JPS6148486A - Metal ceramic binder and manufacture - 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 relates to a metal-ceramic composite and a method for manufacturing the same. More specifically, the present invention relates to a metal-ceramic bonded body in which metal, ceramic, and glass are bonded together by fitting, and a method for manufacturing the same.

(Conventional technology) Ceramics are hard and have excellent wear resistance, as well as excellent mechanical properties and corrosion resistance at high temperatures. Suitable as a structural material for turbocharger rotors. For this reason, the use of ceramics for gas turbine rotors and turbocharger rotors is being considered. For example, US Pat. No. 4,396,445 discloses a turbine rotor in which the blade portion and the shaft portion are made of ceramics. In a turbine rotor with this structure, a threaded portion is provided at one end of the ceramic shaft to secure the metal compressor impeller.

(Problem to be solved by the invention) However, due to the difference in thermal expansion between the metal material that makes up the compressor impeller and the ceramic material that makes up the shaft, the turbine rotor with this structure The disadvantage is that the threaded part of the shaft may be damaged. In addition, threading on ceramics requires advanced technology,
The drawback is that it is time consuming and expensive. As a countermeasure against this problem, Japanese Utility Model Application Publication No. 57-92097 proposes a structure in which a cylindrical part provided at the end of a metal shaft is fitted onto a ceramic shaft of a turbine rotor. However, in this structure, in order to improve the wear resistance of the bearing abutment part on the surface of the metal shaft, if the outer surface of the metal shaft cylindrical part is surface hardened and then the ceramic shaft is fitted, the outer surface hardened part The disadvantage is that a crank occurs. In addition, after fitting a metal shaft and a ceramic shaft, if surface hardening treatment such as nitriding treatment is applied to the surface of the metal shaft,
There are disadvantages in that the tightening force of the fitting part decreases and the fitting part may come off.

Furthermore, when a metal shaft and a ceramic shaft are fitted together and then quenched, due to phase transformation of the metal shaft due to quenching,
There is a drawback that the fitting part may come off. For this reason, the above-mentioned structure has the drawback that the bearing abutting portion on the surface of the metal shaft lacks a wear-resistant ready-made material, making it impractical.

(Means for Solving the Problems) The first object of the present invention is to provide a metal-ceramic bonded body with a large bonding force and a method for manufacturing the same.
The object of the present invention is to provide a metal-ceramic composite body in which the surface of the metal part has excellent wear resistance, and a method for manufacturing the same.

In the present invention, a protrusion provided on a ceramic member is coupled by fitting to a recess provided on a metal member having a hardened zone and a non-hardened zone having a hardness of Hv 250 to 450 on the surface.
It is a metal-ceramic bonded body in which the deformation region of the metal member due to fitting exists within the unhardened zone, and the hardness of the metal member is set to v250 to 450 by heat treatment).
After a part of the surface of the metal member is hardened to provide a hardened zone, a recess is provided in the metal member, and a protrusion provided on the ceramic member is fitted into the recess to be integrally connected. This is a method of manufacturing a metal-ceramic bonded body in which the metal members are fitted so that the deformation region of the metal members due to fitting is within the unhardened zone.

(Function) In the present invention, the hardness can be increased to Hv250-450 by heat treatment.
The convex portion provided on the ceramic member is fitted into the recessed portion provided on the metal member whose surface has been partially surface hardened, and the ceramic member is bonded. In this case, the hardness of the unhardened zone of the metal member constituting the metal-ceramic composite of the present invention is H
If V is less than 250, the tightening force of the joint will be insufficient, which is not preferable. In addition, if the hardness of the non-hardened zone exceeds Hv450,
This is not preferable because the fitting tends to cause the metal member recess to break. The surface hardening treatment of the metal member is carried out at least on the portions of the metal parts constituting the combined body that are worn out due to friction or sliding with other mechanical parts when the metal-ceramic combined body of the present invention is used. By this surface hardening treatment, a hardened layer is formed on the surface of the metal member, and the abrasion resistance of specific parts of the metal part of the metal-ceramic composite of the present invention is improved. As the surface hardening treatment method, methods such as carburizing, nitriding, surface hardening, electric discharge hardening, and plating can be used. Among these surface hardening treatment methods, carburizing,
Nitriding and surface hardening are preferable because a thick surface hardened layer can be obtained. Furthermore, among the various nitriding methods, the ion nitriding method is particularly preferable because it is easy to adjust the area and hardening depth of the surface hardened portion. As the heat treatment for adjusting the hardness of the metal member, quenching, tempering treatment, or precipitation hardening treatment is used. This heat treatment may be performed before surface hardening treatment of the metal member. In this case, the tempering temperature is preferably higher than the surface hardening temperature. If a metal member whose hardness has been adjusted by tempering below the surface hardening treatment temperature is subjected to surface hardening by heating it above the tempering temperature, it is undesirable because the hardness of the unhardened parts inside the metal member will decrease. . Also,
The tempering treatment and the precipitation treatment can also be carried out simultaneously with the surface hardening treatment. In this case, the hardened metal member is heated in a heating furnace in which the atmosphere inside the furnace is a surface hardening atmosphere. On the other hand, when a convex part of a ceramic member and a concave part of a metal member are connected by fitting, deformation occurs in the joint part in proportion to the dimensional difference between the convex part and the concave part. However, since the surface hardened layer is brittle and cannot be plastically deformed, if this surface hardened portion is plastically deformed by fitting, a crank will occur in the surface hardened layer. Therefore, in the metal-ceramic composite of the present invention, such deformation of the metal member occurs in the unhardened zone of the metal member. In this case, a predetermined distance or more is provided between the deformed portion and the hardened surface zone. The size of this gap should be at least a size that does not cause defects such as cranks on the hardened surface part of the metal member due to the effect of deformation when the metal member is deformed due to fitting. It is determined depending on the processing accuracy of the ceramic member and the metal member, the fitting method of both members, the amount of deformation of the metal member, and the shape and dimensions of both members.

For example, a convex part with a diameter of 7.9 mm provided on a ceramic member □, and a convex part with an inner diameter of 6.8
When fitting into a recess of 111, the distance provided between the deformed part of the metal member and the hardened surface zone is preferably 1 or more, and particularly preferably 2 or more. This is particularly preferable since there is no need for particularly high machining accuracy or positioning accuracy of the hardened surface zone. However, if this distance is less than 1+n, it is not preferable because the processing accuracy of the fitting portion of both members and the positioning accuracy of the surface hardening zone must be particularly high. The upper limit of the above distance may be determined as appropriate by taking into account the position of the part on the surface of the metal member that requires wear resistance and the position of the deformed part due to fitting, but if the position and area of the hardened surface part , is determined to be equal to or larger than the position and area of the part requiring wear resistance on the surface of the metal member.

As a result, the surface height of a given part of the metal part is large,
A defect-free metal/ceramic composite of the present invention can be obtained.

The metal material and the ceramic material constituting the metal-ceramic composite of the present invention can be fitted by shrink fitting, cold fitting, or press fitting. Shrink fitting and cold shrinking are performed by machining the diameter of the convex part of the ceramic component to be larger than the inner diameter of the concave part of the metal component, and heating or cooling one of the parts to be fitted to create a dimensional difference between the two parts that can be fitted. This method uses the dimensional difference to fit the two parts together.
This method is preferable as a fitting method for a metal-ceramic composite body in which the size of the fitting portion is large. In addition, metal materials generally have a larger coefficient of thermal expansion than ceramic members, so
Shrink fitting in which the metal member is heated is more preferable because a large dimensional difference can be obtained with a small temperature difference and a stable shrink fitting operation can be performed.

In this case, the tightness of the shrink fit and cold fit is such that the concave part of the metal member and the convex part of the ceramic member are not damaged after the fitting, and the fitting part is maintained under the usage conditions of the metal-ceramic composite of the present invention. The size shall be such that the required tightening force can be obtained.

On the other hand, press-fitting is a method in which a protrusion of a ceramic member is forced into a recess of a metal member with a smaller diameter than the diameter of the protrusion by applying a load. Ru. The above-mentioned dimensional difference between the diameter of the convex part and the inner diameter of the concave part is absorbed by the elastic and plastic deformation of the metal member, so the finished dimensional difference between the convex part and the concave part before press-fitting is larger than in the case of shrink fit or cold fit. Good too. For this reason, press-fitting is a more preferable method for fitting metal-ceramic composite bodies in which the size of the fitting portion is small.

The shape and dimensions of the concave portion of the metal member and the convex portion of the ceramic member are such that they will not be destroyed by the load applied during press-fitting. In addition, the dimensional difference between the diameter of the convex portion and the inner diameter of the concave portion ensures that the fitting has a tightening force suitable for the usage conditions of the metal-ceramic composite of the present invention, and that both the convex portion and the concave portion are destroyed during press-fitting. The size should be small. Therefore, the dimensional difference is preferably such that the convex part of the ceramic member is 1% to 10% larger than the inner diameter of the recessed part of the metal member, and preferably 1% to 5% larger than the inner diameter of the recessed part of the metal member. is more preferable. If this dimensional difference is less than 1%, the clamping force of the press-fitted portion will be insufficient, and there is a risk that the press-fitted portion will come off during use, which is not preferable. Dimension difference is 10%
If the load exceeds this, the load required for press-fitting will become too large.
This is not preferable since the convex portion of the ceramic member may be destroyed or the recessed portion of the metal member may be damaged during press-fitting. In addition, when the above-mentioned dimensional difference is large, a metal member with a low hardness of the unhardened zone,
When the above-mentioned dimensional difference is small, stable bonding strength can be obtained by using a metal member with high hardness. This press-fitting may be performed at room temperature, or may be performed by heating only the metal member or heating both the metal member and the ceramic member. However, the most preferable method is to heat both members and press fit them together.

This is because heating both parts reduces the deformation resistance of the metal part and reduces the load required for press-fitting, which prevents damage to both parts during press-fitting. This is because the tightening force increases based on the difference in thermal expansion between the two. When heating and press-fitting both members, the press-fitting temperature is preferably below the lower of the tempering temperature of the metal member or the softening temperature of the hardened surface layer, and at least the operating temperature of the press-fitting part. .

If the press-in temperature is higher than the tempering temperature of the metal part,
This is undesirable because the hardness of the non-surface hardened portion of the metal member decreases and the tightening force of the press-fit portion decreases. Furthermore, if the press-fitting temperature is higher than the softening temperature of the surface hardening layer, the effect of the surface hardening treatment will be reduced, which is not preferable. Furthermore, if the press-fitting temperature is lower than the operating temperature of the press-fitting part, when the temperature of the press-fitting part rises to the operating temperature, the thermal expansion of the metal member is generally larger than that of the ceramic member, so the press-fitting part loosens and tightens. This is not preferable because it reduces the applied force.

The metal-ceramic bonded body of the present invention is usually put into use after fitting the metal member and the ceramic member together and then performing finishing processing. Therefore, metal parts that require wear resistance during use must exhibit a predetermined surface hardness even if the surface is ground during finishing. However, the hardness of the surface of a metal member and the change in hardness from the surface to the inside of the metal member due to surface hardening treatment vary depending on the type of metal material constituting the metal member, and the surface hardening method and conditions. For this reason, the amount of surface grinding in finishing processing of metal parts that require wear resistance during use is determined depending on the specified surface hardness, the type of metal material composing the metal member, and the surface hardening method and conditions. . Alternatively, the type of metal material constituting the metal member and the surface hardening method and conditions are determined depending on the amount of final grinding and surface hardness of the metal part.

The metal material constituting the metal-ceramic composite of the present invention is a commercially available metal material whose surface can be hardened by methods such as carburizing, nitriding, surface hardening, electric discharge hardening, and plating. For example, when surface hardening is performed by nitriding, iron alloys containing chromium such as stainless steel, alloy tool steel, nickel-chromium-molybdenum steel, chromium-molybdenum steel, aluminum-chromium-molybdenum steel, titanium, zirconium, etc. An alloy containing the elements is preferred. When surface hardening is performed by ion nitriding, aluminum/chromium/molybdenum steel and stainless steel are preferred because they have high surface hardness (and are hardened from the surface to a deep position);
Chrome-molybdenum steel is the most preferred because it is inexpensive.

Construct the metal-ceramic composite of the present invention!
The ceramic material is selected from silicon nitride, silicon carbide, zirconia, alumina, beryllia, sialon, etc. depending on the intended use of the metal-ceramic composite of the present invention. For example, when making a turbocharger rotor or a gas turbine rotor using the metal-ceramic composite of the present invention, the turbine wheel and its subsequent rotating shaft, which are exposed to the high temperature of exhaust gas and rotate at high speed, have high high-temperature strength and specific gravity. Silicon nitride, which has a small value, is preferred.

(Example) Fig. 1 is a diagram showing the metal
FIG. 3 is a partial cross-sectional view of the ceramic bonded body.

An embodiment will be described below based on FIG.

Silicon nitride (hereinafter referred to as silicon nitride) produced by atmospheric pressure sintering on chiseled spots
A ceramic member 10 having a shape shown in FIG. 1 and having a convex portion 11 with a diameter of 7.0 m and a length of 25 mm was produced from a round bar. In addition, aluminum chromium molybdenum Ii (JIS-SACM6
A round bar (hereinafter referred to as nitrided steel) was heated and held at 830°C for 1 hour, quenched in water at room temperature, and then heated and held at 600°C for 1 hour to temper and adjust the hardness to Hv350.

After processing this round bar to a diameter of 9.3 m, a recess 21 having an inner diameter of 6.8 mm and a depth of 1511 mm was machined at one end to produce a metal member 20 having the shape shown in FIG. 1. Next, the outer surface of the section of the metal member up to a position 1711 points away from the end face on the entrance side of the recess is covered with a mild steel cover, and the remaining outer surface (section 1 in Fig. 1) is covered with a pressure crab at an equivalent pressure of 4 Torr. 2 while heating to 550℃ in a mixed atmosphere consisting of nitrogen and hydrogen.
Metal member subjected to 0-hour ion nitriding treatment (metal member A
) and a metal member (referred to as
A metal member (referred to as metal member B) was produced.

By the ion nitriding treatment under the above conditions, the Vickers hardness of the nitrided part surface increased from Hv (0,1) 350 before the nitriding treatment to Hv (0,1) 1100. In addition, the Vickers hardness at a depth of 0.2 mm from the surface is HV (
0,1) showed 700.

The protrusions 11 of the ceramic member 10 were press-fitted into the recesses 21 of the two types of metal members 20 at 350° C. to produce a metal-ceramic bonded body having the shape shown in FIG. 1. Due to this press-fitting, the section from the entrance of the metal member recess to the depth 13 (section C in Figure 1) is deformed, and the diameter of the metal member is approximately 0.2
tm increased. When the outer surface of the deformed portion of the metal member due to this press-fitting was inspected, no abnormality was found in the metal/ceramic composite using metal member A. In the metal/ceramic bonded body using metal member B, many cracks with a length of about 10 mm and a depth of about 0.5 mm were detected along the axial direction of the metal member.

If the surface-hardened portion of the metal member is deformed by press-fitting in this way, cracks will occur on the surface of the metal member, making it impossible to obtain a sound metal-ceramic bond. On the other hand, in the metal-ceramic composite of the present invention using the metal member A in which the deformed portion due to press fitting is not surface hardened, no cracks occur on the surface of the metal member even if the metal member is deformed due to press fitting.

Ceramic members and metal members made of the same material and having the same shape as in Example 1 were produced. Regarding this metal member, 13. '5mm (assume metal member C)
, 14.5mm (metallic member), 15.5mm (metallic member E) The outer surface of the section up to the distant position is covered with a mild steel cover, and the outer surface of the remaining section is covered with Example 1. Three types of metal members were manufactured by performing ion nitriding treatment under the same conditions. The protrusions of the ceramic member were press-fitted into the recesses of these three types of metal members at 350° C. to produce a metal-ceramic bonded body having the shape shown in FIG. 1. This press fit allows
Each metal member was deformed in a section up to a position 13 mm away from the end face on the side of the recess, and its outer diameter increased. When the outer surface of the deformed portion due to the press-fitting of the metal part of each of the above-mentioned metal/ceramic composites and the surrounding area was inspected, no cracks were found on the outer surface of the metal member E. However, near the boundary between the ion-nitrided part and the non-nitrided part of the metal member C, a crack with a length of about 'lin and a depth of about 0.2R was detected along the axial direction of the metal member. In this way, in the metal-ceramic composite of the present invention in which the deformation region of the metal member due to press-fitting and the surface hardening region of the metal member are separated by a predetermined distance or more, even if the metal member is deformed due to press-fitting, the metal member No cracks occur on the surface.

The diameter is 7.9 (h + a, the length is 25
A ceramic member 10 having a shape shown in FIG. 1 and having a protrusion 11 of 1 m in length was produced. In addition, rod-shaped test pieces with a diameter of 9.3 mm and a length of 801 m were prepared from nitrided steel round bars whose hardness was adjusted to the values shown in Table 1, No. 1 to No. 5, by quenching and tempering. A recess 21 having an inner diameter of 7.75 mm and a depth of 15 s1 was machined at one end of this test piece to produce a metal member 20 having the shape shown in FIG. 1. Similarly, a rod-shaped test piece with a diameter of 9.3 mm and a length of 8 Qin was prepared from a nitrided steel round bar which was tempered at 680°C after quenching and whose hardness was adjusted to HV300. The section from one end of this test piece to a position 15 m11 away was covered with a mild steel cover, and the surface of the remaining portion was hardened by ion nitriding under the same conditions as in Example 1. As a result, a metal member was obtained in which the surface hardness of the nitrided portion was Hvlloo and the surface hardness of the non-nitrided portion was HV300. The hardness of the non-nitrided portion does not change even after heat treatment for nitriding.

Next, on the end of the test piece on the non-hardened part side,
Machining a recess 21 with an inner diameter shown in 1IO and a depth of 15 fins,
A metal member 20 having the shape shown in FIG. 1 was manufactured.

Three convex parts of the ceramic member are placed in the recessed parts of these metal members.
Press-fitting was carried out at 50° C. to produce a metal-ceramic bonded body having the shape shown in FIG. Due to this press-fitting, the section from the entrance of the metal member recess to a depth of 13 m+s was deformed.

Next, after processing the outer diameter of the metal member to 9.1 mm and forming a screw 22 of a predetermined size on the end, the part shown in FIG. The ceramic member and the metal member were respectively pulled out in the vertical direction while the press-fitted parts were placed in a chamber and maintained at 350° C., and the load applied to the press-fit portion when pulled out was measured. The obtained results are shown in Table 1. Among the results shown in Table 1, 1lhl~N15 are the pullout load measurement results of metal-ceramic composites whose hardness of the unhardened part of the metal member is within the range of the present invention, and 11m6~N11LlO are the results of the pull-out load measurement of the ceramic member. The difference in size between the diameter of the convex part and the inner diameter of the concave part of the metal member is the result of measuring the pullout load of a metal-ceramic composite body having the size according to the present invention. 11kL101-4102 is a metal-ceramic composite whose hardness of the unhardened portion of the metal member is outside the scope of the present invention, and m103 to Ik104 are metal-ceramic composites whose dimensional difference is outside the scope of the present invention. This is the result.

Flute 1 Back Y: Fζ, OK, N2 IEA! Yo'I! As is clear from Table 1, the metal-ceramic composite in which the hardness of the unhardened portion of the metal member and the dimensional difference between the concave portion of the metal member and the convex portion of the ceramic member are as large as the present invention is 3.
It shows a large pullout load at 50°C. This pull-out load increases as the pull-out temperature decreases, so when the temperature of the fitting portion is 350° C. or lower, the pull-out load exceeds that shown in Table 1. On the other hand, if the hardness of the non-hardened portion of the metal member is below the range of the present invention, the pullout load is small, and if the hardness is beyond the range of the present invention, the recessed portion of the metal member will be damaged by press-fitting. Similarly, if the dimensional difference between the inner diameter of the recess of the metal member and the diameter of the protrusion of the ceramic member is less than the range of the present invention, the pullout load will be small, and if the difference is greater than the range of the present invention, the pullout load will be reduced by press-fitting into the recess of the metal member. This may cause damage to the convex portion of the ceramic member.

Turbine wheel 41 and diameter 9.
A ceramic member 40 having a total length of 60 mm was produced by integrally molding an IN turbine shaft 42 from silicon nitride.

This ceramic member has a diameter of 6 mm at the tip of the turbine shaft.
A convex portion 43 with a length of 13 mm and a length of 13 mm was processed. In addition, the total length is 70 mm from nitrided steel whose hardness has been adjusted to Hv300 by heat treatment.
In, make a round stick with a diameter of 9.1, and from one end of the round stick
The section up to a position 3 square meters away was covered with a mild steel cover, and the surface of the remaining part was hardened by ion nitriding under the same conditions as in Example 1. Next, a recess 52 having an inner diameter of 5.8 mm and a depth of 1 2 inches was machined at the end of the round bar on the non-nitrided portion side, thereby producing a metal member 50. The convex portion 43 at the tip of the turbine shaft is press-fitted into this concave portion 52 at a temperature of 350° C., which is higher than the operating temperature of the fitting portion, and the ceramic member 40 and the metal member 50 are integrally bonded. Turbine shaft 42 and metal turbine shaft 5
The diameter of 1 is 9. OHa, the compressor wheel side rotating shaft 53 is machined to a diameter of 5 mm, and a part of the turbine wheel and turbine shaft are made of silicon nitride, having the shape shown in FIG.
A turbocharger rotor was fabricated with the remaining portion made of nitrided steel. This turbocharger rotor was installed in a bamboo temperature rotation test device and heated to 150,000 r using combustion gas.
A rotation test was conducted at pm for 100 hours, but no abnormality was observed in the fitting portion or the bearing contact surface 54 of the metal turbine shaft.

(Effects of the Invention) As is clear from the above description, the metal-ceramic composite of the present invention has a diameter 1% to 10% larger than the inner diameter of the recess provided in a metal member whose predetermined portion has been surface hardened. Since the convex portions having the above-mentioned shapes are fitted together and are integrally connected, the joint strength is large and the wear resistance of the predetermined portion of the metal member is excellent. In addition, according to the method of the present invention, a large bonding strength can be obtained even if the wall thickness of the recessed part of the metal member is made thinner, so it is possible to increase the diameter of the convex part of the ceramic member by that amount. Therefore, if the metal-ceramic composite of the present invention is used to construct a turbocharger rotor in which part of the turbine wheel and turbine shaft is made of silicon nitride and the other part is made of nitrided steel, responsiveness and durability will be improved. It can be made into an excellent and highly efficient turbocharger rotor.

In this way, the metal-ceramic composite of the present invention takes advantage of the heat resistance, abrasion resistance, high strength, and other properties of ceramics to be used in engine parts such as turbocharger rotors and gas turbine rotors, and structural parts that are subjected to high temperatures and repeated loads. It has the advantage that it can be used as a material and can be provided at low cost and with excellent durability.

[Brief explanation of drawings]

Fig. 1 is a partial cross-sectional view of a metal/ceramic composite for explaining the present invention in detail, Fig. 2 is an explanatory diagram showing a method for a pull-out test of a metal/ceramic composite, and Fig. 3 is a metal of the present invention. - It is an explanatory view showing a vertical cross-sectional view of a press-fitting part of a turbocharger rotor as a specific application example of the ceramic bonded body. 10... Ceramic member small 11... Convex part of ceramic member 20... Metal member 21... Recessed part 22 of metal member... Screws 30a, 30b... Pull rond for pull-out test 31...
Pull-out test grip 40... Ceramic member 41... Ceramic turbine wheel 42... Ceramic turbine shaft 43... Convex portion 50 of ceramic turbine shaft... Metal member 51... Metal turbine shaft 52... ... Concavity 53 of metal turbine shaft ... Compressor wheel side rotating shaft 54 ... Bearing contact surface Mr. Manabu Shiga, Commissioner of the Patent Office1, Indication of the case No. 169254 of 19802, Title of the invention 4, Attorney (correction) statement 1, Title of the invention Metal-ceramic composite and its manufacturing method 2 , Claim 1, A convex portion provided on a ceramic member is coupled by fitting to a recess provided on a metal member having a hardened zone and a non-hardened zone having a hardness of Hv 250 to 450 on the surface, and the fitting. A metal-ceramic composite body characterized in that the deformation region of the metal member is within the unhardened zone. 2. The metal according to claim 1, wherein the deformation region is separated from the hardened zone boundary by a predetermined distance or more. - Ceramic bonded body. 3. The metal-ceramic bonded body according to any one of claims 1 to 2, wherein the hardened zone is ion-nitrided. 4. The metal member is made of stainless steel or an alloy. Tool steel, chrome
The metal-ceramic bond according to any one of claims 1 to 3, wherein the ceramic member is made of one metal selected from the group consisting of molybdenum steel and aluminum-chromium-molybdenum steel, and the ceramic member is made of silicon nitride. body. 5. The metal-ceramic bonded body according to any one of claims 1 to 4, wherein the metal-ceramic bonded body is a turbocharger rotor. 6. In a method of integrally bonding a metal member and a ceramic member, the hardness of the metal member is reduced to HV2 by heat treatment.
50 to 450, and a part of the surface of the metal member is hardened to provide a hardened zone, and then a recess is provided in the metal member, and a protrusion provided on the ceramic member is fitted into the recess to be integrated. 1. A method for manufacturing a metal-ceramic bonded body, which is characterized in that the metal members are bonded in a fixed manner, and the metal members are fitted so that the deformed region of the metal members due to fitting is within a non-hardened zone. 7. The method for manufacturing a metal-ceramic bonded body according to claim 6, wherein the heat treatment is quenching and tempering at a temperature higher than the hardening treatment temperature. 8. The method for manufacturing a metal-ceramic bonded body according to any one of claims 6 and 7, wherein the hardening treatment is by ion nitriding. 9. The quenched metal member is heated to a nitriding temperature in a heating furnace with a nitriding atmosphere, and the surface hardening and tempering of the metal member are performed simultaneously. A method for producing a metal-ceramic bonded body according to any one of Item 8. lOo The metal-ceramic bonded body according to any one of claims 6 to 9, wherein the fitting is press-fitting at a temperature below the tempering temperature of the metal member or above the maximum operating temperature of the fitting part. Manufacturing method. 11. The method for manufacturing a metal-ceramic bonded body according to any one of claims 6 to 10, wherein the diameter of the convex portion on the ceramic member is 1% to 10% larger than the inner diameter of the concave portion on the metal member. . 3. Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a metal-ceramic composite and a method for manufacturing the same. More specifically, the present invention relates to a metal-ceramic bonded body in which a metal and a ceramic are bonded together by fitting, and a method for manufacturing the same. (Prior art) Ceramics are hard and have excellent wear resistance, as well as excellent mechanical properties and corrosion resistance at high temperatures, so they are used in gas turbines that require mechanical strength and wear resistance at high temperatures. It is suitable as a structural material for turbocharger rotors. For this reason, the use of ceramics for gas turbine rotors and turbocharger rotors is being considered. For example, US Pat. No. 4,396,445 discloses a turbine rotor in which the blade portion and the shaft portion are made of ceramics. In a turbine rotor with this structure, a threaded portion is provided at one end of the ceramic shaft to secure the metal compressor impeller. (Problem to be solved by the invention) However, due to the difference in thermal expansion between the metal material that makes up the compressor impeller and the ceramic material that makes up the shaft, the turbine rotor with this structure The disadvantage is that the threaded part of the shaft may be damaged. In addition, threading on ceramics requires advanced technology,
The drawback is that it is time consuming and expensive. As a countermeasure against this problem, Japanese Utility Model Application Publication No. 57-92097 proposes a structure in which a cylindrical part provided at the end of a metal shaft is fitted onto a ceramic shaft of a turbine rotor. However, in this structure, in order to improve the wear resistance of the bearing abutment part on the surface of the metal shaft, if the outer surface of the metal shaft cylindrical part is surface hardened and then the ceramic shaft is fitted, the outer surface hardened part There is a drawback that Krafuku occurs. In addition, after fitting a metal shaft and a ceramic shaft, if surface hardening treatment such as nitriding treatment is applied to the surface of the metal shaft,
There are disadvantages in that the tightening force of the fitting part decreases and the fitting part may come off. Furthermore, when a metal shaft and a ceramic shaft are fitted together and then quenched, due to phase transformation of the metal shaft due to quenching,
There is a drawback that the fitting part may come off. For this reason, the above-mentioned structure has the disadvantage that the bearing abutment portion on the surface of the metal shaft lacks wear resistance, making it impractical. (Means for Solving the Problems) The first object of the present invention is to provide a metal-ceramic bonded body with a large bonding force and a method for manufacturing the same.
The object of the present invention is to provide a metal-ceramic composite body in which the surface of the metal part has excellent wear resistance, and a method for manufacturing the same. In the present invention, a protrusion provided on a ceramic member is coupled by fitting to a recess provided on a metal member having a hardened zone and a non-hardened zone having a hardness of Hv 250 to 450 on the surface.
This is a metal-ceramic composite in which the deformation region of the metal member due to fitting exists within the unhardened zone, and the hardness of the metal member is made Hv250 to 450 by heat treatment, and a part of the surface of the metal member is hardened. After forming a hardened zone, a recess is provided in the metal member, and a protrusion provided on the ceramic member is fitted into the recess to form an integral connection, and furthermore, the deformation area of the metal member due to the fitting is reduced. A method of manufacturing a metal-ceramic composite that fits within the unhardened zone. (Function) In the present invention, the hardness is increased to HV250 to 450 by heat treatment.
At the same time, the convex portion provided on the ceramic member is fitted into the recessed portion provided on the metal member whose surface has been partially surface hardened. In this case, the hardness of the unhardened zone of the metal member constituting the metal-ceramic composite of the present invention is H
If V is less than 250, the tightening force of the joint will be insufficient, which is not preferable. In addition, if the hardness of the non-hardened zone exceeds Hv450,
This is not preferable because the fitting tends to cause the metal member recess to break. The surface hardening treatment of the metal member is carried out at least on the parts where the metal parts constituting the combined body are worn out due to friction or sliding with other mechanical parts when the metal-ceramic combined body of the present invention is used. By this surface hardening treatment, a hardened layer is formed on the surface of the metal member, and the wear resistance of specific parts of the metal part of the metal/ceramics bond of the present invention is improved. The above surface hardening treatment method includes:
Methods such as carburizing, nitriding, surface hardening, electric discharge hardening, and plating can be used. Among these surface hardening treatment methods, carburizing, nitriding, and surface hardening are preferred because they yield a thick surface hardening layer. Furthermore, among the various nitriding methods, the ion nitriding method is particularly preferable because it is easy to adjust the area and hardening depth of the surface hardened portion. As the heat treatment for adjusting the hardness of the metal member, quenching, tempering treatment, or precipitation hardening treatment is used. This heat treatment may be performed before surface hardening treatment of the metal member. In this case, the tempering temperature is preferably higher than the surface hardening temperature. If a metal member whose hardness has been adjusted by tempering below the surface hardening treatment temperature is subjected to surface hardening by heating it above the tempering temperature, it is undesirable because the hardness of the unhardened parts inside the metal member will decrease. . Also, tempering treatment! 1 Precipitation treatment ``Same as surface hardening treatment 11J''''. You can also actually do it. In this case, the hardened metal member is heated in a heating furnace in which the atmosphere inside the furnace is a surface hardening atmosphere. On the other hand, in connection by fitting the convex part of the ceramic member and the concave part of the metal member,
Deformation occurs in the joint portion in proportion to the dimensional difference between the convex portion and the concave portion. However, the hardened surface layer is brittle and cannot be plastically deformed, so if this hardened surface layer is plastically deformed by fitting,
Crank occurs in the hardened surface layer. Therefore, in the metal-ceramic composite of the present invention, such deformation of the metal member occurs in the unhardened zone of the metal member. In this case, a predetermined distance or more is provided between the deformed portion and the hardened surface zone. The size of this gap should be at least as large as not to cause defects such as cranks on the surface hardened part of the metal member due to the shadow of the deformation when the metal member is deformed due to fitting. is determined depending on the processing accuracy of the ceramic member and the metal member, the fitting method of both members, the amount of deformation of the metal member, and the shape and dimensions of both members. For example, a convex part with a diameter of 7.0 mm provided on a ceramic member, and a convex part with an inner diameter of 6.8 mm provided on a metal member with a diameter of 9.3 mm.
When fitting into the recessed portion of the metal member, the distance provided between the deformed portion of the metal member and the hardened surface zone is preferably 11 or more, and particularly preferably 2II11 or more. If this interval is two or more steps, it is particularly preferable because it is not necessary to make the machining accuracy of the fitting portion of both members and the positioning accuracy of the surface hardening zone particularly high. However, if this distance is less than 1 u, it is not preferable because the processing accuracy of the fitting portion of both members and the positioning accuracy of the surface hardening zone need to be particularly high. The upper limit of the above distance may be determined as appropriate by taking into account the position of the part on the surface of the metal member that requires wear resistance and the position of the deformed part due to fitting, but if the position and area of the hardened surface part , is determined to be equal to or larger than the position and area of the part requiring wear resistance on the surface of the metal member. This increases the surface hardness of certain parts of the metal part.
A defect-free metal-ceramic composite of the present invention can be obtained. The metal material and the ceramic material constituting the metal-ceramic composite of the present invention can be fitted by any one of shrink fitting, cold shrinking, and press fitting. Shrink fitting and cold shrinking involve machining the diameter of the convex part of the ceramic member to be larger than the inner diameter of the concave part of the metal member, and then heating or cooling one of the parts to be fitted to create a dimensional difference between the two parts that can be fitted. , since both members are fitted using the dimensional difference,
This method is preferable as a fitting method for a metal-ceramic composite body in which the size of the fitting portion is large. In addition, metal materials generally have a larger coefficient of thermal expansion than ceramic members, so
Shrink fitting in which the metal member is heated is more preferable because a large dimensional difference can be obtained with a small temperature difference and a stable shrink fitting operation can be performed. In this case, the tightness of the shrink fit and cold fit is such that the concave part of the metal member and the convex part of the ceramic member are not damaged after the fitting, and the fitting part is maintained under the usage conditions of the metal-ceramic composite of the present invention. The size shall be such that the required tightening force can be obtained. On the other hand, press-fitting is a method in which a protrusion of a ceramic member is forced into a recess provided in a metal member with a smaller diameter than the diameter of the protrusion by applying a load. The above-mentioned dimensional difference between the diameter of the convex part and the inner diameter of the concave part is absorbed by the elastic and plastic deformation of the metal member, so the finished dimensional tolerance of the convex part and the concave part before press-fitting is larger than that for shrink fit and cold fit. Good too. For this reason, press-fitting is a more preferable method for fitting metal-ceramic composite bodies in which the size of the fitting portion is small. The shape and dimensions of the concave portion of the metal member and the convex portion of the ceramic member are such that they will not be destroyed by the load applied during press-fitting. Further, the dimensional difference between the diameter of the convex portion and the inner diameter of the concave portion is such that the fitting portion has a tightening force suitable for the usage conditions of the metal-ceramic composite of the present invention, and both the convex portion and the concave portion are It should be large enough not to be destroyed. Therefore, the dimensional difference depends on the hardness of the unhardened part of the metal member.
The convex part of the ceramic member is 1% smaller than the inner diameter of the concave part of the metal member.
It is preferable to increase it by 1% to 10%, and 1% to 5%.
If this dimensional difference is less than 1%, the tightening force of the press-fitted part will be insufficient, and there is a risk that the press-fitted part will come off during use.
% or more, the load required for press-fitting becomes too large, which is undesirable because the protrusions of the ceramic member or the recesses of the metal member may be damaged during press-fitting. Note that when the above-mentioned dimensional difference is large, a metal member with a low hardness in the unhardened zone is used, and when the above-mentioned dimensional difference is small, a metal member with high hardness is used to obtain stable bonding strength. This press-fitting may be performed at room temperature, or may be performed by heating only the metal member or heating both the metal member and the ceramic member. However, the most preferable method is to heat both members and press fit them together. This is because heating both parts reduces the deformation resistance of the metal part and reduces the load required for press-fitting, which prevents damage to both parts during press-fitting. This is because the tightening force increases based on the difference in thermal expansion between the two. When heating and press-fitting both members, the press-fitting temperature is preferably below the lower of the tempering temperature of the metal member or the softening temperature of the hardened surface layer, and at least the operating temperature of the press-fitting part. . If the press-in temperature is higher than the tempering temperature of the metal part,
This is undesirable because the hardness of the non-surface hardened portion of the metal member decreases and the tightening force of the press-fit portion decreases. Furthermore, if the press-fitting temperature is higher than the softening temperature of the surface hardening layer, the effect of the surface hardening treatment will be reduced, which is not preferable. Furthermore, if the press-fitting temperature is lower than the operating temperature of the press-fitting part, when the temperature of the press-fitting part rises to the operating temperature, the thermal expansion of the metal member is generally larger than that of the ceramic member, so the press-fitting part loosens and tightens. This is not preferable because it reduces the applied force. The metal-ceramic bonded body of the present invention is usually put into use after fitting the metal member and the ceramic member together and then performing finishing processing. Therefore, metal parts that require wear resistance during use must exhibit a predetermined surface hardness even if the surface is ground during finishing. However, the hardness of the surface of a metal member and the change in hardness from the surface to the inside of the metal member due to surface hardening treatment vary depending on the type of metal material constituting the metal member, and the surface hardening method and conditions. For this reason, the amount of surface grinding in finishing processing of metal parts that require wear resistance during use is determined depending on the specified surface hardness, the type of metal material composing the metal member, and the surface hardening method and conditions. . Alternatively, the type of metal material constituting the metal member and the surface hardening method and conditions are determined depending on the amount of final grinding and surface hardness of the metal part. The metal material constituting the metal-ceramic composite of the present invention is a commercially available metal material whose surface can be hardened by methods such as carburizing, nitriding, surface hardening, electric discharge hardening, and plating. For example, when surface hardening is performed by nitriding, iron alloys containing chromium such as stainless steel, alloy tool steel, nickel-chromium-molybdenum steel, chromium-molybdenum steel, aluminum-chromium-molybdenum steel, titanium, zirconium, etc. An alloy containing the elements is preferred. When surface hardening is performed by ion nitriding, aluminum-chromium-molybdenum steel and stainless steel are preferred because they have high surface hardness and can be hardened from the surface to a deep position.
Chrome-molybdenum steel is the most preferred because it is inexpensive. The ceramic material constituting the metal-ceramic composite of the present invention is selected from silicon nitride, silicon carbide, zirconia, alumina, beryllia, sialon, etc., depending on the intended use of the metal-ceramic composite of the present invention. For example, when making a turbocharger rotor or a gas turbine rotor using the metal-ceramic composite of the present invention,
Silicon nitride, which has high high-temperature strength and low specific gravity, is preferably used for the turbine wheel and its subsequent rotating shaft, which are exposed to the high temperature of exhaust gas and rotate at high speed. (Example) Fig. 1 is a diagram showing the metal
FIG. 3 is a partial cross-sectional view of the ceramic bonded body. An embodiment will be described below based on FIG. Silicon nitride (hereinafter referred to as silicon nitride) manufactured using the pressureless sintering method
A ceramic member 10 having a shape shown in FIG. 1 and having a convex portion 11 having a diameter of 7.0 ml and a length of 25 mm was produced from a round bar. Also, aluminum-chromium-molybdenum steel (JIS-SACM645.
A round bar (hereinafter referred to as nitriding steel) was heated and held at 930"C for 1 hour, then quenched in water at room temperature, and then heated to 60"C.
Heat and hold at 0'C for 1 hour to temper the hardness to H.
Adjusted to v350. After processing this round bar to a diameter of 9.3+im+, a recess 21 with an inner diameter of 6°8+n and a depth of 15mm was machined at one end.
A metal member 20 having the shape shown in the figure was produced. Next, the outer surface of the section of the metal member up to a position 17 + u away from the artificial side end surface of the recess is covered with a mild steel cover, and the remaining outer surface (section A in Fig. 1) is covered with a pressure crab of 4 Torr or the like. A metal member (referred to as metal member A) that was subjected to ion nitriding treatment for 20 hours while heating at 550°C in a mixed atmosphere consisting of a large amount of nitrogen and hydrogen, and the entire outer surface of the metal member (section B in Fig. 1). A metal member (referred to as metal member B) which was subjected to ion nitriding treatment under the same conditions as metal member A was produced. By the ion nitriding treatment under the above conditions, the Vickers hardness of the nitrided part surface increased from Hv (0,1) 350 before the nitriding treatment to Hv (0,1) 1100. Also, the Vickers hardness at a depth of 0.211 from the surface is HV (
0,1) showed 700. The protrusions 11 of the ceramic member 10 were press-fitted into the recesses 21 of the two types of metal members 20 at 350° C. to produce a metal-ceramic bonded body having the shape shown in FIG. 1. Due to this press-fitting, the section from the entrance of the metal member recess to the depth 13 (section C in Figure 1) is deformed, and the diameter of the metal member is approximately 0.2
mm increased. When the outer surface of the deformed portion of the metal member due to this press-fitting was inspected, no abnormality was found in the metal/ceramic composite using metal member A. The metal-ceramic bonded body using metal member B has a length of about IQ mm and a depth of about 0 along the axial direction of the metal member.
．． Many 5-fin cranks were detected. If the surface-hardened portion of the metal member is deformed by press-fitting in this way, cracks will occur on the surface of the metal member, making it impossible to obtain a sound metal-ceramic bond. On the other hand, in the metal-ceramic composite of the present invention using the metal member A in which the deformed portion due to press fitting is not surface hardened, cranks do not occur on the surface of the metal member even if the metal member is deformed due to press fitting. Step 1 A ceramic member and a metal member having the same material and the same shape as in Example 1 were produced. Regarding this metal member, 13.5 ml from each end face of the recess (referred to as metal member C)
, 14.5 (metal parts) , 15.5++m
Three types of metal members were prepared by covering the outer surface of the section up to the distant position with a mild steel cover (referred to as metal member E), and performing ion nitriding treatment on the outer surface of the remaining section under the same conditions as in Example 1. did. The protrusions of the ceramic member were press-fitted into the recesses of these three types of metal members at 350°C to produce a metal-ceramic bonded body having the shape shown in FIG. 1. As a result of this press-fitting, the section of each metal member from the end surface of the recess to a position 13 degrees away was deformed and the outer diameter increased. When the outer surface of the deformed portion due to the press-fitting of the metal part of each of the above-mentioned metal/ceramic composites and the surrounding area was inspected, no cracks were found on the outer surface of the metal member E. However, near the boundary between the ion-nitrided part and the non-nitrided part of the metal member C, a crack with a length of about 2 iris and a depth of about QJmm was detected along the axial direction of the metal member. In this way, in the metal-ceramic composite of the present invention in which the deformation region of the metal member due to press-fitting and the hardened surface of the metal member are separated by a predetermined distance or more, even if the metal member is deformed due to press-fitting, the surface of the metal member is The crank does not occur. S】l"1 From a silicon nitride round bar, the diameter is 7.90 m, and the length is 25 m.
A ceramic member 10 having a shape shown in FIG. 1 and having a +* convex portion 11 was produced. In addition, rod-shaped test pieces with a diameter of 9.3 mm and a length of 8011 were made from nitrided steel round bars whose hardness was adjusted to the values shown in Table 1 N11l to N115 by quenching and tempering. At one end of this test piece there was an inner diameter of 7.751 mm.
1. A concave portion 21 having a depth of 15 mm was processed to produce a metal member 20 having the shape shown in FIG. Similarly, 680℃ after quenching
A rod-shaped test piece with a diameter of 9.3+n and a length of 8 (hm) was prepared from a nitrided steel round bar that had been tempered and the hardness was adjusted to Hv300. was covered with a mild steel cover, and the surface of the remaining part was hardened by ion nitriding under the same conditions as in Example 1. As a result, the surface hardness of the nitrided part was
A metal member was obtained in which the surface hardness of the non-nitrided portion was Hv300. The hardness of the non-nitrided portion does not change even after heat treatment for nitriding. Next, a recess 21 having an inner diameter and a depth of 15 mm as shown in the first table 7 to mIO is machined in the unhardened part (11, jJ) of the test piece, and a metal member having the shape shown in FIG. The convex part 11 of the ceramic member was press-fitted into the recessed part 21 of these metal members at a height of 350'c, and the metal member having the shape shown in FIG.
A ceramic composite was produced. Due to this press-fitting, the section of the metal member from the entrance of the recess 21 to the depth 13 was deformed. Next, after processing the outer diameter of the metal member 20 to 9.1 mm and processing a screw 22 of a predetermined size at the end, the screw 22 is attached to one of the pull rods 30a for the pull plate test as shown in FIG. At the same time as screwing together the pull rod 30 for the other pull plate test.
After holding the ceramic member 10 with the drawing plate test grip 31 screwed into the part 2b, the part shown in FIG. Pull them out vertically,
The load required to pull out the press-fit portion was measured, and the results are shown in Table 1. Among the results shown in Table 1, NIIL1 to 5 are the results of the pull-out load measurement of metal-ceramic composites in which the hardness of the unhardened part of the metal member is within the range of the present invention.
Figure 10 shows the results of measuring the pullout load of a metal-ceramic composite body in which the dimensional difference between the diameter of the convex part of the ceramic member and the inner diameter of the concave part of the metal member is the size of the present invention. 1111110
1 to 1t102 are metal-ceramic composites in which the hardness of the unhardened portion of the metal member is outside the range of the present invention, N[LL0
3 to 104 are the results for metal-ceramic composites in which the above-mentioned dimensional difference is outside the scope of the present invention. Flute 1 Dice Y; N: N: As is clear from Table 1, the hardness of the unhardened portion of the metal member and the dimensional difference between the concave portion of the metal member and the convex portion of the ceramic member are of the size of the present invention. A certain metal-ceramic composite has 3
It shows a large pullout load at 50°C. This pull-out load increases as the pull-out temperature decreases, so if the temperature of the fitting portion is 350°C or less, the pull-out load will be greater than that shown in Table 1. On the other hand, if the hardness of the non-hardened portion of the metal member is below the range of the present invention, the pullout load is small, and if the hardness is beyond the range of the present invention, the recessed portion of the metal member will be damaged by press-fitting. Similarly, if the dimensional difference between the inner diameter of the recess of the metal member and the diameter of the protrusion of the ceramic member is less than the range of the present invention, the pullout load will be small, and if the difference is greater than the range of the present invention, the pullout load will be reduced by press-fitting into the recess of the metal member. This may cause damage to the convex portion of the ceramic member. Plate soil! Diameter 61 dragon turbine wheel 41 and diameter 9. A ceramic member 4 with a total length of 60 mm that is integrally molded with a turbine shaft 42 of l+i+l using silicon nitride.
0 was created. A convex portion 43 having a diameter of 61 Im and a length of 131 m was machined at the tip of the turbine shaft of this ceramic member. In addition, it is made of nitrided steel whose hardness has been adjusted to Hv300 by heat treatment, and the total length is 70 mm and the diameter is 9 mm. Make a round bar of l+n,
The section from one end of the round bar to a position 1311I apart was covered with a mild steel cover, and the surface of the remaining part was hardened by ion nitriding under the same conditions as in Example 1. Next, the end of the round bar on the non-nitrided part side has an inner diameter of 5.8 mm and a depth of 121 ff.
The recess 52 of i was processed to produce the metal member 50. The convex portion 43 at the tip of the turbine shaft was press-fitted into this concave portion 52 at a temperature of 350° C., which is higher than the working temperature of the fitting portion, thereby integrally joining the ceramic 7x member 40 and the metal member 50. Later, the ceramic turbine shaft 42 and metal turbine shaft 51 were machined to have a diameter of 9.0 inches, and the compressor wheel side rotating shaft 53 was machined to a diameter of 511 inches.
A turbocharger rotor having the shape shown in FIG. 3, in which part of the turbine wheel and turbine shaft were made of silicon nitride and the remaining part was made of nitrided steel, was manufactured. This turbocharger rotor was installed in a high-temperature rotation testing device and subjected to a rotation test using combustion gas at 150,000 rpm for 100 hours, but no abnormality was observed in the fitting portion or the bearing contact surface 54 of the metal turbine shaft. (Effects of the Invention) As is clear from the above description, the metal-ceramic composite of the present invention has a diameter 1% to 10% larger than the inner diameter of the recess provided in a metal member whose predetermined portion has been surface hardened. Since the convex portions having the above-mentioned shapes are fitted together and are integrally connected, the joint strength is large and the wear resistance of the predetermined portion of the metal member is excellent. In addition, according to the method of the present invention, a large bonding strength can be obtained even if the wall thickness of the recessed part of the metal member is made thin, so it is possible to increase the diameter of the convex part of the ceramic member by that much. The strength of the convex portion increases. Therefore, if a turbocharger rotor in which a part of the turbine wheel and turbine shaft is made of silicon nitride and the other part is made of nitrided steel is constructed using the metal-ceramic composite of the present invention, a highly efficient turbo with excellent responsiveness and durability can be obtained. Can be a charger rotor. In this way, the metal-ceramic composite of the present invention takes advantage of the heat resistance, wear resistance, high strength, and other characteristics of ceramics to be used in engine parts such as turbocharger rotors and gas turbine rotors, and structural parts that are subjected to high temperatures and repeated loads. It has the advantage that it can be used as a material and can be provided at low cost and with excellent durability. 4. Brief description of the drawings Fig. 1 is a partial cross-sectional view of a metal-ceramic composite for explaining the present invention in detail; Fig. 2 is an explanatory diagram showing a method for a pull-out test of a metal-ceramic composite; FIG. 3 is an explanatory diagram showing a vertical cross-sectional view of a press-fitting portion of a turbocharger rotor as a specific application example of the metal-ceramic composite of the present invention. DESCRIPTION OF SYMBOLS 10... Ceramic member 11... Convex part of ceramic member 20... Metal member 21... Recessed part 22 of metal member... Screws 30a, 30b... Pull rod for pull-out test 31.
... Grip for pullout test 40 ... Ceramic member 41 ... Ceramic turbine wheel 42 ... Ceramic turbine shaft 43 ... Convex part 50 of ceramic turbine shaft ... Metal member 51 ... Metal turbine shaft 52... Concavity of metal turbine shaft 53... Rotating shaft on compressor wheel side 54... Bearing abutment surface enrichment correction Written on August 30, 1985 Michibe Uga, Commissioner of the Japan Patent Office 1. Indication of the case 1981, Peculiar Application No. 169254 2, Name of invention: Kinzuku Kerabodai
Ceramic metal-ceramic composite and its manufacturing method 3, relationship with the amended case Patent applicant Nira Pong Kaishi Name (406) Nippon Insulators Co., Ltd. 4, agent ■, page 8, line 18 of the specification "Precipitation treatment" is corrected to "Precipitation hardening treatment". 2, page 21, line 4 rNo, 7 to N (LIOJ r
Na 6~Pro. 10”, “For pull-out test” in lines 13 and 14 of the same page was corrected to “for pull-out test”, and “Grip for pull-out test” in line 15 of the same page was changed to “Gripper for pull-out test” in line 15 of the same page. "Required for extraction" in line 19 of the same page was changed to "Required for extraction"
Correct.

Claims (1)

[Scope of Claims] 1. A convex portion provided on a ceramic member is fitted into a recessed portion provided on a metal member having a hardened zone and a non-hardened zone having a hardness of 250 to 450 Hv on the surface, and A metal-ceramic bonded body characterized in that the deformation region of the metal member due to bonding is within a non-hardened zone. 2. The metal-ceramic bonded body according to claim 1, wherein the deformation region is separated from the hardened zone boundary by a predetermined distance or more. 3. The metal-ceramic bonded body according to any one of claims 1 to 2, wherein the hardened zone is ion-nitrided. 4. Claim 1, in which the metal member is made of one metal selected from the group consisting of stainless steel, alloy tool steel, chromium-molybdenum steel, and aluminum-chromium-molybdenum steel, and the ceramic member is made of silicon nitride. The metal/ceramic composite according to any of the above. 5. The metal-ceramic bonded body according to any one of claims 1 to 4, wherein the metal-ceramic bonded body is a turbocharger rotor. 6. In a method of integrally bonding a metal member and a ceramic member, the hardness of the metal member is reduced to Hv25 by heat treatment.
0 to 450, and a part of the surface of the metal member is hardened to provide a hardened zone, and then a recess is provided in the metal member, and a protrusion provided on the ceramic member is fitted into the recess to integrate it. 1. A method for manufacturing a metal-ceramic bonded body, which is characterized in that the metal members are bonded in a fixed manner, and the metal members are fitted so that the deformed region of the metal members due to fitting is within a non-hardened zone. 7. The method for manufacturing a metal-ceramic bonded body according to claim 6, wherein the heat treatment is quenching and tempering at a temperature higher than the hardening treatment temperature. 8. The metal according to claim 6 or 7, wherein the hardening treatment is by ion nitriding.
Method for manufacturing ceramic bonded bodies. 9. The quenched metal member is heated to a nitriding temperature in a heating furnace with a nitriding atmosphere, and the surface hardening and tempering of the metal member are performed simultaneously. A method for producing a metal-ceramic bonded body according to any one of Item 8. 10. The metal-ceramic bonded body according to any one of claims 6 to 9, wherein the fitting is press-fitting at a temperature below the tempering temperature of the metal member or above the maximum operating temperature of the fitting part. manufacturing method. 11. The method for manufacturing a metal-ceramic bonded body according to any one of claims 6 to 10, wherein the diameter of the convex portion on the ceramic member is 1% to 10% larger than the inner diameter of the concave portion on the metal member. .