JPS6086202A - Sintering connection of green compact to metal member - Google Patents

Abstract

PURPOSE:To connect a green compact only to the necessary part of a metal member, by bring the green compact comprising components generating a liquid phase during sintering into contact with the metal member on a straight line and heating both of them under vacuum to simultaneously perform liquid phase sintering and connection. CONSTITUTION:A green compact 1 comprising components generating a liquid phase during sintering is formed so as to make the radius of curvature thereof larger than that of a metal member 2 and assembled to the metal member 2 so as to be contacted therewith body 2 comprises a steel material such as carbon steel or alloyed steel and the green compact 1 contains one or more of B, Si, P and C, and a sintering temp. is set to 1,000-1,350 deg.C. Subsequently, the sintered one is heated under vacuum or in a non-oxidative atmosphere and the green compact 1 is subjected to liquid phase sintering and, at the same time, subjected to diffusion connection by utilizing the eutectic liquid phase between the green compact 1 and the metal member 2 to form a sintered body 3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves assembling a powder compact made of components that are in a liquid phase during sintering so that it contacts a metal member only on a curved line or a straight line, and in a non-pressurized state. The present invention relates to a sintering and joining method in which liquid phase sintering and joining are performed simultaneously in vacuum or in a non-oxidizing atmosphere by a single heating operation.

Generally, methods for joining a sintered body to a metal member include a welding method, a ◇Lye 11 method, a diffusion bonding method, and the like.

The welding method uses heat (for sintered bodies with low hardness) and low toughness (
It may crack due to counter attack and cannot be used. Wax 1 is made of silver wax or copper wax and has a d1λ degree of 600 to 9.
00℃, and the waxing temperature is not high, but on the other hand, if you want to use it as a high-temperature heat-resistant member, you can melt some parts of the wax.
11 cannot be used apart from each other. In addition, the strength of the soldering part is not necessarily high enough, and there is still concern about the strength of the soldering part, so there is a problem that it cannot be used when it is necessary to withstand a large load.

Next, the diffusion bonding method is a method commonly used for bonding steel materials, etc., and bonding is generally performed by heating at about 1,000 to 1,300° C. to cause diffusion. However, in this method, in order to make sufficient contact between the sintered body and the metal part, it is necessary to match the surface shapes of the sintered body and the metal part, and to make the surface roughness of the joint surface very fine. In order to smooth the surface, it sometimes requires heating under a load and for a long time.
Further, there are problems such as increased cost and deterioration of a-property due to reheating of the sintered body during diffusion bonding.

For this reason, a method has been proposed in which a green compact is placed coaxially around the outer periphery of a copper phase or cemented carbide by utilizing the shrinkage during sintering, and the bonding is performed by -times of sintering heating. This method can only be used when joining everything in an annular shape, and there are problems such as cracking of the sintered body unless the inner diameter of the green compact is strictly controlled within a certain range.

Making the powder green compact into a sintered compact with substantially 100% true density, maintaining the shape of these sintered compacts in the desired shape, and properly joining the sintered compact to the part of the metal member to be joined. In order to bond the sintered body with a high bonding strength without causing breakage, etc., it is impossible to satisfy the following conditions simply by placing the green compact on the surface of the metal member. Have difficulty. The reason for this is that the powder compact becomes vertical due to the appearance of a liquid phase when heated.

＋l'l g I A powder green compact that undergoes large contraction in all directions, and sintering progresses as it shrinks, moves the metal member by the amount of contraction, so that the final sintered compact The angle becomes 11°・11 at the point where it deviates from the bonding position, and a partial sintering bond occurs with the 9th shrine at a certain point during shrinkage due to sintering, and this bonding force is greater than the shrinkage force of the sintered body. If it is too strong, it will lead to breakage of the sintered body and cause the joining position to be distorted. In particular, these problems become more serious as the size of the sintered body becomes larger.

The purpose of the present invention is to propose a method for solving the above-mentioned problem, and it is possible to join only the necessary parts instead of the entire circumference of a cylindrical body, etc., and the surface of the metal member is The object of the present invention is to provide a method that can join even quadratic curved surfaces.

The present invention will be explained in more detail below.

The material of the powder compact used in the present invention is 1,000 to 1.
It is preferable that a eutectic liquid phase occurs between 350°C and 350°C.

Wood inventors have already shown IJII about boride or complex boride hard sintered alloys containing Fe with a B content of 3 to 20% (Japanese Patent Publication No. 54-27).
818. Tokuko Sho 56-8904. Bureau - Komei 56-157
73. ! 1.5 Publication No. 56-37281° Unexamined Publication No. 58-
671342), which is an ingredient for liquid phase sintering, will be mainly described in detail below.

The hard sintered alloy and powder used in the present invention have a B content of 3 to 2
0%, and contains at least 10% or more of Fe. B exists as a molecule forming a hard phase of boride or complex boride, and imparts high hardness and wear resistance. It also plays an important role in sintering the powder compact and firmly bonding it to the metal member without applying pressure. The amount of hard phase is between 40 and 95%.

The hardness of the sintered body is in the range of I-IRA 80 to 93,
If the hardness can be lowered to about 11RA77, the amount of B gold platinum can be lowered to 2%.

The boride components forming the hard phase are Mo, W, and Ti.

V, Nl), Ta, Zr, ■a of r-11,
Va and ■a group elements and Pc, Cr, Co
, Ni, and Mn, which are iron group metal elements. When C or carbides or nitrides are added, they mainly form a hard phase. The binder phase surrounding the hard phase provides strength and toughness to the sintered body, and is composed of an FC-based alloy component. Cr, Ni.

Addition of MO, W, Co, Co, Mn, etc.: lit
Accordingly, these are present in the hard phase, the binder phase, or both phases, and serve to impart corrosion resistance, heat resistance, and strength to the sintered body;

The particle size of the powder used is 350 mesh (44μ) or less,
The average particle size is preferably 500 meso (25μ) or less, more preferably an average particle size of 03 to 3μ.

The reason for this is to increase the bonding force between the powders when compacting the powder, to prevent chipping or deformation (misalignment) in the powder compact, and to allow the sintering reaction to occur smoothly. To obtain a sintered body with high density, to maintain high mechanical properties such as hardness, transverse rupture strength, and wear resistance of the sintered body, and to increase the bonding strength with metal parts (and prevent defects such as pores at the bonding interface). It is fundamentally important to avoid leaving any residue.Powder particle size is 1.O
O mesh (150 μ) ~ 325 mesh or 50
If the powder contains powder coarser than 0, many pores remain in the sintered body, and it is not possible to obtain a sintered body with true density, and the strength such as transverse rupture strength decreases, causing problems at the bonding interface. However, pores remain and a strong bond cannot be obtained.

In order to make the powder fine, a wet ball mill, a vibrating ball mill, an attritor, or an equivalent grinding means using a solvent such as alcohol or acetone is used. As the powder becomes finer, it becomes more easily oxidized, so use paraffin and stearic acid.

It is preferred to use an appropriate amount of zinc stearate or the like.

After drying and granulating the above finely pulverized powder, the pressing force is 100~
3.000 kg7cm, preferably 150~2,
The powder is compacted into a desired shape at OOOkg/cJ, and the compacted powder density is 3.2 to 5.69/c4, preferably 3.4 to 5.1.
The range is f/c4. This is the true density of the sintered body of 38~
67%, preferably in the range of 40-60%. If the density of the green compact is less than 3.29/cA, the strength of the green compact will be insufficient, and the green compact may break during operations such as handling and transportation. In addition, cracks and pores are likely to form during sintering, and the bonding is often insufficient and unstable. When the green compact density is 5.69/cJ or more, it is difficult to dissipate a small amount of oxide remaining on the powder surface, CO scum caused by this oxide, or pores existing between powder particles. These tend to remain in the center of the sintered body, degrading the mechanical properties of the sintered body.

-J- The powder green body made under the conditions described above is left standing and sintered so that it contacts the metal member only in a straight line or curved line -1-, but the curvature of the side of this powder green body to be joined is It is important that the radius be larger than the radius of curvature of the parts to be joined.As for how large it should be, it is important to , first contact (4'Fi, ji', near e/position)
If the contact is successively farther from j and the size is at least the minimum size that prevents the reverse from occurring, the bonding will be complete and problems such as damage and cracks will not occur.

The shrinkage rate of the powder green body during sintering is %, the radius of curvature of the powder green body to be joined is R=, and the outer diameter of the metal member is tn.
It is more preferable if the relationship with m is maintained. Also, the radius of curvature R
is possible up to infinity (ie, a straight line).

(See FIG. 5) Furthermore, when joining to a flat plate, the radius of curvature R may take a negative value.

Even in the case of a curved surface whose radius of curvature is not constant, the compact size may be calculated based on the maximum radius of curvature so that the above relationship can be maintained.

The basic principle for assembling the powder compact to the metal member is to place the metal part horizontally in stripes and place the powder compact on top of it. By doing so, the powder compact comes into contact with the metal part due to its own weight at the same time as sintering. If necessary, it is also possible to tilt the metal member 1r1 and place the powder compact on the inclined surface. In this case as well, it is necessary to apply the weight of the powder compact to the bonding with the metal member.

The angle of inclination of the metal part is up to 60°, preferably up to 45°.

As a result of various experiments, the metal parts used are JTS standard SS shrine, SC shrine, SB shrine, Jintong steel such as 5TT3, 3U, I material, SCM material, SK shrine, SKS O8',
SKD Shrine.

Low alloy steel such as 5KII material, SUS, SUH material,
Drawing steel, tool steel, stainless steel, heat-resistant steel, high-speed steel,
Cast steel and cast iron-free Fe-based feeds can be used, both of which have a shear strength of 35-50 kJma and a bending strength of 1001
(It is possible to obtain a strong bonding strength of about 100% or more.) The shear strength of a bond such as silver solder is 20 to 251 (F'
That's about it.

Next, the heating conditions for bonding will be described.

Vacuum, reducing or non-oxidizing atmosphere can be used as the heating furnace atmosphere, but vacuum is preferable due to ease of reduction of small amounts of oxides such as B, Cr, and Ti, prevention of oxidation during heating, and workability. is more preferable.

When a page-open furnace is used, the degree of vacuum is in the range of 1 to 10' torr, preferably 10-1 to lQ' torr. When the degree of vacuum is below 1 torr, B, Cr,
Since oxides such as Ti are formed, the lower limit is l torr ,
Preferably it is 10-1 torr. Also,” 2nd Book B,
The reduction of oxides such as Cr and Ti is almost done at up to 10-' torr, and increasing the vacuum level to 10"-5 torr or higher is expensive in terms of equipment, so the upper limit is 10"-5 torr or higher.
-5 torr, preferably 10-4 torr.

As the reducing atmosphere or non-oxidizing atmosphere, T-12
, N2, A, r gas or a gas containing a small amount of CO or CO2, or a mixture of these gases, and B, Cr
In order to prevent the oxidation of these oxides from proceeding or to reduce these oxides, the oxygen potential is lowered and the dew point is lowered to -10°C.
Keep it below.

Next, the heating temperature varies depending on the composition of the powder, but is 1, 1
50~1350℃, preferably 1.180~1.300℃
℃ range. The density of the powder compact used in the present invention is 38 to 67% of the true density, and is 1.C1 to 11. Therefore, the true density is substantially 100%, although it contains an unavoidable small amount of impurity. During sintering, approximately 1% of B1 or B compound contained in the powder and Fc, Ni, Cr, Co, etc.
．． (at 150℃ or higher) (A liquid phase is formed, resulting in a sintered body with almost 100% true density, but the B or I3 compound in the sintered body is sintered within the same sintering temperature range. Fc in metal parts such as iron, steel and alloy steel.

Also, it seems that a part of the liquid phase is formed with the contained Cr, Ni, Co, etc., and the sintering of the powder green compact I'l and the strong bond between the sintered compact and the metal member. It is considered that bonding proceeds almost simultaneously.

Despite the fact that the sintered compact shrinks significantly compared to the powder compact by 12 to 27% in size and 33 to 62% in volume, by selecting the above sintering temperature and the time described later, It is possible to obtain a sintered body with the desired dimensions and shape without deformation (, 1), and to form a strong bond with a shear strength of 351(6) or higher between the joints. When a powder compact is brought into contact with a round rod or tube only in a straight line or curved line, it maintains accurate dimensions and shape after sintering, the joining position is accurate, and the shear strength is extremely high. First, after large dimensional shrinkage occurs and sintering is performed,
It is interpreted that joining with a metal member is being performed.

For example, in the case of joining onto a rod or tube as shown in Figures 1 and 2, the green compact shrinks and becomes a sintered body with almost 100% true density, and the radius is reduced or the rod or tube is bonded by the action of gravity. It is thought that the bonding occurs when the material comes into contact with the pipe or pipe.

``The first technical idea of the present invention is to bring the powder green compact into contact with only a portion of the iron, steel, or alloy steel part that is the joining metal part, so that a gap is left, and The powder compact should be placed in such a position that its own weight will work.Secondly, by using finely pulverized powder with a B content of 3 to 20%, the powder itself will have 100% true density due to B. At the same time as liquid phase sintering, a part of the liquid phase is generated between the metal phase components, so that B reduces and removes oxides on the surface of the metal component and has a cleaning effect, making diffusion bonding extremely easy. In normal expanded 11-cross welding, a large pressure is applied to ensure sufficient bonding, but in the method of the present invention, only the dead weight of the powder compact is used. Generally, no pressure is required.Despite the extremely large shrinkage of 12 to 27% in dimensions, the surface of the metal part 44 and the sintered body come into contact with the entire surface r1 at the final stage of completing sintering. Then, expand f1f and complete the joining.

This completely prevents the phenomenon in which the surface of the sintered body during sintering deviates from the predetermined final position on the surface of the metal part due to movement due to contraction, and the phenomenon in which the sintered body cracks due to partial bonding. This makes it possible to simultaneously perform sintering and bonding at substantially 100% true density while maintaining the desired dimensions and shape at the correct location.

Next, the heating temperature is in the above i'1ll1 degree range,
1. At temperatures below 150°C, a sintered body with true density cannot be obtained, many pores remain, and the bonding strength with the metal RQS shrine is low.
, f, II separation occurs, so the lower limit is 1.15
0°C, preferably 1.180°C. On the other hand, if the heating temperature exceeds 15 degrees, the bonding with the metal part will be %i degree (although it is sufficient, the shape of the sintered body will collapse and it will not be possible to obtain a sintered body with the desired shape and dimensions. Temperature's 1st limit
．． The temperature is 350°C, preferably 1.300°C.

Next, turn the heating port 4 times at 1.150 to 1,350℃.
It is 90 minutes. The reaction of sintering and joining is fast (because it progresses -) -
If the speed of heating +C is delayed to 111 degrees, the desired purpose can be achieved as soon as the scorching temperature +W is reached, but if the sintering or bonding strength is insufficient, η Therefore, the lower limit is set to 5 minutes. In the case of powder green compacts or large metal parts, the amount of processing is even larger) In case 20, there is a delay in partial heating and d111 degree non-uniformity, so the soaking time should be reduced. The upper limit is 90 minutes.

Next, regarding the temperature increase rate, the rate of increase of 41λ in the temperature range from the appearance of a liquid phase to sintering is important, and it is necessary to keep it to 20° C./min or less. ) 7 + A speed is too high, which may result in inaccurate vertical positioning or poor bonding to curved surfaces, so the speed is preferably 20° C./min or less).

- As mentioned above, in the method of the present invention, it is not necessary to apply a load to increase the bonding strength during the sintering and bonding heat treatment, but it is sufficient if the powder compact is brought into contact with its own weight.

Prior to performing the Uri ε bonding process, it is preferable that the surface of the metal assembly be subjected to a process to remove skin by Noyonotofras +-, J&, grinding, or the like. The unevenness created on the joint surface by blasting process '8 affects the joint strength! Increase T.

Table+fii l'l (Q is Rm;+x 5071 and above-
In order to maintain the bonding point, it is necessary to increase the heating temperature, and if the heating temperature is increased by 1, the shape of the sintered body will change.
I won't be able to do it. Therefore, the surface ill Ilj is Rma
x 60μ or less, preferably 3011ν tons, more preferably 10 /l or less.

1. The limit is 0.27z, which is good even when finished to a mirror surface.11,J is good, but usually up to about 0.8μ is fine.

If necessary, degrease the surface of the metal parts with a solvent, or perform surface treatments such as AlnoJ cleaning or pickling.

The tV maintained the desired dimensions and shape according to the manufacturing conditions described in 1-1 below, and the viscous material was firmly bonded to the metal part 44 under the same 11. 'f can be completed. The area to be joined can be changed according to necessity.

In addition, if the heating temperature is high and the metal parts require tempering heat treatment to remove the effects of heating, standard heat treatment or solution treatment may be performed after sintering and joining depending on the material of the metal parts used. Heat treatments such as treatment, quenching, tempering, strain relief, and precipitation treatment can be performed. These heat treatments can be accomplished extremely economically in a single heating and cooling process by immediately performing the desired heating and cooling operations using N2 gas or the like in the same furnace after the sintering and bonding process. Alternatively, heat treatment may be performed in a separate furnace after cooling to −p room temperature.

Even during these heat treatments, the bonding temperature between the sintered body and the metal member is crystallized, and the bonding strength is sufficiently high, so 'f, II 11
However, problems such as 111 do not occur (and changes in mechanical properties such as hardness and transverse rupture strength of the sintered body hardly occur).

For example, baking 7 (C heat treatment is 880~1.000℃, 10~
By heating in N2 gas for 30 minutes and then cooling at a cooling rate of 20 to 50°C/mzn, the crystal grain size and mechanical ease of the metal part can be restored, and the hardness, transverse rupture strength, and structure of the sintered body can be restored. There is no change. 1.000~ for stainless steel
1. After soaking to 150℃, cooling with N2 residue is recommended.
may be used.

The hard sintered alloy bonded metal body of the present invention has a hard sintered alloy of 1
In addition to having a hardness and strength of 1ν and excellent wear resistance, it also has excellent corrosion resistance 1/] and U'1'!;Heat resistance IYI at high temperature
, in order to be able to add oxidation resistance IJ1, the bending strength is 1'1.General resistance 1% N'in, 1lj
4.It can be used in a wide range of applications as a composite of 4 types of abrasive materials, heat resistant and abrasion resistant A1. For example, a flat plate or cylinder,
A large number of metal parts such as rods are arranged on the shrine and joined together to create chuko using ferrous or non-ferrous plates, wires, rods, kite plates where blinds pass through, tsunoid cups, nido titanium, noyozutoplast, etc. Plate for shear 4 wear, coal, coke, ore 1
．． Scraping rods, plates, and wear-resistant members for transport means such as transport conveyors such as Karasu and Shichiment 2 Ash erosion of furnace pipes for coal fires and fluidized bed boilers Uj city lining, @Nondo bomb casings and blades, screw conveyors The wear resistance, corrosion resistance, and heat resistance of the hard alloy invented by Kasagi can be utilized for wear-resistant linings of blades, wear-resistant parts against molten Zn, mines, civil engineering, construction machinery, steel, non-ferrous metals, paper, chemistry, ice utilization machinery, metal processing industries, etc. It can be used in a wide range of fields.

The pulverization of the powder mentioned above, the power of compacting the powder, the density of the compact, the shrinkage amount of the sintered body due to heating, and substantially 100% true densification, and the metal parts and powder. Introducing green compacts, the description of the surface roughness of metal parts applies similarly to N1 and Co-based B-containing powders and liquid-phase sintered alloys containing a large amount of C, Si, and P. It is possible.

In the case of N1-based alloys containing a large amount of B, Si, and C (2 to 4%), the liquid phase appearance temperature drops to about 1.050℃.The liquid phase sintering temperature exceeds 1.350℃. It is difficult to apply this method to powders whose liquid-phase sintering temperature exceeds 1.350° C., since deformation of metal members is likely to occur during heating.

As mentioned above, when using a powder of about 1,100 nits, such as those used for general sintering such as ordinary Fe-based alloys and N1-based alloys, the
% true density cannot be obtained, and the result is a lower-density sintered body with pores remaining, and the number of pores at the bonding interface with the metal part also increases, and the bonding strength decreases. It can be used depending on the target.

Examples of the present invention will be shown below.

Actual hi: Example 1 10%B, ■3%Cr, Fe rL+1. M to the powder of
o powder/14%, Ni powder 39A, Fe powder 6%
, 3% graphite powder and 6% paraffin were mixed, homogenized in a vibrating ball mill, wet-pulverized to 1.57°C, and dried. After that, it is pressed into a semicircle with a density ratio of 51% + = y r [powder (outer radius 44 mm, inner radius 40 mm), and this green compact is molded into 60 outer diameter 5s41 particles with a surface roughness of Rmax 611 m. Place the whole thing on a round bar of approximately Q.5US4Q5 (Fig. 1A) at 3 x 10” torr.
G+'l bonding was performed by baking in a vacuum at 1.275°C for 20 minutes.

(Figure 1B) - The density of the sintered body was 8.2 fj/crl, with no pores observed and the penetration density was substantially 100%.

A sample was taken out from this, and the shear strength was determined by a method similar to the JIS GO61 clad steel shear strength test. As a result, the joint strengths shown in Table 1 were obtained.

The hardness of the sintered body was I-IRA S 7, and the bonding interface was strong with a diffusion of 1 m.

Example 2 13% B, 5% Cr, Fe Bad. The powder contains 50% MO powder, 3% Ni powder, 4% Fe powder, and 0 graphite powder.
4% paraffin and 5% paraffin were mixed, wet-pulverized in a ball mill to an average particle size of 1.31℃m, and after drying, it was made into a semi-cylindrical compact with a density ratio of 48% (outer surface radius 51 mm, inner radius 47 mm). The green compact was molded using a press and placed on a flat surface horizontally placed on a steel pipe with an outer diameter of 76 mm (surface 11° Rmax 10-301°Cm), and the whole (second prisoner) was heated at 4.5 x 10-
2. Sintering and joining were carried out at 1.250° C. for 20 minutes in a vacuum of torr. ((Figure 2B) After sintering and joining, the sintered body was completely joined to the metal member, and microscopic observation of the joint surface confirmed that there were no pores at the interface. No pores were observed, and the hardness was HnA, 90. The bonding strength was 46 k77 mA.

Example 3 Using the same powder as in Example 2, it was molded into an IZ) surface with a density ratio of 45% (outer surface radius 46.5++++n, inner radius 315 mm), and this green compact was Outer diameter 50.5 mm (D SUS
410) Place it on a round bar (Fig. 3A) and
1.250°C, 20 in a vacuum of X 10-3 torr
Separately sintered and joined.

(Figure 3B) 8 mrn x 4 rmn x from this sintered joined body
A 25 mm rectangular parallelepiped was cut out and a three-point bending test was conducted using the joint surface as the load point. As a result, the bonding strengths shown in Table 2 were obtained.

Example 4 Using the same powder as in Example 2, a cylindrical shaped powder compact (outer surface radius 35 mm, inner radius 31.5 ttrm, Fig. 4A
) is placed on a 450-bent pipe with an outer diameter of 505 mm with a gap in the pipe axis direction, and the whole is 45 x 10'-2t (Fig. 4B).
They were sintered and joined in a vacuum at 250° C. for 20 minutes. After sintering and bonding, the highly sintered body shown in FIG. 4C was completely bonded to the metal member with a space between them.

Example 5 Using the same powder as in Example 2, a width of 15 holes and a length of 100 m +
i. Form a plate-shaped powder compact with a thickness of 3 mm, and use the powder for this purpose as R.
A steel pipe having an outer diameter of 76 m and having a surface roughness of max. 15 .mu.m (Fig. 5A) was left stationary and the whole was sintered and joined in a vacuum of 2.times.10@-3 torr at 1.250 DEG C. for 20 minutes.

(FIG. 5B) After sintering and joining, the sintered body was completely joined to the metal member, and it was confirmed by a mathematical test that the joint did not separate even if deformed.

Example 6 Using the same powder as in Example 1, a semi-cylindrical powder compact with a density ratio of 50% (outer radius 35 mm, inner radius 315 mm, medium 1
5 inch) with a press, and this compacted powder is Rmax
It was placed on a steel pipe (carbon content: 009%) with an outer diameter of 50.5 mm and a surface roughness of 10 μm, and the whole was heated to 35 × 1 O-31.
Sintering and joining were carried out in a vacuum at 1.250°C for 20 minutes. After sintering and joining, it was confirmed by a mathematical test that even if the sintered metal was shaped until it broke, the sintered body did not separate from the metal member and was completely joined.

In addition, when a JI812 test piece was cut out from this bonded metal body and a tensile test was performed, the yield point l51<7/, A
, the tensile strength was 35 k7/ma, the elongation was 44%, and the metal member crystal grains were coarsened. A standard heat-treated specimen heated at 950°C for 20 minutes in N2 gas and then cooled at 40°C had a yield point of 26 l (g/mA + tensile strength of 39 Ic).
y/mA + elongation was 43%, and the mechanical properties of the metal member before the sintering process could be restored, and the crystal grains were also restored to the state before the process. The hardness of the sintered body remained unchanged at HnA 87.

[Brief explanation of drawings]

Figure 1, Figure 2, ff! 3, 4, and 5 are drawings showing embodiments of the present invention, and FIG. 1(A),
Figure 2 (A), Figure 3 (A), Figure 4 (B) and Figure 5
Figure (A) is a drawing showing how to assemble a compacted powder body and a metal member. Figure 1 (B), Figure 2 (B), Figure 3 (B),
Figures 4(C) and 5 (rll are drawings showing the state of sintering and joining. 1...Powder compact 2...Metal member 3...Sintered body 1st Figure (c) CB) Figure 2 (,4) (B) Figure 3 (A') (B) (c) (0) Figure 5 (8) (B)

Claims (6)

[Claims] (1) A powder compact made of a component that generates a liquid phase during sintering is used, and the curvature 1'-diameter of the side to be joined of the powder compact is larger than the radius of curvature of the metal members to be joined ( and heated in air or in a non-oxidizing atmosphere in r↓ while assembled so that the powder green body is in contact with the metal member only on a straight line or curved line, 1. A sinter bonding method characterized by performing liquid phase sintering and at the same time performing diffusion bonding (between metal members) using a heavy liquid phase. (2) The metal member is an object having a curved surface consisting of an arc such as a cylinder, a semi-cylindrical shape, an ellipse, etc., and the longitudinal direction is straight or curved. Sinter joining method. (3) The metal member is a copper phase material such as iron, carbon steel 2 alloy steel, tool steel, etc.Claims 1 and 2N
p 1lili, sintering joining method. (4) The powder compact is 13. Contains one or more of Si, P, and C, and has a sintering temperature of 1,000°C to 1.115°C
The sintering and joining method according to claims 1, 2 and 3, wherein the temperature is 0°C. (5) The powder compact has a B content of 3 to 20% and at least 1
Particle size of powder that contains 0% or more of Fe, and after sintering becomes a hard sintered alloy consisting of 40 to 95% of a hard phase mainly composed of boride or complex boride, and a binder phase that binds the hard phase. 350 mesh (44μ) or less, the powder compact is molded into powder to have a compact density of 38 to 67%, and the powder compact is made of iron, m or an alloy as a metal member. -1 to 10-5 torr when partially in contact with steel
After heating to 1.150 to 1.350°C in a vacuum heating furnace, the sintered body is cooled to give a dimensional shrinkage of 12 to 27%, resulting in a sintered body with a true density of 99% or more and substantially 100%. 46. The sintering and joining method according to claim 1, 2, 3, and 4, which performs strong joining to the third metal part. (6) Cooling process after sintering or once cooling (1■
The sintering and joining method according to claims 1, 2, 3, 4, and a15, wherein the joining member is subjected to tempering heat treatment by heating.