JPH0361354A - Method for thermal spraying of ceramic to metallic foil - Google Patents

Abstract

PURPOSE:To obtain the metallic foil thermally sprayed with ceramics with high productivity by spraying and forming the thermally spraying layer of the ceramics on the surface to be thermally sprayed of the metallic foil while injecting water from below the metallic foil, with which the un-winding and taking up are once stopped, then moving the point on the metallic foil thermally sprayed to a prescribed position. CONSTITUTION:The formation of the thermally sprayed layer of the ceramics onto the metallic foil 1, such as copper foil, between the un-winding and taking up sides of devices 2, 3 to un-wind the metallic foil 1 from one side and to take up the same to the other side is executed in the following manner: The un-winding and taking up devices 2, 3 are once stopped to bring the metallic foil 1 into standstill and both ends of the metallic foil 1 in the part to be thermally sprayed are fixed. Water is ejected from plural pieces of water shower nozzles 5 installed below the metallic foil 1 and while the rear surface of the surface 6 thermally sprayed of the metallic foil 1 is cooled by bringing the water into contact therewith, the thermally sprayed 6 to be thermally sprayed is thermally sprayed 7. The metallic foil is thermally sprayed with the ceramics by repeating the stage for forming the thermally sprayed layer of the prescribed ceramics onto the surface 6 and the stage for driving the un-winding and taking up devices 2, 3 after the formation of the thermally sprayed layer and moving the point on the metallic foil 1 to be thermally sprayed up to the prescribed position.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing ceramic sprayed metal foil with excellent productivity.

(Prior Art) Ceramic spraying is widely known as a method of ceramic coating. In particular, since the advent of plasma spraying, it has been used mainly to improve the wear resistance, heat resistance, surface hardness, electrical insulation, and heat insulation properties of metal products due to its excellent durability.
That is, it is widely used for surface modification.

However, when trying to form a ceramic layer on a thin metal foil using this ceramic spraying method, there is a big problem.

The principle of ceramic thermal spraying is to supply ceramic, which is a thermal spraying material, into an ultra-high temperature atmosphere such as a combustion flame of oxygen-acetylene gas or a plasma flame of argon gas, nitrogen gas, helium gas, etc., and melt it. This is because the object is collided with the surface to be thermally sprayed, cooled and solidified.

In other words, when ceramic is sprayed on metal foil under the conditions for spraying on general objects to be sprayed, such as metal plates and metal rolls,
During thermal spraying, the heat of the ceramic adhered to the metal foil in a molten state accumulates in the metal foil, and the metal foil oxidizes or melts and breaks due to the heat, making it impossible to obtain a satisfactory product.

In order to improve this, air nozzles are installed on both sides of the thermal spray gun, which is commonly used in ceramic thermal spraying.
One possible method is to perform thermal spraying while blowing cooling air onto the surface to be thermally sprayed, but even if this method is used, discoloration or breakage of the metal foil during thermal spraying cannot be prevented.

As a result of various studies, it has been found that the only way to obtain defect-free ceramic thermal sprayed metal foil using conventional techniques is to adjust the thermal spraying conditions in a way that reduces the thermal influence on the metal foil.

That is, the output of the thermal spray gun must be kept low, and the amount of ceramic sprayed per unit time must be extremely small.

(Problems to be Solved by the Invention) However, although a good ceramic sprayed metal foil can be obtained according to the above method, there are major problems with this method.

In other words, the output of the thermal spray gun is lowered to reduce the thermal effect on the metal foil, and the amount of ceramic sprayed per unit time is extremely small, resulting in extremely low productivity.

To explain further, the amount of ceramic sprayed per unit time is approximately directly proportional to the deposition rate of the ceramic layer. Therefore, reducing the amount of thermal spraying to an extremely low level results in extremely low productivity. Furthermore, when the output of the thermal spray gun is lowered, the temperature of the flame that melts the ceramic becomes lower, making it difficult to melt the ceramic. Therefore, even if the amount of ceramic supplied to the thermal spray gun is the same, if the output of the thermal spray gun is low, the ceramic will not be completely melted, and the melted material will also adhere to the object to be sprayed due to the low temperature. To<
<, the adhesion efficiency becomes low.

For these reasons, using conventional techniques to form a ceramic layer by thermally spraying ceramic onto metal foil has extremely low productivity, and compared to thermally spraying thick materials such as metal plates, the thermal spraying process is It takes about 10 to 20 times as much time, so mass production cannot be expected.

The present invention aims to improve the above-mentioned drawbacks and provide a highly productive method for manufacturing ceramic sprayed metal foil.

(Means for Solving the Problems) That is, the present invention provides a method for forming a ceramic sprayed layer on a metal foil between the unwinding side and the winding side of a device that unwinds the metal foil from one side and winds it onto the other side. The unwinding and winding device is stopped, the metal foil is held still, and both ends of the area to be thermally sprayed are fixed, and water is jetted out from multiple water shower nozzles that were previously installed below the metal foil. A step of spraying the sprayed surface of the metal foil while cooling it by bringing water into contact with the back surface of the sprayed surface to form a predetermined ceramic sprayed layer, and after forming the ceramic sprayed layer, an unwinding/winding device is used. This method is characterized by repeating the steps of driving the metal foil and then moving the spot on the metal foil to be sprayed to a predetermined position.

In conventional techniques, the most common method for cooling the object to be thermally sprayed is to inject compressed air from an air nozzle attached to a thermal spray gun onto the surface to be thermally sprayed. However, with this method, when spraying onto thin metal foil, the metal foil has a smaller heat capacity than the bulk material that is generally the subject of thermal spraying, so the amount of heat applied to the metal foil during thermal spraying is small. The generated heat tends to accumulate in the metal foil, and the metal foil tends to discolor or break due to the heat. Therefore, a more effective cooling method is required to thermally spray ceramic onto metal foil efficiently and without causing discoloration or breakage.

Therefore, the inventors of the present invention have investigated various effective cooling methods, and have found a method in which cooling water is sprayed onto the back surface of the metal foil in a shower form from a water spray nozzle provided below, and then thermally sprayed while cooling the metal foil. It has proven to be effective.

In this way, the water sprayed out in a shower from the water spray nozzle hits the back side of the metal foil.

It quickly removes the heat transferred to the metal foil during thermal spraying. This can prevent overheating of the metal foil during thermal spraying.

Although various methods can be considered for cooling the back surface of the metal foil with water, the use of a water spray nozzle in the present invention has the following advantages. That is, the water ejected from the water spray nozzle has a shower-like shape, and spreads in all directions as small droplets, making it possible to evenly wet the back surface of the metal foil with a small amount of water. In addition, since fresh cold water is always applied to the back side of the metal foil, a constant cooling capacity can be maintained at all times.

It is very important to cool the back side of the metal foil to be thermally sprayed thoroughly and evenly; for example, if there are areas that are not in contact with water, defects such as discoloration will occur during thermal spraying. I end up. Therefore, in order to perform thermal spraying efficiently, a plurality of spray nozzles are required, and it is necessary to cool a wide area.

In addition, in the present invention, ceramic spraying on metal foil is
A method is adopted in which the metal foil is unrolled from one side and then wound on the other side. This method is different from the conventional batch method in which the metal foil is cut, the metal foil is attached to a jig, and then thermal spraying is applied. It is highly productive because it forms layers. However, in this method of thermal spraying while unwinding the metal foil from one side and winding it up to the other, conventionally the metal foil was moved from the unwinding device to the winding device even during thermal spraying. Therefore, it was difficult to fix both ends of the metal foil on the surface to be thermally sprayed. Therefore, the metal foil sprayed with °C1 had wrinkles due to deformation due to the difference in thermal shrinkage between the ceramic and the metal foil during thermal spraying.

Therefore, in the present invention, the formation of a ceramic sprayed layer on the metal foil between the unwinding side and the winding side of the device that unwinds the metal foil from one side and winds it to the other side is performed by temporarily stopping the unwinding/winding device. By keeping the metal foil stationary and fixing both ends of the sprayed area, it was possible to prevent the ceramic sprayed copper foil from deforming due to the difference in thermal contraction between the ceramic and the metal foil during thermal spraying.

That is, according to the method of the present invention, it is possible to obtain a good ceramic sprayed metal foil without wrinkles while maintaining the high productivity of the method in which thermal spraying is performed while the metal foil is unrolled from one side and wound on the other side.

Here, to fix both ends of the metal foil at the location to be thermally sprayed, a method can be used in which both ends of the τ metal foil are sandwiched and fixed from below using an air cylinder, a hydraulic cylinder, or the like. or
A suction device 4 as shown in FIG. 2 is installed so that the opening surface 11 of the suction device is in contact with both ends of the metal foil at the location to be thermally sprayed, and the air inside the opening 11 is vacuum-sucked to remove the metal. A method of fixing the foil end by adsorbing it to the opening surface 11 can be applied.

Note that the metal foil used in the present invention includes copper foil, nickel foil,
Examples include commonly used metal foils such as aluminum foil, zinc foil, silver foil, stainless steel foil, and invar alloy, alloys thereof, and clad foils. Among them, copper foil is the easiest to use as one circuit layer when ceramic sprayed steel foil is used as a printed wiring board, is very useful, and is particularly suitable.

Alumina is also used as a solvent ceramic.

Ceramics such as titania, zirconia, calcia, magnesia, barium titanate, chromia, mullite, spinel, and cordierite can be used. Among them, there are 11. Alumina, which has a proven track record in a certain number of girders and has good thermal sprayability, is suitable.

(Function) With conventional technology, defects such as discoloration and melting are likely to occur in Kingi leaf due to the thermal effects during thermal spraying.To prevent this, the output of the thermal spray gun must be kept as low as possible, and the The amount of thermal spraying had to be extremely small. For this reason, mass productivity was extremely low, and the yield, ie, the efficiency of adhering ceramic to metal foil, was also low.

However, according to the method of the present invention, the back side of the metal foil to be thermally sprayed is constantly cooled by contact with the water jetted from the spray nozzle installed below, so the heat transferred to the metal foil during thermal spraying is quickly absorbed. It is transmitted to water and can prevent overheating of the metal foil during thermal spraying. This makes it possible to perform high-output, large-volume thermal spraying similar to the thermal spraying on general bulk materials, which was previously impossible, and significantly improves mass productivity and yield.

Furthermore, the present invention has excellent productivity because the thermal spraying onto the metal foil is performed between the metal foil unwinding device and the winding device.

Additionally, during thermal spraying, the unwinding and winding device is temporarily stopped, the metal foil is held still, and the edges of the area to be thermally sprayed are fixed, making it possible to prevent deformation caused by the difference in thermal contraction between the ceramic and the metal foil. Therefore, a good ceramic sprayed copper foil can be obtained.

(Example) An example of the present invention will be described based on FIGS. 1 and 2. A roll-shaped copper foil 1 having a width of 540 mm and a thickness of 18 μm was unwound from an unwinding device 2 and attached to a winding device 3 so as to be wound up. The unwinding device 2 and the winding device 3 are stopped to make the copper foil 1 stand still, and the suction device 4 installed under the copper foil 1 attracts and fixes the copper foil 1 to the opening 11 of the suction device 4. The external appearance of the suction device 4 is shown in FIG. The suction device 4 has an opening 11 on the surface that contacts the copper foil 1, that is, the upper surface, and the opening 11 is shaped to surround the back surface of the sprayed surface 6 of the copper foil 1.

This suction device 4 is connected to a vacuum pump (not shown) using a hose 12.
It has a structure in which the end portion of the copper foil 1 is attracted to the opening 11 by suctioning the air in the frontage 11 . A plurality of water spray nozzles 5 are installed below the sprayed surface 6 of the copper foil 1, that is, inside the suction device 4, on the back side of the copper foil with both ends of the sprayed surface 6 fixed in this manner.
The copper foil 1 was cooled by spraying water in the form of a shower. 100 water spray nozzles 5 were installed in order to uniformly cool the back surface of the surface 6 to be thermally sprayed. In this way, water was applied to the back of the surface to be thermally sprayed 6 to cool it, and then an alumina thermal spray layer was formed on the surface to be thermally sprayed 6 to a thickness of 100 μm using a plasma spray gun 7. The output of the plasma spray gun at this time was a spraying current of 900 A, which is equivalent to or higher than the conditions used when spraying general bulk materials, which could not be applied to metal foil.
, the alumina supply Ik was 50 g/mtn.

After completing the alumina spraying on one sprayed surface 6 in this way, the fixation of the end of the sprayed surface 6 is released, the unwinding device 2 and the winding device 3 are driven, and ν+ylF+
It was moved at the middle pick position.

The above steps were repeated and thermal spraying was performed on the roll-shaped copper foil 1 without cutting the copper foil 1.

The copper foil 1 with the alumina sprayed layer formed in this way has
Discoloration and breakage due to overheating of the copper foil 1, which was a problem in the past,
Further, no deformation or wrinkles caused by the difference in thermal shrinkage between alumina and copper foil 1 during thermal spraying occurred. That is, by cooling the back side of the thermally sprayed surface 6 of the copper foil 1 with water jetted from the water spray nozzle 5, discoloration and breakage of the copper foil 1 due to overheating are prevented, and the copper foil 1 on the thermally sprayed surface 6 is cooled. By adsorbing and fixing the end portion to the opening 11 of the suction device 4, it was also possible to prevent deformation and wrinkles caused by the difference in thermal contraction between the alumina and the copper foil 1 during thermal spraying.

As a result, it was found that the time required to form a 100 μm thick alumina sprayed layer on the sprayed surface 6 with a size of 540 mm square was reduced by using the conventional IF 00 medium + 300 mm metering method to prevent discoloration. Compared to Aritsuji et al., which had a nmln or more, the method of the present invention had a value of 5mIn, which was less than 1/10 of that, making it possible to significantly improve mass productivity. Furthermore, the method of the present invention does not require cutting the rolled copper foil 1.

It is very efficient because the copper foil 1 can be thermally sprayed during unwinding and winding.

(Effects of the Invention) As described above, the method of the present invention, that is, the formation of a ceramic sprayed layer on a metal foil between the unwinding and winding sides of a device that unwinds the metal foil from one side and winds it to the other side. The unwinding/winding device is stopped once, the metal foil is held still, both ends of the metal foil in the area to be thermally sprayed are fixed, and water is jetted out from multiple water shower nozzles installed below the metal foil to coat the metal foil. A step of spraying the sprayed surface of the metal foil while cooling it by bringing water into contact with the back surface of the foil to form a predetermined ceramic sprayed layer, and an unwinding/winding device after forming the ceramic sprayed layer. If a method for thermal spraying ceramic onto metal foil is used, which is characterized in that the process is repeated 4 degrees with the first step of moving the spot on the metal foil to a predetermined position, Discoloration or breakage due to overheating of the foil,
Furthermore, while preventing deformation and wrinkles that occur due to the difference in thermal contraction between ceramic and metal foil during thermal spraying, it is possible to thermal spray with a thermal spray output equal to or higher than that when thermal spraying on general bulk materials, making metal foil excellent for mass production. Ceramic spraying is possible.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing alumina thermal spraying on copper foil according to an embodiment of the present invention, and FIG. 2 is a perspective view of a suction device of the present invention. Explanation of symbols 2... Unwinding device 4... Suction device 6... Surface to be sprayed 1... Copper foil 3... Winding device 5... Water spray nozzle 7... Plasma spray gun 11... Opening 12... Hose

Claims (4)

[Claims] 1. To form a ceramic sprayed layer on the metal foil between the unwinding and winding sides of the device that unwinds the metal foil from one side and winds it to the other, the unwinding and winding device is stopped, the metal foil is stopped, and the metal foil is stopped. Both ends of the metal foil in the thermal spraying section are fixed, and water is jetted out from a plurality of shower nozzles installed below the metal foil to bring the water into contact with the back surface of the surface to be thermally sprayed of the metal foil. The process of thermal spraying to form a predetermined ceramic sprayed layer, and the process of unwinding and after forming the ceramic sprayed layer.
A method for thermally spraying ceramic onto metal foil, characterized in that the process is repeated by driving a winding device and then moving the area on the metal foil to be thermally sprayed to a predetermined position. 2. 2. The method for thermally spraying ceramic onto metal foil according to claim 1, wherein both ends of the metal foil of the thermally sprayed portion are fixed by adsorbing both ends of the metal foil to an opening of a suction device having a suction function. 3. The method of thermal spraying ceramic onto metal foil according to claim 1, wherein the metal foil is copper foil. 4. 2. The method for spraying ceramic onto metal foil according to claim 1, wherein the ceramic to be sprayed has alumina as a main component.