KR20130109238A - High-strength copper alloy forging - Google Patents

Abstract

The present invention relates to a high strength copper alloy forging material having the characteristics of high hardness, high strength, high thermal conductivity. In terms of mass%, it contains 3% to 7.2% of Ni, 0.7% to 1.8% of Si, 0.02% to 0.35% of Zr, and 0.002% to 0.05% of P. In addition, if necessary, a suitable amount of Zr and P are applied by a high strength copper alloy forging material containing 1.5% or less of one, two or more of Cr, Mn, and Zn in total, so that cracks may occur in the material during processing or heat treatment. It can be used suitably for resin injection mold materials, aircraft members, etc., because it can be characterized by high hardness, high strength, and high thermal conductivity after processing and heat treatment.

Description

High Strength Copper Alloy Forgings {HIGH-STRENGTH COPPER ALLOY FORGING}

The present invention relates to a high-strength copper alloy forging material suitable for forging molded article including a resin injection mold material.

Conventionally, alloys having excellent conductivity and thermal conductivity include brass (Cu-Zn-based), bronze (Cu-Sn-based), Be copper, and Corson alloy (Cu-Ni-Si-based). Copper alloys are used. In particular, Be copper and Coulson alloys have been used for resin injection mold materials, aircraft members, and the like, which require strength and hardness along with thermal conductivity. However, the above-mentioned Be copper is concerned about the toxicity of dust generated during melting and processing, and a replacement material is required. In addition, Colson alloys require high thermal conductivity, high strength, and high hardness.

In addition, in general, a Cu alloy tends to crack during forging or heat treatment, and in addition to the improvement of hot workability, the ductility is also required.

 Recently, Mg, Sn, Ti, Zr, Al, Mn, etc. have been added to Cu-Ni-Si-based copper alloys as a method for increasing the strength and increasing the bending workability of the copper alloy foil bands. Copper alloys are proposed (see Patent Documents 1 to 5). Mg and Sn improve the strength by solid solution treatment in the matrix. Since Ti, Zr, Al, and Mn have a strong affinity with sulfur, they form a compound with sulfur, and as a result, segregation of sulfides to grain boundaries causing hot work cracking Will alleviate.

The copper alloy foil bands shown in Patent Literatures 2, 3, and 5 are added with Sn, Mn, Zr, and the like, followed by hot rolling and cold rolling or hot drawing before and after solution treatment and aging treatment. (hot drawing) and cold drawing are repeated to achieve bending workability and strength that exceeds the bending workability and strength of conventional copper alloy foil bands.

Japanese Patent Publication No. 2006-9108 Japanese Patent Publication No. 2008-196042 Japanese Patent Publication No. 2008-223136 Japanese Patent Publication No. 2008-266787 Japanese Patent Publication No. 2010-106363

However, when manufacturing a Cu alloy molded article, processing and molding are mainly performed by hot forging. Therefore, in the case where rolling processing or drawing processing performed in foil band production cannot be used, high strength cannot be obtained even when a forged molded article is manufactured using the components shown in Patent Documents 2, 3, and 5.

In order to acquire such a high strength, it is effective to increase the addition amount of Ni and Si. However, as the amount of Ni or Si increases, the thermal conductivity or hot workability deteriorates. In addition, crystalline materials formed during solidification (agglomeration) or precipitates formed during heat treatment increase, resulting in lowered ductility after heat treatment.

The present invention has been made in the background of the above-described problems, and provides a high strength copper alloy forging material that can be used in forged molded products, including a resin injection mold material, and can provide characteristics of high hardness, high strength, high ductility, and high thermal conductivity. It is for that purpose.

In order to solve the above problems, in the present invention, Cu-Ni-Si-based copper alloys can contain a suitable amount of Zr having an effect of increasing the ductility by suppressing precipitation (precipitation) of Ni ₂ Si to a grain boundary. . In addition, while having the effect of increasing the density of the fine precipitate, it can contain a suitable amount of P to form a compound together with Ni, Si, and Zr, resulting in a material having the characteristics of high hardness, high strength, high thermal conductivity Can be obtained.

According to a first aspect of the invention, based on mass%, it contains 3% to 7.2% Ni, 0.7% to 1.8% Si, 0.02% to 0.35% Zr, and 0.002% to 0.05% P It provides a high strength copper alloy forging material characterized in that.

According to a second aspect of the present invention, by mass%, it contains 3% to 7.2% Ni, 0.7% to 1.8% Si, 0.02% to 0.35% Zr, and 0.002% to 0.05% P . Furthermore, the high strength copper alloy forging material characterized by containing 1.5% or less in total of 1 type, or 2 or more types of Cr, Mn, and Zn is provided.

According to a third aspect of the invention, in the first or second aspect, the high strength copper alloy forging has a 0.2% yield strength of at least 650 MPa, at least 5% elongation, and a conductivity of at least 30% IACS.

According to the present invention, at the time of processing or heat treatment, almost no crack is generated in the material, and a high strength copper alloy forging material having characteristics of high hardness, high strength, and high thermal conductivity can be achieved.

Hereinafter, the reason for composition limitation of each component which concerns on this invention is demonstrated. In addition, all content of the following component is represented by the mass%. In addition, "mass%" and "weight%" are synonymous.

Ni: 3% to 7.2%

Si: 0.7% to 1.8%

By performing the aging treatment, Ni and Si form precipitated particles of the intermetallic compound mainly composed of fine Ni ₂ Si, while significantly increasing the strength of the alloy. In addition, with precipitation of Ni ₂ Si in the aging treatment, the conductivity is improved and the thermal conductivity is improved. However, when the Ni concentration is less than 3% and the Si concentration is 0.7%, the target strength is not obtained. In addition, when the Ni concentration exceeds 7.2% and the Si concentration exceeds 1.8%, Ni ₂ Si, Ni ₅ Si _2, etc. are crystallized or precipitated (precipitated) in a large amount during forging, and as a result, forging or heat treatment Cracks easily occur at the time. Moreover, when Ni concentration exceeds 7.2%, electrical conductivity will also fall and thermal conductivity will fall. In consideration of the balance between manufacturability and characteristics, the lower limit of the Ni concentration is preferably 3.5%, and the upper limit thereof is preferably 6.6%. The lower limit of the Si concentration is preferably 0.8%, and the upper limit thereof is preferably 1.7%. In addition, the Ni / Si ratio is preferably 3.8 to 4.6. Outside this ratio, excess Ni or Si is dissolved in the Cu matrix to lower the thermal conductivity.

Zr: 0.02 to 0.35%

Since Zr has a strong affinity with sulfur, it forms a compound with sulfur and reduces the segregation of sulfides at grain boundaries that cause processing cracks (hot working cracks). Processability). On the other hand, according to the research conducted by the inventors of the present application, the diffusion of Ni or Si containing Zr is suppressed, and as a result, Ni ₂ Si precipitated (precipitated) on the grain boundaries is reduced, and accordingly after aging It has been found that ductility is improved. In order to acquire this effect, the amount of Zr can be contained 0.02% or more. However, when an amount of 0.35% or more is contained, the manufacturability and characteristics are deteriorated due to the increase and coagulation (agglomeration) of crystallization such as Zr oxide and Ni ₂ SiZr. Therefore, the upper limit is made into 0.35%. In view of manufacturability and equity of characteristics, the lower limit thereof is preferably 0.05%, and the upper limit thereof is preferably 0.3%.

P: 0.002 to 0.05%

P improves the strength by increasing the density of fine precipitates, and also forms a compound with Ni, Si, and Zr, which contains a small amount of P in Ni ₂ Si, Ni ₂ SiZr and the like to increase hardness. . P may be contained in an amount of 0.002% or more in order to obtain these effects (strength, hardness, etc.). However, when P is contained in an amount of 0.05% or more, the thermal conductivity greatly decreases. Therefore, the upper limit is made into 0.05%. For the same reason, the lower limit is preferably 0.01%, and the upper limit is preferably 0.04%.

Cr, Mn, Zn: 1.5% or less in total

Cr, Mn, Zn is contained at least 1 type as needed.

Cr has the effect of forming an intermetallic compound with Si, improving strength, and miniaturizing crystal grains. Since Mn has a strong affinity with sulfur, it forms a compound with sulfur and improves workability (hot workability) by reducing the segregation of sulfides at grain boundaries that cause processing cracks (hot work cracks). Zn acts to improve strength by solid solution hardening. In addition, if an inexpensive brass scrap can be used at the time of melting, manufacturing cost can be reduced. However, when Cr, Mn, and Zn are excessively contained on the basis of the total amount, the thermal conductivity decreases. Therefore, it is preferable to make the total amount of Cr, Mn, and Zn into 1.5% or less.

As for the more preferable thing, it is preferable to make the total amount of Cr, Mn, and Zn into 1.0% or less. Moreover, when it contains at least 1 sort (s) among Cr, Mn, and Zn, it is preferable that it is 0.1% or more on the basis of total amount.

The high strength copper alloy forging material of this invention is equipped with said metal composition, and the balance consists of Cu and an unavoidable impurity.

The high strength copper alloy forgings of the present invention can be produced by conventional methods.

The copper alloy used in the present invention may be ingoted by conventional methods. For example, ingots (or ingots) can be obtained by dissolving the material in a vacuum atmosphere, an inert atmosphere, an air atmosphere, or the like. The atmosphere is preferably a vacuum atmosphere or an inert atmosphere. However, the copper alloy may also be solvent, for example, in an atmospheric high frequency furnace. In addition, secondary melting using an electroslag remelting furnace or the like may be performed. It is also possible to obtain a plate by the continuous forging method.

Copper alloys are processed as needed. The content of the processing is not particularly limited in the present invention, and the characteristics of the present invention can be obtained using any processing method. In consideration of productivity (manufacturability), the processing method is preferably hot working, more preferably 600 ° C. or more. However, the same characteristics as those of the hot working can also be obtained by processing at room temperature. Further, the machining may be a combination of hot machining and cold machining. Moreover, as a process, forging is preferable, hot forging is more preferable, and hot processing in 600 degreeC or more is more preferable. As the forging method, for example, a known method such as press, hammer, rolling, or the like can be used.

It is also possible to perform solution treatment on the processed copper alloy material after or during processing. The conditions of the solution treatment are maintained at, for example, 1 to 10 hours at 800 ° C to 1000 ° C, and then cooling at a cooling rate of 5 ° C / sec or more in a temperature range of 500 ° C or higher to sufficiently dissolve Ni and Si. It may include.

The processed copper alloy material may be subjected to either aging treatment or post-processing aging treatment. The conditions of the aging treatment may include, for example, maintaining for 1 hour to 30 hours at 400 ℃ to 500 ℃.

The high strength copper alloy material obtained as a result has the characteristics of 0.2% yield strength of 650 MPa or more, elongation of 5% or more, and conductivity of 30% IACS or more.

Moreover, the high strength copper alloy forging material of this invention has the outstanding characteristic as a forging material. However, in the composition of the present invention, even in a casting material in which the above processing such as forging is not performed, properties such as good ductility can be obtained.

Example

Hereinafter, embodiments of the present invention will be described.

The raw materials were blended so that the composition of compositions in Table 1 (including other unavoidable impurities) was achieved, and the raw materials were dissolved in a vacuum induction melting furnace to form an alloy of 100 mm (diameter) × 200 mm (length). This alloy was subjected to hot forging using a hammer at 900 ° C. to form a plate having a thickness of 25 mm. After holding at 970 ° C. for 4 hours, a solution treatment was performed by water cooling. Thereafter, suitable aging treatments were respectively performed on the materials of each composition at 400 ° C to 500 ° C for 1 to 30 hours to obtain a sample material.

Sample
Material No. Component (mass%)
Aging conditions
(℃ × time) Cu Ni Si Zr P Cr Mn Zn Sum of Cr, Mn and Zn Ni / Si ratio


room
city
Yes One Residue 4.16 0.95 0.09 0.018 - - - - 4.38 475 ℃ × 3 hours 2 Residue 5.15 1.14 0.16 0.017 - - - - 4.52 475 ℃ × 3 hours 3 Residue 4.83 1.12 0.08 0.004 0.43 0.19 0.33 0.95 4.31 450 ℃ × 10 hours 4 Residue 7.20 1.80 0.22 0.034 - - - - 4.00 450 ℃ × 10 hours 5 Residue 3.70 0.92 0.27 0.048 0.02 - - 0.02 4.02 475 ℃ × 3 hours 6 Residue 4.10 0.98 0.09 0.016 0.02 0.40 - 0.42 4.18 475 ℃ × 3 hours 7 Residue 3.10 0.74 0.03 0.020 - - - - 4.19 475 ℃ × 3 hours 8 Residue 5.04 1.17 0.32 0.049 - 0.20 0.50 0.70 4.31 450 ℃ × 10 hours 9 Residue 6.60 1.65 0.12 0.003 0.40 - - 0.40 4.00 450 ℃ × 10 hours


ratio
School
Yes 10 Residue 7.30 1.57 - - - - - - 4.65 425 ° C × 30 hours 11 Residue 4.24 0.99 - - - - - - 4.28 450 ℃ × 1 hour 12 Residue 8.37 0.93 - - - - - - 9.00 475 ℃ × 3 hours 13 Residue 3.77 0.95 0.16 - - - - - 3.97 475 ℃ × 3 hours 14 Residue 4.25 0.93 - 0.055 - - - - 4.57 500 ℃ × 1 hour 15 Residue 4.85 1.18 0.36 0.023 0.49 0.50 0.58 1.57 4.11 450 ℃ × 10 hours 16 Residue 7.77 1.87 0.10 0.022 0.42 - - 0.42 4.16 450 ℃ × 10 hours 17 Residue 2.20 0.55 0.01 0.002 - - - - 4.00 450 ℃ × 1 hour 18 Residue 8.12 2.05 0.12 0.030 - - - - 3.96 450 ℃ × 10 hours 19 Residue 5.33 1.39 0.08 0.006 3.03 0.22 0.15 3.40 3.83 450 ℃ × 10 hours

The prepared sample material was evaluated as follows.

(Tension test)

Room temperature tensile tests were performed on each sample material based on JIS Z2201 (2010) and JIS Z2241 (2010), and 0.2% yield strength (YS), tensile strength (TS), elongation rate, and area reduction (shrinkage rate) were evaluated. . The measurement results are shown in Table 2.

(Vickers hardness)

For each sample material, Vickers hardness was measured at a load of 5 kg based on JIS Z2244 (2010). The measurement results are shown in Table 2.

(Thermal conductivity)

The conductivity was measured for each sample material. As indicated by the Wiedemann-Franz Law, the thermal conductivity is approximately proportional to the conductivity, so it is possible to evaluate the thermal conductivity with conductivity. The measurement results are shown in Table 2.

Sample material
0.2% YS
(MPa) TS
(MPa) Elongation rate
(%) Area reduction rate (%) Vickers Hardness (Hv) Conductivity
(% IACS)

room
city
Yes


One 667 772 8.8 19.0 266 36.1 2 728 809 7.2 20.8 291 35.1 3 750 806 13.2 19.5 296 35.0 4 676 781 6.6 16.0 315 30.2 5 733 789 11.0 22.0 288 31.0 6 699 766 8.1 16.2 264 36.1 7 689 755 6.5 13.0 268 40.0 8 781 866 5.9 18.1 321 33.4 9 651 766 10.0 16.3 292 33.1


ratio
School
Yes


10 513 607 2.4 5.9 277 31.2 11 610 620 1.8 5.9 253 37.7 12 623 764 4.6 10.5 264 29.6 13 616 717 7.6 15.4 255 35.2 14 735 813 1.8 5.2 301 33.2 15 762 830 4.1 13.6 302 29.2 16 740 855 3.6 11.0 322 28.5 17 460 520 6.9 16.2 203 52.5 18 760 856 2.5 8.3 333 23.2 19 712 811 3.0 9.2 297 29.0

As shown in Table 2, the sample material according to the embodiment of the present invention has a 0.2% yield strength of 650 MPa or more, an elongation of 5% or more, a conductivity of 30% IACS or more, and is equal to or greater than the hardness of the sample material of the comparative example. It has a longitude.

 As described above, according to the present invention, by containing an appropriate amount of Zr and P in the Ni-Si-Cu alloy, excellent properties of increasing strength, ductility, and hardness while maintaining high conductivity, that is, high thermal conductivity, are obtained. It was confirmed that it can be done.

As mentioned above, although this invention was detailed also demonstrated with reference to the specific Example, it is clear that various changes and deformation are possible by a person skilled in the art, without deviating from the technical thought and range of this invention. . This application was filed on Feb. 16, 2011. The contents of which are based on Japanese Patent Application No. 2011-030660 filed as a patent application are hereby incorporated by reference.

According to the high-strength copper alloy forging material of the present invention, a proper amount of Zr and P acts so as not to cause cracks in the material during processing or heat treatment. In addition, the forging material of the present invention may have characteristics of high hardness, high strength, and high thermal conductivity after processing and heat treatment, and may be suitably used for resin injection mold materials, aircraft members, and the like.

Claims (3)

In terms of mass%, it contains 3% to 7.2% of Ni, 0.7% to 1.8% of Si, 0.02% to 0.35% of Zr, and 0.002% to 0.05% of P.
High strength copper alloy forgings. In terms of mass%, it contains 3% to 7.2% of Ni, 0.7% to 1.8% of Si, 0.02% to 0.35% of Zr, and 0.002% to 0.05% of P. Furthermore, 1 type (s) or 2 or more types of Cr, Mn, and Zn are contained 1.5% or less in total, characterized by the above-mentioned.
High strength copper alloy forgings. 3. The method according to claim 1 or 2,
0.2% yield strength of at least 650 MPa, elongation at least 5%, and conductivity of at least 30% IACS.
High strength copper alloy forgings.