JP4667977B2 - Copper alloy material for sleeve, manufacturing method thereof and sleeve - Google Patents

Description

  The present invention relates to a copper alloy material used for a sleeve of a hydrodynamic bearing device such as a spindle motor, a manufacturing method thereof, and a sleeve manufactured using the copper alloy material, and more particularly, to a hydrodynamic bearing device using a stainless steel shaft. The present invention relates to a copper alloy material for a sleeve, a manufacturing method thereof, and a sleeve.

  Generally, a sliding member of a hydrodynamic bearing device such as a spindle motor has a shaft (shaft) formed of a steel material such as stainless steel and a sleeve (bearing) of brass (Cu-Sn alloy) in order to reduce wear during sliding. It is formed of a relatively soft metal material such as However, the thermal expansion coefficient of brass is approximately 20 ppm, which is close to that of pure copper, whereas the thermal expansion coefficient of stainless steel is, for example, about 13 ppm in the case of SUS300, so that the conventional spindle motor has a thermal expansion coefficient of the shaft. Is smaller than the thermal expansion coefficient of the sleeve, and when the temperature of the sleeve and the shaft changes due to high-speed rotation, there is a problem that these sliding characteristics become unstable.

  This problem can be solved by setting the thermal expansion coefficient of the sleeve to be equal to or lower than the thermal expansion coefficient of the shaft. For example, Fe-42Ni alloy material, Cu- There are W-based alloy materials, Cu-Mo based alloy materials, Cu-CuO based alloy materials, and the like. However, for example, if the sleeve is formed of a steel material such as stainless steel like the shaft, wear occurs during sliding. In addition, a material used for a sliding member that performs high-precision processing in a manufacturing process such as a sleeve of a spindle motor is required not only to have a low coefficient of thermal expansion but also excellent workability. Since iron-based materials such as Fe—Ni-based alloy materials are difficult to cut, there are problems such as carbide sticking to the cutting edge during cutting, and it is difficult to cut with high accuracy. On the other hand, Cu-W alloy materials, Cu-Mo alloy materials, and Cu-CuO alloy materials have a low thermal expansion coefficient and good thermal conductivity, but these alloy materials must be prepared by a powder method. Furthermore, since the material is also expensive, the manufacturing cost is high, and complete alloying is difficult, so that there is a problem in machinability.

  Therefore, conventionally, the sleeve body is made of an Fe—Ni alloy (Invar) and an Fe—Ni—Co alloy (Super Invar) in order to suppress changes in sliding characteristics due to temperature changes without reducing workability. In addition, a plating layer or a vapor deposition layer made of Cu, Cu—Sn alloy, Cu—Ni alloy, Cu—Zn alloy, Cu—Zn—Sn alloy, or the like is formed as a processing layer on the inner surface, or Cu, Cu -Al alloy, Cu-Sn alloy, Cu-Sn-P alloy, Cu-Si-Sn alloy, Cu-Ni-Zn alloy, Cu-Ni-Fe alloy, Cu-Be alloy or Cu- A bearing device in which a tubular member made of a Zn alloy or the like is fitted has been proposed (see Patent Document 1). The bearing device described in Patent Document 1 suppresses a change in sliding characteristics by forming the sleeve body from an Fe—Ni alloy or Fe—Ni—Co alloy having a lower thermal expansion coefficient than that of a steel material, and further to cutting. Workability is improved by providing a processed layer made of Cu or Cu alloy on the inner surface to be processed.

  Conventionally, a spindle motor has been proposed in which the shaft is made of stainless steel and the sleeve is made of an aluminum silicon alloy so that the linear thermal expansion coefficient of the sleeve is smaller than that of the shaft (patent). Reference 2). In addition, there is a motor bearing in which a portion in contact with the shaft is formed of a polyether aromatic ketone resin containing carbon particles to ensure processability at the time of manufacture and improve slidability (Patent Document 3). reference.).

JP 9-177767 A JP 2004-104982 A JP 2002-115718 A

  However, the conventional techniques described above have the following problems. That is, the bearing device described in Patent Document 1 has a problem in that the number of steps increases and the manufacturing cost increases because a processed layer is formed on the inner surface of the sleeve. In the case of the bearing device described in Patent Document 1, the thermal expansion coefficient of the Fe—Ni alloy material and the Fe—Ni—Co alloy material forming the sleeve body is as low as 1.0 to 4.2 ppm. Most of the copper or copper alloy forming the layer has a high coefficient of thermal expansion of about 17 ppm, and the difference in coefficient of thermal expansion between the sleeve body and the processed layer is large. Due to this temperature change, there is a problem that the clearance (clearance) between the shaft and the sleeve changes, and the sliding characteristics deteriorate. In particular, when an Fe-Ni-Co alloy material is used, the coefficient of thermal expansion is too low at about 1.0 ppm, so that there is a problem that the change in clearance due to temperature change becomes large and the sliding characteristics become unstable. .

  Moreover, since the aluminum silicon alloy material used for the spindle motor sleeve described in Patent Document 2 cannot be manufactured by a normal technique, there is a problem that the cost is greatly increased. In addition, even if it can be manufactured, because the hard crystal Si primary crystal is present in the alloy material, workability is poor, and even if it can be processed into a sleeve, there is a high possibility of damaging the shaft during use. There are also problems. Furthermore, when the sleeve is formed of a polyether aromatic ketone resin containing carbon particles described in Patent Document 3, this material uses not the coefficient of thermal expansion but the slipperiness of carbon. There is a problem in that the durability is drastically reduced when starting.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a copper alloy material for a sleeve having good machinability and excellent thermal stability in sliding characteristics, a method for producing the same, and a sleeve. And

  The copper alloy material for a sleeve according to the first invention of the present application contains Ni: 7 to 25% by mass and Fe: 8 to 35% by mass, and the balance is composed of Cu and inevitable impurities, and has a thermal expansion coefficient. It is 12 to 15 ppm, has a Vickers hardness (Hv) of 100 to 260, and is a solid solution obtained by solution treatment of a molded body produced by casting or powder hot extrusion.

  In the present invention, the Cu-Ni-Fe-based alloy material is optimized for the Ni and Fe contents and has a thermal expansion coefficient of 12 to 15 ppm, which is lower than that of conventional sleeve materials. It is possible to suppress the change in the sliding characteristics due to. Further, since the Vickers hardness (Hv) is set to 100 to 260 and the solid solution is used, the machinability is excellent. And the copper alloy material of this invention can be manufactured by solution-treating the molded object produced by casting or powder hot extrusion.

  The copper alloy material may have a Cu content of 45 to 75 mass%. Moreover, you may make Fe content into 8.5 mass% or more. Thereby, a thermal expansion coefficient can be reduced more, maintaining machinability.

  The method for producing a copper alloy material for a sleeve according to the second invention of the present application includes casting a raw material having a composition containing Ni: 7 to 25% by mass and Fe: 8 to 35% by mass, the balance being Cu and inevitable impurities. Alternatively, a process of obtaining a molded body by hot extrusion of powder, and a solution treatment of the molded body to obtain a copper alloy material having a thermal expansion coefficient of 12 to 15 ppm, a Vickers hardness (Hv) of 100 to 260, and a solid solution. And obtaining a step.

  In the present invention, a raw material having a composition containing Ni: 7 to 25% by mass and Fe: 8 to 35% by mass and the balance consisting of Cu and inevitable impurities is formed by casting or powder hot extrusion, A hydrodynamic bearing device using a stainless steel shaft because the formed body is subjected to solution treatment, a thermal expansion coefficient of 12 to 15 ppm, a Vickers hardness (Hv) of 100 to 260, and a copper alloy material made of a solid solution. As a result, a copper alloy material for a sleeve having good machinability and excellent thermal stability in sliding properties can be obtained.

  In this method for producing a copper alloy material, it is possible to perform drawing after the solution treatment. Thereby, a copper alloy wire having a desired diameter can be easily obtained. The raw material may have a Cu content of 45 to 75% by mass. The raw material may have an Fe content of 8.5% by mass or more.

  A sleeve according to the third aspect of the present invention is a sleeve of a hydrodynamic bearing device using a stainless steel shaft, and is characterized by being manufactured from the above-described copper alloy material.

  In the present invention, Ni: 7 to 25% by mass and Fe: 8 to 35% by mass, with the balance consisting of Cu and inevitable impurities, a thermal expansion coefficient of 12 to 15 ppm, Vickers hardness (Hv) is 100 to 260, and a copper alloy material which is a solid solution obtained by solution treatment of a molded body produced by casting or powder hot extrusion is used. Little change in characteristics and excellent thermal stability. Moreover, since the machinability at the time of manufacture is excellent, it can cut with high precision.

  According to the present invention, the content of Ni and Fe in the Cu-Ni-Fe alloy material is specified, and the formed body formed by casting or powder hot extrusion is formed into a solid solution, and further, thermal expansion is performed. Since the coefficient is 12 to 15 ppm and the Vickers hardness (Hv) is 100 to 260, it is possible to suppress a change in sliding characteristics due to a temperature change and to obtain a good machinability.

  Hereinafter, the copper alloy material according to the embodiment of the present invention will be specifically described. The copper alloy material of this embodiment is a solid solution obtained by solution treatment of a molded body formed by casting or powder hot extrusion, containing 7 to 25% by mass of Ni, 8 to 35% by mass of Fe, and the balance being Cu. The thermal expansion coefficient is 12 to 15 ppm, and the Vickers hardness (Hv) is 100 to 260. For example, this copper alloy material is processed into a sleeve of a spindle motor. In the composition of the copper alloy material of the present embodiment, more preferably, the Cu content is 45 to 75% by mass and the Fe content is 8.5% by mass or more.

Conventionally, a Cu—Ni—Fe alloy material has been used as a magnetic material such as a magnetic scale, and is generally manufactured by hot extrusion of a powder formed by a gas atomizing method or mechanical alloying (for example, a special material). (See Kaihei 9-15770, JP-A-10-53822, JP-A-10-223465, and JP-A-2000-256766). However, the magnetic material usually needs to be subjected to an aging treatment to separate the γ phase into a ferromagnetic γ ₁ phase and a non-magnetic γ ₂ phase, and Cu—Ni produced by such a conventional method. The -Fe alloy material has a hard Fe-Ni-rich (ferromagnetic γ ₁ ) phase, and therefore has low cutting workability and is not suitable for a sliding member such as a sleeve. On the other hand, the copper alloy material of the present embodiment is manufactured by subjecting a molded body obtained by a casting method or a powder hot extrusion method to a solution treatment and a drawing process, and is subjected to an aging treatment. Therefore, each component can be completely dissolved, and the machinability is excellent. In addition, the copper alloy material of this embodiment does not have a ferromagnetic and hard Fe—Ni-rich (ferromagnetic γ ₁ ) phase, and is formed of a solid solution.

  In addition, the Cu—Ni—Fe alloy material takes various thermal expansion coefficients by changing the ratio between the Ni content and the Fe content, and the ratio between the Cu content and the total content of Ni and Fe. sell. FIG. 1 is a ternary phase diagram showing a distribution of thermal expansion coefficients of a Cu—Ni—Fe alloy material. As shown in FIG. 1, in the Cu—Ni—Fe alloy material, the coefficient of thermal expansion is changed by changing the Ni content and the Fe content, so that the contents of Cu, Ni and Fe are within the range of the region 1. Thus, the thermal expansion coefficient can be set to 12 to 15 ppm. When this copper alloy material is processed into a sleeve of a spindle motor and the shaft is formed of stainless steel (Fe-18Cr-8Ni alloy, thermal expansion coefficient: 17.3 ppm) which is generally used at present, the sleeve and the shaft The thermal expansion difference is 2.3 to 5.3 ppm, and the thermal stability in sliding characteristics can be improved as compared with the conventional spindle motor.

  Hereinafter, the reason for the numerical limitation in the copper alloy material of the present embodiment will be described.

Ni: 7 to 25% by mass
When the Ni content is less than 7% by mass, the machinability is improved, but the thermal expansion coefficient is increased. On the other hand, when the Ni content exceeds 25% by mass, the thermal expansion coefficient decreases, but the machinability deteriorates. Therefore, the Ni content is 7 to 25% by mass.

Fe: 8 to 35% by mass
When the Fe content is less than 8% by mass, the machinability is improved, but the thermal expansion coefficient is too large. On the other hand, when the Fe content exceeds 35% by mass, the thermal expansion coefficient decreases, but the machinability deteriorates. Therefore, the Fe content is 8 to 35% by mass. In addition, when Fe content is less than 8.5 mass%, a thermal expansion coefficient may exceed 15 ppm depending on Ni content. For this reason, it is preferable that Fe content shall be 8.5 mass% or more. Thereby, the thermal expansion coefficient can be stabilized in the range of 12 to 15 ppm.

Thermal expansion coefficient: 12 to 15 ppm
In a sliding member of a hydrodynamic bearing device such as a spindle motor, the difference in thermal expansion coefficient between the sleeve and the shaft is preferably 2 to 5 ppm. For example, the shaft is made of stainless steel (Fe-18Cr-8Ni alloy; thermal expansion). In the case of forming at a rate of 17.3 ppm, the thermal expansion coefficient of the sleeve material is 12 to 15 ppm. If the thermal expansion coefficient of the copper alloy material, that is, the sleeve is less than 12 ppm, the clearance between the sleeve and the shaft becomes too large and the rotation becomes unstable, so that the sliding characteristics become unstable. In addition, the clearance between the sleeve and the shaft is secured by cutting, but if the thermal expansion coefficients of the sleeve and the shaft are the same, they are completely locked due to temperature changes. Therefore, in the copper alloy material of the present embodiment, the thermal expansion coefficient is made slightly smaller than the thermal expansion coefficient of the shaft so that a clearance between the sleeve and the shaft can be secured even if the temperature changes. Specifically, in the copper alloy material of the present embodiment, the upper limit value of the thermal expansion coefficient is set to 15 ppm. When the coefficient of thermal expansion of the copper alloy material exceeds 15 ppm, the difference in coefficient of thermal expansion between the sleeve and the shaft becomes small, and troubles such as locking occur due to temperature changes.

Hardness (Hv): 100 to 260
When the Vickers hardness (Hv) is less than 100, it is too soft and difficult to cut. Further, when the Vickers hardness (Hv) exceeds 260, it becomes difficult to cut, so that problems such as losing the cutting edge of a cutting tool used for cutting occur. Therefore, the hardness (Hv) of the copper alloy material of this embodiment is set to 100 to 260. Thereby, hardness suitable for the cutting edge of the cutting tool used for cutting can be obtained, and cutting can be performed with high accuracy. On the other hand, as described above, the Cu—Ni—Fe alloy material used as the magnetic material has been subjected to an aging treatment in the manufacturing process, so that it is ferromagnetic and hard Fe—Ni—rich (ferromagnetic γ ₁ ). There is a phase and its hardness (Hv) can also exceed 260. For this reason, the Cu—Ni—Fe alloy material for the magnetic material does not have the ferromagnetic γ ₁ and has poor machinability compared to the copper alloy material of the present embodiment which is a solid solution.

  In addition, in the copper alloy material of this embodiment, it is preferable that Cu content shall be 45 to 75 mass%. Thereby, the copper alloy material excellent in workability and thermal stability is obtained. On the other hand, if the Cu content is less than 45% by mass, the thermal expansion coefficient can be made lower than 12 ppm, but the workability may be lowered. Moreover, when Cu content exceeds 75 mass%, a thermal expansion coefficient will become higher than 15 ppm and the thermal stability of a sliding characteristic may fall.

  In addition, the mechanical properties of the Cu—Ni—Fe alloy material change depending on the manufacturing method, and the machinability changes. Therefore, in the copper alloy material of the present embodiment, not only the above-described composition but also the manufacturing method is optimized. Hereinafter, the manufacturing method of the copper alloy material of this embodiment is demonstrated. The copper alloy material of this embodiment can be manufactured by solution-treating the molded object shape | molded by casting or powder hot extrusion. For example, when the copper alloy material of this embodiment is produced by a casting method, raw materials such as Cu, Fe, and Ni are melted and cast by a high frequency melting method. Then, for example, after performing a homogenization treatment for 5 to 10 hours under a temperature condition of 950 to 1100 ° C., for example, cold working such as different diameter rolling is performed to form a linear shape or the like. Further, the molded body is subjected to a solution treatment for, for example, 1 hour under a temperature condition of, for example, 950 ° C., and then drawn to obtain a linear material having a desired diameter.

  In the case of the above-described casting method, if there is a problem such as cracking in the molded body or poor dispersion of the additive element, it can also be produced by a powder sintering method. In that case, first, a raw material powder having the above-mentioned composition is prepared by an atomizing method or the like. And after making this raw material powder into a round bar shape by hot extrusion processing, it is subjected to heat treatment, for example, for 5 to 10 hours under a temperature condition of, for example, 950 to 1100 ° C. Or a predetermined shape such as

  As described above, the copper alloy material of the present embodiment has an optimum range as a sliding member that slides with respect to the stainless steel material by optimizing the Ni and Fe contents and manufacturing conditions, that is, Since the Vickers hardness (Hv) is adjusted to 100 to 260 while being adjusted to 12 to 15 ppm, the thermal stability in cutting property and sliding property is excellent.

Hereinafter, the effect of the Example of this invention is demonstrated compared with the comparative example which remove | deviates from the scope of the present invention. First, No. 1 shown in Table 1 below. The raw materials having the composition of 1 to 6 were melted and cast, respectively, and then homogenized at 950 to 1100 ° C. for 5 to 10 hours, further cold-worked (different diameter rolling), with a diameter of 13 mm and a length of 500 mm. Processed into a straight line. These straight lines were subjected to a solution treatment for 30 minutes under a temperature condition of 950 ° C., and then drawn so that the diameter became 10 mm, and Examples 1, 2 and Comparative Examples 1 to 4 A copper alloy wire was prepared. No. 1 shown in Table 1 below. 1 and no. After the raw materials having the composition 2 were melted and cast, they were homogenized at 950 to 1100 ° C. for 5 to 10 hours, further subjected to cold working (different diameter rolling), and processed into a straight line having a diameter of 10 mm. And the solution treatment for 30 minutes was given to this straight line on 950 degreeC temperature conditions, and the copper alloy wire of Example 3 and 4 was produced. Further, the copper alloy wires of Examples 1 to 4 were subjected to an aging treatment for 3 hours under a temperature condition of 550 ° C., thereby producing copper alloy wires of Comparative Examples 5 to 8. The lengths of the copper alloy wires in Examples 1 to 4 and Comparative Examples 1 to 8 were adjusted to 400 mm by cutting. Further, as a conventional example, a commercially available wire rod made of electromagnetic soft iron and high-strength yellow steel, having a diameter of 10 mm and a length of 400 mm was prepared. Table 2 below shows the manufacturing method, thermal expansion coefficient, Vickers hardness (Hv), and presence / absence of phase separation of each wire. In addition, the thermal expansion coefficient shown in the following Table 2 is a value measured with a THEROFLEX TMA5140C manufactured by Rigaku in a temperature range of 20 to 100 ° C., and the Vickers hardness (Hv) is a value measured with a HARDNESS TESTER manufactured by Chukyo Tester Co., Ltd. It is. The presence or absence of phase separation was evaluated by measuring the holding power Hc of each copper alloy wire with a BH tracer made by Riken Denshi. Specifically, when the γ phase is separated into a ferromagnetic γ ₁ phase and a non-magnetic γ ₂ phase, a holding force Hc is generated. Therefore, when the holding force Hc is 0, there is no phase separation, and the holding force Hc is less than 0. Was also large, the phase separation was considered to be present.

  Next, the machinability and sliding characteristics of the copper alloy wires of Examples 1 to 4 and Comparative Examples 1 to 8, the electromagnetic soft iron wire of Conventional Example 1, and the high strength brass wire of Conventional Example 2 were evaluated. As for machinability, the average surface roughness Ra of the processed surface is 0 when each wire is continuously processed into a cylindrical shape having a diameter of 8 mm and a height of 5 mm without using a cutting tool. Evaluation was made based on the number that can be maintained at 25 μm or less. At that time, the processing conditions were a rotation speed of 3000 rotations / minute and a blade feed speed of 0.02 mm / rev. In addition, the average surface roughness Ra of the cylinder obtained by the cutting process was measured with a surfcom manufactured by Tokyo Seimitsu.

The sliding characteristics were evaluated by producing a sleeve by cutting each wire. FIG. 2 is a cross-sectional view schematically showing a method for evaluating sliding characteristics. As shown in FIG. 2, in this embodiment, the shaft 11 uses a stainless steel (Fe-18Cr-8Ni alloy) material having a thermal expansion coefficient of 17.3 ppm at 100 ° C., and its diameter r ₁ is 5 mm. It was. The sleeve 12 is formed by cutting 300 pieces of each of the wire materials of Examples 1 to 4, Comparative Examples 1 to 8, and Conventional Examples 1 and 2 under the same conditions as in the above-described cutting performance evaluation to obtain an outer diameter r _2. 8 mm and the length L was 10 mm, and then the 300th piece was drilled so that the inner diameter was 3 μm larger than the diameter r ₁ (5 mm) of the shaft 11. Then, the shaft 11 is inserted into the hole formed in the sleeve 12, the shaft 11 and the rotating shaft 13 a of the motor 13 are coupled by the connecting member 15, and the lubricating oil 14 is interposed between the shaft 11 and the sleeve 12. Filled. Then, after the shaft 11 and the sleeve 12 are installed in the thermostat 16 and the shaft 11 is rotated at a normal temperature for a certain time, the temperature of the thermostat 16 is raised to raise the temperature of the shaft 11 and the sleeve 12 to 100 ° C. The sliding state at 100 ° C. was confirmed. At this time, the rotation speed of the shaft 11 was set to 8000 rotations / minute. The results are shown in Table 3 below. In Table 3 below, “◯” indicates that the sliding characteristics were good, “Δ” indicates that there was a slight abnormality, and “×” indicates that a defect occurred. The above results are summarized in Table 3 below.

  As shown in Table 3 above, the wire materials of Examples 1 to 4 both had good machinability and sliding properties. In contrast, the wire of Comparative Example 1 having a Ni content of less than 7% by mass and a thermal expansion coefficient exceeding the range of the present invention had good machinability, but had problems during sliding. occured. On the other hand, the wire of Comparative Example 2 in which the Ni content exceeds 25% by mass, the coefficient of thermal expansion is smaller than the range of the present invention, and the hardness (Hv) exceeds the range of the present invention is sliding. Although the property was slightly abnormal, the machinability was poor. Moreover, although the wire content of Comparative Example 3 having an Fe content of less than 8% by mass and a thermal expansion coefficient exceeding the range of the present invention had good machinability, problems occurred during sliding. On the other hand, the wire of Comparative Example 4 in which the Fe content exceeds 35% by mass, the thermal expansion coefficient is significantly smaller than the range of the present invention, and the hardness (Hv) exceeds the range of the present invention, Although the slidability was slightly abnormal, the machinability was poor.

  Furthermore, the wires of Comparative Examples 5 and 6 that were subjected to aging treatment after drawing and the wires of Comparative Examples 7 and 8 that were subjected to aging treatment after solution treatment were any of composition, thermal expansion coefficient, and hardness (Hv). However, the wires of Comparative Examples 5 and 7 had a holding force Hc of 650 Oe, and the wires of Comparative Examples 6 and 8 had a holding force Hc of 550 Oe. It was separated into phases. For this reason, these wires had poor machinability compared with the wires of Examples 1 to 4 in which the holding force Hc was 0. Furthermore, although the wire of Conventional Example 1 had good slidability, it was difficult to process with high precision because of its extremely poor machinability. Furthermore, the wire of Conventional Example 2 had good machinability, but had poor sliding characteristics at high temperatures and locked during rotation.

It is a ternary phase diagram showing distribution of thermal expansion coefficient of Cu-Ni-Fe alloy material. It is sectional drawing which shows typically the evaluation method of the sliding characteristic in the Example of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1; Area | region 11; Shaft 12; Sleeve 13; Motor 13a; Rotating shaft 14; Lubricating oil 15; Connecting member 16;

Claims (8)

Ni: 7 to 25% by mass and Fe: 8 to 35% by mass, with the balance being Cu and inevitable impurities, thermal expansion coefficient of 12 to 15 ppm, and Vickers hardness (Hv) of 100 to 260 A copper alloy material for a sleeve, which is a solid solution obtained by solution treatment of a molded body produced by casting or hot extrusion of powder. 2. The copper alloy material for a sleeve according to claim 1, wherein the Cu content is 45 to 75% by mass. The copper alloy material for a sleeve according to claim 1 or 2, wherein the Fe content is 8.5% by mass or more. A step of obtaining a molded body by casting or powder hot extruding a raw material having a composition containing Ni: 7 to 25% by mass and Fe: 8 to 35% by mass and the balance consisting of Cu and inevitable impurities; And a step of obtaining a copper alloy material made of a solid solution having a coefficient of thermal expansion of 12 to 15 ppm, a Vickers hardness (Hv) of 100 to 260, and a copper alloy material for a sleeve, Manufacturing method. 5. The method for producing a copper alloy material for a sleeve according to claim 4, wherein a drawing process is performed after the solution treatment. The method for producing a copper alloy material for a sleeve according to claim 4 or 5, wherein the raw material has a Cu content of 45 to 75 mass%. The method for producing a copper alloy material for a sleeve according to any one of claims 4 to 6, wherein the raw material has an Fe content of 8.5 mass% or more. A sleeve for a hydrodynamic bearing device, which is manufactured from the copper alloy material according to any one of claims 1 to 3.

Images