Film forming apparatus and film forming method

Abstract

To provide a device and a method capable of forming a smooth film.SOLUTION: This film forming device comprises: an electrode member for forming a film on the surface of a conductive workpiece; a laser irradiation mechanism for smoothing the formed film; and a gas jet mechanism for jetting out an inactive gas to the surface of the workpiece. The electrode member can be charged to a prescribed potential so as to be melted by spark discharge occurring when the electrode member is brought close to the workpiece. The laser irradiation mechanism can irradiate the film formed by the electrode member with a laser in the atmosphere of the jetted inactive gas. The film forming method comprises a film forming step of melting and layering the electrode member through the spark discharge occurring when the electrode member charged to the prescribed potential is brought close to the surface of the workpiece to form a film in the workpiece, and a film smoothing step of irradiating the formed film with the laser to smooth the film in the atmosphere of the inactive gas.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a film forming apparatus and a film forming method. [Background technology]

[0002] Background art in this technical field is found in Japanese Patent Publication No. 2939083 (Patent Document 1), which describes "a build-up repair device for metal members that can significantly reduce the labor and cost of repairs." [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication Patent No. 2939083 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a risk that a smooth film may not be easily formed. [Means for solving the problem]

[0005] In order to solve the above problems, the present application employs the configurations described in the claims, for example. The present application includes a plurality of means for solving the above problems, and examples thereof are as follows.

[0006] an electrode member for forming a film on the surface of a conductive workpiece; a laser irradiation mechanism for smoothing the formed film; a gas ejection mechanism that ejects an inert gas onto the surface of the workpiece; the electrode member can be charged to a predetermined potential so that the electrode member melts due to spark discharge that occurs when the electrode member is brought close to the workpiece; the laser irradiation mechanism is capable of irradiating the film formed by the electrode member with a laser in the atmosphere of the ejected inert gas. Film forming device.

[0007] a film forming process in which an electrode member charged to a predetermined potential is brought close to the surface of a workpiece, causing a spark discharge to occur, thereby melting and laminating the electrode member to form a film on the workpiece; a film smoothing step of smoothing the formed film by irradiating the film with a laser in an inert gas atmosphere, Film formation method. [Effects of the Invention]

[0008] According to the present invention, an apparatus and method that can easily form a smooth film can be provided. Problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of a film forming apparatus. [Figure 2] FIG. 10 is a diagram showing a waveform illustrating the change in intensity of a pulsed laser over time when the laser to be irradiated is a pulsed laser. [Figure 3] FIG. 1 is a schematic diagram of a film forming apparatus (first embodiment). [Figure 4] FIG. 2 is a schematic diagram of a film forming apparatus (a modified example of the first embodiment). [Figure 5] FIG. 1 is a schematic diagram of a film forming apparatus (second embodiment). DETAILED DESCRIPTION OF THE INVENTION

[0010] The outline of the film forming apparatus will be explained with reference to FIG. The film forming apparatus 1 is an apparatus for forming a smooth film on the surface of a conductive target member (hereinafter, sometimes referred to as a workpiece W). The workpiece W may be any conductive material, but may also be, for example, a mold whose main component is iron, used for resin injection molding or aluminum die casting.

[0011] The film forming apparatus 1 includes at least an electrode member 2, a laser irradiation mechanism 3, and a gas ejection mechanism 4. The electrode member 2 is a member for forming a film C1 on the surface of the conductive workpiece W. The laser irradiation mechanism 3 is a mechanism for smoothing the film C1 formed by the electrode member 2. The gas ejection mechanism 4 is a mechanism for ejecting the inert gas G onto the surface of the workpiece W.

[0012] The electrode member 2 is a member for forming a film C1 on the surface of the conductive workpiece W, in other words, a member for supplying a material for the film C1 to be formed on the surface of the workpiece W. The material of the electrode member 2 may be any metal, but the electrode member 2 in the embodiment of this specification is mainly composed of tungsten carbide (WC). The electrode member 2 is a long (rod-shaped) member.

[0013] The electrode member 2 can be charged to a predetermined potential so that the electrode member 2 melts due to spark discharge that occurs when the electrode member 2 is brought close to the workpiece W. That is, the electrode member 2 is connected to a pulse power supply that generates a pulse voltage, and when the electrode member 2 to which a pulse voltage of 20 to 1000 Hz has been applied is brought close to the surface of the workpiece W, a spark discharge occurs between the two, and the electrode member 2 melts due to the spark discharge and is layered on the surface of the conductive workpiece W.

[0014] The electrode member 2 melts due to the heat of the spark discharge and becomes positively charged, and is attracted to the surface of the workpiece W, which is at earth potential, and collides with the surface of the workpiece W, forming an electrode member layer (film C1) with the electrode member molecules. The electrode member 2 is configured to be rotatable, and the rotation of the electrode member 2 can prevent the tip of the electrode member 2 from fusing to the surface of the workpiece W.

[0015] The laser irradiation mechanism 3 is a mechanism for smoothing the film C1 formed by the electrode member 2. The laser irradiation mechanism 3 is capable of irradiating a laser L onto a film C1 formed on the surface of the workpiece W in an atmosphere of the ejected inert gas G. By irradiating the formed film C1 with the laser L, the film C1 can be melted and smoothed.

[0016] The laser L to be irradiated is not particularly limited, and may be a solid-state laser such as a YAG (yttrium aluminum garnet) laser, a gas laser such as a carbon dioxide laser, a liquid laser such as a dye laser, a semiconductor laser, or a fiber laser. These may be used alone or in combination of two or more. The oscillation mode is also not limited, and may be continuous oscillation or pulse oscillation. The wavelength of the oscillated laser is also not limited, but is usually 100 to 10,800 nm.

[0017] The gas ejection mechanism 4 is a mechanism for ejecting the inert gas G onto the surface of the workpiece W. The inert gas G is a gas that is unlikely to undergo chemical reactions, such as argon gas or nitrogen gas. In the embodiment of this specification, the inert gas G is argon gas. By covering the film formed by melting with inert gas G, oxidation of the film can be prevented.

[0018] A film formation method for forming a smooth film will be described below. First, an electrode member 2 to which a pulse voltage is applied is brought close to the surface of the workpiece W, causing a spark discharge to melt and laminate the electrode member 2, thereby forming a film C1 on the surface of the workpiece W (film formation process). The film C1 can be formed in a desired area by moving the electrode member 2 while the electrode member 2 is in close proximity to the workpiece W. Fig. 1 shows the state in which the electrode member 2 is moved to the right and the film C1 is formed. The surface of the film C1 formed by the electrode member 2 is rough, and the distribution of the components of the workpiece W and the electrode member 2 is uneven.

[0019] Next, an inert gas G is ejected toward the formed film C1 by a gas ejection mechanism 4, and a laser L is irradiated onto the film C1 by a laser irradiation mechanism 3 in the atmosphere of the ejected inert gas G to smooth the film C1 (film smoothing step). In the figure, the smoothed film C1 is referred to as film C2. This step makes it possible to smooth the surface of the film C1 formed by the electrode member 2, and also makes it possible to make the distribution of the components of the workpiece W and the electrode member 2 uniform.

[0020] The film C1 can be smoothed over a desired area by moving the gas ejection mechanism 4 and the laser irradiation mechanism 3. Fig. 1 shows a state in which the film C1 has been smoothed by moving the gas ejection mechanism 4 and the laser irradiation mechanism 3 to the right following the electrode member 2.

[0021] As another example, instead of moving the laser irradiation mechanism 3 following the electrode member 2 as in the example shown in Figure 1, after the entire film to be formed is formed by the electrode member 2, the film may be smoothed by the laser irradiation mechanism 3.

[0022] In the film smoothing step, when the laser to be irradiated is a pulsed laser, the waveform showing the change in intensity of the pulsed laser over time may be controlled to a predetermined waveform WF by a laser control mechanism. FIG. 2 illustrates the waveform WF. 2, the horizontal axis represents the elapsed time (ms) and the vertical axis represents the intensity (%). The intensity (%) represents the output ratio of the pulsed laser that the laser irradiation mechanism 3 can output within a given time. The waveform WF includes a first intensity peak value P1 and a second intensity peak value P2.

[0023] The first intensity peak value P1 is the main peak for melting the film C1. The waveform WF has a preheating period T1 during which the intensity is gradually increased until it reaches the first intensity peak value P1, in order to prevent defects from occurring in the film C1 due to rapid heating. After reaching the first intensity peak value P1, the waveform WF has a first post-heating period T2 in which the intensity is gradually reduced in order to prevent defects from occurring in the film C2 due to rapid cooling. The waveform WF has a second post-heating period T3 after the first post-heating period T2, in which the strength is kept constant in order to prevent defects from occurring in the film C2 due to rapid cooling.

[0024] The second intensity peak value P2 is a peak that occurs later in time than the first intensity peak value P1 (the intensity increases after the second after-heating period T3) and has an intensity equal to or lower than the first intensity peak value. The second intensity peak value P2 is for preheating the film C1 to be irradiated with the next shot of the pulsed laser. When moving the pulsed laser, it is preferable to set the overlap rate, which is the rate at which one shot and the next shot overlap, to 50% or more, and more specifically, it may be 75%.

[0025] The waveform WF in FIG. 2 is a waveform for a pulsed YAG laser (wavelength 1064 nm, average output 200 W), but may be for other types of pulsed lasers.

[0026] In the film smoothing step, when the laser L to be irradiated is a pulsed laser, the pulsed laser is defocused and irradiated by a laser control mechanism capable of controlling the defocus amount of the pulsed laser. Defocusing here refers to a state in which the focal point of the pulsed laser is moved away from the surface of the workpiece W, based on a state in which the focal point is positioned on the surface of the workpiece W (surface of the film C1).

[0027] By defocusing and irradiating the pulsed laser, it is possible to irradiate a relatively wide area with a laser of uniform intensity, which prevents defects from occurring in the film C1 due to localized concentrated irradiation of a high-intensity laser and shortens the work time (laser movement time). However, if the defocus amount is too large, the laser intensity decreases and the film C1 cannot be melted, so it is preferable to defocus the laser to an extent that a predetermined laser intensity can be maintained.

[0028] In the film smoothing step, the laser L to be irradiated may be a continuous wave laser, and in particular, a semiconductor laser capable of irradiating a relatively wide area with a laser beam of uniform intensity is preferred. By using a continuous wave semiconductor laser, the film C1 can be efficiently smoothed.

[0029] A smooth film can be easily formed by using the film forming apparatus 1 having the above-described configuration and the above-described film forming method. In particular, when the workpiece W is a mold used for resin injection molding or aluminum die casting, by easily forming a smooth film on-site, it is possible to create added value by extending the life of the mold through preventive maintenance and imparting high functionality.

[0030] Since the laser irradiation in the film smoothing process (smoothing of the film in the final process) is performed in an inert gas atmosphere, the film formation using the electrode member 2 in the film formation process does not have to be performed in an inert gas atmosphere, but it goes without saying that the film formation process may also be performed in an inert gas atmosphere.

[0031] In the film forming apparatus 1, the electrode member 2, the laser irradiation mechanism 3, and the gas ejection mechanism 4 may each be separate (structurally separated) or may be integrated (structurally connected).

[0032] FIG. 3 shows a film forming apparatus 1 (first embodiment) in which an electrode member 2, a laser irradiation mechanism 3, and a gas ejection mechanism 4 are integrated. The film forming apparatus 1 has a main body member B. The main body member B has a grip portion B1 that allows a user of the film forming apparatus 1 to grip the film forming apparatus 1. The main body member B has an electrode member holding portion B2 that holds the electrode member 2. The main body member B constitutes a part of the laser irradiation mechanism 3, and has a laser irradiation section B3 that irradiates a laser. The main body member B constitutes a part of the gas ejection mechanism 4, and has a gas ejection part B4 that ejects an inert gas. The laser irradiation part B3 and the gas ejection part B4 are positioned on the same axis.

[0033] The electrode member 2 is configured so as not to be positioned in the direction of travel of the laser irradiated from the laser irradiation unit B3. Also, the tip of the electrode member 2 that comes into contact with the workpiece W is configured to be positioned away from the irradiated laser. In the first embodiment (FIG. 3), the irradiated laser is located on the left side, and the tip of the electrode member 2 is located on the right side, with each being shifted in the left-right direction. The user can grasp the main body member B of the film forming device 1 and move the film forming device 1 to the right (in the x-axis direction of Figure 3), thereby forming a film C1 on the workpiece W using the electrode member 2 (performing the film formation process), and then smoothing the film C1 using a laser (performing the film smoothing process).

[0034] FIG. 4 illustrates a modified example of the film forming apparatus 1 of the first embodiment described above. The gas ejection mechanism 4 of the film forming apparatus 1 shown in FIG. The gas ejection nozzle 41 is connected to the main body member B. The gas ejection nozzle 41 includes a gas ejection portion 41A that ejects an inert gas. Gas ejection nozzle 41 is a movable member that can move gas ejection part 41A to any position, and is configured so that gas ejection part 41A can be held at the moved position.

[0035] FIG. 5 shows a film forming apparatus 1 (second embodiment) in which an electrode member 2, a laser irradiation mechanism 3, and a gas ejection mechanism 4 are integrated. 5 includes two laser irradiation units B31 and B32, and an electrode member 2 is positioned between the two laser irradiation units B31 and B32. Gas ejection units B41 and B42 are positioned coaxially with the laser irradiation units B31 and B32, respectively.

[0036] As in the first embodiment, the electrode member 2 is configured so as not to be positioned in the direction of travel of the lasers irradiated from the laser irradiation units B31 and B32. Also, the tip of the electrode member 2 that comes into contact with the workpiece W is configured to be positioned away from the irradiated laser. In the second embodiment, the irradiated laser is located on the front side, and the tip of the electrode member 2 is located on the back side, and they are positioned offset from each other in the depth direction. The user grasps the main body member B of the film forming device 1 and moves the film forming device 1 backward (in the x-axis direction of Figure 5), thereby forming a film C1 on the workpiece W using the electrode member 2 (performing the film formation process), and then smoothing the film C1 using a laser (performing the film smoothing process).

[0037] Note that each embodiment of the film forming apparatus 1 shown in Figures 3 to 5 illustrates the operating part (head part) on which the film forming apparatus 1 operates, and the head part is connected to components necessary for operating the electrode member 2, laser irradiation mechanism 3, and gas ejection mechanism 4 described above (e.g., a power supply, a laser control mechanism, or an inert gas cylinder, etc.).

[0038] Although the present invention has been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and improvements are possible within the scope of the gist of the present invention. [Explanation of symbols]

[0039] 1: Film forming device 2: Electrode material 3: Laser irradiation mechanism 4: Gas ejection mechanism C1: Membrane C2: (smoothed) film G: Inert gas L: Laser P1: First intensity peak value P2: Second intensity peak value W: Work WF: waveform

Claims

1. an electrode member for forming a film on the surface of a conductive workpiece; a laser irradiation mechanism for smoothing the formed film; a gas ejection mechanism that ejects an inert gas onto the surface of the workpiece; The electrode member is brought close to the workpiece and a spark discharge occurs, causing the electrode member to emit a spark. The electrode member is chargeable to a predetermined potential so as to melt; The laser irradiation mechanism is configured to irradiate the electrode portion in the atmosphere of the ejected inert gas. A laser can be irradiated onto the film formed of the material, the laser that can be irradiated by the laser irradiation mechanism is a pulsed laser, a laser control mechanism capable of controlling a waveform showing a change in intensity of the pulsed laser over time; The laser control mechanism a first intensity peak value; A peak that appears later in time than the first intensity peak value and is equal to or greater than the first intensity peak value and a second intensity peak value below the first intensity peak value. Film forming device.

2. The electrode material is charged to a specific potential and brought close to the surface of the workpiece, causing a spark discharge. a film forming step of melting and laminating the electrode member to form a film on the workpiece; In an inert gas atmosphere, the formed film is irradiated with a laser to smooth the film. and a film smoothing step of: The laser irradiated in the film smoothing step is a pulsed laser, The waveform showing the change in intensity over time in the pulsed laser is a first intensity peak value; a second peak intensity value that peaks later in time than the first peak intensity value and is equal to or less than the first peak intensity value, Film formation method.

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