JPS61127674A - Structure of bonding ceramic and metal - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention is suitably used in the field of firmly bonding ceramics and metals.

``Conventional technology'' Ceramics and metals are usually joined by brazing, but since ceramics and metals have significantly different coefficients of thermal expansion, this large expansion difference causes considerable strain to remain in the vicinity of the joint. Become. This strain causes destruction of the brittle ceramic OC. In order to prevent this, low expansion metals such as W and Mo, whose coefficient of thermal expansion is close to that of ceramics, are interposed as a buffer layer between the ceramics and metals to be bonded, and these low expansion metals are sandwiched between Cu. A method of joining the ceramics and metals by interposing a cladding material made of the above as a buffer layer has been proposed ("Ceramic-metal joining structure" devised in Japanese Utility Model Application Publication No. 59-160588). .

"Problems to be Solved by the Invention" However, in the former of the above-mentioned conventional techniques, N1 plating is applied to the joint surface to improve the wettability of the silver solder used as a joint material, but the plating adhesive part There is a risk of peeling due to deterioration, and there are inherent unstable factors in terms of quality. Furthermore, the latter has the disadvantage that not only the combinations of metals that can form the cladding material are limited, but also the usage conditions of the bonded structure are limited due to the lack of bonding strength of the cladding material itself.

"Means for Solving the Problems" The present invention solves the above-mentioned problems of the prior art, and its means include forming a buffer layer between one or more low expansion metals and one or more low Young's modulus metals between the ceramic and the metal. In the case where the buffer layer is bonded by interposing it as a bonding layer, the buffer layer has a width of 0.
This is a ceramic-metal bonding structure characterized by having a thickness of 0.04 to 0.4 times and using brazing as a bonding means.

Low expansion metals include W-Ni alloy, W-Cu alloy,
A metal containing W as a main component or a metal containing Mo as a main component, such as a W-Cu-Ni alloy, a W-Ni-Fe alloy, or a W-Fe-Ni-Cr alloy, is suitable. Low Young's modulus materials include Cu + Ag rNi, F
e-Ni 42% alloy, KOMAR, 5US408, etc. are good.

The buffer layer is a composite layer consisting of two or more layers of one or more low-expansion metals and one or more low Young's modulus metals, but if the thickness of the entire layer is less than 0.04 times the longest width of the bonding surface, the bonding strength will deteriorate. Even if it exceeds 0.4 times, no improvement in effectiveness can be expected, and there is a high possibility that the buffer layer will be deformed by impact during use.

It is desirable that the coefficient of thermal expansion of the low expansion metal is 1.7 times or less that of the ceramic to be joined.

In the present invention, ceramics, the above-mentioned buffer layer, and metal are all joined by brazing at the same time.

"Function" A buffer layer of two or more types of low-expansion metals and one or more low Young's modulus metals alleviates the strain at the joint, and brazing is performed by limiting the thickness of the buffer layer to the above range. , the bonding strength is high.

"Example" Ceramics shown in Table 1, cushioning materials shown in Table 2,
The fillers shown in the table and Ibi-type stainless steel with a precipitation value of JIS standard 5US680 were prepared, and these were arranged in the combinations shown in Table 4 as shown in FIG. 1. In the figure, 1 to 5 are cushioning materials, 6 to 11 are brazing materials, 12 are ceramics, and 18
indicates precipitation hardening stainless steel, both have a diameter of 15 m.
It has a disc or cylindrical shape of m. After the above arrangement, 10 T
The results of the I-ZOD impact value measurement by heating at a temperature of 980 to 980°C in a vacuum of
Also listed in the table. As shown in FIG. 2, the knee ZOD impact value was determined by fixing the precipitation hardening stainless steel 18 and using point P of 10 [:Kaku:I] from the joint surface of the ceramic 12 as the impact point.

Table 8 As can be seen from Table 4, the bonding structures 1 to 15 of the present invention all had an impact value of 8 [1 l-an] or more, but the bonding structures 15, 16°19 and 20 outside the scope of the present invention The impact value was as low as less than 8[-.1], and in the joint structures 17 and 18, which were also outside the range, the cushioning material was deformed when the impact value was measured.

"Effects of the Invention" According to the present invention, a joint structure with extremely high joint strength can be applied to various engine parts such as intake and exhaust valves of internal combustion engines.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a ceramic-metal bonding structure according to an embodiment of the present invention. FIG. 2 is a side view for explaining the I-ZOD impact value measuring method. 1-5...buffer layer, 6-11...brazing material, 12...
・Ceramics, 18... Precipitation hardening type stainless steel Diagram 1 Procedures Correction Shoyama Sei) P. 4, 1985 1. Indication of the incident 1985 Patent Application No. 247879 2. Name of the invention Ceramics and metals Connection structure with Description field. 5. Contents of amendment (1) Table 2 on page 7 of the specification will be corrected separately in the paper circular. '.ゝTable 4 on page 9 of the same document is revised in the attached document. In the first line and the second line of page 10, “joint structures 1 to 15 of the present invention” are replaced with “joint structures 1 to 14 and 21 of the present invention”.
~26 has been corrected to ``. that's all

Claims (1)

[Claims] In the case where ceramics and metal are bonded by interposing one or more low expansion metals and one or more low Young's modulus metals as a buffer layer, the buffer layer has a width of 0.04 to 0.04 of the longest width of the bonding surface.
A bonding structure between ceramics and metal, which is 0.4 times thicker and is bonded by brazing.