JPS58196187A - Diffusion joining method - Google Patents

Abstract

PURPOSE:To eliminate the defective contact between objects to be joined and to join said objects uniformly by pressing top and bottom dies while interposing a member softer than the parts to be joined between the top or bottom die and the objects to be welded so that the objects to be joined are diffusion-joined to each other. CONSTITUTION:Objects 3, 4 to be joined are disposed between a top die 1 and a bottom die 2 which are respectively rigid materials. A metallic pad 5 which is a member softer than the objects 3, 4 is interposed between, for example, the die 1 and the object 3. The objects are diffusion-joined in this state under application of pressing force P relatively on both dies 1, 2. Mild steel or copper is usable if the objects 3, 4 are, for example, a Ti-6Al-4V alloy (900-950 deg.C diffusion joining temp.). The objects are joined uniformly by the above-mentioned method; in addition, the manufacturing tolerance of the dies and the influence on the accuracy of a press are decreased; therefore, the cost of jigs and tools and the equipment cost for working are reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a method for diffusion bonding objects to be welded by arranging them between an upper die and a lower die and pressing the two dies relative to each other. .

Recently, as a method for joining thin plate molded products or their materials,
Instead of using conventional rivets or fasteners, a method of directly joining members together in a solid state by diffusion bonding is attracting attention from the perspective of weight and cost reduction. FIG. 1 is a schematic explanatory diagram of the conventional diffusion bonding method. As shown in the figure, a press force P is applied to the contact area between the upper die 1, the lower die 2 and the workpiece 4 to a predetermined amount By applying surface pressure and heating and maintaining it at a temperature at which diffusion bonding occurs, the contact surfaces of the members to which the surface pressure is applied are diffusion bonded. However, this diffusion bonding method has the following drawbacks when the mold is a rigid body.

(1) If there is a manufacturing error in the upper or lower molds or if the precision of the press used is poor, the parallelism between the molds will be disrupted, and the surface pressure on the surfaces to be joined will become uneven, making it impossible to obtain a sound joint.

(11) Even if the press force P is increased forcibly, if the workpiece is a thin plate, a sufficient amount of plastic deformation in the thickness direction cannot be obtained, and the mold tolerance between the contact surfaces cannot be absorbed, so a uniform bond cannot be obtained. do not have.

Using the rigid body shown in Figure 1, Ti-6Al-4v
When we conducted a bonding test on a thin plate (thickness: 1.0 M),
As shown in the results of the ultrasonic flaw detection test in FIG. 6, a problem occurred in which non-uniform bonding occurred. The joining of parts by diffusion bonding in conjunction with the superplastic forming method is a key point in promoting the integrated processing of thin sheet metal structures.

The present invention was proposed for the purpose of solving the drawbacks of the above-mentioned conventional method and establishing a method for uniformizing the bonding quality. In a bonding method in which the objects to be welded are placed and diffusion bonded while the upper mold and the lower mold are relatively pressed, there is a space between the upper mold or the lower mold and the object that is higher than the object to be welded. This relates to a diffusion bonding method characterized by pressing both dies while interposing a soft member.

The present invention will be explained below with reference to FIG. 2, in which 1 is a rigid upper mold, 2 is a rigid lower mold, and 6 is a rigid upper mold.
．． Reference numeral 4 denotes objects to be welded, and these objects 6.4 are placed between the upper die 1 and the lower die 2, as in the conventional method described above. In this case, in the present invention, a metal pad 5 made of a material softer than the object to be welded 6.4 is interposed between the upper die 1 and the object to be welded 6. This method involves diffusion bonding while relatively applying a pressing force P. It should be noted that the metal bat "5" is attached to the workpiece 3. at the diffusion bonding temperature.
Workpiece 3.4 must be made of a metal that is softer than Ti-6At-4V alloy (diffusion bonding temperature 9
00~950r), mild steel, copper, etc. can be used.

In FIG. 2, by relatively pressing the upper and lower dies 1.2 with a press force P, a contact surface pressure C is applied between the workpieces 6.4. In this case, the manufacturing error of mold 1.2,
If a poor contact area with the workpiece 6.4 occurs due to poor press parallelism, the metal pad 5 absorbs the gap irregularity by its own plastic deformation t7 and makes uniform contact. act.

As mentioned above, according to the method of the present invention, the soft metal bat''
The gap irregularity absorbing effect due to plastic deformation in No. 5 provides the following effects.

(11) It is possible to eliminate the poor contact between the objects to be bonded, which occurs in the conventional method, and therefore there is no non-bonded area, and uniform bonding can be obtained. 6
This shows the results of an ultrasonic flaw detection test when diffusion bonding was performed using At-4V, plate thickness 1.011111)Y, and the same pressing force using the mold and metal parapet shown in Figure 2. The bonding effect is very clearly visible.

(21) Not only can the above-mentioned uniform bonding be obtained, but also the effects of mold manufacturing tolerances and press accuracy are reduced, so jigs and tools and processing equipment costs can be reduced.

Note that the metal pad 5 is a consumable item and may be replaced each time, or may be used by being incorporated into a mold.

Furthermore, depending on the shape of the object to be welded, the metal pad 5 may be interposed between the upper mold 1 and the object 6 as shown in FIG. 2, or between the lower mold 2 and the object 4 to be welded. It may be inserted in between.

[Brief explanation of drawings]

Fig. 1 is a schematic explanatory diagram of the conventional method, Fig. 2 is a schematic explanatory diagram of the method of the present invention, Fig. 3 is a diagram showing the ultrasonic flaw detection results of the diffusion bonding area by the conventional method, and Fig. 4 is a diagram of the method of the present invention. It is a figure which shows the ultrasonic flaw detection result of the diffusion bonding area by a method. 1: Upper mold 2: Lower mold 6.4: Object to be welded 5: A member softer than the object to be welded (metal bat °). Sub-agent Patent attorney Teru Ito (2 others) (6) Procedural amendment dated September 1 and 0, 1980 Kazuo Wakasugi, Commissioner of the Patent Office Indication of 4 cases 1982 Patent Application No. 76546 and Relationship between Patent Representative Yano -'-・Pari Agent Address Address 2-29 Toranomon-chome, Minato-ku, Tokyo 105 Date of amendment order July 16, 1980 Target of amendment to erase characters Contents of amendment to Drawing 7 Figures 6 and 4 of the drawing are corrected as shown in the attached sheet. The gong shown above

Claims (1)

[Claims] In the bonding method, the objects to be joined are placed between the upper mold and the lower mold, and the objects to be joined are diffusion bonded while the upper mold and the lower mold are relatively pressed. Between things,
A diffusion bonding method characterized by pressing both dies while interposing a member that is softer than the objects to be bonded.