JP2009062623A - Color marking method by laser - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color marking method, by which a delicate colored pattern can be expressed at a low cost using a laser. <P>SOLUTION: The method of color marking on a metal comprises: irradiating the surface of the metal 6 with the laser 5d so as to discolor the entire or a part of the surface, and; further irradiating the resulting discolored part with the laser 5d so as to change its color into a prescribed color. The method enables formation of a high-saturation, multi-gradation, complex pattern on a metal surface by irradiating the metal surface with the laser beam twice or more. The method further enables formation of a pattern with a higher saturation by performing the first laser irradiation at a high output and performing the second and subsequent laser irradiations at the same or lower outputs. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method of forming a color pattern on a metal surface using a laser or producing an artistic pattern.

A processing method for coloring a metal surface, transparent or translucent glass, plastic, ceramics, or the like by processing characters, patterns, etc. is conventionally performed by, for example, putting a liquid such as ink into a stamped one, There are methods such as painting, printing, etching and blasting.
However, most of these methods are performed manually, and are difficult in terms of mass productivity and quality uniformity.

Further, it is known that when a heat source such as a flame or a laser is applied to the metal surface or the like, the metal surface is discolored.
For example, as described in Patent Document 1, there is a method in which a metal surface is irradiated with a laser and the irradiated surface is heat-treated in a reactive gas. However, in this method, the effect of irradiating the metal surface with the laser may be partially reduced by the heat treatment in the reactive gas.
In addition, as described in Patent Document 2, there is a method of forming a color and a pattern by irradiating a pure titanium metal surface with a laser in air containing nitrogen. However, this method has a disadvantage that it cannot express a delicate color because it simply irradiates a laser on a pure titanium metal surface.
In addition, there is a method in which titanium is deposited on the surface of the substrate, the titanium coating is oxidized, a part thereof is converted into a titanium oxide coating, and the surface is patterned by laser irradiation.

In addition, two layers of the base layer and the upper layer are applied on the substrate, and only the upper layer is sublimated with a laser and the base layer is exposed on the surface, so that only the portion irradiated with the laser has a different color (color of the base layer). There is a way to express.
However, this method has a drawback that it takes time and cost.

  In addition, there is a method of converging laser light inside glass to generate bubbles at the focal point to generate a pattern, but it is difficult to produce colors, and coloring elements such as barium strontium and copper are contained in the glass There is a method of adding color to color the inside of the glass, but there is a problem that the cost becomes high. In addition, there is a problem that there is no method for effectively producing colors on the back surface of glass or the like. There is also a problem that there is no method of emitting light from the inside of the processed material.

On the other hand, regarding the coloration of metal, the formation of an oxide film by anodic oxidation is already known. To express a certain character, pattern, etc. using such a principle, a portion other than the expression portion is a resin film. It is necessary to immerse this in an electrolyte solution and flow an electric current after masking with, for example, a problem in terms of practicality.
JP-A-6-212451 Japanese Patent Laid-Open No. 4-41662

  The present invention is intended to solve such a conventional problem, and an object of the present invention is to provide a laser color marking method capable of expressing a color pattern in detail at low cost.

  According to the present invention, a good color pattern can be obtained effectively and inexpensively by combining a laser beam, a heat treatment furnace, a gas component, and a laser processing method.

  In order to solve the problems of the prior art, in the present invention, a laser beam is irradiated from a laser processing machine onto a metal surface whose entire surface or part thereof has been discolored, and an oxide film is formed on the irradiated part. In laser color marking method that produces desired color using light interference caused by difference in refractive index with metal, laser beam oscillation output, irradiation time, number of repetitions, beam spot from laser processing machine It is characterized in that a predetermined color is developed by selecting the size, focal length, pulse frequency, etc. to predetermined values. As the wavelength of the laser beam, a carbon dioxide laser, a YAG laser, an excimer laser, a YVO4 laser, or a modulation of these lasers is used. Further, the present invention is characterized in that a desired number of colors can be developed at a time by changing the temporal and spatial intervals of irradiation with continuous or pulsed laser, irradiation intensity, or both. Such color marking can be used for color-specific characters / designs, patterns, and artistic expressions.

  In addition, a metal that has been discolored by irradiating a laser beam on a metal surface that has been discolored on the entire surface or part of it in an atmosphere of a hydrocarbon such as hydrogen, ammonia, carbon monoxide, methane, or a combination thereof It is characterized by reducing the color of the surface.

  That is, the present invention irradiates a laser on a metal surface in order to irradiate the metal surface with a laser, discolor all or part of the metal surface, and further irradiate the laser into the discolored portion to change the color. It is a metal color marking method characterized by irradiating a plurality of times more than once.

Further, after inserting and holding the metal in a heat treatment furnace maintained at a temperature higher than room temperature, and discoloring the metal surface,
In order to irradiate the metal surface with a laser, discolor all or part of the metal surface, and further irradiate the laser into the discolored portion to cause discoloration, the laser is irradiated on the metal surface two or more times. It is a metal color marking method characterized by irradiating.

Further, after inserting and holding the metal in a heat treatment furnace maintained at a temperature higher than room temperature, and discoloring the metal surface,
Laser irradiation is performed in an atmosphere of hydrogen, ammonia, hydrocarbons such as carbon monoxide, methane, or combinations thereof, and the discoloration is reduced to reduce the degree of discoloration, and a laser is further applied to the portion where the degree of discoloration is reduced. In order to change the color by irradiating, the metal color marking method is characterized by irradiating the metal surface with the laser twice or more times.

  In these metal color marking methods, when the laser is irradiated a plurality of times, a desired color is developed by the number of repetitions of the laser irradiation.

  In these metal color marking methods, when the laser is irradiated a plurality of times, the laser oscillation output, irradiation time, number of repetitions, beam spot size, focal length, pulse frequency when the laser is a pulse laser, It is characterized in that a desired color is developed by selecting each value of the wavelength and the temporal and spatial intervals of multiple times of laser irradiation.

Further, in these metal color marking methods, when laser irradiation is performed a plurality of times, the subsequent laser irradiation output is set to the same output or low output with respect to the previous laser irradiation output.
However, a single laser irradiation is not an irradiation for each pulse when the pulse is repeatedly irradiated in the continuous irradiation of the pulse laser, but from the irradiation start to the stop regardless of the continuous laser or the pulse laser. It shows one continuous irradiation.

  According to the present invention, a complex pattern can be automatically and efficiently drawn on a metal surface at low cost by irradiating a laser a plurality of times. Thereby, the added value of the product can be enhanced by various and fine colors by color marking.

  As one embodiment of the present invention, as shown in FIG. 1, the surface of a metal 6 such as iron, steel, stainless steel, nickel, chromium, titanium, aluminum, copper and alloys thereof is irradiated with a laser 5d, In this metal color marking method, the entire surface or a part of the surface is discolored, and the discolored portion is further irradiated with a laser 5d to be discolored to a predetermined color. In this method, it is possible to draw a complicated pattern with high saturation and many color gradations on the metal surface by irradiating the metal surface with the laser light two or more times. As the metal form, a plate, a foil, a block, or the like can be used. Moreover, as a metal surface form, it can be applied in a normal grinder, sand blast, grid blast finish, abrasive grains or electrolytic polishing, and mirror finish by anodization. In the method of the present invention, a pattern with higher saturation can be obtained by performing laser irradiation at a high output, the same output, or a low output after performing laser irradiation at a high output. In addition, by changing the focal length of the second and subsequent laser irradiations slightly, it becomes possible to make a rainbow color that changes color depending on the viewing direction.

  Further, as other embodiments of the present invention, metals such as iron, steel, stainless steel, nickel, chromium, titanium, aluminum, copper and alloys thereof should be 200 ° C. or higher than room temperature, preferably 300 ° C. It is inserted and held in a heat treatment furnace maintained at a high temperature of 900 ° C., and after the metal surface is discolored in monochrome and color, it is further irradiated with laser multiple times to discolor to a predetermined monochrome and color. This is a color marking method on a metal surface. By using this method, it is possible to uniformly color the background of the color marking on the metal surface by a laser. As the surface form of the metal, it can be applied in a normal grinder, sand blast, grid blast finish, abrasive grains, anodization, or mirror finish by electropolishing.

  Further, as still another embodiment of the present invention, a metal such as iron, steel, stainless steel, nickel, chromium, titanium, aluminum, copper, and an alloy thereof is desired to have a temperature higher than room temperature of 200 ° C. or higher. After being inserted and held in a furnace at 200 ° C. to 900 ° C. and uniformly discoloring the metal in monochrome and color, a gas such as hydrogen, ammonia, carbon monoxide, hydrocarbons such as methane, or a combination thereof Laser irradiation is performed in an atmosphere to reduce the color change and reduce the degree of color change. As the metal form, a plate, foil, block or the like can be used. One of the features of this embodiment is the use of a heat treatment furnace and the use of laser color reduction. As the surface form of the metal, it can be applied in a normal grinder, sand blast, grid blast finish, abrasive grains, anodization, or mirror finish by electropolishing.

  In this embodiment, the color marking method for metal further comprises changing the focal distance into the discolored portion and irradiating a laser to change the color to a predetermined color. A color on a metal surface, characterized in that after the metal surface is changed in monochrome and color in a furnace, the focal length is changed and laser irradiation is performed once or a plurality of times to change to a predetermined monochrome and color. It is a marking method. By using this method, it is possible to draw a complex pattern with many color gradations on the metal surface, and it is possible to uniformly color the background of the color marking on the metal surface by a laser.

  In each of the embodiments described above, the temporal and spatial intervals at which the pulse laser 5d is irradiated on the surface of the metal 6 such as iron, steel, stainless steel, nickel, chromium, titanium, aluminum, copper and alloys thereof. By changing the irradiation intensity or a combination thereof, it is possible to cause a continuous hue change on the metal surface.

  As an example of the present invention, for example, when # 400 polished SUS304 stainless steel is heat-treated at 800 ° C. for 2 to 5 minutes in a furnace, the surface turns blue, and only a portion irradiated by irradiating a specific portion with a laser A color different from that of the middle processing part can be developed.

  Further, after the color is uniformly darkened in the furnace, the color can be removed by laser irradiation in the air, in a hydrogen atmosphere, or in a nitrogen atmosphere.

  Further, when surface mechanical polishing, surface grinder polishing, surface electrolytic polishing, sand blasting, or shot blasting, different color tones are obtained depending on color gloss.

It is a schematic diagram which shows the color marking method to the metal etc. which concern on this invention. It is a schematic diagram which shows the method of carrying out color marking on the surfaces, such as a metal, concerning this invention.

Explanation of symbols

1 Input editing device (PC)
2 Laser Controller 3 Optical Fiber 4 Cable 5 Laser Oscillator 5a Laser Medium 5b Q Switch 5c Mirror 5d Laser Light 5e Galvano Scanner 5f fθ Lens 6 Work 8 Work Table

Claims (6)

In order to irradiate a metal surface with a laser, change the color of the whole or part of the metal surface, and further irradiate the laser within the discolored portion to change the color, the laser is irradiated on the metal surface two or more times. A metal color marking method characterized by comprising:
However, a single laser irradiation is not an irradiation for each pulse when the pulse is repeatedly irradiated in the continuous irradiation of the pulse laser, but from the irradiation start to the stop regardless of the continuous laser or the pulse laser. It shows one continuous irradiation. After inserting and holding the metal in a heat treatment furnace maintained at a temperature higher than room temperature, and discoloring the metal surface,
In order to irradiate the metal surface with a laser, discolor all or part of the metal surface, and further irradiate the laser into the discolored portion to cause discoloration, the laser is irradiated on the metal surface two or more times. A method for color marking of metal, characterized by irradiating.
However, a single laser irradiation is not an irradiation for each pulse when the pulse is repeatedly irradiated in the continuous irradiation of the pulse laser, but from the irradiation start to the stop regardless of the continuous laser or the pulse laser. It shows one continuous irradiation. After inserting and holding the metal in a heat treatment furnace maintained at a temperature higher than room temperature, and discoloring the metal surface,
Laser irradiation is performed in an atmosphere of hydrogen, ammonia, hydrocarbons such as carbon monoxide, methane, or a combination thereof, the discoloration is reduced to reduce the degree of discoloration, and a laser is further applied to the portion where the discoloration degree is reduced. In order to change the color by irradiating, a metal color marking method characterized by irradiating a laser on a metal surface two or more times.
However, a single laser irradiation is not an irradiation for each pulse when the pulse is repeatedly irradiated in the continuous irradiation of the pulse laser, but from the irradiation start to the stop regardless of the continuous laser or the pulse laser. It shows one continuous irradiation.   The metal color marking method according to any one of claims 1 to 3, wherein a desired color is developed according to the number of repetitions of the laser irradiation when the laser is irradiated a plurality of times.   When irradiating the laser multiple times, the oscillation output of the laser, irradiation time, number of repetitions, beam spot size, focal length, pulse frequency and wavelength when the laser is a pulse laser, time of multiple laser irradiations The metal color marking method according to any one of claims 1 to 3, wherein a desired color is developed by selecting each value of the spatial interval.   6. The method according to claim 1, wherein, when irradiating a plurality of times of laser, the output of the subsequent laser irradiation is set to the same output or a low output with respect to the output of the previous laser irradiation. Metal color marking method as described.

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