurer arranged downstream of the coating device is preferably used. The coating thickness can be adjusted by adjusting the strip speed and the atomization rate by a coating thickness measurer located downstream.

Drawings

Further advantages and features of the method according to the invention and of the device according to the invention result from the embodiments which are further elucidated below with reference to the drawings. Wherein:

fig. 1 shows a schematic, simplified side view of an embodiment variant of the device according to the invention.

Detailed Description

Fig. 1 schematically shows a very simplified side view of an embodiment variant of a device 1 according to the invention.

The apparatus 1 is suitable for carrying out the method according to the invention, in which method a metal strip 10 is treated with a metal base material 12 according to the principle of Physical Vapor Deposition (PVD), wherein the thickness of the coating is adjusted by the parameters of strip speed and atomization rate according to the following formula.

Wherein:

the plant 1 comprises first a continuous processing line 2, in which processing line 2 the metal strip 10 is first unwound by a first coiling device 11 and then wound again at the end of the processing line 2 by a second coiling device 13. Inside the processing line 2, the metal strip 10 moves in the direction of movement of the arrow 3 and in this case passes through a plurality of stations.

In the embodiment variant described here, the apparatus 1 comprises a pickling device 14 arranged in the processing line 2 and a coating device 16 arranged downstream.

The surface of the metal strip 10, for example a steel strip, is prepared in the pickling device 14 so that it can be subsequently coated in the coating device 16.

In the coating device 16, the metal strip 10 is then coated at least on one side, preferably on both sides, with a metal base material 12, for example a zinc layer, according to the principle of Physical Vapor Deposition (PVD). The coating thickness can be set by the parameters of the strip speed and the atomization rate according to the above formula.

For example, if different coating thicknesses are to be set, the strip speed can be adjusted by changing the above formula. Thus, the following formula applies:

the same relationship applies to width variations or combination variations.

If all process adjustment parameters, such as the atomization rate and the width, remain unchanged, only the following formula applies:

as long as all process control parameters, such as the atomization rate and the coating thickness, are unchanged, only the following formula applies:

accordingly, coating thickness variations or width variations can be adjusted up to a particular height without changing the atomization rate.

However, the speed of the conversion process is limited by the speed variation per unit time. The atomization rate must be adjusted if large variations in coating thickness and/or width are to be achieved.

In the method according to the invention, it is therefore provided that, in the event of a change in the thickness and/or width of the coating of the metal strip 10, the atomization rate and the strip speed are simultaneously varied, so that the change in the thickness of the coating can be carried out directly independently of the thermal atomization process. In other words, in the case of coating thickness variations, the atomization rate can be adjusted in advance.

To this end, the device 1 comprises a control unit 18 which, in the event of a change in the coating thickness and/or a change in the width of the metal strip 10, simultaneously varies the atomization rate and the strip speed, so that the coating thickness change can be carried out directly independently of the thermal atomization process. In the embodiment variant shown here, the control unit 18 is EDV-enabled and also comprises a memory unit 19 in which the numerical pairing of the nebulization rate and the strip speed for each time interval is stored. These numerical pairings may be based on past data or models, for example.

For example, if a new coating thickness that is reduced by 25% is to be applied to the metal strip 10, the atomization rate is reduced by the control unit 18. The slow reduction of the atomization rate lasts for several minutes, at which stage compensation is made by continuous adjustment in the form of a lifting strip speed based on a numerical pairing, so that the thickness of the coating deposited on the subsequent metal strip immediately corresponds to the desired target coating thickness.

This must be taken into account if necessary, since the efficiency also varies. A coating thickness measurer 20, by means of which the coating is controlled, is therefore additionally arranged in the processing line 2 downstream of the coating installation 16.

By means of this measurement value, correction values can be determined and adjusted. The following formula applies:

accordingly, the above formula can be rewritten as:

as can be seen from fig. 1, the coating thickness measuring device 20 is connected to the control unit 18, so that, if a predetermined value is undershot or exceeded, the coating can be readjusted according to the mathematical relationship shown to achieve a uniform coating.

List of reference numerals

1 apparatus

2 processing line

3 arrow head

10 metal strip

11 first winding device

12 metal base material

13 secondary take-up device

14 acid washing device

16 coating device

18 control unit

19 memory cell

20 coating thickness measurer