JPS59123746A - Wear-resistant sintered composite member - Google Patents

Abstract

PURPOSE:To obtain a firmly-bonded wear-resistant composite member at a low cost by combining a sliding surface part made of a wear-resistant sintered body of high alloy powder with a base material part for supporting the sliding surface made of a sintered body of low ferroalloy powder and by bonding them together by the mutual diffusion of liq. phases of the powders produced during sintering. CONSTITUTION:The titled member is composed of a sliding surface part made of a wear resistant sintered body of high alloy powder and a base material part for supporting the sliding surface made of a sintered body of one or more kinds of low ferroalloy powders each having an m.p. equal to or higher than the m.p. of the high alloy powder. The sintered bodies are bonded together by the mutual diffusion of liq. phases of the powders produced during sintering.

Description

[Detailed description of the invention] The present invention relates to sintered wear members.

Conventionally, internal combustion engines, such as rocker arm tips, etc.
Various sintered materials have been put into practical use for paulownia sliding parts that are subject to high surface pressure, but various high-alloy sintered materials are being developed and studied in response to even more severe usage conditions. However, these materials are expensive, resulting in high costs. In the above-mentioned sliding member, the parts that require progressive wear, which is essential for the sliding function, are the claws in the surface layer, so expensive sintered material is used only on the surface, and the rest is used to reduce wear resistance. A wear member has been developed in which the cost is reduced by substituting a ``e:'' and joining the two to form a 4-coat structure.

On the other hand, there are various methods for joining different glaze sintered materials, such as infiltration, brazing, and others, but diffusion joining at the same time as sintering is preferred because of its low cost and high reliability. However, conventional diffusion bonding was performed at a temperature below the melting point of the base material, resulting in insufficient liquid phase of the base material at the bonding surface, making it impossible to achieve optical bonding.

The present inventor proposed that a low-alloy iron-based powder having a melting point equal to or higher than that of the wear-resistant sintered material be used as a base material to replace the expensive wear-resistant sintered material of the sliding member. By heating both materials to a temperature above the melting point (liquid phase formation temperature) of the base material and performing sintering and diffusion bonding, an inexpensive sintered image that is firmly bonded is created. After discovering that the paulownia tree is worshiped as a drinker, he completed the present invention.

Therefore, an object of the present invention is to provide a strongly bonded, inexpensive sintered composite wear-resistant member.

The sintered composite wear-resistant member according to the present invention has a sliding surface portion made of a wear-resistant sintered body of high-alloy powder, and one or more types of low alloy powder having a melting point equal to or higher than that of the high-alloy powder. The sintered bodies of the sliding surface and the base material are made of both the high-alloy powder and the low-alloy iron powder. They are characterized by being diffusion bonded to each other by the liquid phase during sintering.

In the first aspect of the sintered composite wear-resistant member of the present invention,
Base material part l''i1i1 consists of a sintered body of low-alloy iron-based powder having a melting point equal to or higher than that of the high-alloy powder.
A low-alloy iron-based powder (first base material and second
It consists of a sintered body of base material). In the embodiment A2, when the base material part is composed of two types of sintered bodies, the sintered joint member is a liquid of three types of powder materials, namely, one type of high-alloy powder and two types of low-alloy iron powder. Each layer is strongly diffusion-bonded.

In this application, the term "powder melting point" refers to the temperature at which a liquid phase begins to form in the powder, that is, the liquid phase forming temperature.

In the present invention, the high-base metal powder wear-resistant sintered body constituting the sliding surface portion is made of a conventional anti-alloy wear-resistant sintered alloy, but preferably has a weight ratio of Cr: 2.5 to 25.0. %,
Mn: 0.1 to 5.0%, P: O to α8, Si: Q, 5 to 2-0%, Cu: 1. Cl-5,
0%, Mo: 3.0% Tsukashita.

C: 1.5 to 3.5%, balance Fe and sintered alloy consisting of impurities below 2% υ, and this proportion of Cr, Mn,
P.

In addition to Si, Cu, Mo and C, W
: 0.1-5.0%, V: Q, 1-5.0%,
Nb: 0. i ~2.5%, Ti:01~2
．． Examples include sintered alloys containing one or more selected from 5% and Ta:α1 to 15% in an amount of 01 to 1cLo% in terms of maxim 1.

In the present invention, a conventional low alloy iron sintered alloy is used as the low alloy iron powder sintered body having a melting point equal to or higher than that of the learning alloy powder, which constitutes the base material part, but Cu:
A sintered alloy containing 1.5-2αO% and/or C: 15-4.0%, the balance consisting of Fe and impurities below 2%9, or P: [12-0.8% and B: α05- 1.0
A sintered alloy containing one or two selected from % and 5 to 4.0% of C:Q, the balance being Fe and impurities of 2% is preferred.

The sintered composite wear-resistant member of the present invention is produced by molding a high-alloy powder into the shape of a sliding surface and using one or more types of low-alloy iron having a melting point equal to or equal to that of the high-base metal powder. A molded body of a predetermined shape of a base material consisting of a base material made of a powder based on Sugitaka and a melting point crucible of a powder with the highest melting point among the low alloy iron powders is heated to form both a Sugitaka alloy powder and a low alloy powder. Simultaneously with sintering, both materials can be manufactured by diffusion bonding to each other using the liquid phase generated during sintering.

The heating temperature should be such that the entire powder bed of both the high base metal powder and the low alloy iron powder becomes a liquid phase, but the higher the temperature, the faster the diffusion bonding and the stronger the joints are bent.

Heating for sintering and bonding is usually carried out in a non-oxidizing atmosphere or a reducing atmosphere, such as an inert gas such as nitrogen or argon, ammonia decomposition gas, reducing scum such as hydrogen scum, or vacuum. The reaction can be carried out under pressure or reduced pressure, and sometimes preferred is ammonia decomposition residue.

By such heating, strong diffusion bonding can be obtained in a short time due to the liquid phase generated during sintering of the high base metal powder and the low alloy iron powder.

Each of the high-alloy wear-resistant powder and the low-alloy iron-based powder may be an alloy powder, a mixed single powder, or a mixed powder of an alloy powder and a single powder. These powders are blended to give a desired composition. For example, in order to obtain a high alloy powder sintered body suitable for the sliding surface portion, the composition in terms of weight ratio is Cr:
2.5-25. [1%, Mn: [1,3,Q%,
P: 0.2~[1,s%, Si: l115~2.0
%, Cu: tO ~ 5.0%, Mo: in% Tsukashita, C
11゜5~35 sparrow, balance Fe and impurities of 2% or less,
Or Cr, kjn, P, Si, C in the above proportions
In addition to u, Mn and C, the M amount ratio W: α1~
5.0%, V: α1-50%, Nb: α1-2. ．． 5
%, Ti + 0.1-2.5%, Ta: 0.1
z 1.5% of one or more types in total a1-100
%, the balance is konjac and 2% impurities,
Blend alloy powder and/or single powder. On the other hand, in order to reduce the preferable low alloy iron powder for the base material, for example, 2%
Cu: 1.5 to 2 in total to Fe powder containing the following impurities
0% and/or C: 0.5 to 4.0% by cooling Cu powder and/or carbon powder (e.g. graphite powder), or add the above ground powder to a total of P: 0.2 to 4.0%. a8
% and/or B: 105 to 1.0, and C: o,
Contains powder so that the concentration is ~4.0%.

Compound powder (for example, FeB powder) and/or alloy powder are blended.

The powder blended to a predetermined composition is preferably compression molded into a predetermined shape to facilitate sintering of the powder.

1-6 illustrate rocker arm tips for internal combustion engines made in accordance with the present invention.

Figure 1 shows the case where the base metal part is made of one type of low-alloy iron powder sintered body, and Figures 2 and 3 show the case where the base metal part consists of two types of low-alloy iron powder sintered body. show.

Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

Example 1 Sliding Co., Ltd. Part material: Cr: 18%, M
o: 1%, Cu: 2%, P: 0.5%, Si: 1%,
Mn: Q, 5%.

C is added to the alloy powder consisting of the balance Fe and impurities of 2% or less.
: A molded body of mixed powder (density 6.2f/(7) to which graphite powder is added so as to have a concentration of 2.5%) is used as a base material.
u: 8%, C: [18%, remainder Fe (contains 2% or less impurities) molded body of single mixed powder (density 6.87/
cd) and the whole was heated to 1120℃ in ammonia decomposition gas.
sintering and diffusion bonding are performed simultaneously by heating for 20 minutes.
A sintered body having the shape shown in Fig. 1 was produced.

Example 2 Weight ratio Cr: 2. s%, Cu:1.
0%, P: 0.8%, Si: 2.0%, Mn: 0.1%
, balance Feb and less than 2% impurities: 1. A molded body of powder (density 6.5fltyl) was used, to which graphite powder was added so as to give a density of 1.5%. A molded body of annual leave powder mixture consisting of 2% impurities (contains 2% industrial impurities) is connected, and further B: 0°5% as a second base material.
C.

A molded body of a mixed powder (FeB is used as a source of B) of a powder bed of a part body and a compound powder (FeB is used as a source of B) having a composition of 20% Fe, the balance being Fe (including less than 2% impurities). 5f/c
yd) on the side 1 on the mother chestnut, and place the whole in vacuum at 1120
After sintering and diffusion bonding at ℃ for 20 minutes, a first sintered body having the shape shown in FIG. 2 was scooped out.

Example The sliding part material has a weight ratio of Cr: 25.0%, M.

: l O%, Cu: 5.0%, P: 0.2%,
Si: cL: 5%, Mn: 6.0%, remainder ratio, and alloy powder consisting of impurities of 2% or less, C: 3.
A molded body of polymerized powder (density 6.0?/cffl) to which graphite powder was added to give a concentration of 5% was used, and on top of it, Cu: 2Q% and the balance Fe (impurities of 2% or less) were added as the first base material. include)
As a single mixed powder and a second mother powder consisting of p:o-s%
, the density of each compact is 6.5?, which is made of mixed powder made by adding graphite powder to C: 2% to an alloy powder consisting of the balance Fe (including impurities of less than 2%). /cm) was heated 11 times to give a composite sintered body having the shape shown in FIG. 2.

Example 4 As a sliding part material, instead of the alloy powder used for the sliding part material of Example 1, W: 5. A molded body (density 6-, ar/i) of the mixed powder used as the second base material in Example 3 was stacked and molded as a whole using an alloy powder having a composition containing 0%, and this was molded in an ammonia decomposition gas atmosphere. 115
Sintering and bonding were performed at 0° C. for 20 minutes to obtain a composite sintered body having the shape shown in FIG.

Example 5 As a material for the sliding surface, the composition of the alloy powder used for the material for the sliding surface in Example 1 was further added ■: 01%.

A compact of a mixed powder of alloy powder containing 2.5% Nb and graphite powder (2-5% of the total) (density &IS'/, d
), P:Q as the first base material, 2%, balance F
C:
4. A molded body of mixed powder (@ degree 6.4f/crI) to which graphite has been added so as to have a concentration of Sintering and diffusion bonding were performed in the decomposition residue at 1150° C. for 20 minutes to obtain a composite sintered body having a shape as shown in FIG.

Example 6 As a sliding part, in addition to the composition of the alloy powder used for the sliding surface part material in Practical Example 1, W: 0.1% V: s
os, Nb: α1%, 'I'i: 1.0%
A molded body (density io y7= ) of mixed powder consisting of a base metal powder bed and graphite powder (2.5% of the total) having a composition including Ta: :
Alloy powder KC consisting of α8% and balance II'e (contains impurities below 2%): A compact of mixed powder to which graphite powder is added to give a concentration of 0.5% (density 6.5'?/c+1) .) to 1
Well, as a soft 2 base material, C: ZO force, remainder F'e (2%
A molded body of mixed powder containing the following impurities (
@ Degree & 5? /Tan) and heat the whole thing in a vacuum at 1150℃.
The composite sintered body was sintered and bonded at IIJ1 for 20 minutes to form a composite sintered body in the shape shown in Figure 2.

Comparative Example 1 Sintering and bonding of Example 1 at 1050°C, which is lower than the temperature of the base material.
I went there for 120 minutes.

Comparative Example 2 The same molded body as that of Example fji 1 was used as the sliding surface material, and the base material was a single mixed powder molded body (density 6 .5 f
/cd), and the whole was sintered and joined in the same manner as in Example 1.

Comparative Example 3 A composite sintered body was obtained in the same manner as in Example 6 except that pure iron powder (containing 2% or less of impurities) was used as the first base material.

Comparative Example 4 A composite sintered body was obtained in the same manner as Comparative Example 2 except that sintering and bonding were performed at 1000° C. for 60 minutes.

Table 1 shows the liquid phase generation temperature (melting point), sintering/bonding temperature, and bonding evaluation of the obtained composite sintered body of each material used in the above Examples and Comparative Examples.

In the zygosity column of Table 1, ○...Good △・・・moderate ×...Poor means.

Table 1 From the results in Table 1, it can be seen that in the examples of this application, the sliding surface material and the base material are sintered and bonded at a temperature higher than the melting point, so the liquid phase generated when both materials are sintered creates a strong diffusion bond. However, in the comparative example, the first base material was sintered and bonded at a melting point below 9, so it can be seen that optical bonding cannot be obtained by short-term heating. In Comparative Example 1, the bondability was extremely low even if the sintering time was prolonged due to insufficient liquid phase amount and insufficient diffusion due to the low sintering temperature, and in Comparative Examples 2 and 6, the Since there is no effect of promoting diffusion bonding with the aid of the liquid phase of the material, the bonding force is insufficient compared to Examples 1 to 3 even under the same sintering conditions, and it is necessary to Sintering at high temperature and for a long time as in Example 4 is f'EP.

[Brief explanation of drawings]

Figure 1 is a plan view and front cross-sectional view of a rocker arm chip whose base material is made of one type of low-base metal iron thread powder sintered body. Figures 2 and 3 are base materials made of two types of low-alloy iron. FIG. 2 is a plan view and a front cross-sectional view of a rocker arm tip made of a microstructure.

Claims (7)

[Claims] (1) A sliding surface portion made of a wear-resistant sintered body of high-alloy powder;
a base material part for supporting the sliding surface, which is made of a sintered body of a type 1 or type 2 in-situ low alloy iron powder having a melting point equal to or higher than that of the elevated gold powder; The sintered composite material is characterized by the fact that the sintered bodies of the moving surface part and the base material part are diffusion bonded to each other by the liquid phase of both the high-alloy powder and the low-alloy iron powder produced during sintering. Wear parts. (2) The member according to claim 1m, wherein the base material portion is made of one type of low-alloy iron powder sintered body. (3) A member according to claim 1, in which the base material portion is composed of two types of low-alloy iron powder sintered bodies. (4) High alloy powder wear-resistant sintered body has a weight ratio of Cr:
2.5~2s, Q%, Mn: 01~3.0%,
P:Q, 2-118%. Si:l: 1.5-20%, CLI: 1.0-5.
0%, Mo: 10% υ C: 1. s~55%, remainder F
The member according to any one of claims 1 to 3, which is a sintered alloy comprising: e and 2% impurity (7J). (5) The wear-resistant sintered body of high alloy powder has the composition stated in the fourth aspect of the claim, and further has a weight ratio of W: α1 to 50%.
, V: (N13.0%, Nb: 0.1-25%. T1: α1-2.5% and Ta, CL 1-1.5
1st or 2nd place selected from % overall cL1~
io,. The member according to any one of claims 1 to 4, which is a sintered alloy containing %. (6) At least one sintered body of the base material has Cu: t5 to 20.0% and/or C:[15
~4.0%. The member according to any one of claims 1 to 5, which is a sintered alloy comprising the balance Fe and 2% or less of impurities. (7) At least one sintered body of the base material has a weight ratio TeP:
I12~cL8% O and E: 0.05~1.0%
1 or 2a=, C: 0.5 and 4.0%, the balance is Fe, and any of claims 1 to 6 is a sintered alloy consisting of impurities of 2 or less. Element.