JP2013159828A - Electrode for electric discharge surface treatment and manufacturing method of electrode for electric discharge surface treatment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode or the like for electric discharge surface treatment having many options for material particles and capable of performing stable electric discharge.SOLUTION: An electrode for electric discharge surface treatment generates electric discharge between a treated material (18) and the electrode to form a film (20) on the surface of the treated material by the energy, and has: a material particle part (30) including material particles (14) to become a material for the film; and a conductive path part (32) continuously formed from one end part (10a), which supplies electric power, to the other end part (10b), which is to be a starting point of the electric discharge, wherein the volume resistance rate of the conductive path part is lower than that of the material particles part.

Description

  The present invention relates to a discharge surface treatment electrode used for discharge surface treatment and a method for producing the discharge surface treatment electrode.

  Electrical discharge machining and electrical discharge surface treatment have been developed as techniques for generating electrical discharge between a material to be processed and an electrode installed in an oil liquid and using the energy of the electrical discharge. Whereas it is sufficient that the electrode used for electric discharge machining can realize electric discharge machining, the electric discharge surface treatment is performed by compression-molding material particles that form a film to be formed on the material to be processed, and an electrode having voids inside. Such electrodes are required to have properties and functions different from those of electrodes used for electric discharge machining. That is, at least a part of the constituent material of the discharge surface treatment electrode needs to move to the surface of the material to be treated by the discharge energy, and the constituent material, strength (easy to break), conductivity, etc. are for electric discharge machining. This is very different from the electrode.

  As a conventional technique related to such an electrode for discharge surface treatment, for example, an electrode using a green compact obtained by press-molding a metal powder or a metal compound powder is disclosed (see Patent Document 1, etc.). The electrode for discharge surface treatment according to the prior art ensures the required strength and conductivity by pressing and molding metal powder or metal compound powder with soft metal powder such as Ag as required. It is something to try.

  In addition, as another conventional technique related to a discharge surface treatment electrode, a discharge surface treatment electrode mixed with carbon or graphite has also been proposed (see Patent Document 2, etc.). However, such an electrode for discharge surface treatment is merely a mixture of carbon powder for the purpose of increasing the amount of carbon contained in the electrode in order to increase the hardness of the hard coating formed on the material to be treated. There is no suggestion that carbon powder is used as a conductive material, and the disclosed carbon powder has poor dispersibility and may be an electrode with low electrical conductivity, and is not an aspect that can function suitably as a conductive material. In addition, when the material particles used are non-conductive, the electrical conductivity is too low, and there is a possibility that the material particles cannot be used as an electrode.

  Furthermore, as a method for evaluating an electrode for discharge surface treatment, there has been proposed a method for determining whether or not the electrode is easily collapsed and the adhesion between the material particles is appropriate by measuring the electrical resistance by a four-short needle method. (Refer to patent document 3 etc.).

Republished WO99 / 46423 Republished WO99 / 47730 JP 2009-102747 A

  The strength and conductivity of the discharge surface treatment electrode according to the prior art largely depend on the properties of the powder particles themselves, so that the usable powder particles are limited, and it is desired to move them to the surface of the material to be treated. Even if it is a material, it may be difficult to employ | adopt as a material particle used for the electrode for discharge surface treatment. In addition, since the carbon powder, material particles, and voids contained in the electrode are not uniformly dispersed in the electrode, the discharge becomes unstable and the film thickness formed on the surface of the material to be processed may become non-uniform. there were.

  In addition, evaluation of the electrode for discharge surface treatment by measuring electric resistance is effective for discriminating between good products and defective products, but does not directly reduce the occurrence of defective products in the manufacturing process. Therefore, the discharge surface treatment electrode according to the prior art has a problem that it is difficult to adopt material particles having poor conductivity and it is difficult to obtain a stable discharge.

  The present invention has been made in view of such problems, and the object thereof is to provide a discharge surface treatment electrode capable of performing stable discharge with many selections of material particles and a method for producing the discharge surface treatment electrode. It is to be.

In order to solve the above-described problems, an electrode for discharge surface treatment according to the present invention is:
An electrode for discharge surface treatment that generates a discharge between the material to be treated and forms a film on the surface of the material to be treated by its energy,
A material particle portion containing material particles to be the material of the coating;
A conductive path portion formed so as to continue from one end portion to which power is supplied to the other end portion serving as a starting point of the discharge, and having a volume resistivity lower than that of the material particle portion.

  The electrode for discharge surface treatment according to the present invention has a conductive path portion that has a volume resistivity lower than that of the material particle portion and serves as a conductive path in the electrode, in addition to the material particle portion including the material particles that become the material of the coating film. The electrode for discharge surface treatment according to the prior art was basically composed of a single layer. However, the electrode for discharge surface treatment according to the present invention has a conductive path portion, so Therefore, stable discharge can be realized. Therefore, the discharge surface treatment electrode according to the present invention can discharge even when the material particle portion has low conductivity. In addition, even when the material particles are not uniformly dispersed and a part having a high volume resistivity is formed in a part of the material particle part, a place where a reliable conductive path by the conductive path part is a starting point of discharge It is possible to suppress variation in discharge characteristics. Therefore, the discharge surface treatment electrode according to the present invention can prevent the discharge state from becoming unstable during the discharge treatment, and can implement a highly accurate discharge surface treatment.

  Further, the electrode for discharge surface treatment according to the present invention employs material particles having relatively low conductivity by the conductive path portion supplementing conductivity, or mixes particles having low conductivity inside the material particle portion. Depending on the properties of the film to be formed on the surface of the material to be treated in the discharge surface treatment, various kinds of material particles and the like can be included.

  For example, the material particle part and the conductive path part may be arranged along a direction substantially perpendicular to the current direction of the conductive path part.

  By arranging the material particle part and the conductive path part alternately along a direction substantially perpendicular to the current direction of the conductive path part, an arbitrary part in the material particle part is arranged close to the conductive path part. Therefore, the conductive path portion can suitably supplement the conductivity of the material particle portion.

  Further, for example, a plurality of the conductive path portions may be formed in a layer shape or a rod shape with the material particle portion interposed therebetween.

  Since a plurality of conductive path portions are formed in layers or rods with the material particle portion in between, any part of the material particle portion is disposed close to the conductive path portion. Therefore, the conductive path portion can suitably supplement the conductivity of the material particle portion.

Moreover, the manufacturing method of the electrode for discharge surface treatment which concerns on this invention is a manufacturing method of the electrode for discharge surface treatment which generate | occur | produces discharge between material to be processed, and forms a film on the surface of said material to be processed with the energy. There,
A step of alternately laminating a material particle layer containing material particles as a material of the coating and a conductive member layer containing a conductive member having higher conductivity than the material particles;
And sintering the laminated material particle layer and the conductive member layer.

  The discharge surface treatment electrode manufacturing method according to the present invention includes a step of alternately laminating material particle layers and conductive member layers, whereby the discharge surface treatment electrode manufactured by such a manufacturing method includes material particles. The material particle part by the layer and the conductive path part by the conductive member layer are laminated, and the conductive path part can supplement the conductivity of the material particle part. The discharge surface treatment electrode according to the prior art has a single-layer structure, and is intended to stabilize the discharge by forming the entire structure as homogeneously as possible. Therefore, a two-layer structure of a material particle layer and a conductive member layer is formed. The method for producing an electrode for discharge surface treatment according to the present invention is epoch-making. In addition, by forming a laminated structure, an arbitrary portion in the material particle layer that becomes the material particle portion after sintering is disposed in proximity to the conductive member layer that becomes the conductive path portion after sintering. The discharge surface treatment electrode manufactured by the method can realize stable discharge and film formation.

In addition, the discharge surface treatment electrode manufacturing method according to the second aspect of the present invention is for discharge surface treatment in which a discharge is generated between a material to be treated and a film is formed on the surface of the material to be treated by the energy. An electrode manufacturing method comprising:
Arranging a film-like or rod-like conductive member having a higher conductivity than the material particles as the material of the coating in a mold; and
Filling the material particles in a mold in which the conductive member is disposed;
Forming the molded body by compression molding the conductive member and the material particles;
Sintering the molded body.

  Unlike the manufacturing method according to the second aspect, the method of alternately stacking the two layers, and the manufacturing method in which the conductive member is placed in the mold in advance, the material particle portion and the conductive path portion after the sintering An electrode for discharge surface treatment having a two-layer structure can be produced.

FIG. 1 is a conceptual diagram showing an outline of surface treatment using a discharge surface treatment electrode according to an embodiment of the present invention. FIG. 2 is a conceptual diagram for explaining the structure of a discharge surface treatment electrode according to an embodiment of the present invention. FIG. 3 is a flowchart showing the method for manufacturing the electrode for discharge surface treatment according to the first embodiment of the present invention. FIG. 4 is a conceptual diagram showing an intermediate product in the method for manufacturing the electrode for discharge surface treatment according to the first embodiment of the present invention. FIG. 5 is a flowchart showing a method for manufacturing an electrode for discharge surface treatment according to the second embodiment of the present invention. FIG. 6 is a conceptual diagram showing an intermediate product in the method for manufacturing the electrode for discharge surface treatment according to the second embodiment of the present invention.

  The discharge surface treatment electrode according to an embodiment of the present invention will be described below with reference to the drawings and the like.

First Embodiment FIG. 1 is a conceptual diagram showing an outline of a discharge surface treatment using a discharge surface treatment electrode 10 according to a first embodiment of the present invention. In the discharge surface treatment, a discharge is generated between the material to be treated 18 installed in the machining liquid 16 and the discharge surface treatment electrode 10, and the hard film 20 is formed on the surface of the material to be treated 18 by the energy. The coating film 20 formed in the discharge surface treatment is formed using the electrode material of the discharge surface treatment electrode 10 that has been melted during discharge, particularly the material particles 14.

  The discharge surface treatment electrode 10 is used by being attached to an electrode attachment portion 26 that is electrically connected to a power source 24. One end portion 10a of the discharge surface treatment electrode 10 is in contact with the electrode mounting portion 26, and power from the power source 24 is supplied to the discharge surface treatment electrode 10 from the one end portion 10a. The power source 24 is also electrically connected to the material to be treated 18, controls the potential difference between the discharge surface treatment electrode 10 and the material to be treated 18, and between the discharge surface treatment electrode 10 and the material to be treated 18. A pulsed discharge is generated. The other end portion 10b of the discharge surface treatment electrode 10 is an end portion of the discharge surface treatment electrode 10 on the side close to the material 18 to be processed, and a starting point of discharge is generated during the discharge surface treatment.

  FIG. 2 is a conceptual diagram for explaining the internal structure of the discharge surface treatment electrode 10 and shows a cross section of the discharge surface treatment electrode 10. The discharge surface treatment electrode 10 has a structure in which the material particle portions 30 and the conductive path portions 32 are alternately arranged along the X-axis direction. In the cross section shown in FIG. 2, the material particle part 30 and the conductive path part 32 each form a band-like layer extending in the Y-axis direction, and form a laminated structure laminated along the X-axis direction. Note that the Y-axis direction shown in FIG. 2 is directed from one end portion 10a that is the power supply side end portion of the discharge surface treatment electrode 10 to the other end portion 10b that is the end portion on the discharge base point side. The X-axis direction is a direction perpendicular to the Y-axis direction.

  The material particle portion 30 includes material particles 14 that are materials of the coating film 20 (see FIG. 1) formed on the surface of the material 18 to be processed. In addition to the material particles 14, the material particle portion 30 may include a soft metal that adjusts the bonding property between the material particles 14, carbon formed by carbonization of the resin, and the like.

  The conductive path portion 32 is formed so as to continue from one end portion 10a to the other end portion 10b. The conductive path portion 32 has a volume resistivity lower than that of the material particle portion 30 and can be mainly made of metal such as Fe, Ni, or Cu having good conductivity, but is not particularly limited. In addition to the conductive member that imparts conductivity to the conductive path portion 32, the conductive path portion 32 may include carbon formed by carbonization of the resin, material particles 14, and the like. A part of the contained material may be common to the portion 30.

  The conductive path portion 32 is continuous from one end portion 10a to which power is supplied in contact with the electrode mounting portion 26 to the other end portion 10b adjacent to the material 18 to be processed. A current flows in the path portion 32 along the Y-axis direction. In the present embodiment, the conductive path portion 32 is layered, and a plurality of conductive path portions 32 are formed with the material particle portion 30 interposed therebetween. However, the conductive path portion 32 may be rod-shaped or film-shaped. In addition, the conductive path portion 32 is preferably arranged evenly with respect to the material particle portion 30. This is because the conductive path portion 32 is the starting point of discharge, and heat is generated at this location, and the discharge surface treatment is performed, so that the particles of the material particle portion 30 are not separated too far from the conductive path portion 32. By disposing, stable discharge surface treatment can be performed.

  FIG. 3 is a flowchart showing a method of manufacturing the discharge surface treatment electrode 10 shown in FIG. 2, and FIGS. 4A to 4C show intermediate products in the method of manufacturing the discharge surface treatment electrode 10. FIG. In step S001 shown in FIG. 3, a material particle layer 30a as shown in FIG. 4A is formed.

The material particle layer 30a is a portion that becomes the material particle portion 30 (see FIG. 2) after the sintering process (step S004 in FIG. 3). For example, the material particle layer 14 is mixed with a resin as a binder and an organic solvent to form a sheet. It is formed in a shape. The material of the material particle 14 is not particularly limited, but titanium (Ti), titanium hydride (TiH ₂ ), titanium carbide (TiC), titanium nickel alloy (TiN), tungsten carbide, chromium carbide, cobalt, BN, B4C, boron A conductor such as a chemical compound, MoSi2, iron oxide, or zinc oxide can be used. Further, by covering the material particles 14 with a phenol resin or the like, it is possible to employ a nonconductor as the material particles 14. The carbon coated with the material particles 14 is carbonized in the sintering process (step S004 in FIG. 3). After the sintering process, the material particles 14 are coated with the conductive carbon, so that the conductivity inside the material particle portion 30 is increased. This is because a route is formed. Therefore, by coating with resin, as the material of the material particles 14, non-conductor such as titanium oxide (TiO ₂ ), alumina, chromium oxide, zirconia, and chromia, yttria, ceria, calcia, gray alumina, alumina - titania, mullite, SiO _2, can be employed beryllia and the like.

  The material particles 14 included in the material particle layer 30a may be a powder generated by pulverization with a ball mill or the like, or may be an aggregate in which the powder is aggregated. Although the particle diameter of the material particle 14 is not specifically limited, For example, it can be set as about 1-100 micrometers. As the resin contained in the material particle layer 30a, epoxy resin, polyamide, or the like can be used in addition to the phenol resin, and the organic solvent may be appropriately selected depending on the resin and the like, and is not particularly limited.

  In step S002 shown in FIG. 3, a conductive member layer 32a as shown in FIG. 4B is formed. The conductive member layer 32a is a portion that becomes the conductive path portion 32 (see FIG. 2) after the sintering step (step S004 in FIG. 3). For example, a powdered conductive member, a resin as a binder, and an organic solvent are mixed. And formed into a sheet shape. As the conductive member included in the conductive member layer 32a, a material having higher conductivity than the material particles 14 included in the material particle layer 30a is preferably used. For example, Fe, Ni, Cu, Ag, W, or the like is employed. Can do. The resin and the binder contained in the conductive member layer 32a are not particularly limited as is the case with the material particle layer 30a. Note that the conductive member layer 32a is not limited to the one containing a powdery conductive material and a binder, and may be configured only by a film-like, linear, or net-like conductive member.

  In step S003 shown in FIG. 3, as shown in FIGS. 4B and 4C, the material particle layers 30a and the conductive member layers 32a are alternately laminated to obtain a laminate. In step S004 shown in FIG. 4, the laminated body formed in step S003 is sintered to obtain the discharge surface electrode 10 as shown in FIG. Although the sintering temperature in the sintering process of step S004 is not specifically limited, For example, it can be set as about 700 to 3000 degreeC.

  In FIG. 4A to FIG. 4C, the method of laminating the sheet-shaped material particle layer 30a and the conductive member layer 32a once has been described. However, the material particle layer 30a and the conductive member layer 32a are separated from each other. The method of stacking is not limited to this, and for example, the material particle layer 30a and the conductive member layer 32a may be stacked by alternately spreading the powdered material particles 14 and the conductive member inside the mold. .

  The discharge surface treatment electrode 10 shown in FIG. 1 and FIG. 2 has a conductive path portion 32 that continues from one end portion 10a on the power feeding side to the other end portion 10b on the discharge starting side. Stable discharge can be realized by supplementing the conductivity of the particle part 30 with the conductive path part 32 having a lower volume resistivity. Even when the uniformity of the material particle part 30 is inferior, the presence of a reliable conductive path called the conductive path part 32 causes a stable discharge at the other end 10b of the discharge surface treatment electrode 10. It is possible to form a uniform film 20 with the material 18 to be treated. The discharge surface treatment electrode 10 can also be expected to increase the transfer efficiency of the material particles 14 by realizing a stable discharge.

  Further, the discharge surface treatment electrode 10 has the conductive path portion 32 supplementing the conductivity of the material particle portion 30, so that the discharge surface treatment electrode 10 has a material particle portion 30 having a single layer. Even if the volume resistivity is high, the discharge surface treatment electrode 10 can function well. Accordingly, the discharge surface treatment electrode 10 can include various types of material particles 14 depending on the properties of the coating 20 that is desired to be formed on the surface of the material 18 to be treated in the discharge surface treatment.

  Furthermore, the material particle portions 30 and the conductive path portions 32 are alternately arranged along a direction (X-axis direction) substantially perpendicular to the current direction (Y-axis direction) of the conductive path portions 32, thereby Since an arbitrary part comes to be disposed close to the conductive path portion 32, the conductive path portion 32 can more appropriately supplement the conductivity of the material particle portion 30. The coating film 20 formed by the discharge surface treatment using the discharge surface treatment electrode 10 may include not only the material particles 14 but also the conductive member of the conductive path portion 32, and the coating film 20 is formed of the material particles 14. It is also possible to use a compound formed by a reaction between the conductive member and the conductive member. As described above, the discharge surface treatment electrode 10 can also change the characteristics of the coating 20 by adjusting the material of the conductive member included in the conductive path portion 32.

Second Embodiment As shown in FIGS. 3 and 4, the discharge surface treatment electrode 10 as shown in FIGS. 1 and 2 is not limited to the method of laminating the material particle layer 30 a and the conductive member layer 32 a. It can be manufactured by the following method. FIG. 5 is a flowchart showing a manufacturing method according to the second embodiment, and FIGS. 6A and 6B are conceptual diagrams showing intermediate products in the manufacturing method according to the second embodiment.

  In step S101 shown in FIG. 5, a conductive member 32b (see FIG. 6A) and material particles 14 (see FIG. 6B) used for manufacturing the discharge surface treatment electrode 10 are prepared. The material of the conductive member 32b prepared in step S101 is the same as the conductive member used in the conductive member layer 32a formation step (step S002) shown in FIG. 3, but the shape is as shown in FIG. 6A. It is rod-shaped. Further, the material particles 14 prepared in step S101 are the same as the material particles 14 used in the forming step (step S001) of the material particle layer 30a shown in FIG.

  In step S <b> 102 of FIG. 5, as shown in FIG. 6A, the rod-shaped conductive member 32 b is arranged in the mold 40. For example, the conductive members 32b are arranged at predetermined intervals in the X-axis direction and the Z-axis direction, but are preferably arranged at substantially equal intervals. The conductive member 32b used in the second embodiment may be in the form of a film. In that case, in step S102, the conductive member 32b is arranged at a predetermined interval along the X-axis direction or the Z-axis direction. Also good.

  In step S103 of FIG. 5, as shown in FIG. 6B, the material particles 14 are filled into the molding die 40 in which the conductive member 32b is disposed. Furthermore, in step S104, as shown in FIG. 6B, the conductive member 32b and the material particles 14 are compression-molded to form a molded body. In step S105, the compact formed in step S104 is sintered to obtain the discharge surface treatment electrode 10. The sintering temperature in step S105 may be approximately the same as the sintering temperature in step S004 of FIG.

  In this way, the two-layer structure of the material particle part 30 and the conductive path part 32 after sintering is also obtained by a manufacturing method in which the conductive member 32b is placed in the mold 40 in advance without using a method of alternately stacking two layers. The discharge surface treatment electrode 10 can be manufactured. In addition, the discharge surface treatment electrode 10 manufactured by the manufacturing method according to the second embodiment also has the same effects as the discharge surface treatment electrode 10 manufactured by the manufacturing method according to the first embodiment.

DESCRIPTION OF SYMBOLS 10 ... Electrode for discharge surface treatment 10a ... One end 10b ... The other end 14 ... Material particle 16 ... Processing liquid 18 ... Material to be processed 20 ... Film 24 ... Power supply 26 ... Electrode attaching part 30 ... Material particle part 30a ... Material particle layer 32 ... conductive path portion 32a ... conductive member layer 32b ... conductive member 40 ... molding die

Claims (5)

An electrode for discharge surface treatment that generates a discharge between the material to be treated and forms a film on the surface of the material to be treated by its energy,
A material particle portion containing material particles to be the material of the coating;
Formed from one end to which electric power is supplied to the other end that is the starting point of the discharge, and a conductive path having a lower volume resistivity than the material particle,
An electrode for discharge surface treatment.   2. The discharge surface treatment electrode according to claim 1, wherein the material particle part and the conductive path part are arranged along a direction substantially perpendicular to a current direction of the conductive path part.   3. The discharge assertion processing electrode according to claim 1, wherein a plurality of the conductive path portions are formed in a layer shape or a rod shape with the material particle portion interposed therebetween. A method for producing an electrode for discharge surface treatment, wherein a discharge is generated between the material to be treated and a film is formed on the surface of the material to be treated by its energy,
A step of alternately laminating a material particle layer containing material particles as a material of the coating and a conductive member layer containing a conductive member having higher conductivity than the material particles;
Sintering the laminated material particle layer and the conductive member layer;
A method for producing an electrode for discharge surface treatment comprising A method for producing an electrode for discharge surface treatment, wherein a discharge is generated between the material to be treated and a film is formed on the surface of the material to be treated by its energy,
Arranging a film-like or rod-like conductive member having a higher conductivity than the material particles as the material of the coating in a mold; and
Filling the material particles in a mold in which the conductive member is disposed;
Forming the molded body by compression molding the conductive member and the material particles;
Sintering the molded body;
A method for producing an electrode for discharge surface treatment comprising

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