JPH02217435A - Manufacture of fe-cu-ni series alloy sintered member - Google Patents

Abstract

PURPOSE:To suitably regulate the dimensional change of the Fe-Cu-Ni series alloy sintered member at the time of sintering by using Ni-Cu series or Ni-Cu- Mo series alloy powder along with each raw material powder of Fe, Cu and Ni and then executing sintering. CONSTITUTION:Fe powder, Cu powder and Ni powder as raw material powder are mixed with Ni-Cu series alloy powder or Ni-Cu-Mo series alloy powder and the mixture is sintered to obtain the Fe-Cu-Ni series alloy sintered member. Since the alloy powder to be added has the m.p. higher than the sintering temp., it is considered that the expansion due to the alloying by solid phase diffusion is not generated. Thus, at the time of mixedly using these alloy powders in various blending ratios, the dimensional change can suitably be regulated without changing the componential proportion as a whole.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing two sintered Fe-Cu-Ni alloy members obtained by mixing and sintering Fe powder, Cu powder, N1 powder, etc. In particular, the present invention relates to a method in which dimensional changes during sintering can be arbitrarily adjusted. In addition, in the present invention, Fe-
Cu-Ni alloy refers to C and M in addition to Fe, Cu, and Nt.
[Prior art] The powder metallurgy method omits steps such as rolling, forging, and casting, and mixes metal powder, compression molds it, and then sinters it. This is a method of making fired crystals. Powder metallurgy can easily produce materials that are difficult to manufacture using conventional melting methods, such as materials with high melting points such as W and Mo, porous materials such as oil-impregnated bearings and filters, and tool materials such as cemented carbide and cermet. can be manufactured. Not only that, but
It has many excellent advantages, such as improved material yield due to non-cutting, manufacturing advantages such as high dimensional accuracy, and material advantages such as less segregation and anisotropy that tend to occur with melted materials. There have also been many attempts to manufacture various parts, which were conventionally manufactured by melting methods, by powder metallurgy.

Various types of steel members manufactured by powder metallurgy are known, including Fe-C alloys.

Fe-C-Cu alloy, Fe-Cu alloy, Fe-C-
Cu-Ni alloy and Fe-C-Cu-N i -M
There are o-based alloys, etc.

By the way, the raw material powder used in sintering is a mixture of single powders of various metals, and those having a particle size of 63 μm or less are generally used. In particular, Ni has a particle size of 5
Inco Ni powder of about μm size is used, and it is said that the desired sintering strength cannot be obtained with high melting point metals unless the particle size is 10 μm or less. In addition, in the powder metallurgy method, Fe
When adding zero to powder, it is generally added in the form of graphite, and when manufacturing these sintered parts, about 1% of zinc stearate is added as a lubricant. .

[Problems to be Solved by the Invention] Cu is an element that melts during sintering to promote sintering and improve the strength, while Nf is an element that improves the strength of the sintered member 6. It is also said that the addition of these elements has the effect of improving hardenability. However, Cu and Ni
When blending, a phenomenon occurs in which the dimensions of the sintered member vary depending on the blending ratio. In particular, when the amount of Cu added is increased, a large abnormal expansion phenomenon called so-called Cu-Growth occurs. This is because the sintering temperature is C
It is said that this is because the Cu powder melts when the temperature reaches or exceeds the melting point of u, diffuses into the Fe powder, and forms a solid solution leaving an outflow hole. On the other hand, when the amount of Ni added is increased, the sintered member slightly shrinks. Therefore, when it becomes necessary to change the amount of added components for the purpose of increasing strength, a problem arises in that an expensive mold must be remade in order to cope with the increase in the amount of shrinkage after the mold is opened. In addition, if the mold dimensions do not match due to some factors such as sintering conditions or raw material conditions, it would be convenient if the dimensional change could be largely controlled without changing the component ratio, but currently there is no such method. has not been developed. It is also known that the amount of abnormal expansion due to Cu can be reduced by increasing the amount of graphite added, but controlling it by changing the amount of C also changes the characteristics of the sintered member. As a practical matter, this is not a desirable means, nor is it sufficient.

The present invention was made under these circumstances, and
The purpose is to provide a manufacturing method that can appropriately adjust dimensional changes during sintering of a Fe-Cu-Ni based alloy sintered member.

[Means for Solving the Problems] The method of the present invention that achieves the above object uses Fe powder, Cu powder, and Ni powder as raw material powders, and produces a Fe-Cu-Ni alloy sintered member by a powder metallurgy method. In addition to the above raw material powder, N1-Cu alloy powder or N
This is a method for producing a Fe-Cu-Ni alloy sintered member, the gist of which is sintering using an i-Cu-Mo alloy powder.

[Function] In the past, it was not always easy to obtain high-quality metal powder suitable for powder metallurgy, but electrolysis, reduction,
With the development of technology such as the injection method (atomization method), it has become possible to obtain high quality metal powder. In particular, advances in atomization technology have made it possible to obtain fine powders of alloys such as Ni-Cu and N1-Cu-Mo.

The present inventors manufactured a Fe-Cu-Ni based alloy sintered member by combining various raw material powders, and conducted various studies from the viewpoint of dimensional changes. As a result, when sintering using Ni-Cu alloy powder, N1-Cu-Mo alloy powder, etc., compared to when using single metal powders of Ni, Cu, and Mo, It has been found that even if the weight ratio is the same, the expansion ratio is different.

The reason why such a phenomenon occurs can be considered as follows. That is, the melting point (or liquid phase generation point) of a single metal powder of Cu is 1083°C, and under normal sintering conditions (1120~b), Cu melts and permeates between iron powder particles to form an alloy. Cu-Growth occurs, but N
For i-Cu alloy powder and Ni-Cu-Mo alloy powder, the melting point (or liquid phase generation point) is higher than the sintering temperature <(Ni-C
1310° C. for the U-based material and 1300° C. for the Ni-Cu-Mo based material), it is considered that these alloy powders do not melt and are alloyed by solid-phase diffusion, so no expansion occurs.

Therefore, by mixing and using N1-Cu alloy powder and NL-Cu-Mo alloy powder in various compounding ratios, it is possible to appropriately control dimensional changes without changing the overall component ratio. be. Furthermore, by using these alloy powders, even if it becomes necessary to increase the weight percentage of the Cu component that causes abnormal expansion, the degree of expansion can be suppressed within a predetermined range. There is no need to change the mold.

The present invention will be explained in more detail below with reference to examples, but the following examples are not intended to limit the method of the present invention.
Any design changes based on the above and below intentions are included within the technical scope of the present invention. For example, in the following examples, an alloy powder with a ratio of Cu to Ni of 1:1 was used, but it goes without saying that any other ratio may be used.

Further, in the following example, a case is shown in which dimensional changes are controlled by mixing and sintering single metal powders of Cu and Ni and Cu-Ni alloy powder (or Cu-Ni-Mo alloy powder). Depending on the amount of dimensional change required, Cu-Ni powder may be added to Fe powder without using Cu or Ni powder.
It is also possible to mix and sinter a Cu-Ni-Mo alloy powder (or a Cu-Ni-Mo alloy powder).

[Example] Example I Fe powder, Cu powder, NL powder, simple graphite powder, and zinc stearate as a lubricant were mixed in the proportions shown in Table 1 below and sintered.

Table 1 (% by weight) The size distribution of this sintered trunk member was as shown in FIG.

Next, the proportion of Cu powder was increased from 1.5% to 2% and sintered in the same manner, and the size distribution of the obtained sintered member was investigated, and the results shown in FIG. 2 were obtained. As is clear from these results, even if the amount of Cud was increased by only 0.5%, significant expansion occurred and the product significantly exceeded the upper limit specifications.

Therefore, when NL--Cu alloy powder (Ni:Cu=1:1) was added and sintered so as to have the ratio shown in Table 2, the same size distribution as shown in FIG. 1 was obtained.

Table 2 (% by weight) Example 2 Raw powders were mixed in the proportions shown in Table 3 below and sintered using a mold, resulting in the size distribution shown in FIG. 3.

Table 3 (!li amount %) Therefore, Ni-Cu-M was adjusted to the proportions shown in Table 4 below.
When o-based gold powder (Ni:Cu:Mom 4:4:1) was added and sintered, a normal size distribution as shown in FIG. 4 was obtained.

[Effects of the Invention] As described above, according to the present invention, the dimensional change during sintering of the Fe-Cu-Ni alloy member can be adjusted to a desired range.

[Brief explanation of the drawing]

1 to 4 are graphs showing the size distribution of various sintered members.

Claims (1)

[Claims] In producing a Fe-Cu-N based alloy sintered member by powder metallurgy using Fe powder, Cu powder and Ni powder as raw material powders, in addition to the above raw material powders, Ni-Cu based alloy powder or Ni-Cu- A method for producing a Fe-Cu-Ni based alloy sintered member, characterized in that Mo based alloy powder is used in combination for sintering.