JP3534973B2 - Manufacturing method of brazed joint - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to brazing and joining a metal member and a ceramic member by brazing.
It relates to a process for the preparation of the body, specifically engine tappet, used in the rocker arm, other engine components, tools, etc., brazed joined body of the metallic member and the ceramic member (hereinafter, simply referred to as conjugate) manufacturing method Regarding

[0002]

2. Description of the Related Art Ceramic members (hereinafter also simply referred to as ceramics) have excellent properties such as heat resistance and thermal shock strength. It is suitable. But,
Ceramics are rarely used alone by themselves, and are usually used as various kinds of parts as a joined body brazed to a metal member.

FIG. 4 shows an example of a joint structure in which the joint body 101 is an engine tappet. This one is
The metal member 201 constitutes the engine tappet body, and the ceramic member 301 forms a cam sliding surface of the engine tappet so that both are flat brazed joint surfaces 202,
It is brazed at 302. By the way, in each of the components (metal member 201, ceramic member 301) before joining forming such a joined body 101, the brazing joint surfaces (hereinafter, also simply referred to as joint surfaces) 202 and 302 and the outer peripheral surface (side surface) 203. Chamfers of a predetermined size (usually 45 degree chamfers) 204, 304, 3 at the angle (ridgeline) formed with 303
05 can be attached. Such chamfers 204, 304, 3
No. 05 is for preventing chipping, cracking, etc. at the corners during the manufacture of each part and during the subsequent handling, but not only for the brittle ceramic member 301, but also for the metal member 201. Usually, a chamfer of a predetermined size is attached.

These chamfers 204, 304 and 305 are
The larger the size, the more effective it is in preventing the occurrence of chips, but
Usually, C is set to about 0.1 to 0.4 (mm), the metal member 201 is attached in the processing step, and the ceramic member 301, which is a super-difficult-to-cut material, is chamfered 304, 305 during firing.
A chamfer of a predetermined size is attached at the stage of the green compact before firing so as to form. Such a conventional bonded body is manufactured by brazing a chamfered ceramic member and a metal member with active brazing or the like.
It is used as an engine tappet, etc., with the chamfer still present.

[0005]

However, including the joined body 101 having the structure shown in FIG. 4, the metal member 201 and the ceramic member 301 having the chamfers 204 and 304 on the outer peripheral edges of the joint surfaces 202 and 302 are brazed together. In each case, each chamfer 20
It is more difficult for the brazing material (layer) 401 to be filled in the portions 4, 304 than in the portion of the flat joint surface inwardly. For this reason, the brazing material 401 does not evenly and sufficiently reach the outer peripheral surfaces 203 and 303 of the metal member 201 and the ceramic member 301, and there is a tendency for filling failure to occur, and as shown in FIG. It is general. This is because a pressure is applied evenly to the molten brazing between both members so that the brazing material layer has a constant thickness (generally 15 to 30 μm, depending on the bonded body) when brazing. Take 204,304
This is because the space between the joint surfaces 202 and 302 becomes wider toward the outer peripheral surface at the portion of (2), and pressure is less likely to be applied.

For this reason, this kind of bonded body usually has a notched structure which is slightly constricted in the outer peripheral edge of the brazing material layer, that is, the bonding surface (interface). That is, a minute notch groove is formed on the outer peripheral edge of the brazed joint surface of both members, so that when an external force is applied, stress is concentrated on the outer peripheral edge. Such stress concentration is particularly remarkable in a case where a tappet for an engine (hereinafter, also simply referred to as a tappet) is used under severe conditions and a shock load is applied to a portion near the outer periphery of the ceramic member.

Further, at the chamfered portion of the outer peripheral edge of the joint surface of each member forming this kind of jointed body, the brazing material layer sandwiched between the chamfered portions is thicker than the inner side portion and goes to the outer side. As the distance between the bonding surfaces becomes wider and pressure is less likely to be applied, voids (pores / air bubbles) are likely to be included in the brazing material layer, and the filling density becomes relatively low. Therefore, if stress concentration occurs in such a chamfered portion, the brazing material layer in that portion is likely to be deformed or cracked. If such deformation or crack develops in the brazing material layer, the impact resistance of the ceramic member will decrease, causing damage to the ceramic member such as chips or cracks or peeling, which will result in damage as a bonded body. .

As described above, in the conventional joining structure, particularly those that are used under severe conditions such as tappets, the stress concentration in the minute notch groove at the outer peripheral edge of the joining surface and the filling density of the brazing material can be prevented. There is a problem that the outer peripheral edge of the brazing material layer becomes a starting point and causes deformation or cracks due to the lowness or the like, or the ceramic may be broken due to the deformation or cracks. The present invention is to eliminate such problems in brazed joints such as tappets, and to obtain a brazed joint having high durability and reliability.

[0009]

In order to solve the above problems, the present invention according to claim 1 brazes a metal member and a ceramic member having chamfers on the outer peripheral edge of a brazing joint surface. A method of manufacturing a brazed joint by manufacturing the ceramic member , wherein the ceramic member is plate-shaped.
The metal member having one main surface as the brazing joint surface
After the brazing assembly by brazing, the same diameter outer peripheral surface so chamfer the outer edge of each brazed joint surface is not present
In addition, regarding the outer peripheral surface of the ceramic member,
A method for manufacturing a brazed joined body, which comprises grinding and finishing the entire plate thickness . And as for this invention of Claim 2 , the said ceramic member has a plate thickness of 1-3 mm.
The brazing according to claim 1, characterized in that
It is a method for manufacturing a bonded body . Furthermore, in the invention according to claim 3, the metal member forms a tappet body for an engine, and the ceramic member forms a cam sliding surface of the tappet for an engine. It is a manufacturing method. In the present specification, grinding means grinding or polishing.

As described above, according to the present invention, the metal member and the plate shape are
The ceramic member has the same outer peripheral surface so that there is no chamfer on the outer peripheral edge of each brazed joint surface , and
For the outer peripheral surface of the rack member, the entire plate thickness is ground and finished.
Since there is no notch groove on the outer peripheral edge of the brazing joint surface, stress concentration does not occur unlike the conventional joint structure, and there is no defective filling portion of the brazing material layer. As a result, even when the bonded body receives an impact load, the outer peripheral edge of the brazing material layer does not act as a starting point to cause deformation or cracks in the brazing material layer, thus preventing damage or peeling of the ceramic member.

In such a joined body, after chamfering is provided on the outer peripheral edge of each brazing joint surface, a metal member and a ceramic member are brazed to form a brazing joint body, and then each brazing joint surface is formed. Same outer peripheral surface so that there is no chamfer on the outer peripheral edge of
The diameter, and the outer peripheral surface of the ceramic member is a plate
It can be manufactured by grinding the entire thickness . After the brazed joint is made in this way, it is finished by grinding, so that at the manufacturing stage of each part, the angle between the joint surface and the outer peripheral surface can be chamfered as before. It does not affect the measures against damage such as chips and cracks on the top. For the grinding, a grindstone such as a diamond grindstone capable of grinding both metal members and ceramic members may be used.

The chamfer provided on the outer peripheral edge of the joining surface of the metal member and the ceramic member forming the brazed joint is usually
The size is 0.1 to 0.4 mm. On the other hand, misalignment during joining (maximum radial position (core) on the joining surface)
The deviation error) is about 0.4 mm. The outer diameter of the part (face) that should be the joint surface of each member before joining should take into account the size of the chamfer attached to each member and this allowable maximum positional deviation error, and that chamfer exists after grinding. Instead, the dimensions may be set so as to have a predetermined size (diameter).

[0013] Normally the plate-shaped ceramic member has a thickness 1
It is thin, about 3 mm . However, in the present invention, the ceramic
Member therefore the brazed its outer peripheral surface including the outer periphery of the joint surface thickness entire have Grinding finish up, the strength of even the grinding operation Shi is easy ceramic member are also suitable. On the other hand, the grinding range from the joint surface of the metal member may be appropriately set from the joint surface depending on the material and shape of the metal member, the use of the joint body, and the like. When the joining surface is a flat surface, it is appropriate to grind it in a direction perpendicular to it.

When the entire outer peripheral surface of the ceramic member is ground, the chamfer attached to each component before joining is also removed at the outer peripheral edge of the surface (opposite surface) opposite to the brazing surface. It may end up. Therefore, in such a case, before or after grinding the outer peripheral surface, or at the same time as the grinding, the outer peripheral edge of the surface of the ceramic member opposite to the brazing surface is chamfered. Good thing.

The brazing surface is usually a flat surface, but the present invention can be applied to a surface other than a flat surface such as a spherical surface.
The shape of the joint surface is an appropriate shape depending on the application, type, etc. of the brazed joint, but a typical example is a circle, an ellipse, or a polygon such as a substantially square or a rectangle.
In the above means, the metal member and the ceramic member may be appropriately selected depending on the bonded body. Examples of the metal member include carbon steel, nickel chrome molybdenum steel, SUS304, etc., and examples of the ceramic include sialon, silicon nitride (Si3 N4), silicon carbide (SiC), alumina (A).
l2 O3) and the like are exemplified. Further, as the brazing material, titanium-based active brazing material (Ti-In-Cu-Ag-based activation brazing material) is exemplified. It should be metallized.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment in which a joined body according to the present invention is embodied will be described in detail with reference to FIG.
However, the joined body 1 in this example is a mushroom-shaped tappet for an engine (hereinafter, also simply referred to as tappet), and the metal member 2 forming the mushroom-shaped tappet body has a large diameter in concentric with the cylindrical portion 3. The end surface of the circular umbrella portion 4 forms a joint surface 5, and a ceramic member (circular thin plate) 11 forming a cam contact surface (sliding surface) 11 joins one main surface to the joint surface 5. The surface 12 is brazed with, for example, an active brazing material 21.

In the joined body 1 of this example, the entire outer peripheral surface 13 of the ceramic member 11 and the outer peripheral surface 6 of the circular umbrella portion 4 of the metal member 2, including the outer peripheral edge of the brazing material 21, are joined to each other by the respective joint surfaces 5. , 12 have the same diameter D1 so that there is no chamfer on the outer peripheral edge.
It is ground and finished in parallel (short cylindrical shape). Thus, there is no notch groove on the outer peripheral edge of the joint surface 5, 12 of each member 2, 11, and the brazing material layer 21 has a substantially constant thickness over the entire joint surface. In this example, the outer peripheral edge of the surface 14 of the ceramic member 11 opposite to the joint surface 12 is chamfered by grinding before or after grinding the outer peripheral surface.
Is attached.

In the tappet 1 of the present example, stress concentration does not occur in the outer peripheral portions of the joint surfaces 5 and 12, and the brazing material layer 21 also has a constant thickness and has a poor filling property. Therefore, the outer peripheral edge of the brazing material layer 21 does not serve as a starting point and is not deformed or cracked. Therefore, it is possible to effectively prevent the ceramic member 11 from being damaged.

Now, a method of manufacturing such a brazed joint body 1 will be described. As the metal member 2, a chamfer 2b of a certain size is provided on the outer peripheral edge of the brazing joint surface 5 of the circular umbrella portion 4 as shown by the chain double-dashed line in FIG. Prepare one with a larger diameter D2. Also,
As the ceramic member 11, a chamfer 11b of a certain size is provided on the outer peripheral edge of the brazing joint surface 12 as shown by the chain double-dashed line in FIG. 1, and the diameter D11 is larger than the outer diameter D1.
Prepare one with. However, before joining, the outer diameter D2 of the circular umbrella portion 4 of the metal member and the outer diameter D11 of the ceramic member 11 take into consideration the size of each chamfer 2b, 11b and the positional deviation error at the time of joining with respect to D1. , C does not leave chamfers 2b and 11b when the maximum allowable position shift and D
Set the size to 1 so that it can be ground. Then, after brazing these, the outer peripheral surfaces 6 and 13 of the brazed joined body 1 including the outer peripheral edge of the brazing material layer 21 are ground to D1 so that chamfers 2b and 11b do not exist, thereby making it desirable. The joined body 1 is manufactured.

It should be noted that the conjoined body 1 having a concentric diameter and a circular cross section (having a circular joint surface) 1 like the engine tappet of the preceding example is preferably manufactured as follows. That is, the metal member 2 before joining has the circular umbrella portion 4
Chamfering the outer diameter D2 of the product to the desired diameter D1 (product outer diameter)
The size is set to be twice the size of b (in the case of a chamfer other than 45 degrees, the size of the chamfer is 2k in the radial direction (bonding surface direction)). That is, the metal member 2 uses the chamfer 2b having a size 2k as a grinding allowance, and for example, when C0.3 is 0.3 m.
Let m be the grinding allowance. On the other hand, the ceramic member 11 before joining
Even if there is a maximum allowable positional deviation when brazing the outer diameter D11, the grinding allowance is increased so that the chamfer 11b is always located outside (the outer peripheral side) of the chamfer 2b of the metal member 2. Set it.

A ceramic member 1 is attached to such a metal member 2.
After brazing No. 1, the bonded body is rotated around the axis J of the cylindrical portion 3 of the metal member 2, and the grinding allowance of the outer circumference of the circular umbrella portion 4 of the metal member 2, that is, the chamfer 2b having a size of 2k is ground. Thus, the outer peripheral surface 6 of the circular umbrella portion 4 of the metal member 2 and the outer peripheral surface 13 of the ceramic member 11 are ground. When the sizes of the members 2 and 11 are set in this way and the amount of grinding of the metal member 2 is small when grinding is performed after brazing, the grinding efficiency can be increased for the following reasons.

In such grinding, since the ceramic is ground together with the metal, a diamond grindstone having abrasive grains having a hardness higher than that of the ceramic is used as the grindstone. When the diamond member grinds the metal member 2, ,
The grindstone (diamond abrasive grains) largely falls off, resulting in a decrease in grinding efficiency. However, if the above is done, the grinding allowance of the metal member 2 can be minimized, and this problem can be reduced.

In the above, the outer peripheral surfaces 6 and 13 of both members 2 and 11 having the same diameter D1 are ground by sandwiching the brazing material layer 21, but as shown in FIG.
The outer peripheral surface 13 may be ground over its entire thickness, and the outer peripheral surface 6 of the circular umbrella portion 4 of the metal member 2 may be ground by a predetermined dimension S from the joint surface 5. The two-dot chain line in FIG. 2 shows the shape before grinding. Since the metal member has a cup shape such as a cup-shaped engine tappet, it is suitable when the grinding range becomes large and the grinding efficiency deteriorates when the outer peripheral surface is finished to have the same diameter. Even in this case, it is preferable that the outer peripheral edge of the surface 14 of the ceramic member 11 opposite to the joint surface 12 is chamfered by grinding.

The tappet of the above embodiment (FIG. 1) (Sample N)
1 to 5) and a comparative tappet without grinding (Sample No.
6 to 10) were each manufactured, and a predetermined durability test was performed to confirm the deformation of the brazing material layer 21, the state of destruction of the ceramic member 11, and the like. The contents of the durability test (motoring test) are as follows, and the results are as shown in Table 1. Test content: Tappet clearance; double the standard (0.
6 mm), rotation speed; Eng. max rotation speed x 200
%, Endurance count; target value 2 × 10 ⁷ cycles.

However, in the case of this example (Sample Nos. 1 to 5), the outer diameter D2 of the circular umbrella portion 4 of the metal member 2 before joining is φ3.
3.7 mm, the outer diameter D11 of the ceramic member is φ34.5
The chamfers 2b and 11b each have a size of C0.3, and the maximum allowable positional deviation during brazing is 0.
The metal member was brazed to 4 mm, and then the outer diameter of the metal member was ground with a 0.35 mm (grinding allowance) diamond wheel on one side to make the entire outer circumference φ33.0 mm, and chamfering was completely removed. Further, in the comparative examples (Sample Nos. 6 to 10), the outer diameters D2 and D11 of the respective members before joining were both φ33.0 mm.
The size of each chamfer is C0.3,
The size of the maximum allowable positional deviation during brazing was 0.4 mm, and brazing was performed.

The metal member 2 forming the joined body is JIS
SNCM630 (Ni-Cr-Mo steel), and its joint surface (end surface) 2a is Ra (center line average roughness) 0.4.
Grinded to μm. The thickness T of the circular umbrella portion 4 is 3.5 mm. On the other hand, the ceramic member 11 is
90% by weight of Si3 N4 powder was mixed with Y2 O3 -Al2 O3 based sintering aid and forming binder, and formed into a disk shape by a die press, followed by firing in N2 gas atmosphere, and then both Ra for the circular surface (joint surface) (centerline average roughness)
It is formed into a disk having a thickness of 1.5 mm by grinding (polishing) to 0.3 μm. The chamfering C of the ceramic member
0.3 is attached to the outer peripheral edge of both sides.

The brazing conditions in this test are as follows. Between the joint surface 12 of the ceramic member 11 and the joint surface 4 of the tappet body 1, a diameter φ31 mm and a thickness of 0.
Ti-In-Cu-Ag formed in 05 mm foil shape
Active brazing material (Ti; 1.5%, In; 12.5%, C
u; 27%, Ag; 60%) with a surface pressure of 0.22 g / cm ² and held under vacuum at 820 ° C. for 1 hour and 30 minutes,
It was cooled to 80 ° C. in an N 2 gas displacement cooling furnace over 1 hour 30 minutes and brazed. Incidentally, the brazing material layer 3 after this joining
The thickness of 1 is in the range of 15 to 30 μm.

[0028]

[Table 1]

In this test, the example products (Sample No. 1
5), up to 2 × 10 ⁷ , no abnormality was found in the brazing material layer, the bonding state, the ceramic member, etc.
It can be seen that the impact resistance is clearly improved over that of Nos. 6 to 10). This demonstrates that the presence of chamfers on the outer peripheral edge of the joining surface certainly reduces the durability, albeit a minute amount, while at the same time, removing it definitely enhances the durability. ing.

Next, the same sample as above was put into each of the five samples, and the examples (Sample Nos. 1 to 5) and the comparative examples (Sample No. 1 to 1) were prepared.
For 5), impact resistance was tested. However, the contents of the test are as follows. As shown in FIG. 3, on the surface 14 of the ceramic member 11 of the joined body (sample), a diameter of 10 m
A columnar metal (SKD11) pin P having a length of 15 mm and a length of 15 mm is parallel to the axis of the pin P with a diameter of the surface 14 of the ceramic member 11 of 10 mm, and is placed at the left and right center in FIG. An impact load was applied to the ceramic member 11 via the pin P, and the load at which the ceramic member 11 cracked was measured. However, the load is 5000 kgf to 1
It increased by 000 kgf. The results are shown in Table 2.

[0031]

[Table 2]

From this test result, the product of Example (Sample No. 1
It can be seen that the impact resistance of Samples No. 5 to 5) is clearly improved as compared with the comparative example products (Sample Nos. 6 to 10). In this way, in the brazed joint body, the outer peripheral surface is ground and finished so that chamfers do not exist on the outer peripheral edges of the brazed joint surfaces of the metal member and the ceramic member. Can increase its durability.

In the above description, the brazed joint is described as being embodied in an engine tappet, but the joint according to the present invention is not limited to this, and other rocker arms, valve bridges, etc. The present invention can be applied to a brazed joint body of a metal member such as an engine part or a tool and a ceramic member. The present invention is not limited to the above-described embodiments, and can be embodied with various design changes without departing from the scope of the invention.

[0034]

As is apparent from the above description, according to the present invention, the outer peripheral surfaces have the same diameter so that chamfers do not exist on the outer peripheral edges of the brazing joint surfaces of the metal member and the plate-shaped ceramic member.
In addition, regarding the outer peripheral surface of the ceramic member,
Since the entire plate thickness is ground and finished, there is no notch groove on the outer peripheral edge of the brazing joint surface, so stress concentration does not occur unlike the conventional joint structure, and the brazing joint surface There is no defective filling portion of the brazing material layer even at the outer peripheral edge. As a result, even when the bonded body receives an impact load, the outer peripheral edge of the brazing material layer does not act as a starting point to cause deformation or cracks in the brazing material layer, thus preventing damage or peeling of the ceramic member. As described above, according to the present invention, it is possible to obtain a brazed joined body having excellent impact resistance, and when embodied in a joined body such as an engine tappet or rocker arm for which this impact resistance is particularly required. In addition, its durability or reliability can be significantly improved.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view showing an example of an embodiment in which a joined body according to the present invention is embodied as a tappet and an enlarged view of essential parts thereof.

FIG. 2 is an enlarged sectional view of an essential part showing another embodiment.

FIG. 3 is a plan view illustrating a position where a shock is applied to a ceramic member in a shock test.

FIG. 4 is a partially cutaway front view and a partially enlarged view of a tappet in a conventional joined body.

[Explanation of symbols]

1 brazed joint 2 metal members 5 Brazing joint surface of metal member 6 Outer peripheral surface of metal member 11 Ceramic member 12 Brazing surface of ceramic member 13 Outer peripheral surface of ceramic member 14 Surface of the ceramic member opposite to the brazing surface 15 Chamfer on the outer edge of the opposite side 21 Raw material layer

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-63-239169 (JP, A) JP-A-60-255679 (JP, A) JP-A-60-82267 (JP, A) JP-A-9- 32515 (JP, A) JP 8-232612 (JP, A) JP 1-170704 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C04B 37/00-37 / 04

Claims (3)

(57) [Claims] 1. A method for producing a brazed joint by brazing a metal member and a ceramic member, wherein a chamfer is provided on the outer peripheral edge of the brazed joint surface, wherein the ceramic member is plate-shaped. It is a thing and its one main surface is in front
After said metal member and brazed to brazed assembly as serial brazed joint surface, the same diameter outer peripheral surface so chamfer the outer edge of each brazed joint surface is not present, yet the cell
A method for manufacturing a brazed joined body, characterized in that the outer peripheral surface of the lamic member is ground to the entire thickness . 2. The plate thickness of the ceramic member is 1 to
The one according to claim 1, which is 3 mm.
Method for manufacturing brazed joint . 3. The method for manufacturing a brazed joint according to claim 1, wherein the metal member forms a tappet body for an engine, and the ceramic member forms a cam sliding surface of the tappet for an engine.