JP2006117493A - Joined structure of ceramic member and metallic member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a good joined body of a ceramic member and a metallic member where a porous ceramic member functions as a porous body and where cracks are not caused at the joined part of the ceramic member and the metallic member. <P>SOLUTION: In the joined structure of the ceramic member 1 and the metallic member 2, an annular spot facing part 2a is formed on the inner peripheral surface of at least one side of the cylindrical metallic member 2 and an annular grooved part 2b communicating to the annular spot facing part 2a along the outer periphery at one end surface of the ceramic member 1 is formed on the inner surface of the metallic member 2. One side of the cylindrical ceramic member 1 is inserted in the annular spot facing part 2a and the outer peripheral surface of the ceramic member 1 and the inner surface of the metallic member 2 are brazed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a joint structure between a ceramic member and a metal member, and more particularly to a joint structure when the ceramic member is made of porous ceramics.

  Porous ceramics have excellent heat resistance, and because of their chemical stability, they are expected to be used as membranes, for example, separation membranes and filters, in processes where organic membranes cannot be applied. These are rarely used alone as a ceramic member, and most of them are used as a joined body with a metal member such as a mounting bracket. Therefore, it is necessary to join the metal member. As such a joining technique, a joining method such as press fitting, shrink fitting, brazing, or the like is used. However, when joining with excellent airtightness is required, a joining method by brazing has been frequently used.

  The active metal brazing method and the metallized brazing method are mainly used as the joining method by brazing of the ceramic member. In particular, the active metal brazing method is more complicated than the metallized brazing method. Because it is not necessary, it is attracting attention.

  In the active metal brazing method, a brazing material containing an active metal such as titanium (Ti) or zirconium (Zr) is interposed and heated to a temperature at which the brazing material melts, so that the active metal reacts with the ceramic and becomes strong. A reaction layer is formed. As a result, a joined body is obtained in which the ceramic member and the metal member are firmly bonded via the brazing material.

  However, porous ceramics with high porosity have lower mechanical strength than non-porous ceramics, so cracks often occur during brazing with joint structures similar to non-porous ceramics. There was a problem that it was difficult to get.

Therefore, it has been proposed to use a porous ceramic member whose pores are filled with ceramics (see, for example, Patent Document 1 below). As a result, it is possible to provide a ceramic member that does not cause cracks or the like at the joint portion between the ceramic member and the metal member.
JP 2001-220252 A

  However, if a porous ceramic member whose pores are filled with ceramics is used, the pores are buried and the function as a porous body is lost, and liquid or liquid is lost via the pores of the ceramic member. It becomes impossible to transmit gas. Therefore, in the case where the ceramic member is used for the purpose of allowing liquid or gas to permeate, it is impossible to employ this joining structure.

  In addition, it is conceivable to fill the pores with ceramics only at the joint between the ceramic member and the metal member, but it is extremely difficult to fill only a portion of the ceramic member with ceramics.

  Accordingly, the present invention has been completed in view of the above-described problems, and an object of the present invention is to make a porous ceramic member function as a porous body and to prevent cracks and the like from being generated at the joint portion between the ceramic member and the metal member. The object is to provide a good joined body of a member and a metal member.

  The joining structure of the ceramic member and the metal member according to the present invention is such that an annular countersunk portion is formed on at least one inner peripheral surface of the cylindrical metal member, and the cylindrical member is formed on the countersunk portion. A ceramic member and metal member joining structure in which one end is inserted and the outer peripheral surface of the ceramic member and the inner peripheral surface of the metal member are brazed, and the ceramic member is formed on the inner surface of the metal member. An annular groove portion that communicates with the counterbore portion is formed along the outer periphery of the one end face of the head.

  In the above structure, the ceramic member and metal member joining structure according to the present invention is preferably such that one end surface of the ceramic member is in contact with the metal member inside the groove. .

  In the joining structure of the ceramic member and the metal member according to the present invention, an annular countersunk portion is formed on the inner peripheral surface of at least one end of the cylindrical metal member, and one end of the cylindrical ceramic member is formed on the countersunk portion. The ceramic member and the metal member are joined to each other by brazing the outer peripheral surface of the ceramic member and the inner peripheral surface of the metal member, and are seated along the outer periphery of the ceramic member on the inner surface of the metal member. By forming the annular groove portion communicating with the feeding portion, the space between the outer peripheral surface of the metal member and the inner circumferential surface of the seat feeding portion becomes thin, and the joint portion between the ceramic member and the metal member is further thickened by the groove portion. As a result, the stress due to the difference in thermal expansion between the ceramic member and the thick metal member hardly acts on the porous ceramic member, and the groove is formed. Since the brazing material that joins the Mick member and the metal member does not collect at the corners on the outer periphery of the end surface of the ceramic member, the ceramic member and the metal member that do not generate cracks at the joint portion of the ceramic member with the metal member are good. Can be provided.

  In the above structure, the ceramic member and the metal member according to the present invention preferably have a structure in which one end surface of the ceramic member is in contact with the metal member inside the groove. It is possible to accurately and easily manage the length of the joint portion.

Next, the joining structure between the ceramic member and the metal member of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a sectional view showing an example of an embodiment of a bonding structure between a ceramic member and a metal member of the present invention, and FIG. 2 is another example of an embodiment of a bonding structure between a ceramic member and a metal member of the present invention. 1 is a ceramic member having a cylindrical shape made of porous ceramics, 2 is a metal member having a cylindrical shape in which an annular counter-sink portion 2a is formed on at least one inner circumferential surface, and 3 is a metallization. Is a layer.

  And the joining structure of the ceramic member and metal member of this invention inserts the one end part of the ceramic member 1 in the countersink part 2a of the metal member 2, and the outer peripheral surface of the ceramic member 1, the inner peripheral surface of the metal member 2, and And an annular groove portion 2b communicating with the countersink portion 2a along the outer periphery of the ceramic member 1 is formed.

  Specifically, in FIG. 1, a metal member 2 is brazed to both ends of a ceramic member 1 via a brazing material layer 3 containing an active metal component. Further, a groove portion 2b is formed along the portion of the countersink portion 2a where the outer peripheral portion of the end surface of the ceramic member 1 faces the countersink portion 2a.

  2 has a structure in which the metal member 2 of FIG. 1 is divided, and a protrusion 2d is formed on the inner peripheral side end surface of the cylindrical metal member 2 in contact with the end surface of the ceramic member 1, and the metal member 2 of FIG. A cylindrical support member 2c is joined to the metal member 2 by brazing or welding so as to extend the outer peripheral surface. In the structure of FIG. 2 as well, a groove 2b is formed between the support member 2c and the protrusion 2d.

The ceramic member 1 is made of alumina (Al ₂ O ₃ ) ceramics, mullite (3Al ₂ O ₃ .2SiO ₂ ) ceramics, aluminum nitride (AlN) ceramics, cordierite (2MgO · 2Al ₂ O ₃ · 5SiO ₂ ). It is a cylindrical body or a tubular body made of a porous ceramic such as ceramics or zirconia (Zr) ceramics. In addition, the shape of the cylinder can be appropriately selected according to the application, such as a cylindrical shape or a polygonal cylindrical shape.

  The porous ceramic member 1 has an average pore diameter of about 0.1 to 100 μm and a porosity of about 20 to 60%. The ceramic member 1 is formed into a predetermined shape and size by powder press molding using a mold and then firing. The porosity is the ratio of the volume of the pores contained in the ceramic member 1 to the entire volume of the ceramic member 1.

  The metal member 2 is necessary for attaching the ceramic member 1 to an external device or the like. The metal member 2 is a cylindrical body or a tubular body made of a metal such as iron (Fe) -nickel (Ni) -cobalt (Co) alloy, Fe-Ni alloy, stainless steel (SUS). Those having a thermal expansion coefficient close to that of the ceramic member 1 to be joined are preferable, and an Fe—Ni—Co alloy, an Fe—Ni alloy, or the like is preferably used.

  The metal member 2 is formed in a predetermined shape and size by, for example, applying a conventionally known metal processing method such as a rolling method or a punching method to an ingot (lumb) made of, for example, an Fe—Ni—Co alloy. In addition, the shape of the cylinder can be appropriately selected according to the use, such as a cylindrical shape or a polygonal cylindrical shape, like the ceramic member 1.

  Then, at the joint portion with the ceramic member 1, a countersink portion 2 a is provided so that the end portion of the ceramic member 1 is fitted. By providing the countersunk portion 2a, circumferential positioning can be performed so that the cylindrical ceramic member 1 and the cylindrical metal member 2 are coaxial. Furthermore, when the countersink part 2a is brought into contact with the end surface of the ceramic member 1, the insertion length of the ceramic member 1 can be positioned. Moreover, since the joint part of the metal member 2 is arrange | positioned on the outer side of the outer peripheral surface of the ceramic member 1 by providing the countersunk part 2a in the metal member 2, the ceramic member 1 and the metal member 2 are brazed. After that, the stress due to the difference in thermal expansion from the metal member 2 applied to the ceramic member 1 acts as a compressive stress. Since the ceramic member 1 is resistant to compressive stress, the ceramic member 1 is unlikely to be damaged such as cracks.

  In addition, the countersunk portion 2 a of the metal member 2 reduces the thickness of the portion of the metal member 2 joined to the outer peripheral surface of the ceramic member 1, thereby reducing the stress due to the difference in thermal expansion applied to the ceramic member 1. is there.

  Although it is conceivable that the countersunk portion is provided on the inner peripheral side of the end face of the ceramic member 1, in this case, the ceramic member 1 is arranged outside the metal member 2, and therefore, after brazing applied to the ceramic member 1. The stress due to the difference in thermal expansion is applied as a tensile stress in the circumferential direction of the ceramic member 1, and the ceramic member 1 is likely to be damaged such as cracks. Since the thickness of the member 2 increases, the stress due to the difference in thermal expansion from the metal member 2 acting on the ceramic member 1 increases, which is not suitable.

  Even if the countersunk portion 2 a of the metal member 2 is provided, the ceramic member 1 may be damaged depending on the porosity of the porous ceramic member 1. However, in the present invention, a groove portion 2b connected to the countersink portion 2a is formed along the outer periphery of the end surface of the ceramic member 1 on the surface of the bottom surface of the countersink portion 2a facing the end surface of the ceramic member 1, and this groove portion 2b. As a result, the periphery (the support member 2c in FIG. 2) of the thin countersunk portion 2a that supports the outer periphery of the ceramic member 1 becomes longer in the axial direction. The distance between the joint portion of the ceramic member 1 and the thick portion of the metal member 2 is increased because the periphery of the countersunk portion 2a is elongated in the axial direction, and thermal expansion between the metal member 2 and the ceramic member 1 is increased. The stress due to the difference can be alleviated, and even if a large stress due to the difference in thermal expansion with the metal member 2 is generated, the periphery of the thin countersunk portion 2a located on the outer peripheral side of the groove 2b serves as a buffer for stress relaxation. It functions, and it becomes possible to relieve | moderate the stress by the thermal expansion difference with the metal member 2 added to the ceramic member 1 significantly.

  Furthermore, if the protrusion 2d of the metal member 2 is in contact with the inside of the groove 2b, the axial insertion length of the ceramic member 1 can be easily positioned, and the joining portion between the metal member 2 and the ceramic member 1 can be easily positioned. This is preferable because the length can be accurately controlled.

  Further, the surplus brazing material when the ceramic member 1 and the metal member 2 are joined flows into the groove portion 2 b, and the brazing material joining the ceramic member 1 and the metal member 2 is a corner portion on the outer periphery of the end face of the ceramic member 1. Don't get stuck in. Therefore, stress due to a difference in thermal expansion from the brazing material does not act on the ceramic member 1, and damage to the ceramic member 1 due to brazing material accumulation can be reliably prevented.

  Moreover, when the diameter of the metal member 2 is small and it is difficult to process the groove portion 2b on the bottom surface of the countersink portion 2a, the metal member 2 has one end surface that contacts the end surface of the ceramic member 1, as shown in FIG. The cylindrical support member 2c is joined to the outer peripheral portion of one end surface of the metal member 2 by brazing, welding or the like so as to extend the outer peripheral surface of the metal member 2 while forming the protruding portion 2d on the inner peripheral side of The countersink portion 2a is formed by the support member 2c, and the groove portion 2b is formed between the support member 2c and the protruding portion 2d.

  The brazing material layer 3 is made of active metal brazing, and the joining between these two members is performed by an active metal brazing method. As the active metal brazing material used for this joining, a paste or plate-like material in which Ti or Zr is added to a silver (Ag) -copper (Cu) eutectic composition is used. The ratio of the active metal component contained in the brazing material is usually about 1 to 10% by weight.

  Such a brazing material layer 3 is formed at the joint between the ceramic member 1 and the metal member 2, and brazing is performed at a temperature of about 800 ° C to 900 ° C. Since each member has a different coefficient of thermal expansion, stress is generated in each member by brazing. In particular, when the stress generated in the ceramic member 1 exceeds the strength of the ceramic member 1, the ceramic member 1 is destroyed. Therefore, the metal member 2 to be joined has a larger coefficient of thermal expansion than the ceramic member 1. It is good. Thereby, since the compressive strength of the ceramic member 1 is stronger than the tensile strength, when the cylindrical metal member 2 and the ceramic member 1 are brazed, a compressive stress is generated in the ceramic member 1. The inner periphery of the metal member 2 is in contact with the outer periphery.

  As described above, it is possible to provide a good joined body of the ceramic member 1 and the metal member 2 in which the porous ceramic member functions as a porous body and the ceramic member 1 and the metal member 2 are less likely to crack. it can.

  It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. For example, in the above embodiment, the case where the brazing material layer 3 is made of active metal brazing has been described. However, metallization of tungsten (W), molybdenum (Mo), manganese (Mn), or the like is made at the joint portion of the ceramic member 1. A so-called metallized brazing method may be used in which a layer is formed and the metallized layer and the metal member 2 are joined using a brazing material such as Ag brazing or Ag-Cu brazing.

  Further, the outer peripheral side of the end surface of the ceramic member 1 may be cut out so as to reduce the outer diameter of the cylinder of the ceramic member 1, and may be inserted and joined to the countersunk portion 2 a of the metal member 2. In this case, the outer peripheral surface of the metal member 2 and the outer peripheral surface of the ceramic member 1 can have the same outer diameter.

It is sectional drawing which shows an example of embodiment of the joining structure of the ceramic member and metal member of this invention. It is sectional drawing which shows the other example of embodiment of the joining structure of the ceramic member and metal member of this invention.

Explanation of symbols

1: Ceramic member 2: Metal member 2a: Countersink part 2b: Groove part 3: Brazing material layer

Claims (2)

An annular countersunk portion is formed on the inner peripheral surface of at least one end of the cylindrical metal member, and one end of the cylindrical ceramic member is inserted into the countersunk portion, and the outer peripheral surface of the ceramic member and the A joining structure of a ceramic member and a metal member formed by brazing the inner surface of the metal member,
A joining structure between a ceramic member and a metal member, wherein an annular groove portion communicating with the counter-sink portion is formed on an inner surface of the metal member along an outer periphery of one end surface of the ceramic member. The joining structure of a ceramic member and a metal member according to claim 1, wherein one end surface of the ceramic member is in contact with the metal member inside the groove.

Images