JPS61136064A - Coupling for ceramic with metal - Google Patents

Abstract

PURPOSE:To minimize use of metal with low expansion coefficient by affixing a metal member having a low expansion coefficient to the mother material of metal as coupling part for a ceramic member. CONSTITUTION:A base metal 1 made of SUS 304L and a pure titanium ring 3 of JIS2 type are ultrasonic cleaned in athetone and laid one over another concentrically by their joint faces 4 to be followed by diffusive jointing. There after the fastening part 3a at the time when a seal ring 2 of SiC is hot fitted is machined. Seal ring 2 is hot fitted on this part at a temp. of 120 deg.C. Besides lesser use of titanium, most of the machining process is made at the base metal 1 to minimize machining of the titanium part, which will ensure that a mechani cal seal is manufactured very cheaply.

Description

[Detailed Description of the Invention] (Field of Application of the Invention) This invention relates to the improvement of a ceramic-metal joint formed by shrink-fitting a ceramic part to a metal base material, and is applicable to mechanical devices such as submersible pumps. It can be used to make seals, general bearings, rotating shafts, etc.

(Prior Art) In recent years, mechanical seals such as submersible pumps, general bearings, and rotating shaft gaskets are required to have wear resistance, so ceramics have been increasingly used in recent years.

However, since ceramics are generally expensive, the cost must be reduced as much as possible. For this reason, taking a mechanical seal as an example, conventionally, as shown in Fig. 1, a metal base 1. a, 1
Ceramic seal rings 2a and 2b were shrink-fitted to the seal ring 2a and 2b to make only the sliding part made of ceramic.

However, in order to shrink fit the two, a metal with a low expansion coefficient is used for the metal base metal in order to prevent destruction by reducing the compressive force that acts on the ceramic to less than necessary due to temperature changes during processing and use. has been done. Metals with low expansion coefficients include titanium and its alloys, cemented carbide, and iron-nickel-cobalt alloys, but cemented carbide is extremely difficult to machine, and iron-nickel-cobalt alloys have poor corrosion resistance. Since corrosion resistance is sometimes required for mechanical seals such as submersible pumps, titanium and its alloys are often used.

(Problem to be solved) Metals with low expansion coefficients are generally expensive, and titanium and its alloys are particularly expensive compared to metals such as stainless steel. Because machining is difficult and time-consuming, mechanical seals, bearings, rotating shafts, and other joints made by shrink-fitting ceramics to low-expansion-coefficient metals have become extremely expensive. Therefore, it has been desired to obtain such a bonded body at low cost.

(Means for solving the problem) When shrink-fitting a ceramic part to a metal base material, after joining a metal with a low coefficient of expansion to a metal base metal that is inexpensive and easy to machine, the ceramic part is Shrink fit.

(Function) Only the tightening part of the metal base metal during shrink fitting is made of a metal with a low coefficient of expansion that is difficult to machine, and the rest is made of cheap and easy-to-machine metal, reducing material costs and ease of processing. An inexpensive joined body can be obtained from both sides.

(Example 1) One implementation envy for mechanical seals of submersible pumps 5 An example will be explained using FIG. 2.

5USz1304L base metal 1 (outer diameter 94, titanium ring joint outer diameter 72, inner diameter 50, thickness 20 tab) and J
A pure titanium ring 3 of type I82 (outer diameter 94, inner diameter 74, thickness 10) was ultrasonically cleaned in acetone and then diffusion bonded for 0 minutes. Thereafter, the tightening portion 3a when the SiC seal ring 2 was shrink-fitted was cut. And seal ring 2 (outer diameter 90, inner diameter 76, thickness 7) is attached to this part.
were shrink-fitted at 120°C. Since the amount of titanium used is very small and most of the machining is done on the base metal 1 and the machining of the titanium part is kept to a minimum, the mechanical seal can be manufactured at a very low cost.

(Embodiment 2) An embodiment in which one mole is attached to a mechanical seal of a submersible pump will be described with reference to FIG.

After ultrasonic cleaning, a JIS Class 2 pure titanium ring 5 (outer diameter 94, inner diameter 88, thickness 7 mm) flat 6 was placed on the same base metal 1 as in Example 1, concentrically stacked on the bonding surface 4, and diffusion bonded. After that, the shrink fit is tightened by cutting the part 5a and using an SIC seal ring 6 (outer diameter: 90 mm, inner diameter: 76 mm).
, thickness 7 mm) were shrink-fitted. The effects of this embodiment are the same as those of the first embodiment.

(Example 3) An example of a rotating shaft will be described using FIG. 4.

5 JI class 82 titanium shaft 8 (outer diameter 30, length 15) with machined US804L rotating shaft 7 (outer diameter 30 mm) and shrink-fit tightening part 9 (inner diameter 20 mm, depth 10 mm)
After ultrasonic cleaning in acetone, they were stacked concentrically at the bonding surface 10 and heated at a temperature of 960°C in a vacuum of about 1O-4 Torr.
Diffusion bonding was performed at a pressure of 0.5 ky/ma and a time of 30 minutes. After that, the SiC sliding rotating shaft 11 (outer diameter 30mm
, the outer diameter of the shrink-fit portion was 20 mm, and the same length was 10 mm), and the shrink-fit portion was shrink-fitted at 120°C.

The effect of this embodiment is also similar to the previous embodiment.

(Other Examples) As the low expansion coefficient metal used in the present invention, titanium and its alloys are preferable when corrosion resistance and flatness are required, but when corrosion resistance is not required, nickel and its alloys, iron, nickel, etc. It can be an alloy of cobalt or the like.

In addition, common steel materials such as stainless steel and iron are used as inexpensive alloy metals.

As the ceramic, general ceramics such as silicon nitride, sialon, alumina, and zirconia are used in addition to silicon carbide.

In addition to diffusion bonding, brazing, soldering, welding, and other pressure welding methods are used as bonding methods, but the diffusion bonding method is particularly desirable when precision bonding and corrosion resistance are required.

Naturally, a diffusion bonding method using an insert material is also applicable.

(Effects of the Invention) As described above, according to the present invention, the amount of metals with low expansion coefficients that are expensive materials such as titanium and titanium alloys can be minimized, and most of the metals can be made inexpensive. Since it can be made from a metal that is easy to process, it is not only cheaper in terms of material cost, but also eliminates the need for extensive machining such as cutting, drilling, and threading, which would be required if the entire alloy was made of titanium. It is also cheaper in terms of processing, so a very inexpensive joined body can be obtained.

[Brief explanation of the drawing]

It is a schematic side view. In the drawing, 1 is a 5US304L base metal (metal base material), 3 and 5 are pure titanium rings (low expansion coefficient metal parts), 2 and 6 are SiC seal rings (ceramic parts), and 7 is a rotating part. The shaft (metal base material), 8 is a titanium shaft (low expansion metal part), and 11 is a sliding rotation shaft (ceramic part).

Claims (5)

[Claims] (1) In a ceramic-metal bonded body formed by shrink-fitting a ceramic component to a metal base material, a metal component with a low coefficient of expansion is joined to the metal base material, and the tightening portion of the ceramic component is bonded to the metal base material. The above-mentioned joined body formed by forming. (2) The joined body has the metal base material as a base metal, the low expansion coefficient metal ring is joined to the base metal to form the tightening part, and a ceramic seal is attached to the tightening part. The joined body according to claim 1, which is a mechanical seal formed by shrink-fitting a ring. (3) In the joined body, the metal base material is used as a base metal, the low expansion coefficient metal ring is joined to the base metal to form the fastening part, and the fastening part is made of a ceramic material. The joined body according to claim 1, which is a bearing formed by shrink-fitting rings. (4) The joined body has the metal base material as a rotating shaft, the metal component with a low expansion coefficient is joined to the rotating shaft to form the fastening part, and a ceramic sliding member is attached to the fastening part. The joined body according to claim 1, which is a rotating shaft formed by shrink-fitting a rotating shaft. (5) Claims 1, 2, 3, and 4, wherein the metal with a low expansion coefficient is titanium or an alloy thereof.
Zygote as described in section.