JPS61207554A - Manufacture of heat resistant and high conductivity dispersion strengthened copper alloy material - Google Patents

Abstract

PURPOSE:To manufacture the titled material, by using mixture of Cu-Al alloy powder and powder in which Cu in the surface layer part is converted to oxide. CONSTITUTION:Molten alloy composed of 0.05-3wt% Al and the balance Cu is made to powder, and A powder composed of <=297mu Cu-Al alloy powder is prepd. On the other hand, powder A is oxidized by air under <=300 deg.C temp., to prepare powder B in which Cu in surface layer part of powder A is converted to oxide. Next, powders A and B are mixed uniformly, these are pressed and green compact is enclosed into vessel made of Cu or Cu alloy. Under such a state, green compact is heated, internal oxidation is performed selectively, to form oxidized phase of Al component in Al powder. Further, a prescribed hot working is applied, to obtain Cu-Al2O3 dispersion hardened alloy material having a prescribed shape contg. vessel material as outer skin.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a method for producing a heat-resistant, highly conductive dispersion-strengthened copper (Cu) alloy material, and in particular to a method for producing a heat-resistant, highly conductive dispersion-strengthened copper (Cu) alloy material, while maintaining the excellent properties of such a dispersion-strengthened alloy material. This invention relates to an economically advantageous manufacturing method that simplifies the manufacturing process.

(Conventional technology) &FJ (Cu) matrix with alumina (A#zOa)
Alloys with dispersed ions have excellent heat resistance and electrical conductivity, and are therefore attracting attention as materials for electrical parts such as spot welding electrode materials, lead frame materials, and electrical switches. By the way, research on the performance and manufacturing of Cu alloy materials strengthened by dispersing A A 203 has been conducted for a long time.
No. 617, Japanese Unexamined Patent Publication No. 59-31'838, etc. disclose manufacturing techniques using an internal oxidation method.

In all of these prior art, CIJ-All powder is basically mixed with a suitable oxidizer powder, specifically Cu 20 powder, etc., and after compression, the mixture is heated at a high temperature, for example, 850 to 1000 cm. This method uses internal oxidation treatment at a temperature of C to strengthen dispersion.
In addition to these basic steps, after the internal oxidation treatment, an excess of unreacted oxidant (Cuz
O) If the reduction treatment (e.g., 700 to 9
00°C heat treatment) is added, or in addition to the oxidation process, the internal oxidation treatment world UH gas is kept non-oxidizing (deaeration treatment is performed when the mixture is sealed in the can body). ), or processes such as recrystallization treatment of Cu, -Al powder at high temperature (Japanese Patent Publication No. 55-39617), pulverization treatment of oxidizing agent powder (Japanese Patent Laid-open Publication No. 59-31838), etc. may be added. Become.

Incidentally, the conventional process for obtaining a β203 dispersion-strengthened Cu alloy extruded rod seen in the prior art is as follows (1) to (
Therefore, it is necessary to take step 12). That is, preparation of [11Cu-Aff alloy powder (A agent), (2) preparation of an oxidizing agent (B agent) by air oxidation of the A agent at high temperature, (pulverization of the 31B agent, (4) A agent and Mixing of B agent (stoichiometric amount), (5) Compressing the mixture, (6) Enclosing the compressed body in a can, (7) Degassing inside the can and enclosing Ar scum, (
8) Internal oxidation treatment (850-1000°C), (9) Reduction treatment - crushing (700-900°C), (River) canning (A
(11) deaeration, (12) hot pressing, and (11) agricultural trowel.

(Problem) As described above, in the conventionally known manufacturing method of Δ1203 dispersion-strengthened Cu alloy material, an extremely large number of steps or operations are required, and in addition, the manufacturing process is complicated. There is an inherent problem in that the manufacturing cost of such alloy materials increases significantly due to their fragility and troublesomeness, and therefore, their practical application is only seen in a limited number of sectors.

(Solution Means) Here, the present invention has been made in comparison with the current situation, and as a result of intensive study on simplifying the process of internal oxidation treatment using powder, the present invention has improved heat resistance and electrical conductivity. It was completed based on the discovery of a means to effectively obtain Cu-A#203 dispersion-strengthened alloy material without any damage, and this enables significant cost reductions compared to conventional products. It has become.

That is, in the present invention, 0.05 to 3.0% by weight of Al
A molten alloy containing Cu and the remainder being Cu is powdered by gas atomization or water atomization to form a powder with a diameter of 297 μm.
Cu-A7 below! While preparing powder A consisting of an alloy powder, producing powder B by oxidizing the powder A in air at a temperature not exceeding 30θ°C to convert Cu in the surface layer of the powder A into an oxide; Next, the A powder and the B powder are uniformly mixed, and the resulting compression molded product is sealed in a predetermined container made of Cu or Cu alloy. By heating the compact to selectively perform internal oxidation to form an oxide phase of the Al component in the A powder, and then subjecting it to a predetermined hot working process, a predetermined shape having the container material as an outer skin is formed. Cl1-AI! 203 dispersion strengthened alloy material is obtained.

Here, the A powder used in the present invention is:
Contains 0.05 to 3.0% 80 by weight, and the balance is C
A molten alloy consisting of u is pulverized by a normal gas atomization or water atomization method, in other words, a method in which compressed gas or a water jet is applied to the flow of the molten alloy to scatter it and pulverize it (spray method). It is a fine Cu-A1 alloy powder obtained by
The Al alloy powder is prepared so that its particle size is 297 μm or less. In addition, this Cu-A7!
When the particle size of the alloy powder becomes larger than 297 μm, the selective internal oxidation treatment described below, in other words, the Al component in the Cu=A4 alloy powder is selectively oxidized to produce A! 2z O
3, and there is a problem that the internal oxidation (oxidation of Al) is poor during the dispersion treatment to form such an oxide phase in the powder, so the powder obtained by the atomization method described above When the particle size of the alloy powder is large, classifying and sieving operations may be performed as necessary.
2! It is necessary to prepare it as a powder with a particle size of l 7 tt m or more.

In addition, in the Cu alloy molten metal for preparing the CII-A 48 alloy powder as the A powder, if the Aff content is less than 0.05% by weight, the final product C14-Ae203 dispersion strengthened dispersion strengthened alloy heating material , especially 7
There is a problem that the heat resistance deteriorates at temperatures of 00'C or higher, and there is also a problem that the electrical conductivity of the final product decreases when the Al content exceeds 3.0% by weight. Therefore, it has good heat resistance and electrical conductivity at temperatures of 700°C or higher, such as an lAC3 value of 50% or higher.
In order to obtain the second material, the amount of AP in the molten Cu alloy that is milled needs to be regulated to 0.05 to 3.0% by weight.

On the other hand, the B powder used in the present invention is prepared by using the A powder obtained as described in -1- and separately adding 3 O
By air oxidation at a temperature not exceeding fl °C, the surface layer of 71 to 01] as lithox is converted into oxide, Zunawara Cu, without sintering the A powder.
2F:') or at least converted to Cu 0 in powder form, with a particle size similar to that of untreated Δ□ powder.

As described above, the present invention is characterized in that the A powder particles are air oxidized to form oxidizing agent powder without sintering them. This is based on the results of the present inventors' inspection and found that the sintering phenomenon occurs at a temperature of approximately 350 °C or higher. The desired air oxidation (annealing) treatment is performed at a temperature of about 300°C for about 10 minutes to 2 hours by flowing air while fluidizing the A powder.And, Through such oxidation treatment, the A powder is oxidized and increased in weight, and the B powder is
It becomes a powder, but the weight gain due to oxidation is generally 0.
．． It is kept within the range of 5% to 1.0%, thereby reducing Δ
15) C11 in the final surface layer is effectively converted into an oxide such as Cu2O or Cu2O.

By the way, as mentioned earlier, one method of obtaining oxidizer powder (B powder) for oxidizing powder A is to air oxidize Cu-An alloy powder. The annealing temperature when performing air oxidation is
In order to perform the oxidation more completely, it is generally carried out at a high temperature; for example, in the aforementioned Japanese Patent Application Laid-Open No. 59-31838, it is necessary to oxidize the powder at a temperature of 400 to 700'C. It has been made clear that. However, when such conventional high-temperature oxidation treatment is performed, the Cu-Al1 alloy powder starts to undergo a sintering phenomenon, and therefore, the subsequent mixing-compression-internal oxidation process In order to proceed smoothly, a step of pulverizing this sintered oxidizing agent powder is necessary. However, in the present invention, as clarified as one of the features of the present invention, the B powder is sintered, and therefore the conventional pulverization step is completely unnecessary and is therefore omitted. This made it possible to adopt a new manufacturing process.

Next, Powder A and Powder 13 obtained in this way are uniformly mixed for internal oxidation treatment, but the mixing ratio at that time is generally stoichiometric, in other words, the deviation is By oxidizing the Δp acid component in the A powder, Al2
In the amount of 13 powder containing oxygen as Cu2O and CuO corresponding to the oxygen amount set as 03, the A powder and the B powder are mixed.

However, in the present invention, it is not necessary that the △ powder and the B powder are completely mixed in stoichiometric amounts, and the mixing ratio of the B powder is approximately 50% to 200% of the stoichiometric amount. It is possible to make changes within the range, and even when such changes are made, there is no noticeable difference in the performance of the final product.

Moreover, when mixing the A powder and the B powder, since the B powder is derived from the A powder and has the same particle size, the mixing of the A powder and the B powder is as follows. By pulverizing the conventional sintered material into powder, the process can be carried out even more effectively and a uniform mixture can be easily obtained. Incidentally, if this mixing is not uniform, a problem arises in that the subsequent internal oxidation treatment cannot be carried out satisfactorily.

This homogeneous mixture of powder A and powder B is then compression molded according to a normal method at a relative density of generally 80% or more to form a compression molded body (green compact) in a predetermined shape. Cu or Cu alloy (phosphorus deoxidized copper, Cu
-Ni alloy, Cu-3n alloy, etc.), and under that condition, the compression molded body, specifically the container, is heated in the same manner as in the past, and heated to a high temperature (850~1
000°C) to selectively internally oxidize the AI! A by oxidizing the ingredients
IltO3 and its oxide phase is formed in the powder. That is, Cu, O and Al zO
Utilizing the difference in oxide formation free energy between AA203 and AA203, Al in powder A is oxidized to AltO3 by CuzO in powder B, and the hardening action based on the dispersion state of this AA203 improves the desired material properties. It will be used.

Furthermore, in the present invention, the compression molded body obtained as described in -F and composed of internally oxidized Cu AN20s dispersion-strengthened alloy powder is housed in such a container. In other words, the product is left in an internally oxidized state without being subjected to conventional reduction treatment at high temperatures, pulverization, inclusion in the can (Ar gas inclusion), degassing treatment, etc. In order to obtain the desired material form, predetermined hot processing such as hot extrusion, hot rolling, etc. is performed. Through this hot processing, the compression molded product is made of a predetermined shape (: uA A'
20:1 dispersion-strengthened alloy material, which includes:
Further, after such hot working, cold working is performed as necessary.

By the way, in general, when molding a predetermined member from powder by hot working, a process of filling the powder into a can, blowing air, and then hot working is adopted. The purpose of air operation is to prevent the oxidation of powder and the generation and absorption of hydrogen due to steam decomposition. For example, in the case of A11 alloy powder, 10-
It is common to degas to 3 to 1 O-4 Torr.

However, if a mixture of the Cu-An alloy powder and the oxidizing agent is housed in a can to internally oxidize the Cu-An alloy powder with an oxidizing agent, and hot working is performed without degassing, residual air There are concerns that the progress of oxidation and the increase in residual oxides will lead to a decrease in electrical conductivity, a decrease in cold workability, etc. On the other hand, when degassing is carried out, depending on the degree of vacuum, Cu and O may decompose, and there is a concern that the amount of oxygen required to oxidize AN may be insufficient. In any case, this results in an excess or deficiency of oxygen compared to the initially calculated stoichiometric amount.Therefore, in the past, the reaction was completed with a slight excess of oxygen, and then the excess oxygen was removed by reduction treatment. The conventional process is completed by taking the step of removing it in the process.

However, from a practical standpoint, this excess oxygen (C
The important point is to what extent LI20 (existing as LI20 and CuO) can be tolerated, but in the present invention, even if such a degassing process (and Ar encapsulation) step is omitted, When manufacturing plates, bars, wire rods, etc., through hot working and subsequent cold working, there is almost no problem in the workability and performance of the products.

Therefore, in the present invention, when enclosing a compression molded body made of a mixture of powder A and powder B in a predetermined container,
This made it possible to omit the degassing (and Ar encapsulation) step. However, it goes without saying that in the present invention, there is no problem even if such a degassing step is adopted.

The reason why the above-mentioned degassing step can be omitted in the present invention has not yet been clarified, but it is likely that (the B powder as an oxidizing agent is different from conventional ones and has an extremely low One major reason is thought to be that only the Cu in the surface layer is oxidized at high temperatures.

In addition, one of the major features of the present invention is that the reduction step after internal oxidation, which was the biggest bottleneck in conventional processes, can be omitted, making it possible to significantly simplify the manufacturing process. It has become. In addition, in the present invention, even if CuO, C1JzO exists to some extent in the compression molded product, it does not affect the workability or material performance in any way, and the original characteristics of the dispersion strengthened alloy are maintained. This is possible. This is thought to have been made possible by the use of a powder that is effective as an oxidizing agent and by improving the mixing state of powder A and powder B.

In addition, according to the present invention, by hot working a container containing a compression molded body subjected to internal oxidation treatment, such a container remains as an outer skin of a processed product such as an extruded material or a rolled material,
As a result, C remains as an unreacted substance in these materials.
It is effective in preventing embrittlement of uO and Cu2O due to reducing gases (for example, hydrogen embrittlement). As described above, the presence of the outer skin is effective in the present invention, but such outer skin can be removed if necessary and applied to the intended use. For example, in applications such as welding electrode tip materials, LJ, such a skin is unnecessary. In addition, in the case of applications that require an outer skin, when manufacturing hollow materials such as pipe materials by hot working, there is a limit to the presence of container material as an outer skin on the entire surface of such a hollow 1A, so Cu A
I! If 203 exposed portions exist, it is necessary to separately protect such exposed portions by metallizing or the like.

(Effect of the invention) As described above, according to the present invention, the predetermined Cu-Aff2
03 Dispersion-strengthened alloy can now be manufactured according to a significantly simplified process without deteriorating its excellent performance, and as a result, the manufacturing cost can be effectively reduced. Although it was known that the performance was improved due to the high
The Cu-A42 (L+) dispersion-strengthened alloy material, which had been put off for practical use, can now be supplied to various fields at a low cost.

(Examples) In order to clarify the present invention more specifically, some examples of the present invention will be given below, but it is understood that the present invention is not limited in any way by the description of such examples. , it goes without saying.

First, Cu-0.08% by weight A7! The molten alloy obtained by vacuum melting the alloy in a high frequency furnace was made into powder by the usual argon gas atomization method. Then, from the obtained powder, those having a diameter of 297 μm or less were collected and used as the following samples.

That is, a part of the Cu powder was made to flow for 20 minutes.
Annealed in air at 0°C for 1 hour, C was added to the powder surface.
U2O was formed and used as the oxidizing agent (B powder). Note that the oxidation weight increase in air oxidation due to this annealing was 0.7%.

Next, the unannealed material (A powder) and the above B powder are mixed at a stoichiometric (10:1) mixing ratio of 50:1 to 50:1.
They were blended at a ratio of 3:1 and mixed uniformly using a mixer. After this mixing, the homogeneous mixture was
-axis compression molding was performed at a molding pressure of 0 kgf/cl into a rod shape with a diameter of 63.9 mm and a length of 15 mm. The relative density of the obtained green compact was about 90%.

Next, the green compact was placed in a bottomed cylindrical container made of phosphorus-deoxidized copper and having an inner diameter of 64 mm, a wall thickness of 2.5 mm, and a height of 200 mm. Then, the upper opening of this container is closed using a disc having an air bleed port for degassing or a disc without this air bleed port as the top lid, and the gap between the top lid and the cylindrical container is closed by T.
It was sealed by joining by IG welding. In addition, for the container provided with the air bleed port, the air inside was removed using a vacuum device and the container was sealed to obtain a billet for processing.

The thus obtained processing fillets, which were simply a powder compact sealed in a cylindrical container, and the processing billets, which were vacuum degassed, were each subjected to internal oxidation treatment at 950°C for 5 hours. Thereafter, using a horizontal indirect extruder, it was extruded into a bar with a diameter of 20 mm.

At this time, the container material, phosphorus-deoxidized copper, located on the outside of the powder compact remained as the outer skin of the extruded rod over the entire length.

In addition, in order to investigate the cold workability of the obtained various extruded rods, we conducted ordinary swaging processing (20 mmφ - 10 dragon ψ) and drawing processing (10 mmφ - 10 mmφ), respectively.
1+nmψ), subsequent swaging processing and drawing processing were possible for all extruded rods without intermediate annealing. As a result, it became clear that more than 99% cold working was possible, and it was accepted that there would be no problems as a practical material.

In addition to the cold workability evaluation results, the various extrusion mills were evaluated for their performance, ie, electrical conductivity, hardness, tensile strength, and heat resistance, and the results are shown in Table 1 below.

As is clear from the results in Table 1, in the various extruded materials obtained according to the present invention, the hardness, tensile strength,
There was no effect of degassing on electrical conductivity, indicating desirable performance as a dispersion-strengthened material. From this result, it is understood that the degassing step is not necessarily an essential step in the present invention. Furthermore, regarding the mixing ratio of powder A and powder B, they are approximately the same from 15/1 to 5/1.
Although good performance was obtained, when it exceeded 30/1, it was observed that heat resistance tended to decrease, and at 3/1, it was observed that electrical conductivity and cold workability tended to decrease.

Applicant Sumitomo Light Metal Industries Co., Ltd. Procedural amendment stamp button 1, Indication of case 1985 Patent side No. 47897 2, Title of invention Method for manufacturing heat-resistant, highly conductive dispersion-strengthened copper alloy material 3, Person making amendment case Relationship with Patent Applicant Name (227) Sumitomo Light Metal Industries, Ltd. 4, Column 6 of Detailed Description of the Invention in the Attorney's Specification, Contents of Amendment (1) "85o~" on page 4, line 6 of the specification ]000'C
Correct J to "700-1000°C".

(2) On page 8, lines 2 and 3, at least 1 conversion is required” is changed to “
I am correcting it to ``I will force you to convert it.''

(3) “850 to +000” on page 11, lines 12 to 13 of the same
Correct 0'CJ to 1-700 to 1000℃.

(4) Table 1 on page 20 of the same page is corrected as shown in the attached sheet.

Below -1-

Claims (1)

[Claims] Contains 0.05-3.0% Al by weight and the balance is Cu
Powder A, which is a Cu-Al alloy powder with a diameter of 297 μm or less, is prepared by pulverizing the molten alloy by gas atomization or water atomization.
A B powder is produced by converting Cu in the surface layer of the A powder into an oxide by air oxidation at a temperature not exceeding 00°C, and then uniformly mixing the A powder and the B powder,
Then, the compression molded body obtained by compression molding is sealed in a predetermined container made of Cu or Cu alloy, and in the enclosed state, the compression molded body is heated to selectively perform internal oxidation, By forming an oxide phase of the Al component in the powder A and then subjecting it to a predetermined hot working process, a C of a predetermined shape having the container material as an outer skin is formed.
A method for producing a heat-resistant, highly conductive dispersion-strengthened copper alloy material, which comprises obtaining a u-Al_2O_3 dispersion-strengthened alloy material.