JP2007313550A - Method for joining ceramic, and joined member obtained thereby - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To firmly join a ceramic material and a metallic material being different materials at ordinary temperature in an atmospheric enviroment without using adhesives or joining agents. <P>SOLUTION: A soft metal material represented by aluminum, copper or the like is superimposed on a ceramic member, and a rotary rod is inserted under pressure from the upper part of the metal material, so as to generate frictional heat between the rotary rod and the metal member. In this way, only the metal member in the vicinity of the joining boundary is locally softened and plastically fluidized. The softened and plastically fluidized metal material in the vicinity of the joining boundary is directly pressed against the ceramic material, so as to be joined. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a method for firmly bonding a ceramic material and a metal material, which are different materials, in a normal temperature / atmosphere atmosphere without using an adhesive or a bonding agent.

  As represented by electronic parts, biomaterials, heat-resistant and wear-resistant structural members, various ceramic materials are widely used in both functions and structural characteristics.

  In the use cases of these ceramic materials, it is rather exceptional that the ceramic material is used alone, and the ceramic material is often used by being bonded to a metal material.

The bonding method between the ceramic material and the metal material is generally performed by an adhesive made of an epoxy resin or the like as the simplest method.
For example, a piezoelectric ceramic piezoelectric element plate constituting a bimorph piezoelectric actuator and a metal electrode plate or reinforcing plate are joined by an adhesive (Patent Document 1).

  On the other hand, it is known that the adhesive strength of epoxy resin is about half when it is 80 ° C. or higher compared to 25 ° C. For this reason, when using this joining member in a high temperature state, or in order to obtain higher joining strength, there is a limit in correspondence with joining with an adhesive made of epoxy resin or the like.

  In general, soldering using solder and silver solder are typical methods for joining ceramic materials to metal materials in order to cope with use in high temperature conditions and to obtain higher joint strength than joining with adhesives. Joining is performed by brazing using a hard brazing.

  In the joining method of the ceramic material and the metal material using the solder, the surface of the joint portion of the ceramic material or the high melting point metal material is preliminarily subjected to metal plating, and after the solder is attached to the metal plating portion, A method of heating and soldering the ceramic material and the metal material is used. (Patent Document 2)

On the other hand, in the ceramic material-metal material joining method using hard solder,
In the same manner as described above, a hard solder having a melting point of 450 ° C. or higher such as silver solder is attached to a joint portion of a ceramic material or a refractory metal material having a metal layer formed on the surface in advance, and the ceramic material and the metal material are heated to a high temperature. Heating and brazing,
A method of performing brazing after performing surface treatment on the bonding surface of the ceramic member (Patent Document 3),
It has been known.
JP 2000-340850 A JP 2005-82431 A JP 2004-292233 A

  Bonding of a ceramic material to a metal material with an adhesive made of an epoxy resin or the like has a low bonding strength and a low heat resistance temperature. For this reason, the condition range in which the ceramic material-metal material assembly can be used industrially is naturally limited.

  On the other hand, in the soldering method in which solder is attached using hard solder, powder solder or solder paste, since the metal member and the brazing material or solder are both metal materials, the bonding strength between the metal member and the brazing material or solder is However, since the ceramic member and the brazing material or solder are different materials, the bonding strength between the ceramic member and the brazing material or solder is low, and only a low bonding strength is often obtained.

For this reason, the method of brazing the ceramic member and the metal member after etching the surface of the ceramic member with an alkaline solution such as potassium hydroxide to roughen the surface of the ceramic member,
A method of performing soldering by heating after applying metal plating to the surface of the ceramic or metal joint part in advance and attaching solder to the metal plating part,
The ceramic member and the metal member are joined after metallization treatment is performed in which a titanium-based active metal is applied and subjected to high temperature treatment to diffuse titanium in the ceramic or react with the ceramic to form a metal layer on the surface of the ceramic. Application of various joining methods such as methods has been proposed.

However, in both methods, the process becomes complicated and it takes a long time to complete the process.
Productivity is inferior because it is a process in an atmosphere control vessel.
Alternatively, the generation / residue of thermal stress accompanying heating and cooling results in a decrease in strength of the joined body.
Have such difficulties.

  In order to solve the above-mentioned problems, the present invention makes it possible to bond by directly pressing a metal material that is locally softened and plastically flowed in the vicinity of the bonded interface, not the entire bonded member, by mechanical frictional heat generation, and directly pressed against the ceramic material. This is a completely new joining method.

  In this joining method, a frictional heat is generated between the rod and the metal material by press-inserting a rod rotating at a high speed of 1000 rpm or more into the metal member.

Joining is performed by pressing the metal material softened and plastically flowed by frictional heat generated between the rod and the metal material against the ceramic material. (Figure 1)

  In the joining method of the present invention, it is not necessary to perform pretreatment on the surface of both the ceramic member and the metal member, so that the process can be simplified.

  Further, since the bonding is performed at normal temperature, there is no fear that the bonding strength is lowered without causing thermal stress due to the difference in thermal expansion coefficient between the ceramic member and the metal member.

Furthermore, this bonding process can be performed in an open atmosphere, and the pressure holding time of the rod material is completed in an extremely short time of about 10 seconds or less. It is a process that is so simple that it cannot be compared with existing diffusion bonding methods that require time retention.

  A ceramic material is made of a metal material that is made of plastic material such as aluminum and copper (preferably 5 mm or less in thickness) superimposed on a ceramic member, and a rotating rod is inserted under pressure from the top of the metal material and plastically fluidized by friction stirring. The ceramic material and the metal material are joined. At this time, the rotation speed of the rotating rod is preferably 2000 to 3000 rpm.

  At this time, in order to avoid breakage of the ceramic member, a gap is formed between the tip of the rotating rod inserted in the metal material and the surface of the ceramic member, and the bonding is performed without direct contact.

  The clearance between the tip of the rotating rod and the surface of the ceramic member is preferably 20 to 30% of the diameter of the rotating rod.

  The target ceramic materials include all oxides such as alumina, nitrides such as silicon nitride, carbides such as silicon carbide, and the like, and are not particularly limited as a material.

On the other hand, the target metal material is mainly a soft metal typified by copper and Al, which can be easily softened with a normal tool steel rod material, but if it is a metal material capable of softening plastic flow, The material is not particularly limited.

  An example of an actual ceramic-metal joint is shown. (FIG. 2) It can be seen that the ceramic material and the metal material are bonded using the method of the present invention.

  FIG. 3 shows the interface fractured by the post-joining shear test for the A5052Al alloy and the silicon nitride joined body.

  From the figure, a part of silicon nitride is adhered to the Al alloy side, and a part of the silicon nitride is peeled and depressed on the corresponding silicon nitride side.

From this, it can be seen that in this bonded body, a bonding strength higher than that of the silicon nitride base material was formed at the bonding interface between the two materials.

  As a general application method, by joining ceramic members and metal members, by utilizing the advantages of both ceramic materials such as corrosion resistance and wear resistance and metal materials having high toughness, High structure and functional characteristics are expected to be expressed, and it can be used widely as various structural and functional members.

By utilizing the present invention for dental treatment, it is possible to join hydroxyapatite which is a main component of teeth and a silver alloy.
Thereby, the adhesion | attachment of the crown currently performed with the adhesive agent and adhesion | attachment of a prosthesis can be performed more firmly.

  In addition, depending on the progress of future technology, it is expected that it may be developed as a technology that supports silver joints directly to the patient's teeth on the spot where treatment is performed, and that complements conventional joints with adhesives. .

Application of the present technology to bonding between ceramics and metal materials in various electronic parts and semiconductor parts can be cited as the most effective and wide range of application examples.

It is a conceptual diagram of the metal / ceramic joining by friction stirring which concerns on this invention. An example of joining of an Al alloy / silicon nitride joined body is shown. The fracture | rupture example of the junction part of Al alloy / silicon nitride joined body is shown.

Claims (2)

In the ceramic joining method of joining the first member made of ceramic and the second member made of metal, the first member and the second member are overlapped, and then the second member is subjected to frictional stirring, and the first member A ceramic joining method comprising joining a member and a second member. A ceramic joining member joined by the ceramic joining method according to claim 1.