JP2001138041A - Method of manufacturing sintered metal joined body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a sintered metal joined body with which the development of defective joining is securely prevented by allowing brazing filler metal to sufficiently permeate at high speed into a gap between the joining surfaces of both metallic members to be joined, the effect caused by the dimensional variation of the metallic members at the sintering is restrained and a firmly joined sintered metal body can be obtained. SOLUTION: In the manufacturing method of the sintered metal joined body for joining, at the same time with sintering, a first metallic member 1 and a second metallic member 2 being unsintering metallic members, the first metallic member 1 having a recessed part 1a and a through-hole 3 is fitted into the second metallic member 2 having a projecting part 2a and grooves 7 radially extending from the projecting part 2a, and a laid. Furthermore, the brazing filler metal 4 is inserted into the through-hole 3, and these first metallic member 1, second metallic member 2 and brazing filler metal 4 are heated to execute the sintering and the brazing of the first metallic member 1 and the second metallic member 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a sintered metal joined body in which unsintered metallic members are sintered and simultaneously joined by brazing.

[0002]

2. Description of the Related Art A method of manufacturing a sintered metal joined body in which unsintered metal members are sintered and brazed at the same time is, for example, one of the methods of manufacturing a planetary carrier constituting a part of a vehicle transmission. Also known as
This method will be described with reference to FIG.

In this figure, a first metal member 51 and a second metal member 52 are both unsintered compacts made of a metal based on iron. A concave portion 51a is formed at a lower portion of the first metal member 51, that is, at a joint surface 55a side. The concave portion 51a is to be fitted with the convex portion 52a formed on the second metal member 52. Also, the first
In the metal member 51, a through hole 53 penetrating vertically is formed in advance. A brazing material 54 is inserted into the through hole 53. The upper part of the second metal member 52, that is, the joining surface 5
On the 5b side, a convex portion 52a that fits into the concave portion 51a of the first metal member 51 is formed. The concave portion 51a and the convex portion 52a extend linearly along the same direction. By fitting the concave portion 51a and the convex portion 52a, the first direction is perpendicular to the direction in which the concave portion 51a and the convex portion 52a extend, that is, in the horizontal direction in FIG.
The metal member 51 and the second metal member 52 can be prevented from being displaced from each other.

[0004] The brazing material 54 is formed in a solid state into a cylindrical shape, and is inserted into the through hole 53 of the first metal member 51. The composition of the brazing material 53 is, for example, Ni
The basic composition is about 40%, about 40% Cu, and about 16% Mn. A flux is appropriately added to the brazing material 54. For example, when a B (boron) -based flux is added,
The oxidation of the brazing material can be suppressed to improve the wettability of the brazing material. Conversely, when an Fe (iron) -based flux is added, the melting point of the brazing material is raised to increase the viscosity, that is, to increase the wettability. Can be reduced.

A first metal member 51 is mounted on the upper side of the second metal member 52 so that the concave portion 51a and the convex portion 52a are fitted to each other, and a brazing material 54 is inserted into a through hole 53 of the first metal member 51. Insert In such a state, the first metal member 51 and the second
Is heated to a sintering temperature at which both of the metal members 52 can be sintered. The brazing material 54 begins to melt below this sintering temperature. The melted brazing material 53 flows downward, penetrates between the joining surfaces 55a and 55b, and joins the first metal member 51 and the second gold shoulder member 52 by brazing. When a predetermined sintering temperature is reached, the first metal member 51 and the second metal member 52 are sintered. At this time, the first metal member 51 and the second metal member 52 undergo some dimensional changes due to sintering. If the composition of the first metal member 51 is different from the composition of the second metal member 52, the ratio of the dimensional change is often different. In such a case, the first metal member 51 and the second metal member 5
2 may be displaced from each other, and may be brazed in that state. However, since the concave portion 51a and the convex portion 52a are fitted, no positional shift occurs near the fitting portion between the concave portion 51a and the convex portion 52a. By doing this,
A sintered metal joined body of the first metal member 51 and the second metal member 52 is obtained. Such a method is widely used because the sintering step and the joining step of the unsintered metal members can be made into one and the operation can be simplified.

[0006]

The size and shape of the fitting portion for positioning, that is, the concave portion and the convex portion, are variously limited depending on the use and function of the sintered metal joint product. However, they need to extend linearly along the same direction as each other. In addition, the direction in which the displacement can be prevented is determined, and in order to prevent the displacement in multiple directions, a large number of fitting portions must be provided in the same metal member. Therefore, the area occupied on the metal member was not small at all. In addition, there is a step, which is inevitable due to the function given to the member, in the setting required portion of the fitting portion, and the area of the fitting portion is reduced as much as possible in order to inhibit or bias the penetration of the brazing material. There is a need. Further, since the fitting portion and the portion into which the brazing material is inserted are different, a serious problem occurs that the brazing material does not sufficiently penetrate to the fitting portion. In the concave portion and the convex portion, stress concentration tends to occur at the corner portion, and if such a portion is not sufficiently joined, the reliability and durability of the sintered metal joined product as a product will be significantly reduced. In order to solve such a problem, a device has been devised in which a B-based flux or the like is added to the brazing filler metal to improve the wettability of the brazing filler metal and penetrate it to every corner. However, in this case, the cone material permeates a large amount into the first or second metal member. This is because the metal member before sintering is an aggregate of metal powder or fine particles, and therefore has a very large void. As a result, the brazing material does not sufficiently penetrate into the joint surfaces where the brazing material is originally supposed to penetrate, which may have an adverse effect of causing a joint failure. Such a method is not a sufficient solution. It was difficult.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and sufficiently infiltrates a brazing filler metal at a high speed between bonding surfaces of metal members to be bonded, thereby reliably preventing the occurrence of defective bonding, and at the same time firing. It is an object of the present invention to provide a method for manufacturing a sintered metal joined body that can suppress the influence of a dimensional change of a metal member at the time of sintering and can obtain a strongly joined sintered metal joined body.

[0008]

According to the first aspect of the present invention,
A method for producing a sintered metal joined body for simultaneously sintering and joining a first metal member and a second metal member, which are unsintered metal members, wherein the first and second metal members are provided. When forming the first metal member, the first metal member is fitted with the concave portion on the joint surface with the second metal member, and the second metal member is fitted with the concave portion on the joint surface with the first metal member. The first metal member is formed with a hole having an opening that opens to the bottom surface of the concave portion of the first metal member.
The metal member is placed on the second metal member by fitting the concave portion and the convex portion, and a brazing material is inserted into the hole, and the first and second metal members and the brazing material are inserted. Is heated to sinter the first and second metal members and braze the first and second metal members.

[0009] With this configuration, the brazing material can be permeated from the convex portion of the second metal member to between the joining surfaces. For this reason, since the brazing material permeates first from the fitting portion formed by the concave and convex portions where the brazing material does not easily penetrate, it is possible to reliably prevent poor joining at the fitting portion. In addition, since the brazing material permeates from the upper convex portion to the lower bonding surface, the brazing material can be easily permeated between the bonding surfaces.

According to a second aspect of the present invention, in the method for manufacturing a sintered metal joined body according to the first aspect, when the second metal member is formed, the first metal member is formed of the first metal member. On the joint surface with the metal member, a plurality of radially extending grooves are formed extending from the upper end surface of the convex portion through the side surface of the convex portion in a direction away from the convex portion with the convex portion as a starting point. I do.

With this configuration, the molten brazing material can flow through the groove and diffuse on the second metal member. Therefore, the molten brazing material can be sufficiently penetrated between the joining surfaces of the first metal member and the second metal member, and the speed at which the molten brazing material penetrates between the joining surfaces can be improved. it can. Further, it is not necessary to specifically improve the wettability of the brazing material, and the flux added to the brazing material for the purpose of improving the wettability is unnecessary or the required amount can be reduced.

The invention described in claim 3 is the first or second invention.
In the method for producing a sintered metal joined body according to the above, wherein the holes are:
It is characterized by being a through hole orthogonal to the joining surface.

With this configuration, a solid brazing material can be inserted into the through hole from above the through hole.
Preparation work before joining the metal member and the second metal member can be simplified.

According to a fourth aspect of the present invention, in the method for manufacturing a sintered metal joined body according to any one of the first to third aspects, the convex portion has a truncated cone shape, and the concave portion corresponds to the convex portion. It is characterized in that it has a shape that changes.

With this configuration, even when the first metal member and the second metal member undergo dimensional changes during sintering, the directionality of the dimensional changes can be eliminated. Further, since the corners are eliminated, it is possible to prevent stress concentration from occurring when the dimensions change, and to prevent damage to the metal member. Further, since the displacement between the first metal member and the second metal member can be prevented in any horizontal direction except the rotation direction, the area of the portion occupied by the concave portion or the convex portion on the metal member can be prevented. Can be reduced.

According to a fifth aspect of the present invention, in the method for manufacturing a sintered metal joined body according to any one of the first to fourth aspects, when the concave portion and the convex portion are fitted, the concave portion and the convex portion And a gap is formed between them.

[0017] With this configuration, the brazing material can easily flow between the concave portion and the convex portion. Therefore, the brazing material can be diffused and permeated around the fitting portion, and the vicinity of the fitting portion can be securely joined.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a method for manufacturing a sintered metal joined body according to the present invention will be described below with reference to FIGS.

In these figures, the first metal member 1 and the second metal member 2 are both unsintered compacts made of a metal based on iron. A concave portion 1a is formed in a lower portion of the first metal member 1, that is, on the joining surface 5a side. The concave portion 1a is fitted with the convex portion 2a formed on the second metal member 2, and is concave in a truncated cone shape so as to correspond to the convex portion 2a having a truncated cone shape. Further, a through-hole (hole) 3 penetrating in the vertical direction is formed in advance so as to open toward the concave portion 1a of the first metal member 1. A brazing material 4 is inserted into the through hole 3. Second
On the upper side of the metal member 2, that is, on the side of the joint surface 5 b, as shown in FIG. The protrusion 2a is sized to form a gap 6 between the top of the protrusion 2a and the bottom of the recess 1a when fitted to the recess 1a. The gap 6 is for allowing the brazing material 4 to efficiently penetrate between the joint surfaces 5a and 5b or to flow into the groove 7 when the molten brazing material 4 flows. When the concave portion 1a and the convex portion 2a are fitted to form a fitting portion, the first metal member 1 and the second metal member 2
It is possible to prevent any positional deviation from occurring in any of the horizontal directions except the rotation direction.

On the joining surface 5b side of the second metal member 2, a groove 7 for flowing the molten brazing material 4 is formed. The groove 7 is formed radially and linearly from the outer peripheral wall of the convex portion 2a around the convex portion 2a. Also,
The end of the groove 7 on the side of the convex portion 2a communicates with the gap 6, and the brazing material 4 flowing into the gap 6 is efficiently poured into the groove 7 at a high speed.
It can be diffused and penetrated between the joining surfaces 5a and 5b.

The brazing material 4 is formed in a solid state into a cylindrical shape, and is inserted into the through hole 3 of the first metal member 1. The composition of the brazing material 4 is not particularly limited as long as it can surely join the first metal member 1 and the second metal member 2. Suitable examples are standard brazing materials, such as about 40% Ni, about 40% Cu, and Mn.
Those having a basic composition of about 16% are mentioned. Depending on the situation, a B-based or Fe-based flux may be appropriately added to the brazing material 4.

Next, a joining method will be described. The first metal member 1 is placed on the upper side of the second metal member 2 so that the concave portion 1a and the convex portion 2a are fitted, and the brazing material 4 is inserted into the through hole 3 of the first metal member 1. . In such a state, the whole is heated to a sintering temperature at which both the first metal member 1 and the second metal member 2 can be sintered. The brazing material 4 begins to melt at a temperature lower than the sintering temperature, and the molten brazing material 4 flows downward, that is, into the gap 6, and diffuses almost uniformly in the gap 6 radially. Then, the brazing material 4 flows into the groove 7 or penetrates between the joining surfaces 5a and 5b. The brazing material 4 that has flowed into the groove 7 diffuses onto the joining surface 5b at a higher speed than the brazing material 4 that has directly penetrated between the joining surfaces 5a and 5b from the gap 6, and
a, between the 5b, so that a wide range of joint surfaces 5a,
5b questions can be spread. Thus, the first metal member 1 and the second metal member 2 are brazed. Note that some of the brazing material 4 may permeate into the first metal member 1 and the second metal member 2. The flux is appropriately added to reduce the wettability of the brazing material 4.

When heating continues and reaches a predetermined sintering temperature, the first metal member 1 and the second metal member 2 are sintered. At this time, the first metal member 1 and the second metal member 2
Causes some dimensional change by being sintered. However, since the concave portion 1a and the convex portion 2a are fitted,
The vicinity of the fitting portion between the concave portion 1a and the convex portion 2a does not shift in any horizontal direction except the rotation direction. Thus, a sintered metal joined body of the first metal member 1 and the second metal member 2 is obtained.

In the above manufacturing method, the first metal member 1 is placed on the second metal member 2 and then the brazing material 4 is passed through the through hole 3.
, But the order of these steps is not limited. For example, the first metal member 1 may be placed on the second metal member 2 after the brazing material 4 is inserted into the through hole 3 of the first metal member 1 in advance.

As a modification of the present embodiment, a cylindrical member 8 may be interposed between the through hole 3 and the brazing material 4 as shown in FIG. The tubular member 8 is made of, for example, a steel material made of an ingot material, and the brazing material 4 is
From the inner peripheral wall of the first metal member 1. In this way, almost all of the brazing material 4 flows downward, that is, flows into the gap 6.
Therefore, more brazing material 4 can be poured into the groove 7 or permeated between the joint surfaces 5a and 5b.

In the method for manufacturing a sintered metal joined body according to the present embodiment, the convex portion 2 a formed on the second metal member 2 is used.
Has a truncated conical shape, the concave portion formed in the first metal member 1 has a shape corresponding to the convex portion, and the convex portion 2a and the concave portion 1a constitute a fitting portion. Therefore, even when the first metal member 1 and the second metal member 2 undergo dimensional changes during sintering, the directionality of the dimensional changes can be eliminated. Since the corners are eliminated, it is possible to prevent the occurrence of stress concentration when the dimensions are changed, and to prevent the first metal member 1 or the second metal member 2 from being damaged. Further, since the displacement between the first metal member 1 and the second metal member 2 can be prevented in any horizontal direction except the rotation direction, the first metal member 1 or the second metal member 2 can be prevented. The area of the portion occupied by the concave portion 1a or the convex portion 2a in the member 2 can be reduced. Further, a through hole 3 is formed so as to have an opening in the concave portion 1a of the first metal member 1 so that a brazing material 4 can be inserted. Therefore, the brazing material 4 can be made to permeate from the convex portion 2a of the second metal member 2 toward the joint surfaces 5a and 5b. As a result, the brazing material 4 penetrates through the fitting portion where the brazing material 4 does not easily penetrate, that is, the concave portion 1a and the protruding portion 2a, so that it is possible to reliably prevent poor joining at the fitting portion. In addition, since the brazing material 4 penetrates from the upper convex portion 2a to the lower joining surfaces 5a and 5b, the brazing material 4 can easily penetrate between the joining surfaces 5a and 5b. Further, a gap 6 is formed in a fitting portion between the convex portion 2a and the concave portion 1a, and a groove 7 communicating with the gap 6 is radially extended from the convex portion 2a on the joint surface 5b side of the second metal member 2. I have to. As a result, the brazing filler metal 4 is moved from the gap 6 to the groove 7.
Into the joint surface 5b at a high speed from the fitting portion, so that the brazing material 4 can sufficiently penetrate between the joint surfaces 5a and 5b. In addition, since the brazing material 4 is allowed to flow through the groove 7, it is not necessary to particularly improve the wettability of the brazing material 4 and the flux such as B type is unnecessary or the necessary amount can be reduced. .

[0027]

As described above, according to the method for manufacturing a sintered metal joined body according to the present invention, the brazing material is sufficiently penetrated at a high speed between the joining surfaces of the metal members to be joined.
While reliably preventing the occurrence of bonding failure, suppressing the influence of dimensional change of the metal member during sintering, it is possible to obtain a strongly bonded sintered metal joined body, without increasing the number of steps, A highly reliable and durable sintered metal joined body can be manufactured. Further, the flux added to the brazing material for improving the wettability of the equipment is unnecessary or the required amount can be reduced, and the manufacturing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining one embodiment of a method for manufacturing a sintered metal joined body according to the present invention, and is a side sectional view of a fitting portion.

FIG. 2 is a plan view of a second metal member in FIG.

FIG. 3 is a view showing a modification of the embodiment of the method for manufacturing a sintered metal joined body according to the present invention, and is a side sectional view of a fitting portion.

FIG. 4 is a view for explaining an example of a conventional method for manufacturing a sintered metal joined body, and is a side sectional view of a fitting portion.

FIG. 5 is a plan view of a second metal member in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st metal member 1a concave part 2 2nd metal member 2a convex part 3 through-hole (hole) 4 brazing material 5a, 5b joining surface 6 gap 7 groove

Claims (5)

[Claims] 1. A method of manufacturing a sintered metal joined body for sintering and joining a first metal member and a second metal member, which are unsintered metal members, at the same time, In forming the second metal member, the first metal member has a concave portion on the joint surface with the second metal member, and the second metal member has a concave portion on the joint surface with the first metal member. And a hole having an opening opening at the bottom surface of the concave portion of the first metal member is formed, and the first metal member is formed in the concave portion with the concave portion. The first and second metal members and the brazing material are heated to fit the first and second metal members and the first and second metal members. Sintering of the second metal member and brazing of the first and second metal members to produce a sintered metal joined body. Method. 2. When forming the second metal member, a joining surface of the second metal member with the first metal member is formed from an upper end surface of the convex portion through a side surface of the convex portion. 2. The method for manufacturing a sintered metal joined body according to claim 1, wherein a plurality of grooves extending radially from the protrusions in a direction away from the protrusions are formed. 3. The method for manufacturing a sintered metal joined body according to claim 1, wherein the hole is a through hole orthogonal to the joining surface. 4. The production of the sintered metal joined body according to claim 1, wherein the convex portion has a truncated cone shape, and the concave portion has a shape corresponding to the convex portion. Method. 5. When the concave portion and the convex portion are fitted,
The method according to claim 1, wherein a gap is formed between the concave portion and the convex portion.