JPH0452201A - Manufacturing method for high-strength structural members - Google Patents

Abstract

PURPOSE:To obtain the above high strength structural member by stirring and mixing main metal powder specifying vol. partial ratio of amorphous phase covered with oxide film and adding metal powder having low hardness and high ductility, enclosing fine crushed pieces of the oxide film with produced plastic deformed material to make agglomerated powder and executing forming treatment to aggregate of the agglomerated powder. CONSTITUTION:The main metal powder 1 covering surface with oxide film 3 and having 50% vol. partial ratio A(Vf) of the amorphous phase, the adding metal powder 2 having low hardness and high ductility and reinforcing material, are mechanically stirred and mixed, and the fine crushed pieces of oxide film 3 and the above reinforced material are enclosed with the plastic deformed material 20 produced from the added metal powder 2 to execute covering on surface of the main metal powder. By this method, the agglomerated powders 4 aggregating the plural number of main metal powders 1 are manufactured through plastic deformation 20 and successively, the forming treatment is executed to the aggregate of the above agglomerated powder 4 to make the structural member.

Description

[Detailed description of the invention] A1 Purpose of the invention (1) Industrial application fields The present invention relates to a method of manufacturing a high strength structural member.

(2) Conventional technology Conventionally, as a manufacturing method for this type of member, a green compact is formed using a metal powder having an amorphous phase volume fraction A (Vf) of 50% or more, and then the green compact is There is a known method of hot extrusion processing.

(3) Problems to be Solved by the Invention The surface of the metal powder with a high volume fraction A (Vf) of amorphous rights is covered with a thicker oxide film than the crystalline metal powder. In order to avoid this, processing must be performed at a low extrusion ratio, so the oxide film cannot be removed during the processing, and as a result, it is impossible to bond the amorphous phases together, so the parts There is a problem in that it is not possible to sufficiently increase the strength of the steel.

In view of the above, the present invention makes it possible to realize bonding between amorphous phases by removing an oxide film from a metal powder with a high volume fraction A (Vf) of amorphous phases by employing simple means. It is an object of the present invention to provide the aforementioned manufacturing method.

B9 Structure of the invention (1) Means for solving the problem The present invention provides a metal powder whose surface is covered with an oxide film and whose volume fraction A (Vf) of an amorphous phase is 50% or more, and a low hardness,
In addition, by mechanically stirring and mixing high ductility additive metal powder,
Agglomeration in which a plurality of raw metal powders are aggregated via the plastically deformed material by taking in microscopic fragments of the oxide film by the plastically deformed material generated from the added metal powder and directly covering the surface of the metal powder. The first feature is that the powder is produced and then the aggregate of the agglomerated powder is subjected to a molding treatment.

The present invention provides a metal powder whose surface is covered with an oxide film and whose volume fraction A (Vf) of an amorphous phase is 50% or more, low hardness,
and mechanically stirring and mixing a highly ductile additive metal powder and a reinforcing material, and incorporating the fine fragments of the oxide film and the reinforcing material by plastic deformation products generated from the additive metal powder;
The first step is to coat the surface of the metal powder as it is to produce an agglomerated powder in which a plurality of raw metal powders are aggregated through the plastically deformed material, and then to perform a molding treatment on the aggregate of the agglomerated powder. 2.

(2) Effect In the first feature, since the surface of the main metal powder from which the oxide film has been removed is covered with the plastically deformed material, oxidation is prevented again.

During the forming process, when the aggregate is compressed at a low working rate, the plastically deformed material is excluded from between the main metal powders due to its high ductility, so A bond is achieved. Furthermore, since the plastically deformed material fills the pores of the member, the material can be made to have a high density.Furthermore, the plastically deformed material becomes a composite body incorporating minute fragments of the oxide film, so it has high strength.

In this way, high strength of the member is achieved.

According to the second feature, in addition to the above, the reinforcing material provides an oxide film removal action and a reinforcing action on plastically deformed objects,
Further increase in strength of the member is achieved.

(3) The surface of the example is covered with an oxide film, and the volume fraction of the amorphous phase is A(V
Examples of metal powders with f) of 50% or more include amorphous single-phase alloy powders with an amorphous phase volume fraction A (Vf) of approximately 100% and mixed phase alloys of an amorphous phase and a crystalline phase. Powder is used. The surface layer of this mixed alloy powder becomes an amorphous tank because it is rapidly cooled during production.

The amorphous single-phase alloy powder has A 1 asN i s Y
Io, ARaaN i IoCem, Al;! aa
N j roD Vh, AI! *sN js Ys
COx, AfssF eq,s Y? ,S,A
I! soN i IoCa Io, MggzN is
Yro, MgthNt+oce+ocr4, Mg7sN
An alloy powder having a composition such as i+sce+o (values are atomic %) falls under this category.

In addition, the mixed alloy powder includes A19tFes Ys, A
/! wsNts Yl. Bt, Al. NtsY+. Nb
, ,AffissNi,Cab,AI! to Nit
Ys, AlqrF eh Ys, Mg5sN
This includes alloy powders having compositions such as i*CeF, Mg5hNt*Ym (values are atomic %), and the like.

In addition, even if the composition is the same as that of the alloy powder in which the volume fraction A (Vf) of the amorphous phase is approximately 100%, due to the difference in cooling rate during manufacturing, the powder with a small average diameter becomes amorphous. If the average diameter is large, it will be a crystalline single-phase structure, and if the average diameter is between these, it will be a mixed structure of an amorphous phase and a crystalline phase.

Examples of additive metal powders with low hardness and high ductility include aluminum powder, aluminum alloy powder, magnesium powder,
Magnesium alloy powder, copper powder, copper alloy powder, etc. are used. These have a crystalline phase volume fraction C (Vf) of 100
%.

As a means for mechanically stirring and mixing the main metal powder and the additional metal powder, a rotary ball mill, a high-energy ball mill (a vibrating rotary ball mill, a forced stirring ball mill, etc.) or the like is used.

FIG. 1 is an explanatory diagram showing the manufacturing method of the present invention with a focus on powder.

In the step (a) in the figure, a predetermined amount of additive metal powder 2 is blended with main metal powder 1. The surface of the main metal powder is covered with a comparatively thick oxide film 3. In the step (b) in step (i), both powders 1 and 2 are put into a rotating ball mill and mixed with strong stirring.

As a result, the oxide film 3 is peeled off from the surface of the main metal powder 1 and pulverized into fine pieces. On the other hand, as the added metal powder 2 is compressed, a plastically deformed material 20 is generated from the added metal powder 2, and the plastically deformed material 20 takes in minute pieces and covers the surface of the main metal powder 1.

In step (ii), a plurality of raw metal powders 1 are aggregated via the plastically deformed material 20 in a rotary ball mill, thereby producing agglomerated powder 4.

In this agglomerated powder 4, the surface of the main metal powder from which the oxide film 3 has been removed is covered with the plastically deformed material 20, so that oxidation is prevented again. In this case, as the main metal powder 1 becomes finer, ignition due to its oxidation becomes a problem, but this problem is also eliminated. Furthermore, when the plastically deformed material 20 is an aluminum-based metal, which is easily oxidized, not only the individual metal powders 1 are covered with the plastically deformed material 20, but also the agglomerated powder 4 using the plastically deformed material 20 as a binder.
In this form, the surface area of the plastically deformed material 20 can be reduced, so that its oxidation can be suppressed, and the agglomerated powder 4 also has the advantage of being easier to handle than micron-order powder.

In the step (c) in the figure, a structural member is formed by starting a molding process, for example, hot extrusion, at a temperature lower than the crystallization temperature Tx of the main metal powder 1 on an aggregate of the agglomerated powder 4, for example, a green compact. obtain.

When forming an aggregate from the agglomerated powder 4, the plastically deformed material 20 is interposed between the main metal powders 1, so that the aggregate has good formability. And the aggregate has a low processing rate (low extrusion ratio)
When compressed under the plastic deformation 2. is excluded from the main metal powder 1 due to its high ductility, so that bonding between the amorphous phases is realized. In this case, the plastically deformed object 2
Even if an oxide film is formed on the 0 surface, it is so thin that it is removed during the molding process. Furthermore, since the plastically deformed material 2o fills the pores of the member, the material can be made to have a higher density.Furthermore, the plastically deformed material 20 becomes a composite body incorporating minute fragments of the oxide film 3, so it has high strength. .

In this way, high strength of the member is achieved.

When aiming to further increase the strength of a structural member, it is an effective means to mix a hard reinforcing material together with the additive metal powder 2.

By employing such means, it is possible to obtain an oxide film removal effect and a strengthening effect on the plastically deformed object 20 by the reinforcing material. This type of reinforcing material includes powders such as SiC, fibers, whiskers, and the like.

[Example ■]

By applying the high pressure He gas atomization method, A! ,.

A metal powder was prepared consisting of N15Y*Cog alloy (values in atomic %) and having an average diameter of less than 22 μm.

Volume fraction A (Vf) of amorphous phase in the current metal powder
was 95% or more, and the crystallization temperature Tx was 290°C.

Further, pure aluminum powder having an average diameter of less than 16 μm was prepared as an additive metal powder.

Various mixed powders with various volume fractions P (Vf) of the main metal powder and additive metal powder were prepared, and these powders were milled using a planetary rotary ball mill to obtain an average diameter of 10 mm as raw material powder.
Various types of agglomerated powders with a diameter of 0 μm were produced.

The conditions for producing these aggregated powders are as follows. That is, Ar
In an atmosphere, the mixed powder and a chrome mesh ball with a diameter of 10 square meters were placed in a rotating ball mill at a ratio of 1:10.
The mixture was stirred and mixed for 3 hours at a rotational speed of 45 rpm.

For comparison, raw material powders were made of the main metal powder that had not been subjected to the rotary ball mill treatment, the main metal powder that had been subjected to that treatment, and the main metal powder and the additive metal powder that had not been subjected to the treatment. I prepared something.

Various structural members were manufactured by implementing the following methods using the various raw material powders described above.

(i) As shown in Fig. 2 (6), the raw material powder 5 is put into a rubber compact body 8 consisting of a main body 6 and a lid body 7, and then subjected to a cold isostatic press under a pressure of 4000 kgf/cj. (
CIP) was applied.

(ii) As shown in the same figure (b), by the cold isostatic press, the diameter is 58 mm, the length is 65 mm, and the density is 75%.
A short cylindrical green compact 9 was obtained.

(I) As shown in FIG.
Loaded to 0. This compact body 10 has an outer diameter of 78 mm, a peripheral wall thickness of 1031 m, a bottom wall thickness of 15 am, and a length of 80 mm.

(iv) As shown in Figure (d), the compact 9 was loaded together with the compact 10 into the container 12 of the single-acting hot extrusion processing machine 11 with the bottom wall of the compact 10 facing forward in the extrusion direction. 0, 13 is a die, 14 is a die hole, 15 is a die backer, 16 is a stem, and 17 is a dummy block.

In the hot extrusion processing machine 11, the maximum pressing force was set to 500 tons, the inner diameter of the container 12 was set to 80 tons, and the preheating temperature of the container 12 was set to a predetermined temperature as described later.

Next, the stem 16 was advanced to apply a load to the contracted body 10 through the dummy block 17, and the contracted body 10 was deformed and brought into close contact with the container 12 under a surface pressure of about 30 kgf/d. As a result, the temperature of the powder compact 9 rises rapidly, and when the temperature reaches a temperature 5°C lower than the temperature of the container 12, the compact 9 is extruded together with the compact 10, and the powders are bonded together. As a result, a round bar-shaped structural member was obtained.

Table I shows the processing conditions and physical properties of the structural members of each Production Example 1-Xn[.

In Table I, production examples I to
% or less, and the processing start temperature is set below the crystallization temperature Tx (290°C) of the main metal powder, and the structural members obtained by these methods have an amorphous phase. It can be seen that the volume fraction A (Vf) is high and the strength is high.

The blending effect of the added metal powder in the agglomerated powder appears from its volume fraction P(Vf) of 2%, and the upper limit is 25%. If the volume fraction P (Vf) of the additive metal powder is less than 2%, no matter how fine the powder is used, it cannot be uniformly dispersed and the above-mentioned blending effect cannot be obtained. %, the layer of plastically deformed material becomes too thick and the bonding between the amorphous phases is hindered, resulting in a significant decrease in the strength of the member as in Production Example (3).

In the case of production example ■, crystallization of the green compact occurs, and
It cannot be extruded because the processing temperature is low and the extrusion ratio is high.

In the case of production examples (1) to (XI), the strength of the member was low because the oxide film of the raw material powder was not removed.

In the case of Production Example This reduces the strength of the member.

In the case of production example Xrf1, the strength of the member is low because the oxide film of the main metal powder and the additive metal powder prevent bonding between the amorphous phases.

[Example ■]

The same raw metal powder and additive metal powder as in Example (2) were prepared. In addition, SiC with an average diameter of less than 22 μm is used as a reinforcing material.
A powder was prepared, and the volume fraction P (Vf) of the reinforcing material was set to 10% in the mixed powder of the additive powder and the reinforcing material.

Various mixed powders with various volume fractions P (Vf) of the main metal powder and the additive metal powder containing reinforcing material were prepared, and mixed powders with an average diameter of 100 μm were prepared from these powders using a rotary ball mill similar to Example ①. A flocculated powder was produced. The conditions for producing these agglomerated powders are the same as in Example I.

Various structural members were manufactured by carrying out the same method as in Example I using the various agglomerated powders.

Table (2) shows the processing conditions and physical properties of the structural members for each of Production Examples XIV to XX.

In Table H, Production Examples XIV to XX are Production Examples I to XX in Table I.
■Corresponds to each.

As is clear from comparing Table I and ■, Production Examples XIV~
The structural member manufactured by XX achieves reinforcement of the desired deformed product by adding the reinforcing material, and therefore has improved strength compared to the structural member manufactured by Production Examples I to ①.

However, in Production Examples
compared to that of structural members.

When using magnesium powder or magnesium alloy powder as the additive metal powder, the volume fraction P (Vf) of each powder in the agglomerated powder is set to 2% or more and 18% or less, preferably 5% or more and 15% or less. When using copper powder or copper alloy powder, the volume fraction p(vf) of each powder in the agglomerated powder is set to 2% or more and 20% or less, preferably 5% or more and 15% or less. The reason for defining the range of each volume fraction P (Vf) in this way is the same as in the case of aluminum powder.

However, since the volume fraction P(Vf) of the added metal powder has a close relationship with the total surface area of the main metal powder, the optimum value of the volume fraction P(Vf) can be determined depending on the average diameter of the main metal powder. also changes.

Effect of the C1 Invention According to the invention described in claim (1), by subjecting the agglomerated powder aggregate specified as above to a molding treatment,
A high-strength structural member can be obtained.

According to the invention described in claim (2), it is possible to obtain a structural member with further improved strength.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, with FIG. 1 being a microscopic explanatory diagram of the structural member manufacturing side, and FIG. 2 being a macroscopic explanatory diagram of the structural member manufacturing side. Fig. 2 1...Main metal powder, 2...Additional metal powder, 20...Plastic (a) (b) (C) deformable product, 3...Oxide film, 4...Agglomerated powder , 9...Powder compact (aggregate) 1...Hot extrusion processing machine patent applicant Honda Motor Co., Ltd.

Claims (2)

[Claims] (1) a main metal powder (1) whose surface is covered with an oxide film (3) and whose volume fraction A (Vf) of an amorphous phase is 50% or more;
Additive metal powder (2) with low hardness and high ductility is mechanically stirred and mixed to form micro-fractures of the oxide film (3) by plastically deformed products (2_0) generated from the additive metal powder (2). By taking in the main metal powder (1) and coating the surface of the main metal powder (1), the plurality of main metal powders (1) are transformed into the plastically deformed material (2).
A method for manufacturing a high-strength structural member, characterized in that agglomerated powder (4) is produced through agglomerated powder (4), and then a molding process is performed on the aggregate (9) of the agglomerated powder (4). (2) a main metal powder (1) whose surface is covered with an oxide film (3) and whose volume fraction A (Vf) of an amorphous phase is 50% or more;
The oxide film (3) is formed by plastically deformed material (2_0) produced from the additive metal powder (2) by mechanically stirring and mixing the additive metal powder (2) with low hardness and high ductility and the reinforcing material. By taking in the micro-fractures and the reinforcing material and coating the surface of the main metal powder (1), agglomeration is created in which a plurality of metal powders (1) are aggregated via the plastically deformed material (2_0). A method for producing a high-strength structural member, comprising producing powder (4) and then subjecting an aggregate (9) of the agglomerated powder (4) to a molding treatment.