JP5066797B2 - A film forming method and a method for producing a film forming work. - Google Patents

Description

  The present invention provides a metal powder, a powder of a metal compound, or a powder molded body obtained by molding a ceramic powder, or the heat-treated powder molded body, as an electrode, and between the electrode and the workpiece in a working fluid or a gas atmosphere. A method for forming a discharge surface treatment film and a method for producing a film-formed workpiece, in which a pulsed discharge is generated and an electrode material or a material obtained by reacting the electrode material with the pulsed discharge energy on the workpiece surface is generated by the discharge energy. It is about.

  For example, Patent Document 1 discloses a surface modification technique using electric discharge. An amorphous layer such as silicon (Si) or a fine crystal layer is formed on the surface modification target surface by discharge. Another surface modification technique is disclosed in Patent Document 2. At least one surface of a structure made of iron (Fe) based alloy, nickel (Ni) based alloy, or cobalt (Co) based alloy such as carbon steel, low alloy steel, austenitic stainless steel or ferritic stainless steel is used. An electrode having a high corrosion resistance element is used, and an electric discharge machining treatment is performed in oil or water to remove the initial surface of the member and to form an electric discharge machining alloy layer having excellent corrosion resistance on the surface. Further, the electric discharge machining alloy layer formed by this surface modification treatment method is irradiated with energy such as a laser beam, an electron beam, or a TIG arc to remelt the electric discharge machining alloy layer and a part of the member to be treated. And then rapidly solidifying to form a remelted surface alloy layer.

  In addition to the surface modification technique, techniques for forming a metal or ceramic film on the surface of the workpiece include electroless plating, electrolytic plating, PVD (Physical Vapor Deposition), thermal spraying, welding, and the like. Electroless plating is a method in which a metal is deposited on the surface of an object to be processed from an aqueous solution using a chemical reaction. Electrolytic plating is a method in which one electrode is ionized and electrons are exchanged on the other electrode to form a film on the object to be processed. PVD is a method of forming a film by ionizing a metal gas evaporated in a vacuum and striking it against a substrate to which a negative voltage is applied. These methods consist in depositing a film on the surface of the workpiece, and the adhesion between the workpiece and the film is not sufficient.

  As a film forming technique for improving the adhesion between the workpiece and the film, there is a surface treatment using electric discharge as disclosed in Patent Document 3. This discharge surface treatment is a transfer processing method in which an electrode having the same size as the film to be formed is used, and a plurality of pulse discharges are generated between the workpiece and the electrode to form the film.

JP-A-62-24916 JP-A-6-182626 International Publication WO99 / 558744

  In the prior art, an electric discharge machining alloy layer is provided on the surface of a workpiece using electric discharge, and then a part of the layer is melted by irradiation with a laser beam or an electron beam, and then remelted by rapid solidification by self-cooling. A layer was formed. When the adhesion between the EDM alloy layer and the metal to be processed is insufficient, the defects are eliminated by remelting the EDM alloy layer and a part of the metal to be processed by irradiating a laser beam or an electron beam. In addition, a remelted surface alloy layer in close contact with the metal to be processed was formed. In this prior art, a laser or an electron beam is used to diffuse ceramics or the like into the workpiece metal and expand the alloy layer. In order to improve the corrosion resistance of the surface of the workpiece metal, it is better that the alloy layer is thicker. However, when a film is formed on the workpiece and the desired performance is desired for the film, the characteristics of the alloy layer are the desired properties. Therefore, the thickness of the alloy layer of the film and the workpiece is preferably as thin as possible.

  The density of the coating by spraying or discharging in which fine particles are melted and deposited on the workpiece is generally smaller than that of a metal solid. This is because slight voids are formed in the coating. In addition, since the melted particles are laminated to form a film, there are spaces between the particles (grain boundaries) in the film. When the film receives a shearing force due to friction, the grain boundary becomes a base point, and the film wears. Moreover, the grain boundary becomes a resistance, and the thermal conductivity of the film is lowered.

  Therefore, in the present invention, after forming a thick film by using electric discharge, a film forming method for suppressing the expansion of the alloy layer and improving the density and strength of the film and reducing the grain boundaries and voids. provide.

  The film forming method according to the present invention comprises a metal powder, a powder of a metal compound, or a powder molded body obtained by molding a ceramic powder, or the heat-treated powder molded body, as an electrode in a working fluid or in a gas atmosphere. A step of generating a pulsed discharge between the electrode and the workpiece, and forming a discharge surface treatment film comprising the electrode material or a material obtained by reacting the electrode material with the pulsed discharge energy on the workpiece surface by the discharge energy; and And heating the formed discharge surface treatment film by irradiating energy.

  Furthermore, when the discharge surface treatment film is formed, a film in which the thermal conductivity of the discharge surface treatment film is 30 W / mK or less is formed.

  Furthermore, the thermal conductivity of the electrode material in a metal solid is 90 W / mK or more.

Further, Cu, Cu alloy, Ag, Ag alloy, Al, Al alloy, Ni, Ni alloy, Co, Co alloy are used as the electrode material of the powder molded body electrode.

  Furthermore, a discharge surface treatment film is formed and energy is irradiated at multiple points.

  Furthermore, when the spot of energy irradiated to the discharge surface treatment film is moved parallel to the diagonal line of the irradiation surface and reaches the boundary line between the coating part and the non-coating part, the incident angle and reflection angle from this boundary line become equal. Thus, the irradiation energy spot scanning direction is changed.

  Further, the incident angle and the reflection angle from the boundary line between the coating part and the non-coating part that determine the changing direction of the irradiation energy spot scanning are periodically made different sizes.

  Further, the discharge surface treatment coating is polished after being irradiated with energy and heated.

  The film forming method according to the present invention comprises a metal powder, a powder of a metal compound, or a powder molded body obtained by molding a ceramic powder, or the heat-treated powder molded body, as an electrode in a working fluid or in a gas atmosphere. A step of generating a pulsed discharge between the electrode and the workpiece, and forming a discharge surface treatment film comprising the electrode material or a material obtained by reacting the electrode material with the pulsed discharge energy on the workpiece surface by the discharge energy; and And applying a pressure to the formed discharge surface treatment film.

  Furthermore, when the discharge surface treatment film is formed, a film in which the thermal conductivity of the discharge surface treatment film is 30 W / mK or less is formed.

  Furthermore, the thermal conductivity of the electrode material in a metal solid is 90 W / mK or more.

  Further, Cu, Cu alloy, Ag, Ag alloy, Al, Al alloy, Ni, Ni alloy, Co, Co alloy are used as the electrode material of the powder molded body electrode.

  A method of producing a film-forming workpiece according to the present invention includes a discharge surface treatment of a powder molded body obtained by molding a metal powder, a metal compound powder, or a ceramic powder, or the heat-treated powder molded body. Discharge surface treatment coating made of a material in which the electrode material or the electrode material reacts with the pulsed discharge energy due to the discharge energy by generating a pulsed discharge between the electrode and the workpiece facing each other The discharge surface treatment film thus formed is irradiated with energy and heated.

  A method of producing a film-forming workpiece according to the present invention includes a discharge surface treatment of a powder molded body obtained by molding a metal powder, a metal compound powder, or a ceramic powder, or the heat-treated powder molded body. Discharge surface treatment coating made of a material in which the electrode material or the electrode material reacts with the pulsed discharge energy due to the discharge energy by generating a pulsed discharge between the electrode and the workpiece facing each other And a pressure is applied to the formed discharge surface treatment film.

  In the film forming method according to the present invention, a thermal spray coating is formed on a workpiece surface by thermal spraying with a reduced amount of heat for melting a metal powder, a metal compound powder, or a ceramic powder, and the formed thermal spray coating is irradiated with energy. Then, the film portion near the boundary with the workpiece surface is heated.

  In the film forming method according to the present invention, a sprayed coating is formed on the surface of the workpiece by spraying at a reduced rate at which the molten metal powder, metal compound powder, or ceramic powder collides with the workpiece, and energy is applied to the sprayed coating. Is used to heat the coating portion near the boundary with the workpiece surface.

  According to the present invention, the properties of the coating such as strength, thermal conductivity, density, and surface roughness can be improved by irradiating and heating the coating formed by the discharge surface treatment. Further, in the discharge surface treatment, the discharge current treatment and the discharge time can be controlled to form a discharge surface treatment film suitable for energy irradiation having a low thermal conductivity and a high temperature by retaining the irradiation energy in the film. If a film having a low thermal conductivity is formed by discharge surface treatment, and the film is irradiated with energy and heated, expansion of the alloy layer formed at the interface between the film and the workpiece can be suppressed.

Embodiments of a discharge surface treatment method according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a simplified configuration diagram of an apparatus for performing a film forming method according to a first embodiment of the present invention. In FIG. 1, a machining tank 5 is filled with a machining liquid 7, and a workpiece 6 and a bed 4 that supports the workpiece 6 are disposed in the machining tank 5. On the other hand, an electrode 3 is provided at the tip of the main shaft 1, and this electrode 3 is immersed in the machining liquid 7. In addition, the electrode 3 and the bed 4 are connected to a power supply 2 for discharge surface treatment. In this case, the electrode 3 is connected to the cathode of the discharge surface treatment power source 2, and the workpiece 6 is connected to the anode of the discharge surface treatment power source 2. A pulsed discharge is generated between the electrode 3 and the workpiece 6 by the voltage applied between the electrode 3 and the workpiece 6, and a discharge surface treatment film is formed on the workpiece surface.

The workpiece 6 on which the discharge surface treatment film is formed is moved to the laser processing apparatus by the workpiece moving means A. In the figure, reference numeral 9 denotes a partial reflection mirror disposed opposite to the total reflection mirror 8, and this partial reflection mirror and the total reflection mirror constitute a stable laser resonator. 10 is a laser beam generated in the laser resonator, 11a and 11b are Brewster windows that transmit only the P-polarized component of the laser beam 10 and reflect the S-polarized component, 12 is a quarter-wave plate, and 13 is a laser oscillator. This is a discharge tube. 14 is an electro-optic amplitude modulator, 15 is a pulse generator that generates a pulse voltage that is repeatedly applied to the electro-optic amplitude modulator, and 17 is a wavelength conversion element that can convert the wavelength of the laser beam 16 emitted from the laser oscillator. , 19 is a beam splitter. The laser beam reflected by the beam splitter 19 is guided to the condensing optical system 21 by the transmission optical path system 20 and is condensed on the film formed on the surface of the workpiece 6.

  By using a robot arm or the like for the workpiece moving means A, an automatic production line including a discharge surface treatment device and a laser processing device can be provided.

  The principle of discharge surface treatment for forming a film on the surface of the workpiece 6 is shown in FIG. In this figure, the electrode used is a metal, a metal compound, or a ceramic powder formed by molding several μm, or a heat-treated electrode after molding. Metals include alloys as well as simple metals. A metal compound is a compound of a metal and a nonmetal. The main shaft is servoed so that the electrode is the cathode and the workpiece is the anode, so that they do not contact each other. The space between the electrode and the workpiece is filled with the machining fluid, and electric discharge is generated between them. The workpiece and the electrode are melted and vaporized by the heat of discharge. Part of the molten electrode (molten particles) is transported toward the workpiece surface by the blast generated by vaporization. When it reaches the workpiece surface, it resolidifies and becomes a coating.

  A process for manufacturing an electrode for discharge surface treatment is shown in FIG. A metal powder or ceramic powder having an average particle size of 4 μm or less is placed in a mold and pressed by a punch. By applying a predetermined pressing pressure to the powder, the powder becomes a solid and becomes a green compact. In order to improve the transmission of the pressing pressure to the inside of the powder during pressing, the moldability can be improved by adding wax such as paraffin to the powder by about 1% to 10% by weight.

  The compression-molded green compact can be used as it is as an electrode for discharge surface treatment as long as a predetermined hardness is obtained by compression, but the strength can be increased by heating. When wax is used, the wax is removed by heating to a temperature higher than the melting point of the wax. In this way, an electrode for discharge surface treatment is obtained.

  A discharge surface treatment film is formed on the workpiece surface by discharge with the electrode produced in the above process, and heated by irradiation with energy. For heating to irradiate energy, resistance heating or radiation heating by a resistance heating element, induction heating or plasma heating or radiation heating by coil induction current, electron beam heating by electron beam, laser radiation heating by laser light, solar radiation by sunlight There are heating, arc heating by arc current, plasma heating, arc radiation heating and the like.

  A schematic diagram of energy irradiation is shown in FIG. The focus of the laser beam or electron beam is defocused so as to cover the entire discharge surface treatment film 6a, thereby expanding the irradiation range. When the focus is on the surface of the coating, the spot is scanned so that energy can be applied to the entire coating. In order to improve the characteristics of the film with the energy of a laser or an electron beam, the film does not necessarily have to be melted. This is because even if the substance does not reach the melting point, it can start diffusing at about the Debye temperature where the lattice vibration becomes intense. When the coating is heated to a temperature higher than the Debye temperature, the bond strength between the particles in the coating increases, the hardness increases, and the tensile strength also improves. Also, the thermal conductivity is improved. The Debye temperature of the metal is considerably lower than the melting point. For example, the Debye temperature of Cu (copper) is 343K and the melting point is 1358K, and the Debye temperature of Fe is 470K and the melting point is 1811K.

A Ti—Al—V alloy was used as a workpiece, and a Cu—Sn—Ni alloy film was formed thereon by discharge surface treatment. The discharge current was 8 A, the discharge time was 64 μs, the rest time was 1024 μs, and a film having an area of 10 mm × 10 mm and a film thickness of 0.4 mm was formed. The thermal conductivity of the formed film was 5 W / mK. The coating was irradiated once with a CO ₂ laser processing machine. Table 1 shows the irradiation conditions. The output was set to 3 kW, and laser light was continuously applied for 0.3 s while blowing argon gas to prevent oxidation. The focal point of the laser is at 110mm of the coating surface,
Defocused.

  FIG. 5 shows cross-sectional photographs of the coating before and after irradiation. Before irradiation, it can be seen that there are a large number of voids inside the coating, and the thermal conductivity and strength are low. On the other hand, after laser irradiation, voids are reduced and a dense film can be formed. The Vickers hardness of the film before irradiation was 50 HV, but after irradiation, it was improved to 250 HV, which is equivalent to the Vickers hardness of the metal solid of the Cu—Sn—Ni alloy. Further, the density of the film, which was 6 g / cm 3 before irradiation, could be improved to 8.5 g / cm 3 by irradiation. Furthermore, the thermal conductivity of the coating could be improved to 50 W / mK.

  In order to improve the properties of the coating by irradiating energy, the thermal conductivity of the discharge surface treatment coating needs to be 30 W / mK or less. This is because when the thermal conductivity of the coating increases, even if the coating absorbs the energy of the laser beam or electron beam, it is quickly conducted to the workpiece and the coating does not reach a high temperature above the Debye temperature. Further, when a film having a thermal conductivity higher than this is formed, a large discharge energy is used, and the workpiece is removed or deformed, resulting in the same problem as in conventional welding.

  The coating stores the absorbed energy inside the coating, and when the temperature becomes high, diffusion bonding between particles inside the coating can be promoted. In order to improve the film characteristics using laser light or an electron beam, the thermal conductivity of the discharge surface treatment film must be reduced. If the thermal conductivity of the coating is high, energy such as laser light or electron beam is transmitted to the workpiece, diffusion proceeds at the interface between the coating and the workpiece, the alloy layer where the coating and workpiece are mixed increases, Or generate. Since this alloy layer differs from the desired film properties, it should be as small as possible. The lower limit of the thermal conductivity of the coating is about 0.1 W / mK. If the temperature is lower than this, the temperature rises too much to evaporate, and the latent heat of evaporation takes heat away and the coating cannot be melted. Considering the speed of heat conduction to the workpiece and the influence of the workpiece, the thermal conductivity of the coating is preferably 1 W / mK or more and 8 W / mK or less.

  A method for forming a film having a low thermal conductivity by discharge surface treatment will be described. In the discharge surface treatment, a small discharge is repeatedly generated as described above, and a film is formed by stacking small bulges (projections). When the discharge current is increased or the discharge time is increased, the protrusion formed by one discharge becomes larger. As the protrusions increase, the space formed between the protrusions also increases. That is, the film has many voids. A film with many voids has a low thermal conductivity.

  The electrode material that becomes the coating film is more likely to form voids as the thermal conductivity in the metal solid state before electrode production is larger. In the discharge surface treatment, a discharge is generated on the formed film, and a film is further deposited. The heat of the discharge is also transmitted to the deposited film, strengthening the bonding between the particles forming the film, or melting to fill the voids and re-solidify. When the thermal conductivity of the metal solid is large, the heat of discharge can be transferred to the workpiece even if the area of the joint between the particles is small, and the voids in the coating are not filled. This phenomenon becomes prominent when the thermal conductivity of the metal solid is 90 W / mK or more, and particularly preferably 100 W / mK or more. Examples of the material having a thermal conductivity of 90 W / mK or higher include Al (aluminum), Cu (copper), Ag (silver), Ni (nickel), Co (cobalt), and alloys thereof.

  According to the present embodiment, energy can be applied to the discharge surface treatment coating to improve the coating properties such as strength, thermal conductivity, and density. Further, in the discharge surface treatment, it is possible to control the discharge current and the discharge time so that the irradiated energy stays in the film, and the temperature becomes high, and the film having a low thermal conductivity and suitable for energy irradiation can be formed. If a film having a low thermal conductivity is formed by discharge and energy is applied to the film, expansion of the alloy layer formed at the interface between the film and the workpiece can be suppressed.

  In Example 1, the characteristics of the coating were improved by irradiating the laser beam of 3 kW once. When the area of the coating is large, it is necessary to irradiate the coating several times by moving the irradiation position of the laser beam. When a large amount of energy is applied to a film having improved properties such as thermal conductivity and strength, the work is damaged, and the alloy layer in which the film and the work are mixed becomes large or an intermetallic compound is generated. When processing an area larger than the spot size with a laser beam or an electron beam, it is necessary to improve the characteristics of the coating little by little from the surface with a small energy. Even if the film is not larger than the energy spot size, the same can be said when the film thickness is thick.

  An attempt was made to improve the properties of the coating by irradiating a 20 mm × 20 mm coating with laser light. Since the laser spot size is about φ10 mm, the laser beam was irradiated at the apex of a 10 mm × 10 mm square contained in the coating. The number of irradiations at each vertex is five. Table 2 shows the laser light irradiation conditions. Laser light was irradiated at a frequency of 10 Hz and a duty of 50% for 0.1 s. That is, the irradiation time of one laser beam is 0.05 s. The material of the film irradiated with laser light is a Cu—Ni alloy, and the film formed by the discharge surface treatment has a thermal conductivity of 12 W / mK. The hardness of the film before laser irradiation was 100 HV, whereas the hardness of the film after laser irradiation was 300 HV. Further, the thermal conductivity of the coating was improved to 80 W / mK by laser irradiation. As a result of observing the cross section of the coating, the alloy layer did not appear to expand.

  When irradiating the film with energy by changing the irradiation position, it is possible to increase the uniformity of the film by irradiating with a large spot size, as compared with irradiating with a small spot size. In general, the beam intensity of energy such as laser light is not uniform on the irradiated surface but has an intensity distribution as shown in FIG. Therefore, as shown in FIG. 7, the uniformity of the film can be increased by adjusting the overlapping portion by shifting the irradiation position according to the intensity distribution of the irradiation energy. When the coating is not a flat surface but a curved surface, it can be applied to a curved coating by reducing the spot size and finely changing the irradiation position. Further, the beam shape can be appropriately changed according to the shape of the coating. By changing the number of times of irradiation for each irradiation position, it is possible to change the characteristics for each location of the coating. Further, the laser oscillation mode can be changed to TEM00 mode oscillation, TEM01 mode oscillation, multimode oscillation, or the like depending on the application.

  According to the present embodiment, the discharge surface treatment film larger than the energy spot size can be irradiated with multiple points of energy, and the characteristics of the film such as strength, thermal conductivity and density can be improved. Further, in the discharge surface treatment, it is possible to control the discharge current and the discharge time to form a coating film suitable for energy irradiation having a low thermal conductivity that tends to cause the energy to stay in the coating film and become high temperature. If a film having a low thermal conductivity is formed by discharge and energy is applied to the film, expansion of the alloy layer formed at the interface between the film and the workpiece can be suppressed.

  In order to bond metals, there is a method of applying pressure in addition to raising the temperature. When metal is brought into contact and pressure is applied, a non-moving body film such as an oxide film on the surface is broken and the metal surface is exposed and bonded. Since the temperature hardly rises, the alloy layer at the interface between the coating and the workpiece is not enlarged, and no intermetallic compound is generated.

  A 10 mm × 10 mm Cu—Sn—Ni alloy film was formed by discharge surface treatment. The porosity of the film obtained by binarizing the cross-sectional photograph of the film was about 10%, and the thermal conductivity of the film was 20 W / mK. A load of about 10 tons was applied to the coating for 5 s. The film hardness before the pressure load was 150 HV, but after the pressure load, the film hardness was improved to 300 HV. The porosity of the coating decreased to 1%. Further, since the protrusions were crushed by applying pressure, the surface roughness was also improved.

  According to the present embodiment, pressure can be applied to the discharge surface treatment coating, and the properties of the coating such as strength, thermal conductivity, density, and surface roughness can be improved. Moreover, since no heat is applied, the alloy layer formed at the interface between the coating and the workpiece is not enlarged, and no intermetallic compound is generated.

  When the discharge surface treatment film is irradiated with energy and heated, the surface roughness of the film can be reduced. A discharge surface treatment film of TiC (titanium carbide) having a diameter of 18 mm was irradiated with an electron beam. Since the spot size of the electron beam is several μm to several tens of μm, the spot was scanned to irradiate the entire surface of the coating. The surface roughness of the coating film before irradiation with the electron beam was Ra = 3 μm, but it was lowered to Ra = 1 μm by the irradiation with the electron beam.

  According to the present embodiment, when the discharge surface treatment film is irradiated with energy and heated, the surface roughness of the film can be improved.

  In this embodiment, an example will be described in which the film formed by the discharge surface treatment is irradiated with an electron beam to improve the density and thermal conductivity of the film.

  After compressing and molding Cu—Sn—Ni powder having an average particle size of 1.5 μm, an electrode for discharge surface treatment is prepared by heat treatment, and using the electrode, a discharge current of 8 A, a discharge time of 1024 μs, and a rest time of 4096 μs. Under the conditions, a film of φ10 mm × 1.5 mm was formed. The thermal conductivity of the coating is about 2 W / mK. In order to form a coating film having a low thermal conductivity by the discharge surface treatment as described above, the discharge time is preferably set to 256 μs or more. This is because when the discharge time is longer than 256 μs, the particles forming the coating film become large and the space formed between the particles also becomes large. For this reason, the area through which heat passes is reduced, and the thermal conductivity is lowered.

  The coating was irradiated with an electron beam 5 times every 30 seconds. Table 3 shows the electron beam irradiation conditions. The spot diameter of the electron beam is about φ0.01 mm, and the spot is scanned so as to have an irradiation area of 10 mm × 10 mm. The spot is moved in parallel with the diagonal line, and when it reaches the side, it is bent so that the incident angle and the reflection angle become equal, and the reflection angle is slightly changed and moved immediately before the locus becomes a quadrangle. With this series of scanning patterns, the entire irradiation surface is irradiated with an electron beam.

  The film surface photographs before and after irradiation are shown in FIG. Although the surface is smooth before irradiation, it has no metallic luster, has many voids (bubbles) inside the coating, and has a low density and thermal conductivity. The film density before irradiation was 6.0 g / cm 3. After the electron beam irradiation, the film had a copper-colored metallic luster unique to the Cu alloy, and the film density increased to 8.2 g / cm 3. The thermal conductivity was 2 W / mK before irradiation, but increased to 35 W / mK by irradiation. Depending on the state of the film surface after irradiation, the film may be further polished.

  As described above, in order to form heat spots and advance melting, it is necessary to lower the thermal conductivity of the coating.

  Although the discharge surface treatment has been described as a method for forming a film having low thermal conductivity, the amount of heat for melting the powder even by thermal spraying is reduced, or the speed at which the powder collides with the workpiece is reduced. Thus, a similar film can be formed. Therefore, if a film formed by thermal spraying and having a low thermal conductivity is also irradiated with an electron beam or a laser, the density and thermal conductivity of the film can be improved.

  By irradiating the film formed by the discharge surface treatment with an electron beam according to this embodiment, the characteristics such as the thermal conductivity and density of the film can be improved, and heat is generated by the friction between the bearing on which the film is applied and the shaft. In such a case, the heat is scattered to the surroundings by a film having a high thermal conductivity, so that the temperature rise of the shaft and the bearing can be suppressed and seizure or the like can be prevented.

  Although several examples have been described above, the main purpose of these examples is to densify a somewhat sparse film formed by discharge surface treatment. From the viewpoint of densification of the sparse film, the original film may have the same effect other than the discharge surface treatment. For example, a coating formed by thermal spraying. The thermal spray coating is a porous coating, and densification is a major issue. The method described in the embodiment of the present invention is also effective for the thermal spray coating.

  In addition, although the material of the electric discharge surface treatment film of Examples 1-5 is a metal, it has confirmed that the same effect as the case of a metal can be acquired not only with a metal but with a metal compound or ceramics as a material. .

  Further, undulation may be formed on the surface of the coating after the discharge surface treatment coating is irradiated with energy such as laser or electron beam. In this case, the surface needs to be polished.

It is a simple block diagram of the apparatus which enforces the film-forming method of Example 1 of this invention. It is the schematic explaining the principle of discharge surface treatment. It is a flowchart which shows the concept of the manufacturing process of the electrode for discharge surface treatment. It is a schematic diagram which irradiates energy. It is a cross-sectional photograph of the coating film before and after laser light irradiation. It is a figure which shows the beam intensity distribution in a laser beam irradiation surface. It is a figure which shows the beam intensity in a laser beam irradiation duplication part. It is the film surface photograph before and after electron beam irradiation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main axis | shaft 2, Power supply for discharge surface treatment, 3 Electrode, 4 Beds, 5 Processing tank, 6 Workpieces, 7 Processing liquid, 8 Total reflection mirror, 9 Partial reflection mirror 10, 16, 18 Laser beam, 11a, 11b Brewster Window, 124 quarter wave plate, 13 discharge tube, 14 electro-optic amplitude modulator, 15 pulse generator, 17 wavelength conversion element, 19 beam splitter, 20 transmission optical path system, 21 condensing optical system.

Claims (13)

A powder molded body obtained by molding a metal powder, a metal compound powder, or a ceramic powder, or the heat-treated powder molded body, is used as an electrode, and a pulse-like shape is formed between the electrode and the workpiece in a working fluid or a gas atmosphere. Forming a discharge surface treatment film having a thermal conductivity of 30 W / mK or less, which is caused by the discharge energy and the electrode material or the electrode material reacts with the pulsed discharge energy by the discharge energy;
Irradiating the formed discharge surface treatment film with energy, and heating the discharge surface treatment film to a Debye temperature or higher and lower than a melting point;
A film forming method comprising:   2. The film forming method according to claim 1, wherein when the discharge surface treatment film is formed, a film having a lower limit of thermal conductivity of the discharge surface treatment film of 0.1 W / mK is formed.   2. The film forming method according to claim 1, wherein the electrode material has a thermal conductivity of 90 W / mK or more in a metal solid.   2. The film forming method according to claim 1, wherein Cu, Cu alloy, Ag, Ag alloy, Al, Al alloy, Ni, Ni alloy, Co, Co alloy are used as an electrode material of the powder molded body electrode.   The film forming method according to claim 1, wherein a discharge surface treatment film is formed and energy is irradiated at multiple points.   When the spot of energy irradiated to the discharge surface treatment film is moved parallel to the diagonal line of the irradiation surface and reaches the boundary line between the coating part and the non-coating part, the incident angle and reflection angle from this boundary line become equal. 5. The film forming method according to claim 1, wherein the irradiation energy spot scanning direction is changed.   5. The incident angle and the reflection angle from the boundary line between the coating part and the non-coating part that determine the direction of changing the irradiation energy spot scanning are periodically made to have different sizes. A film forming method according to claim 1.   The film forming method according to claim 1, wherein polishing is performed after the discharge surface treatment film is heated by irradiating energy. A powder molded body obtained by molding a metal powder, a metal compound powder, or a ceramic powder, or the heat-treated powder molded body, is used as an electrode, and a pulse-like shape is formed between the electrode and the workpiece in a working fluid or a gas atmosphere. Generating a discharge, and forming a discharge surface treatment film made of a substance obtained by reacting the electrode material or the electrode material with the pulsed discharge energy on the work surface by the discharge energy;
Applying pressure to the formed discharge surface treatment film without heating;
A film forming method comprising:   The film forming method according to claim 9, wherein the thermal conductivity of the electrode material in a metal solid is 90 W / mK or more.   10. The film forming method according to claim 9, wherein Cu, Cu alloy, Ag, Ag alloy, Al, Al alloy, Ni, Ni alloy, Co, Co alloy are used as an electrode material of the powder molded body electrode.   A metal powder, a powder of a metal compound, or a powder molded body obtained by molding a ceramic powder, or the heat-treated powder molded body is opposed to a work as an electrode for discharge surface treatment, and a pulse is applied between the electrode and the work. The discharge surface treatment film having a thermal conductivity of 30 W / mK or less is formed on the workpiece surface by generating a discharge in the form of an electrode material or a material obtained by reacting the electrode material with the pulsed discharge energy. A method of producing a film-forming workpiece, wherein the formed discharge surface treatment film is irradiated with energy, and the discharge surface treatment film is heated to a Debye temperature or higher and lower than a melting point.   A metal powder, a powder of a metal compound, or a powder molded body obtained by molding a ceramic powder, or the heat-treated powder molded body is opposed to a work as an electrode for discharge surface treatment, and a pulse is applied between the electrode and the work. By forming a discharge in the form of a discharge, a discharge surface treatment film made of the electrode material or a substance obtained by reacting the electrode material with the pulsed discharge energy is formed on the workpiece surface by the discharge energy, and the formed discharge surface treatment film is heated. A method of producing a film-forming workpiece, wherein pressure is applied without performing.

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