JPWO2008142804A1 - Magnetron ceramic parts, magnetron using the same, and method for producing magnetron ceramic parts - Google Patents

Abstract

The present invention relates to a ceramic part for magnetron with improved bonding strength of a metallized layer. The ceramic component is a ceramic component for a magnetron having a ceramic body portion (1) made of an alumina sintered body and a Mo-Mn metallized layer (9, 10) provided on a part of the surface of the ceramic body portion. The ceramic body is an alumina sintered body having a grain boundary phase containing Mn, and has a Mn rich phase between the ceramic body and the Mo-Mn metallized layer.

Description

  The present invention relates to a ceramic component used in a magnetron such as a magnetron stem used in a microwave heating apparatus such as a microwave oven, a magnetron using the ceramic component, and a manufacturing method thereof.

  Conventionally, what is shown in FIG. 1 is known as a stem used for the cathode support part of a magnetron (Japanese Patent Publication No. 4-75618 (patent document 1)). In the figure, reference numeral 1 denotes a stem body portion made of ceramics, and the stem body portion 1 is formed with a through hole 2 penetrating between both end faces. A washer joint surface 3 is formed on both side surfaces of the stem body 1, and an envelope joint surface 4 is formed on one side surface with a step around the washer joint surface 3. Lead portions 5 and 6 are inserted as through-holes 2 in the stem body portion 1 as cathode support rods, and washers 7 and 7 joined to the lead portions 5 and 6 and the washer joint surface 3 of the stem body portion 1 by brazing. Is bonded and sealed by brazing. The lead portions 5 and 6 are made of Mo having excellent high temperature strength because they are used at high temperatures. A metal envelope 8 is joined and sealed to the envelope joint surface 4 of the stem body 1 by brazing. Metallized layers 9 and 10 are respectively formed on the washer joint surface 3 and the envelope joint surface 4 of the stem body 1, and the washer 7 and the metal envelope 8 are brazed.

  Further, the joint portion between the lead portions 5 and 6 and the washer 7 serves as a sealing portion for the outside air of the stem body portion 1. For this reason, Ni plating is applied to the surfaces of the metallized layers 9 and 10 at the joint portions between the lead portions 5 and 6 and the washer 7 in order to improve the paste of the brazing material and improve the joint sealing property. In the figure, reference numeral 11 denotes a cathode filament, and reference numerals 12 and 13 denote end shields for holding the cathode filament 11 to the lead portions 5 and 6.

  Conventionally, an alumina sintered body has been used for the stem body 1, and a metalized layer of Mo alone has been used for the metalized layer 9. However, since the Mo metallized layer has low bonding strength with Ni plating, a Mo—Mn-based metallized layer has been used in recent years (Japanese Patent Laid-Open No. 2002-56783 (Patent Document 2)). This increases the bonding strength between the metallized layer and the Ni plating, and further increases the bonding strength and confidentiality between the Ni plating layer and the washer, thereby improving the sealing effect.

  As described above, when the Mo—Mn metallized layer is formed, the bonding strength is improved as compared with the case where the Mo metallized layer is formed. However, the metallization process for forming the Mo—Mn-based metallization layer becomes complicated compared to the case of forming the Mo metallization layer, and thus has not been sufficiently improved in terms of yield. In addition, Ni plating on the Mo-Mn metallization layer is essential to improve the bondability between the Mo-Mn metallization layer and the washer, but the plating yield has not been improved sufficiently.

Patent Document 1: Japanese Patent Publication No. 4-75618 Patent Document 2: Japanese Patent Application Laid-Open No. 2002-56783

[Disclosure of the Invention]
An object of this invention is to provide the ceramic component for magnetrons with high joining strength of a metallization layer. It is another object of the present invention to provide a method for manufacturing a magnetron ceramic component that significantly improves the yield.

  The ceramic component for a magnetron of the present invention is the ceramic component for a magnetron having a ceramic body made of an alumina sintered body and a Mo-Mn metallized layer provided on a part of the surface of the ceramic body. The main body is an alumina sintered body having a grain boundary phase containing Mn, and has a Mn rich phase between the ceramic main body and the Mo-Mn metallized layer.

  The Mn-rich phase preferably has an average thickness of 2 to 15 μm. The Mn-rich phase preferably has a glass phase as a main phase.

  The bonding strength of the metallized layer is usually 40 kgf / cm or more, preferably 60 kgf / cm or more.

  The metallized layer forming part on which the metallized layer is formed in the ceramic body part preferably has a surface roughness Ra of 0.1 μm or more. Of the ceramic body, the metallized layer forming part on which the metallized layer is formed preferably has a surface roughness Ra of 0.4 to 3.0 μm. It is preferable that the metallized layer forming part on which the metallized layer is formed in the ceramic main body part is a sintered surface. The color of the alumina sintered body is preferably in the range of x = 0.440 ± 0.020 and y = 0.350 ± 0.020 in the XYZ chromaticity diagram.

  The magnetron ceramic component is preferably a magnetron stem.

  Moreover, the magnetron of the present invention is characterized by using the above-mentioned ceramic part for magnetron.

  Furthermore, the method for manufacturing a ceramic part for magnetron according to the present invention includes a method for manufacturing a ceramic part for magnetron having a ceramic body made of an alumina sintered body and a metallized layer formed on the ceramic body. A step of preparing a ceramic body made of an alumina sintered body having a grain boundary phase, and applying a Mo-Mn paste to a part of the ceramic body and firing at 1350-1500 ° C. in a reducing atmosphere. And a step of forming a metallized layer.

  In the step of forming the metallized layer, the Mo-Mn paste is applied to a part of the ceramic body, dried at 40 to 120 ° C, and then fired at 1350 to 1500 ° C in a reducing atmosphere. preferable.

  The step of forming the metallized layer is preferably performed until the color of the ceramic body changes. The color of the ceramic main body after the change is preferably in the range of x = 0.440 ± 0.020 and y = 0.350 ± 0.020 in the XYZ chromaticity diagram. The step of forming the metallized layer is performed by firing until the color of the ceramic body is in the range of x = 0.440 ± 0.020, y = 0.350 ± 0.020 in the XYZ chromaticity diagram. Is preferred.

  In the step of forming the metallized layer, the flow rate of the reducing atmosphere gas is preferably 100 liters / minute or more. The ceramic body is preferably an alumina sintered body having a Mn content of 1 to 5% by mass. The grain boundary phase of the alumina sintered body constituting the ceramic body is preferably a glass phase.

  The Mo-Mn paste is subjected to a pulverization treatment for 40 hours or more for each of Mo powder having an average particle size of 0.5 to 10 μm and Mn powder having an average particle size of 0.5 to 10 μm, and then mixed with a binder. It is preferable that it is prepared. The Mo-Mn paste is prepared by mixing Mo powder having an average particle size of 0.5 to 1.0 μm and Mo powder having an average particle size of 1.3 μm or more, Mn powder, and a binder. It is preferable that

  After the step of forming the metallized layer, it is preferable to have at least one of a step of inserting a lead portion or a step of performing Ni plating on the metallized layer. In the step of applying Ni plating, it is preferable to perform a barrel-type electrolytic plating method by mixing a ceramic part for magnetron and a metal dummy member. The ceramic body portion is a stem body portion, and it is preferable that a deposited layer made of a glass phase is formed between the ceramic body portion and the metallized layer. In the step of forming the metallized layer, it is preferable to circulate a reducing atmosphere when firing. The magnetron ceramic component is preferably a magnetron stem.

  A method for manufacturing a ceramic part for magnetron according to the present invention is the method for manufacturing a ceramic part for magnetron having a ceramic body made of an alumina sintered body and a metallized layer formed on the ceramic body. 40 for each of a step of preparing a ceramic body made of an alumina sintered body containing a grain boundary phase and a Mo powder having an average particle size of 0.5 to 10 μm and a Mn powder having an average particle size of 0.5 to 10 μm. After performing the crushing treatment for more than an hour, mixing with a binder to prepare a Mo-Mn paste, applying the Mo-Mn paste to a part of the ceramic body, and drying, And a step of forming a metallized layer by firing at 1350 to 1500 ° C. in a reducing atmosphere.

  Furthermore, the method for manufacturing a ceramic part for magnetron according to the present invention includes a method for manufacturing a ceramic part for magnetron having a ceramic body made of an alumina sintered body and a metallized layer formed on the ceramic body. A step of preparing a ceramic main body made of an alumina sintered body containing a grain boundary phase, and a Mo-Mn paste is a Mo powder having an average particle size of 0.5 to 1.0 μm and an average particle size of 1.3 μm or more. Mo powder mixed with Mo powder, Mn powder, a step of preparing a Mo-Mn paste by mixing with a binder, and applying the Mo-Mn paste to a part of the ceramic body and drying. And forming a metallized layer by firing at 1350 to 1500 ° C. in a reducing atmosphere. .

[The invention's effect]
According to the present invention, the bonding strength of the metallized layer is improved, and the reliability of the magnetron ceramic component is improved. In addition, according to the present invention, the yield of magnetron ceramic parts such as a magnetron stem is greatly improved.

  In addition to the magnetron stem shown in FIG. 1, the magnetron ceramic component of the present invention can be applied to a ring-shaped insulating sealing member used at the tip of the cathode of the magnetron. In other words, it can be applied to various members such as a ring shape and a stem shape as long as it is a member that maintains insulation with a metal member at the cathode support portion of the magnetron and seals it using a metallized layer to maintain airtightness. is there.

  The method of manufacturing a ceramic part for magnetron according to the present invention includes a ceramic body part made of an alumina sintered body, and a method for manufacturing a ceramic part for magnetron having a metallized layer formed on the body part. A step of preparing a main body portion made of an alumina sintered body, a step of applying a Mo-Mn paste to a part of the main body portion and forming a metallized layer by firing at 1350 to 1500 ° C. in a reducing atmosphere. It is characterized by comprising. It is also effective to perform a step of drying at 40 to 120 ° C. after applying the Mo—Mn paste.

(Process for preparing the ceramic body)
First, a step of preparing a ceramic body made of an alumina sintered body having a grain boundary phase containing Mn is performed.

  The ceramic main body used in the present invention is made of an alumina sintered body containing Mn. The content of Mn in the alumina sintered body is preferably 1 to 5% by mass, more preferably 1.5 to 3.5% by mass. Since the alumina sintered body contains Mn, the sinterability is improved and the wettability with the metallized layer is improved, so that the bonding strength with the Mo-Mn metallized layer is improved. When the Mn content is less than 1% by mass, the structure is not densified, and the bonding strength with the Mo—Mn metallized layer may not be sufficiently improved. On the other hand, if it exceeds 5% by mass, the alumina sintered body may not be densified.

  The alumina sintered body containing Mn is colored brown. Since this brown alumina sintered body changes its color to pink in the metallization process described later, it is also preferable in that the degree of completion of the metallization process can be visually confirmed.

  The alumina sintered body containing Mn can be obtained by mixing alumina (aluminum oxide) powder and a Mn compound such as manganese oxide and manganese carbonate, and molding and sintering. In addition, the hole for inserting the lead part and the convex part (step) for forming the metallized layer require a process such as grinding to form after firing, and the productivity deteriorates. It is better to have it.

  Moreover, the alumina sintered compact containing Mn can form the grain boundary phase which consists of a glass phase in an alumina sintered compact by baking after mix | blending a specific sintering auxiliary agent. It is preferable that the grain boundary phase is a glass phase because the glass phase is likely to precipitate on the surface in the firing step when forming the metallized layer described later.

Examples of the sintering aid used in the present invention include silicon oxide (SiO ₂ ), magnesium oxide (MgO), and calcium oxide (CaO). The sintering aid is preferably blended in the alumina sintered body so that at least one of Si, Mg and Ca is contained in a total amount of 1 to 10% by mass in terms of a single metal element.

The added sintering aid reacts with the Mn compound to form a grain boundary phase composed of a glass phase such as MnO—SiO ₂ —MgO, MnO—SiO ₂ , or MnO—MgO in the alumina sintered body. The alumina sintered body is densified by this grain boundary phase. Further, the glass phase in the alumina sintered body penetrates into the voids of the Mo-Mn metallized layer when the Mo-Mn metallized layer is fired to strengthen the metallized layer. For this reason, when the grain boundary phase which consists of a glass phase is formed in an alumina sintered compact, the joint strength of the ceramic main-body part which consists of an alumina sintered compact, and a Mo-Mn metallization layer will improve. The alumina sintered body used in the present invention is originally familiar with the Mo-Mn metallized layer because Mn is contained in the alumina sintered body. By forming a grain boundary phase composed of a glass phase, it is possible to improve the familiarity with the Mo-Mn metallized layer.

  Note that whether or not the grain boundary phase of the alumina sintered body is a glass phase can be confirmed by X-ray diffraction. Specifically, since the glass phase does not have crystallinity, it is understood that the grain boundary phase is a glass phase when no peak is detected in the grain boundary phase subjected to X-ray diffraction.

  The size and shape of the ceramic main body are not particularly limited. For example, when used for a stem, a cylindrical shape having a diameter of about 10 to 20 mm and a length of about 7 to 15 mm can be mentioned. Further, when the ceramic body is a ring-shaped ceramic member, the outer diameter is preferably 10 to 20 mm, the height is 5 to 20 mm, and the wall thickness is preferably about 0.8 to 3 mm. The wall thickness is appropriately set depending on the required insulation.

  Of the surface of the ceramic body made of an alumina sintered body, the metallized layer forming part on which the metallized layer is provided may be a surface subjected to mechanical polishing using a diamond grindstone, or polishing that is not polished after firing. A loess surface (sintered surface) may be used.

  That is, conventionally, in order to increase the bonding strength of the metallized layer, the surface of the alumina sintered body was mechanically polished and polished to a flat surface with a surface roughness Ra of less than 0.1 μm. This is because the metallized layer has a sufficiently high bonding strength and does not require mechanical polishing. Thus, the reason why the bonding strength between the alumina sintered body and the metallized layer of the present invention is high is that both the alumina sintered body and the metallized layer contain Mn, and the grain boundary phase in the alumina sintered body is in the metallized layer. This is considered to be due to precipitation and formation of a Mn-rich phase containing a large amount of Mn at the interface between the alumina sintered body and the metallized layer.

  For this reason, the metallized layer forming part of the ceramic body part may have a surface roughness Ra (centerline average roughness) of usually 0.1 μm or more, preferably 0.4 to 3.0 μm. it can.

  In general, the metallized layer forming portion has a higher bonding strength with the metallized layer as the surface roughness is smaller. However, in the present invention, even if the surface roughness Ra is rough as in the above range, Since the bonding strength is sufficiently high, it is not necessary to perform mechanical polishing, and the manufacturing cost can be reduced. In the present invention, barrel polishing for deburring may be performed.

(Process for forming a metallized layer)
Next, a Mo—Mn paste is applied to a part of the ceramic body, dried at 40 to 120 ° C., and then fired at 1350 to 1500 ° C. to form a metallized layer. A place where the metallized layer is formed is arbitrary, and a place where energization is desired, a place where sealing is desired via Ni plating, or the like is appropriately selected.

  The Mo—Mn paste is a mixture of Mo powder, Mn powder and an organic binder. The organic binder used in the present invention is not particularly limited as long as it is burned off by a drying process or a baking process. The Mn powder may be a powder of Mn alone or a Mn compound powder such as MnO. A preferable example of the organic binder is ethyl cellulose.

  The Mo-Mn paste was prepared by subjecting Mo powder having an average particle size of 0.5 to 10 μm and Mn powder having an average particle size of 0.5 to 10 μm to a crushing treatment for 40 hours or more, It is preferably prepared by mixing. The ratio of Mo to Mn in the Mo—Mn paste is 4 to 12% by mass, preferably 6 to 8% by mass when the total of Mo and Mn is 100% by mass. The series of steps for adjusting the Mo—Mn paste is preferably performed in an inert atmosphere such as nitrogen. In particular, since Mn is an active metal, it is preferably treated in an inert atmosphere.

  In general, when a Mo—Mn metallized layer is formed, voids are easily formed in the metallized layer. The voids are mainly formed by gaps formed when the organic binder is burned off. If the particle sizes of the Mo powder and the Mn powder are large, the gaps are likely to increase. Accordingly, in order not to form voids in the metallized layer, it is necessary to prepare fine and uniform Mo powder and Mn powder.

  In the present invention, since no voids are formed in the metallized layer, each of the Mo powder having an average particle diameter of 0.5 to 10 μm and the Mn powder having an average particle diameter of 0.5 to 10 μm is crushed for 40 hours or more. It is preferable to use the obtained Mo powder and Mn powder. By crushing Mo powder and Mn powder separately, a more uniform powder can be obtained.

  The crushing time is preferably a long time such as 40 hours or more. The reason for this is that Mo is a heavy metal with a high specific gravity, so if you try to crush it in a short time, the load on the crusher is large, reducing the life of the crusher, and increasing the manufacturing cost in return. It is. Further, since Mn is an active metal, there is a risk of ignition if it is crushed finely in a short time. The upper limit of the crushing time is not particularly limited, but if the time is too long, the production time becomes long, so 100 hours or less is preferable.

  A more preferable aspect of the pulverization treatment is to use pulverized Mo powder and Mn powder each having an average particle diameter of 1 to 4 μm and separately pulverize them for 60 to 80 hours. The crushing method may be either dry or wet, but the wet method is preferable because it can suppress the ignition characteristics of Mn. The pulverized Mo powder and Mn powder are preferably dried. The crushing treatment may be performed using a hard medium such as an alumina ball. The pulverization treatment is preferably performed until the average particle size of the pulverized Mo powder and Mn powder is about 0.2 to 2.0 μm, respectively.

  Further, a method using two types of Mo powders, that is, Mo powder having an average particle size of 0.5 to 1.0 μm and Mo powder having an average particle size of 1.3 μm or more is also effective as the Mo powder. By using two kinds of powders having different average particle diameters, the gaps between the Mo particles (gap between grain boundaries) can be reduced, so that the gaps when the resin binder is burned out can also be reduced. Further, the Mn component becomes a glass phase and can enter the gaps between the Mo particles to reinforce the metallized layer. In addition, when using 2 types of Mo powder from which an average particle diameter differs, it mixes so that the mixed Mo powder may become an average particle diameter of 0.7-2.0 micrometers. The crushing treatment may or may not be performed after mixing.

  When using two types of Mo powders, Mo powder having an average particle size of 0.5 to 1.0 μm and Mo powder having an average particle size of 1.3 μm or more, the pulverized Mo powder is sieved to obtain an average particle size of 0. Two types of Mo powders having an average particle size of 1.3 μm or more may be prepared.

  After pulverizing the Mo powder and Mn powder, a predetermined amount of Mo powder and Mn powder are weighed out and mixed with an organic binder. As a mixing method of the Mo powder, the Mn powder, and the organic binder, it is preferable to use a mixing method with a high load such as a three roll after mixing in a container. The organic binder is preferably mixed for 10 to 30 hours.

  The Mo-Mn paste prepared in this way is uniformly mixed with Mo powder and Mn powder, and further has an appropriate viscosity, so that it does not easily cause a problem of flowing down even when applied to the ceramic body. . For this reason, even if a paste is applied to the back surface in addition to the front surface, the paste does not flow down, so that all metallized layers can be dried in a single drying step.

  The application of the Mo—Mn paste is preferable because the mass productivity increases when a screen printing method is used. The coating thickness of the Mo—Mn paste is preferably 10 to 40 μm. If the coating thickness is less than 10 μm, the thickness of the Mo layer may vary after the metallized layer is formed, and the bonding strength may be reduced. On the other hand, if it exceeds 40 μm, the joint strength is not improved by a predetermined value or more, which is not economical.

  The drying temperature in a drying process is 40-120 degreeC normally, Preferably it is 50-100 degreeC, More preferably, it is 50-80 degreeC. Examples of the drying atmosphere used in the drying step include air, an inert atmosphere (such as nitrogen and argon), and a reducing atmosphere. Among the reducing atmospheres, a hydrogen-containing atmosphere is preferable, and an inert gas (argon, nitrogen, etc.) containing 10 to 20 vol% of hydrogen is more preferable. The drying time is 5 to 30 minutes, preferably 10 to 20 minutes. Since an unnecessary binder in the Mo—Mn paste can be removed in advance by performing the drying step, it is preferable because the glass phase easily enters the gap between the metallized layers at the time of firing to form the metallized layer.

In addition, the Mn oxide in an alumina sintered compact and Mo-Mn paste is reduced by performing a drying process in a reducing atmosphere. When the Mn oxide is reduced, the reaction of forming a glass phase between Mn and another oxide, for example, a sintering aid such as SiO ₂ and MgO, becomes significant in the firing step, and voids in the metallized layer It becomes easy to enter the glass phase. As a result, the bonding strength of the metallized layer is improved, which is preferable.

  A baking process is performed after a drying process. A calcination temperature is 1350-1550 degreeC, Preferably it is 1400-1480 degreeC. The firing time is preferably in the range of 30 minutes to 5 hours. A reducing atmosphere is used as the atmosphere.

  The firing time is preferably 1 hour or longer. Firing for 1 hour or more is preferable because a deposited layer formed by uniformly depositing the glass phase in the alumina sintered body on the surface of the alumina sintered body is easily formed. The deposited layer consisting of the glass phase precipitates between the surface of the alumina sintered body and the Mo-Mn metallized layer, and enters the voids in the metallized layer to reduce the voids, so that the metallized layer is densified and the alumina sintered Bonding strength between the ceramic main body made of the body and the metallized layer is improved.

  The average thickness of the metallized layer is usually 10 to 100 μm, preferably 20 to 50 μm. If it is less than 10 μm, the bonding strength tends to be insufficient. If the thickness exceeds 100 μm, it becomes difficult for the glass phase to precipitate in the gaps of the metallized layer, so that the variation in bonding strength tends to increase.

  In the present invention, since both the alumina sintered body and the Mo metallized layer contain the Mn component, when the glass phase is precipitated on the surface of the alumina sintered body, the Mn in the Mo metallized layer is taken in and a large amount of Mn is contained. A glassy Mn-rich phase can be formed. By forming a phase containing a large amount of Mn, the bonding strength between the ceramic body made of the alumina sintered body and the Mo metallized layer can be improved.

  The Mn-rich phase is present when the Mn distribution looks phase-like when the junction cross-section of the alumina sintered body and the metallized layer is examined by surface analysis using EPMA (magnification of about 1000 times). Can be confirmed. The average thickness of the Mn-rich phase is preferably 2 to 15 μm. If the thickness is less than 2 μm, the improvement of the bonding strength is small, and if it exceeds 15 μm, the amount of the glass phase is too large and the flatness of the surface of the metallized layer may be impaired. When the flatness of the surface of the metallized layer is impaired, the bonding strength of the Ni plating layer on the surface of the metallized layer varies, and the airtightness is adversely affected when incorporated in the magnetron. Moreover, it is most preferable that the length of the Mn-rich phase in the lateral direction is continuously present on the entire surface of the bonding interface, but if it is 5 μm or less, there may be a gap (a region where the ratio of Mn is small).

  It is preferable to circulate a reducing atmosphere during firing. When firing in a reducing atmosphere, the vitreous grain boundary phase in the ceramic body is mainly reduced. Reduced oxygen derived from the grain boundary phase reacts with hydrogen to become water. Since the firing atmosphere is a high temperature of 1350 ° C. or higher, the water becomes water vapor, but if too much water vapor remains, the metallized layer is adversely affected. For this reason, it is preferable to circulate a reducing atmosphere during firing to remove water vapor.

  The flow rate of the reducing atmosphere gas is usually 100 L / min (= liter / min) or more, preferably 100 to 300 L / min, and more preferably 130 to 250 L / min. If the flow rate of the reducing atmosphere gas is less than 100 L / min, it is not preferable because it is difficult to remove water vapor generated by the reduction reaction. On the other hand, when the flow rate exceeds 300 L / min, it is not preferable because a load is imposed on the management of the supply device, and the reaction between the reducing atmosphere and the ceramic body tends to vary.

  The firing furnace for performing the firing process may be either a continuous furnace or a batch furnace. It is preferable to use a Mo board as a member for mounting the ceramic body. When performing the metallization process by continuous operation of the firing furnace, it is preferable to control the flow rate of the reducing atmosphere gas.

  When the metallized layer is completed by firing, the color of the alumina sintered body changes. For example, what was brown turns into pink. This indicates that the Mn oxide in the alumina sintered body has been reduced. When the Mn oxide is reduced, an effect is obtained in which the glass phase generated by reacting with another sintering aid enters the voids of the metallized layer. In particular, when exposed to a high temperature by the firing process, the glass phase is precipitated from the inside of the alumina sintered body to the surface side, and further fills the gaps in the metallized layer in the metallized layer. As described above, the alumina sintered body of the present invention can be easily checked for the presence or absence of metallization because the progress of metallization can be visually confirmed with color change during firing. The above-mentioned pink color is a concept including a beautiful pink color to a cloudy pink color (red bean color).

  The pink color of the alumina sintered body after the formation of the metallized layer is preferably in the ranges of x = 0.440 ± 0.020 and y = 0.350 ± 0.020 in the XYZ chromaticity diagram. The XYZ chromaticity diagram is a color system defined by the CIE (International Commission on Illumination). In Japan, it is defined in JIS-Z-8701. The measurement conditions are preferably measured using a color difference meter according to JIS-Z-8722.

  When the pink color of the alumina sintered body after forming the metallized layer is in the range of x = 0.440 ± 0.020, y = 0.350 ± 0.020 in the XYZ chromaticity diagram, the metallized layer is bonded. Strength is improved. The pink color of the alumina sintered body is caused by the glass phase being deposited between the metallized layer and the alumina sintered body to form a deposited layer. As the glass phase precipitates, the manganese oxide is reduced and the amount of oxygen in the manganese oxide decreases, so the color changes. For this reason, by using the color change of the alumina sintered body as a guide for measuring the degree of deposition of the glass phase, it is possible to visually confirm the progress of metallization. In other words, firing is performed so that the color of the alumina sintered body after forming the metallized layer is in the range of x = 0.440 ± 0.020, y = 0.350 ± 0.020 in the XYZ chromaticity diagram. It is preferable. The alumina sintered body before the metallization step is preferably brown as described above, and preferably x = 0.450 ± 0.020 and y = 0.400 ± 0.020 in the XYZ chromaticity table. That is, a brown (x = 0.450 ± 0.020, y = 0.400 ± 0.020) alumina sintered body is pink (x = 0.440 ± 0.020, y = 0.350 ± 0). It is a preferable process to heat and metallize until .020).

(Process of inserting lead part)
After the metallization process is completed, a process of inserting the lead part into the ceramic body part as necessary is performed. The lead portion is preferably made of a refractory metal such as Mo or stainless steel. The length of the lead portion is arbitrary. When manufacturing a magnetron stem, a lead insertion / fixing step is performed. The insertion / fixation process means a process of sequentially inserting and fixing the lead portion. When manufacturing a device other than the magnetron stem, there is no need to insert and fix the lead portion, and a plating step described later is performed as necessary. The lead portion may be fixed after Ni plating.

  The lead portion is inserted with a hole in the ceramic body portion and then fixed with a brazing material. The brazing material is preferably an Ag-based brazing material. Examples of the Ag-based brazing material include Ag, Ag-Cu, and Ag-Sn. A particularly preferred Ag-based brazing material is one containing 71 to 73% by mass of Ag and 27 to 29% by mass of Cu and having a eutectic composition. The brazing temperature is usually 700 to 900 ° C. The stem portion of a magnetron such as a microwave oven generally rises only to a temperature of 400 ° C. or lower, but it is preferable to use a brazing material having a melting point of 700 ° C. or higher to ensure a heat-resistant margin.

(Ni plating process)
After inserting the lead portion, a step of applying Ni plating on the metallized layer is performed. The thickness of the Ni plating is preferably in the range of 1 to 5 μm.

  It is preferable to perform the Ni plating step by barrel-type electrolytic plating because mass productivity of magnetron ceramic parts can be improved. When barrel-type electrolytic plating is used, the electrolytic solution and ceramic parts (for example, a stem with leads) can be uniformly mixed in the rotating container, so that 1000 or more ceramic parts can be plated at a time. Since alumina is an insulator, the ceramic body is not plated with Ni. Ni plating is performed on the metallized layer and the lead portion, which are conductors.

  When performing barrel type electrolytic plating, it is preferable to mix a metal dummy member in the plating bath because the yield of Ni plating can be improved.

  The metal dummy member is a metal member that improves the electroconductivity of the electrolytic solution and increases the plating efficiency by mixing in the plating bath. In addition, since the metal dummy member serves as a cushion, it can be suppressed that the ceramic main body portions collide and are damaged. For this reason, when a metal dummy member is used when performing barrel type electrolytic plating, the yield of Ni plating is improved and the bonding strength of Ni plating is also increased.

  Examples of the material of the metal dummy member include simple metals such as iron and stainless steel and alloys.

  Examples of the shape of the metal dummy member include the shapes shown in FIGS. 2A, 2B, 3 and 4.

  FIG. 2A is a front view of an example of a metal dummy member, and FIG. 2B is a perspective view of the metal dummy member shown in FIG. FIG. 3 is a front view of another example of the metal dummy member. FIG. 4 is a front view of still another example of the metal dummy member. In the figure, d1 is the outer diameter of the eyelet-shaped portion, d2 is the inner diameter of the main body of the dummy member, and L is the length of the metal dummy member.

  A metal dummy member 20 shown in FIGS. 2A and 2B is provided with a grommet-shaped portion 22 at one end in the longitudinal direction of a cylindrical main body portion 21. Here, the eyelet-shaped portion means a portion formed in a ring shape. A metal dummy member 20 </ b> A shown in FIG. 3 is provided with eyelet-shaped portions 22 and 22 at both ends in the longitudinal direction of a cylindrical main body portion 21. The metal dummy member 20 </ b> B shown in FIG. 4 is composed of only a columnar main body 21.

  The shape of the metal dummy member is from a simple cylindrical shape such as the metal dummy member 20B shown in FIG. 4 to a cylindrical main body such as the metal dummy members 20 and 20A shown in FIGS. There are various types including those provided with eyelet-shaped parts in the parts. The shape of the main body 21 is not limited to a cylindrical shape, and may be a quadrangular prism, a polygonal column, a triangular prism, a triangular pyramid, or a spherical shape. Of these, the shape of the main body portion 21 is preferable because it does not damage the ceramic main body portion, such as a cylinder or a sphere.

  The metal dummy member is preferably smaller than the ceramic body, and specifically, the volume of the metal dummy member divided by the volume of the ceramic body (volume of the metal dummy member / volume of the ceramic body) Is preferably from 0.01 to 0.2. If the ratio of (volume of the metal dummy member / volume of the ceramic body) is less than 0.01, the metal dummy member is too small and it is necessary to throw in a large amount of dummy members, Since a problem also arises, it is not preferable. On the other hand, if the ratio of (volume of the metal dummy member / volume of the ceramic body portion) exceeds 0.2, the ratio of the dummy member in the electrolyte solution becomes too large and the amount of the ceramic body portion that can be processed decreases. Since manufacturing efficiency falls, it is not preferable.

  It is preferable that 5-30 vol% of metal dummy members are mixed with respect to the total volume of the ceramic body in the plating bath. If it is less than 5 vol%, the effect of mixing cannot be obtained sufficiently, and if it exceeds 30 vol%, the amount of stems that can be treated at one time decreases, which is not preferable. Note that the mixing ratio of the metal dummy member when plating the stem with lead is also calculated by the total volume of the ceramic main body excluding the volume of the lead.

  As a specific example in which the ratio of the volume of the metal dummy member to the volume of the ceramic body portion of the metal dummy member is 0.01 to 0.2, d1 is 2 to 5 mm, d2 is 1 to 3 mm, and L is The thing of 3-6 mm is mentioned.

  The temperature of the electrolytic bath is usually about 40 to 70 ° C., and the plating time is usually 30 to 60 minutes.

  When the above barrel electrolytic plating method is used, even if 1000 or more ceramic bodies or even more than 2500 ceramic body parts and stems with leads are processed in a processing time of 30 to 60 minutes, the yield of Ni plating is 90%. % Or more, and further 95% or more. The number of ceramic body parts that can be processed at one time depends on the size of the electrolytic bath, the size of the lead part, etc. Even if 2500 to 3500 leaded stems are processed, the yield is 90% or more, and more than 95%. can do.

  According to the above-described method for manufacturing a magnetron ceramic part, the yield can be greatly improved. Specifically, the yield can be greatly improved to 90% or more even when manufactured through complicated processes such as formation of a metallized layer, fixation of leads, and formation of Ni plating. In addition, the bonding strength of the metallized layer and Ni plating can be improved. For this reason, it is possible to manufacture a highly reliable magnetron having good sealing properties when mounted on the magnetron.

  The effect of the present embodiment was confirmed using a process for manufacturing a magnetron stem having a shape as shown in FIG. 1 as an example of a method for manufacturing a magnetron stem. The stem main body used in the following examples is provided with a convex portion (step) for forming a metallized layer at the tip of an alumina sintered body having a diameter of 15 mm and a length of 10 mm. Further, a sintered surface (surface roughness Ra 1.25 μm) was used as the metallized layer forming surface.

[Example 1, Comparative Examples 1 to 3, Reference Example 1]
In Example 1, Comparative Examples 1 to 3, and Reference Example 1, a magnetron stem was manufactured by the following steps.

Example 1: Step A1 → Step B1 → Step C1 → Step D1 → Step E1 → Step F1
Comparative Example 1: Step A2, Step B1, Step C1, Step D1, Step E1, Step F1
Comparative Example 2: Step A1 → Step B2 → Step C2 → Step D1 → Step E1 → Step F1
Comparative Example 3: Step A1, Step B1, Step C1, Step D2, Step E1, Step F1
Reference Example 1: Process A1 → Process B1 → Process C1 → Process D1 → Process E1 → Process F2
Each process is as follows.

Step A1: An alumina sintered body obtained by adding Mn oxide (MnO ₂ ), silicon oxide and magnesium oxide as a sintering aid to alumina and firing it was used as a stem body. The Mn content in the alumina sintered body was 3.0 wt% in terms of Mn simple substance, 1.9 wt% in terms of Si simple substance, and 2.4 wt% in terms of Mg simple substance. Moreover, when the component of the grain boundary phase in the alumina sintered body was analyzed by the X-ray diffraction method, no crystal peak was detected and it was found to be a glass phase.

  Process A2: The same alumina sintered body as process A1 was prepared except not containing Mn.

  Step B1: Mo powder having an average particle diameter of 2 μm and Mn powder having an average particle diameter of 2 μm were crushed using a ball mill for 75 hours. After drying the Mo powder and the Mn powder, the Mo powder, the Mn powder, and ethyl cellulose as a binder were mixed. After mixing for 10 hours by the single roll method, mixing was performed for 17.5 hours by the three roll method. By this step, a Mo-Mn paste containing 7% by mass of Mn was prepared. This step was performed in a nitrogen atmosphere.

  Step B2: A Mo-Mn paste was prepared using the same step as Step B1 except that crushing treatment was not performed.

  Step C1: A Mo—Mn paste was screen-printed at a predetermined position of the stem body with a coating thickness of 20 μm and dried at 70 ° C. for 15 minutes under a reducing atmosphere (inert atmosphere containing 15 vol% hydrogen). The flow rate of the reducing atmosphere gas was 195 L / min.

  Step C2: The same drying step as Step C1 was performed except that drying was performed at 65 ° C. in the atmosphere.

  Step D1: A metallized layer was formed by heat treatment at 1425 ° C. for 2.5 hours under a reducing atmosphere (inert atmosphere containing 15 vol% hydrogen). The heat treatment was performed while circulating a reducing atmosphere. The flow rate of the reducing atmosphere gas was 195 L / min.

  Step D2: A metallized layer was formed by the same method as in Step D1, except that the heat treatment was performed in the air.

  Step E1: The lead portion made of Mo was inserted into the through hole of the stem main body portion, and brazed to the washer of the stem main body portion with an Ag—Cu (Ag 73 wt%, Cu 27 wt%) brazing material.

  Step F1: For 3000 stems with leads, a metal dummy member whose main component is iron so that the volume ratio is 10 vol% (the shape shown in FIG. 2 is provided with an eyelet-shaped portion and d1 is 2 mm, d2 was 1 mm and L was 4 mm), and barrel-type electrolytic plating was performed at 50 ° C. for 40 minutes.

  Step F2: Barrel-type electrolytic plating was performed in the same manner as in Step F1, except that no metal dummy member was used.

Magnetron stems were manufactured in the following examples and comparative examples by combining the steps, and the yield and the bonding strength of the metallized layer were determined. Yield was determined as a ratio of 3000 magnetron stem body parts prepared, and finally the number of magnetron stems that could be manufactured divided by 3000. As the bonding strength of the metallized layer, a Kovar plate was brazed to the Ni-plated metallized layer, and the Kovar plate was peeled off to determine the tensile strength (kgf / cm). This operation was performed for 100 magnetron stems, and the average value of the tensile strength was defined as the average bonding strength (kgf / cm). Further, the lowest value of the tensile strength was defined as the minimum bonding strength (kgf / cm). In the metallization process (process C-process D), the presence or absence of the change of the color of the alumina sintered compact which comprises a stem main-body part was observed. The color of the alumina sintered body was also measured. The presence or absence of the formation of a precipitation layer composed of a glass phase was also observed between the alumina sintered body and the metallized layer. The presence or absence of the deposited layer was judged by looking at the cross section of the bonding interface. The results are shown in Table 1.

  As can be seen from the table, Example 1 has a high yield. Also, a high value of the bonding strength was obtained. Although not shown in the table, in Example 1, the maximum value of the bonding strength was 102 kgf / cm.

  On the other hand, although the comparative example 1 had a high apparent yield, since the alumina sintered body did not contain Mn, the bonding strength of the metallized layer was low. In Comparative Example 2, the bonding strength of the metallized layer was low because the preparation of the paste and the drying process were insufficient.

  In Comparative Example 3, since the metallization process was not performed in a reducing atmosphere, the Mn oxide of the alumina sintered body was not reduced, so that the glass phase moved little and the bonding strength of the metallized layer was lowered. In Reference Example 1, since a metal dummy member was not used in the plating process, there were many plating defects and the yield was lowered.

  Moreover, all the colors of the alumina sintered body of Example 1 were in the range of XYZ chromaticity diagram (x = 0.440 ± 0.020, y = 0.350 ± 0.020). On the other hand, all of Comparative Example 1 were outside the above range. Some of Comparative Examples 2 and 3 showed a color outside the above range, and those having a color outside the above range had low bonding strength of the metallized layer.

[Examples 2 to 5]
A magnetron stem was manufactured in the same manner as in Example 1 except that Step B1 was changed as shown in Table 2, and the same measurement was performed. The results are shown in Table 2.

  As can be seen from the table, Example 4 with a short crushing time and Example 5 in which the Mo powder and the Mn powder are larger than the preferred range tend to have a reduced yield and bonding strength. In addition, although not shown in a table | surface, all the Examples 2-5 confirmed the change of the color of an alumina sintered compact in the metallization process.

  In all of Examples 2 to 5, the color of the alumina sintered body was in the XYZ chromaticity diagram (x = 0.440 ± 0.020, y = 0.350 ± 0.020). .

[Examples 6 to 8]
A magnetron stem was manufactured in the same manner as in Example 1 except that the step F1 was changed as shown in Table 3, and the same measurement was performed. The results are shown in Table 3.

  As can be seen from the table, when the added amount of the metallic dummy member is less than 5 vol% as in Example 6, the effect of improving the plating failure is small since the effect of improving the conductivity is small. Further, when the plating time is short as in the seventh embodiment, it causes a plating failure.

  On the other hand, when Example 8, Example 9, and Example 1 are arranged in the order of good yield, the former is better in the order of Example 8, Example 1, and Example 9. From this comparison, it can be said that the yield is improved when the metal dummy member has the eyelet-shaped portion. This is thought to be because the eyelet-shaped portion serves as a cushion and suppresses collision between the stems.

[Examples 10 to 13]
Next, using the same method as in Example 1, the amount of stem to be processed was changed as shown in Table 4, and the yield was measured. The results are shown in Table 4.

  As can be seen from the table, it was confirmed that even if the number of stems increased, a high yield was exhibited.

  As described above, the method for manufacturing the magnetron stem according to the present example has a good yield and the joint strength of the metallization layer of the stem obtained is high. Therefore, a highly reliable magnetron stem can be manufactured, and as a result, the reliability of the magnetron using the stem can be improved.

[Examples 14 to 17, Comparative Examples 4 to 5]
Next, what changed the conditions of process D1 of Example 1 as Table 5 was set as Examples 14-17 and Comparative Examples 4-5. For each magnetron stem, the presence or absence of a deposited layer, the average value of the bonding strength, and the minimum value were determined. The results are shown in Table 6.

  As can be seen from the table, it was confirmed that a deposited layer composed of a glass phase was present in the form of a layer when the firing time was 1 hour or longer as in Examples 15 to 17. On the other hand, when the firing time was 40 minutes as in Example 14, the deposited layer was mottled in stripes and was not layered.

  In addition, in the case where the firing temperature was too low as in Comparative Example 4, the deposited layer was insufficient and voids were observed in the metallized layer. For this reason, the bonding strength of Comparative Example 4 was very low. On the other hand, when the firing temperature was too high as in Comparative Example 5, the amount of precipitation of the glass phase was too large, and swelling was confirmed in the metallized layer, resulting in a decrease in bonding strength.

[Example 1B, Examples 18 to 20, Comparative Examples 1B to 3B]
Magnetron stems obtained by the manufacturing steps of Example 1 and Comparative Examples 1 to 3 were prepared, and the presence or absence of a Mn-rich phase between the metallized layers and the bonding strength were measured. Moreover, what changed the manufacturing process as follows was prepared as Examples 18-20, and the same measurement was performed. A sintered surface (surface roughness Ra 1.25 μm) was used as the metallized layer forming surface.

  Regarding the analysis of the Mn-rich phase, EPMA surface analysis was performed on Mn in the field of view of about 100 μm wide × 70 μm long in the bonded cross section of the alumina sintered body and the metallized layer. The average thickness, the minimum thickness, and the maximum thickness of the Mn rich phase were measured by image analysis of the EPMA surface analysis results. This operation was performed at three arbitrary locations, and the average value was shown in the table with the smallest value among the three locations as the minimum thickness and the largest thickness as the maximum thickness.

  In Example 1B, Examples 18 to 20, and Comparative Examples 1B to 3B, a magnetron stem is manufactured by the following steps.

Example 1B: Process Comparative Example 1B Similar to Example 1 Process Comparative Example 2B Similar to Comparative Example 1 Process Comparative Example 3B Similar to Comparative Example 2 Process Comparative Example 3B Similar to Comparative Example Example 18 18: Process A3 → Process B1 → Process C2 → Process D1 → Process E2 → Process F1 → Process E3
Example 19: Process A3 → Process B3 → Process C2 → Process D1 → Process E2 → Process F1 → Process E3
Example 20: Process A3 → Process B4 → Process C2 → Process D1 → Process E2 → Process F1 → Process E3
Step A3: An alumina sintered body obtained by adding Mn carbonate (MnCO ₃ ), silicon oxide and magnesium oxide as a sintering aid to alumina and firing it was used as the stem body. The Mn content in the alumina sintered body was 2.8 wt% in terms of Mn simple substance, 1.8 wt% in terms of Si simple substance, and 2.5 wt% in terms of Mg simple substance. Moreover, when the component of the grain boundary phase in the alumina sintered body was analyzed by the X-ray diffraction method, no peak was detected and it was found that the glass phase was a glass phase.

  Step B3: A mixed Mo powder was prepared by mixing Mo powder having an average particle size of 0.8 μm and Mo powder having an average particle size of 1.5 μm in a mass ratio of 50:50. Further, Mn powder having an average particle size of 1.8 μm was crushed for 70 hours using a ball mill. After drying the mixed Mo powder and the Mn powder, the mixed Mo powder, the Mn powder, and ethyl cellulose as a binder were mixed. After mixing for 13 hours by the single roll method, mixing was performed for 20 hours by the three roll method. By this step, a Mo-Mn paste containing 7% by mass of Mn was prepared. This step was performed in a nitrogen atmosphere.

  Step B4: A mixed Mo powder was prepared by mixing Mo powder with an average particle size of 0.9 μm and Mo powder with an average particle size of 1.4 μm in a mass ratio of 50:50. Moreover, Mn powder with an average particle diameter of 1.6 μm was prepared. The mixed Mo powder and Mn powder were each pulverized for 65 hours using a ball mill. Thereafter, the mixed Mo powder and the Mn powder were dried, and the mixed Mo powder, the Mn powder, and ethyl cellulose as a binder were mixed. After mixing for 20 hours by the single roll method, mixing was performed for 25 hours by the three roll method. By this step, a Mo-Mn paste containing 7% by mass of Mn was prepared. This step was performed in a nitrogen atmosphere.

  Step E2: The lead portion made of Mo was inserted into the through hole of the stem body portion, and the lead portion was not brazed and fixed.

Step E3: After the step F1 (plating treatment), the Mo lead portion inserted into the through hole of the stem body portion was brazed in the same manner as in the step E1.

As can be seen from the table, in the magnetron stems according to Example 1B, Examples 18 to 20, and Comparative Examples 2B to 3B, a Mn rich phase was confirmed between the alumina sintered body and the metallized layer. Comparing Example 1B and Example 18, Example 1B had a more uniform Mn-rich phase because it was dried in a reducing atmosphere in Step C2.

  FIG. 5 shows an example of the results of EPMA analysis (Mn surface analysis) in a cross section including the bonding interface of Example 18. FIG. 6 shows an example of the Mn surface analysis result of the EPMA analysis in the cross section including the bonding interface of Example 19. FIG. 7 shows an example of the Mo surface analysis result of EPMA analysis in the cross section including the bonding interface of Example 19. FIG. 8 shows an example of the Si surface analysis result of EPMA analysis in the cross section including the bonding interface of Example 19. FIG. 9 shows the results of EPMA analysis (Mn surface analysis) in a cross section including the bonding interface of Comparative Example 1B.

  5-9, the code | symbol 31 shows a ceramic main-body part (alumina sintered compact), the code | symbol 32 shows a Mn rich phase, and the code | symbol 33 shows a Mo-Mn metallization layer.

  From Example 19 and Example 20, those using two kinds of Mo powder having an average particle size can reduce the gap between the Mo powders, so that the thickness of the Mn-rich phase can be easily made uniform, and the bonding strength can be improved. I understood. The Mn rich phases of Example 1B and Examples 18 to 20 were all glass phases. In the Mn rich phases of Example 1B, Examples 18 to 20, and Comparative Examples 2B to 3B, no rich phase of components other than Mn (Si, Mg added as a sintering aid) was confirmed. That is, the sintering aid component other than Mn was uniformly dispersed in the metallized layer without forming a rich phase.

  On the other hand, since Comparative Example 1B did not contain Mn in the alumina sintered body, a Mn rich phase was not confirmed. In Comparative Example 2B, the maximum thickness of the Mn-rich phase was large. This is considered to be because the gap between the Mo powders was increased because the Mo powder was not crushed. Furthermore, it is considered that Comparative Example 3B was caused because the metallization step (step D2) was not performed in a reducing atmosphere, and the amount of precipitation of the glass phase containing Mn from the alumina sintered body was small.

  In Comparative Example 2B and Comparative Example 3B, the maximum gap between the Mn-rich phases was large. Here, the maximum gap between the Mn-rich phases is a cross-sectional photograph of the gap portion when a gap portion where the Mn-rich phase is discontinuous occurs in the spreading direction of the Mn-rich phase, that is, in the direction perpendicular to the thickness direction. It means the maximum width measured. From the results of Comparative Example 2B and Comparative Example 3B, it was found that the bonding strength of the metallized layer was lowered when the precipitation form of the Mn-rich phase was insufficient.

  The colors of the alumina sintered bodies of Example 1B and Examples 18 to 20 are all in the XYZ chromaticity diagram (x = 0.440 ± 0.020, y = 0.350 ± 0.020). It was in.

[Examples 21 to 23]
In Examples 21 to 23, a magnetron stem was manufactured by the following steps.

Example 21: Process A3 → Process B1 → Process C3 → Process D1 → Process E2 → Process F1 → Process E3
Example 22: Process A3 → Process B1 → Process C2 → Process D3 → Process E2 → Process F1 → Process E3
Example 23: Process A3 → Process B1 → Process C3 → Process D3 → Process E2 → Process F1 → Process E3
Step C3: Drying was performed at 60 ° C. for 20 minutes in the air.

  Step D3: A metallized layer was formed by heat treatment at 1460 ° C. for 1.5 hours under a reducing atmosphere (inert atmosphere containing 10 vol% hydrogen). The heat treatment was performed while circulating a reducing atmosphere. The flow rate of the reducing atmosphere gas was 150 L / min.

The same measurements as in Example 18 were performed on Examples 21 to 23. The results are shown in Table 8.

  As can be seen from the table, good results were obtained for the magnetron ceramic part according to this example.

  Magnetron ceramic parts and magnetron using the same according to the present invention are used for ceramic parts such as magnetron stems used in microwave heating equipment such as microwave ovens, magnetrons using such ceramic parts, etc. Can do.

  Moreover, the manufacturing method of the ceramic component for magnetrons based on this invention can be used for manufacture of the said ceramic component.

Sectional drawing which shows an example of the magnetron using the stem for magnetrons of this invention. The figure which showed an example of the metal dummy members of this invention. The figure which showed another example of the metal dummy members of this invention. The figure which showed another example of the metal dummy members of this invention. The figure which shows an example of the EPMA (Mn surface analysis) result of the joining interface of Example 18. The figure which shows an example of the EPMA (Mn surface analysis) result of the joint interface of Example 19. The figure which shows an example of the EPMA (Mo surface analysis) result of the joint interface of Example 19. The figure which shows an example of the EPMA (Si surface analysis) result of the joining interface of Example 19. The figure which shows an example of the EPMA (Mn surface analysis) result of the joining interface of the comparative example 1B.

Claims (28)

In a ceramic part for a magnetron having a ceramic body made of an alumina sintered body and a Mo-Mn metallized layer provided on a part of the surface of the ceramic body,
The ceramic body is an alumina sintered body having a grain boundary phase containing Mn,
A magnetron ceramic component comprising a Mn-rich phase between the ceramic body and the Mo-Mn metallized layer.   2. The ceramic part for magnetron according to claim 1, wherein the Mn-rich phase has an average thickness of 2 to 15 [mu] m.   3. The ceramic part for magnetron according to claim 1, wherein the Mn-rich phase has a glass phase as a main phase. 4.   The ceramic part for a magnetron according to any one of claims 1 to 3, wherein a bonding strength of the metallized layer is 40 kgf / cm or more.   4. The ceramic part for magnetron according to claim 1, wherein a bonding strength of the metallized layer is 60 kgf / cm or more. 5.   6. The magnetron according to claim 1, wherein the metallized layer forming part in which the metallized layer is formed in the ceramic body has a surface roughness Ra of 0.1 μm or more. Ceramic parts.   6. The metallized layer forming part in which the metallized layer is formed in the ceramic body part has a surface roughness Ra of 0.4 to 3.0 [mu] m. Ceramic parts for magnetron.   The ceramic part for a magnetron according to any one of claims 1 to 5, wherein a metallized layer forming part in which the metallized layer is formed in the ceramic main body part is a sintered surface.   The color of the alumina sintered body constituting the ceramic body is in the range of x = 0.440 ± 0.020, y = 0.350 ± 0.020 in the XYZ chromaticity diagram. Item 9. The ceramic part for magnetron according to any one of Items 1 to 8.   The ceramic part for magnetron according to any one of claims 1 to 9, wherein the ceramic part for magnetron is a stem for magnetron.   11. A magnetron using the magnetron ceramic component according to claim 1. In a method of manufacturing a ceramic part for magnetron, which includes a ceramic body portion made of an alumina sintered body and a metallized layer formed on the ceramic body portion,
Preparing a ceramic body made of an alumina sintered body having a grain boundary phase containing Mn;
A step of applying a Mo-Mn paste to a part of the ceramic body and forming a metallized layer by firing at 1350-1500 ° C. in a reducing atmosphere;
A method for producing a ceramic part for magnetron, comprising:   In the step of forming the metallized layer, the Mo—Mn paste is applied to a part of the ceramic body, dried at 40 to 120 ° C., and then fired at 1350 to 1500 ° C. in a reducing atmosphere. The method of manufacturing a ceramic part for a magnetron according to claim 12,   The method of manufacturing a ceramic part for a magnetron according to claim 12, wherein the step of forming the metallized layer is performed until the color of the ceramic body changes.   The color of the ceramic main body after the change is in the range of x = 0.440 ± 0.020 and y = 0.350 ± 0.020 in the XYZ chromaticity diagram. Of manufacturing ceramic parts for magnetron.   The step of forming the metallized layer is performed by firing until the color of the ceramic body is in the range of x = 0.440 ± 0.020, y = 0.350 ± 0.020 in the XYZ chromaticity diagram. The method of manufacturing a ceramic part for magnetron according to any one of claims 12 and 13.   The method for producing a ceramic part for a magnetron according to any one of claims 12 to 16, wherein in the step of forming the metallized layer, the flow rate of the reducing atmosphere gas is 100 liters / minute or more.   The method for manufacturing a ceramic part for a magnetron according to any one of claims 12 to 17, wherein the ceramic body is an alumina sintered body having a Mn content of 1 to 5 mass%.   The method for producing a ceramic part for a magnetron according to any one of claims 12 to 18, wherein the grain boundary phase of the alumina sintered body constituting the ceramic body is a glass phase.   The Mo-Mn paste is subjected to a pulverization treatment for 40 hours or more for each of Mo powder having an average particle size of 0.5 to 10 μm and Mn powder having an average particle size of 0.5 to 10 μm, and then mixed with a binder. The method for producing a ceramic part for magnetron according to any one of claims 12 to 19, wherein the ceramic part is prepared as described above.   The Mo-Mn paste is a mixture of Mo powder having an average particle size of 0.5 to 1.0 μm and Mo powder having an average particle size of 1.3 μm or more, Mn powder, and a binder. The method for producing a ceramic part for magnetron according to any one of claims 12 to 20, wherein the ceramic part is prepared.   The magnetron according to any one of claims 12 to 21, further comprising at least one of a step of inserting a lead portion and a step of performing Ni plating on the metallized layer after the step of forming the metallized layer. Of manufacturing ceramic parts for automobiles.   23. The method of manufacturing a magnetron ceramic part according to claim 22, wherein in the Ni plating step, the magnetron ceramic part and a metal dummy member are mixed and a barrel electrolytic plating method is performed. The ceramic body is a stem body,
The method for manufacturing a magnetron stem according to any one of claims 12 to 23, wherein a deposited layer made of a glass phase is formed between the stem body and the metallized layer.   The method for producing a magnetron stem according to any one of claims 12 to 24, wherein in the step of forming the metallized layer, a reducing atmosphere is circulated during firing.   26. The method for producing a magnetron ceramic component according to claim 12, wherein the magnetron ceramic component is a magnetron stem. In a method of manufacturing a ceramic part for magnetron, which includes a ceramic body portion made of an alumina sintered body and a metallized layer formed on the ceramic body portion,
Preparing a ceramic body made of an alumina sintered body containing a grain boundary phase containing Mn;
Each of the Mo powder having an average particle size of 0.5 to 10 μm and the Mn powder having an average particle size of 0.5 to 10 μm was subjected to crushing treatment for 40 hours or more, and then mixed with a binder to obtain a Mo-Mn paste. A step of preparing;
A step of forming the metallized layer by applying the Mo-Mn paste to a part of the ceramic body and drying, followed by firing in a reducing atmosphere at 1350-1500 ° C;
A method for producing a ceramic part for magnetron, comprising: In a method of manufacturing a ceramic part for magnetron, which includes a ceramic body portion made of an alumina sintered body and a metallized layer formed on the ceramic body portion,
Preparing a ceramic body made of an alumina sintered body containing a grain boundary phase containing Mn;
The Mo-Mn paste is a mixture of Mo powder having an average particle size of 0.5 to 1.0 μm and Mo powder having an average particle size of 1.3 μm or more, Mn powder, and a binder. Preparing a system paste; and
A step of forming the metallized layer by applying the Mo-Mn paste to a part of the ceramic body and drying, followed by firing in a reducing atmosphere at 1350-1500 ° C;
A method for producing a ceramic part for magnetron, comprising:

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