JPH02159332A - Magnetic cu alloy and its manufacture - Google Patents

Abstract

PURPOSE:To improve the electric conductivity and magnetic characteristics in the Cu alloy by subjecting a mixed body of Cu or a Cu alloy contg. a fine body of ferromagnetic metals to hardening under specific conditions. CONSTITUTION:By volume, 10 to 85% powder of a ferromagnetic body of Fe, Ni, Co or their alloys or the like and Cu or a Cu alloy are mixed. The mixed body is subjected to hardening at 600 to 800 deg.C under >=10kg/mm<2> pressure. Or, the mixed body is subjected to compacting at a room temp. under >=50kg/mm<2> pressure and is thereafter subjected to heat treatment at 600 to 800 deg.C. Since the Cu alloy has high electric conductivity and has ferromagnetism, it can be used as an electromagnetic wave shield material, a solid rotor of an induction motor including a linear motor or the like.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a magnetic Cu alloy used in electromagnetic shielding materials and solid rotors of induction motors including near motors, and a method for producing the same. The present invention relates to a magnetic Cu alloy having high ferromagnetism and a method for producing the same.

[Prior Art] With the development of office automation and factory automation, electrical equipment equipped with magnetic disk storage devices is increasingly being used, and a magnetic shield structure is required to retain records on the magnetic disk storage device. is becoming increasingly important, and it is also legally mandated to prevent electromagnetic noise from affecting other electrical equipment.

An example of such a motor is a precision motor used to drive the magnetic head of a magnetic disk storage device, which of course requires an electromagnetic shielding structure, but there is also a need to further improve its shielding performance. There is.

On the other hand, steel plate laminated rotors are commonly used in conventional induction motors, but it is difficult to convert speed with high precision with these rotors, and solid rotors with high low-speed torque are being reconsidered for use in assist motors that require control. , a material that is ferromagnetic and has high electrical conductivity is desired as a rotor material.

As described above, magnetic materials with excellent electrical conductivity and magnetic performance are required as electromagnetic shielding materials and rotor materials for induction motors, but the currently used magnetic A1 alloy is not yet sufficient in terms of performance. There is still room for improvement. In other words, magnetic A1 alloy is made by dispersing and molding ferromagnetic powder such as iron powder into AI powder, and it is used to improve shielding performance (reflection efficiency, etc.) as an electromagnetic wave shielding material and electromagnetic properties as a rotor material for induction motors. need to improve electrical conductivity and magnetic performance. In this respect, AI can be said to be a metal with relatively high electrical conductivity, but recent demands for higher electrical conductivity are desired.

However, since it is impossible for the magnetic A1 alloy to exceed the physical property values inherent to A1, the electrical conductivity of the magnetic A1 alloy has reached a plateau. In addition, when dispersing iron powder etc. in A1 and hot pressing, the temperature is approximately 500℃.
When heated at a temperature exceeding
There is a problem in that intermetallic compounds such as Is are generated and the magnetic properties of the compact are significantly reduced, so hot pressing is carried out at a temperature lower than this. However, when molding is carried out at a temperature below 500°C, it is necessary to apply considerably high pressure, which leaves processing strain inside the molded product, which causes the ferromagnetic material to be unable to fully demonstrate its original performance. There is.

[Problems to be Solved by the Invention] The present invention has been made in view of these circumstances, and has physical properties such as electrical conductivity and magnetic properties that could not be achieved with conventional magnetic A1 alloys. The purpose of this invention is to provide an alloy and a method for manufacturing the same.

[Means for Solving the Problems] The magnetic alloy of the present invention that achieves the above object is as follows:
The gist is that it contains 10 to 85% by volume of fine particles of ferromagnetic metal, and that the ferromagnetic metal is integrated with Cu or Cu alloy by metallic bonding without forming an intermetallic compound, and In the method of the present invention for producing the magnetic alloy, a mixture containing io ~ 85% by volume of ferromagnetic metal particles and the remainder being Cu or a Cu alloy is heated at a temperature of 600 to 800°C at a rate of 10 kg/ The gist is that the material is solidified and molded by applying a pressure of am2 or more, or compacted at a pressure of 50 kg/mm' or more at room temperature, and then heat-treated at 600 to 800°C.

[Function] The magnetic alloy according to the present invention is made of C, which has higher electrical conductivity than AI.
U or Cu alloy is used as the base metal. In other words, as a magnetic alloy with high electrical conductivity, it has traditionally been lightweight;
It is common knowledge in the field to use A1 as the base metal from the viewpoint of formability and economic efficiency, and Cu has a higher specific gravity and is inferior in formability (cold workability) and economy than AI. The adoption of this was completely unthinkable. However, compared to A1, Cu has the characteristic that it is difficult to form intermetallic compounds with ferromagnetic materials, especially Fe, and by modifying the molding conditions, etc., it is possible to form intermetallic compounds that adversely affect magnetic performance and cause processing distortion. It was discovered that it is possible to obtain a magnetic alloy with excellent magnetic performance by preventing this, and furthermore, by utilizing the characteristic of Cu or Cu alloy that electrical conductivity is superior to AI, it can be used for applications such as electromagnetic shielding materials and rotor materials for induction motors. The inventors have discovered that a magnetic alloy suitable for this purpose can be obtained, and have thus completed the present invention.

In the magnetic Cu alloy of the present invention, the ferromagnetic material is Fe.
, Ni, Co, and their alloys, etc., and the ferromagnetic material must be contained in a volume percentage of 10 to 85%.0 Effective when the content of the ferromagnetic material is less than 10% in volume percentage. -If the content of the ferromagnetic material exceeds 85% by volume, a healthy solidified state cannot be obtained even if the solidification molding conditions are adjusted, and as a base metal. Cu and Cu alloys are exemplified, and among these, Cu alloys are not particularly limited as long as they have electrical conductivity that basically exceeds that of AI and have satisfactory formability, but preferred Cu alloys include: Cu-Cd, Cu
-Ag, Cu-Zr alloy, etc. In addition, in the present invention, in order to obtain magnetic performance without anisotropy, it is necessary that the ferromagnetic material and Cu or Cu alloy are integrated in a homogeneous state. The material is required to be dispersed in the matrix of Cu or Cu alloy. As mentioned above, it is essential that the ferromagnetic material and Cu or Cu alloy are integrated by metallic bonding without forming intermetallic compounds, and the formation of intermetallic compounds may cause a decrease in magnetic properties. As mentioned above, in order to obtain such a magnetic Cu alloy, it is necessary to adopt the conditions of the present invention detailed below.

That is, in producing the magnetic Cu alloy of the present invention described above, there are two methods described below, one of which is to contain 10 to 85% by volume of ferromagnetic metal microspheres, and the remainder is Cu or Cu alloy. The mixture was heated at a temperature of 600 to 800°C for 1
This is a method of hot pressing by applying a pressure of 0 kg/mm2 or more, and in this method, it is difficult to obtain a healthy solidified state if the heating temperature is less than 600°C, and in addition, excessive pressure is applied during pressure molding. Therefore, as mentioned above, processing strain remains in the molded product and the magnetic properties deteriorate. It should be noted that if the molding pressure is low enough not to cause processing distortion, the molding will be insufficient. On the other hand, if the heating temperature exceeds 800℃, C
Interdiffusion solid solution between u and the ferromagnetic material progresses to form an intermetallic compound, which deteriorates the electrical conductivity and magnetic properties of the compact.

Further, if the molding pressure is less than 10 kg/gi'', the pressing force is insufficient even in hot pressing, and a healthy solidified state cannot be obtained.

Another method for manufacturing the magnetic Cu alloy of the present invention is to cold press a mixed raw material having the above composition, and then heat treat it to achieve diffusion between the metals and achieve integration through metal bonding. After performing powder compaction by applying a pressure of 50 kg/av" or more at room temperature, the obtained molded product is
The heat treatment is performed at a temperature of 00°C. This method has the advantage of being able to obtain high dimensional accuracy because it uses cold forming, and is advantageous for forming products with small and complex shapes. Since the bonding between the bodies is not sufficient, it is necessary to cause atomic diffusion at the interface between the microscopic bodies through heat treatment after molding to eliminate processing distortion and improve the bonding state between the microscopic bodies. If the cold forming pressure is less than 50 kg/++a', it is not possible to obtain a good cold forming condition, and even if sufficient heat treatment is performed thereafter, the microscopic objects cannot be sufficiently bonded to each other. Can not. Furthermore, if the heat treatment temperature is less than 600°C, not only will it be impossible to obtain a good microscopic bonding state due to insufficient diffusion, but also
Processing strain remains and magnetic properties deteriorate. On the other hand, if the heat treatment temperature exceeds 800° C., the diffusion solid solution between Cu and the ferromagnetic material progresses to form an intermetallic compound, resulting in deterioration of electrical conductivity, magnetic properties, etc.

In the present invention, the ferromagnetic microscopic bodies are exemplified in the form of powder, flakes, fibers, etc., and there is no particular limitation on the size, but for example, if the particle size is 2.
A particle size of about 0 to 200 μm is recommended, and the size of the Cu or Cu alloy microscopic object is not particularly limited, but it is recommended that it be a powder with a particle size of about 200 μm or less.

[Example] As shown in Table 1, various ferromagnetic microscopic bodies and Cu powder were mixed. In the case of hot forming (・N001-28), a CI with a diameter of 70II+m and a length of 150ohm is made from the mixture.
Preform the P molded body or the inner dimension is 70+a in diameter.
The mixture was filled into a bottomed container with a length of 180 mm and a thickness of [■], and then extrusion pressed to form a molded body, and hot pressed at the respective temperatures and pressures. In addition, in the case of cold forming (Examples 29 to 42), the above mixture was molded into a mold with a diameter of 45 mm.
They were filled into a forging die, cold pressed at a predetermined pressure, and then heat treated.

No., magnetic flux density (Bl..2 units gauss
) was measured. The results are shown in FIG.

Remarkable magnetic properties are not developed until the volume fraction of the ferromagnetic material reaches 6%, but when it exceeds 6%, magnetic properties are gradually developed, and above 10%, a clear increase in magnetic performance is observed. It was done. As shown in Nos. 5 to 9, it can be seen that magnetic performance can be further improved by further increasing the volume fraction of the ferromagnetic material. However, as seen in No. 9.10, when the volume fraction exceeds 90%, the strength of the molded product decreases,
%, it was not possible to produce a measurement test piece.From the experimental results of 0 or more, in a magnetic Cu alloy with a matrix of non-magnetic Cu, the volume fraction of ferromagnetic material was set to 10 to 8.
It is considered effective to set it to 5%.

Next, FIG. 2 shows the experimental results for molded products No. 11 to 18. When the molding temperature is lower than 600° C., the strength of the molded product is low and it is not possible to obtain a good molded product. It is thought that on the low temperature side, the degree of bonding decreases because the movement of atoms near the powder interface due to diffusion is small. In the region of low strength, the electrical resistance value is also high. Also No, 1~2
Judging from the experimental results in 1, the molding pressure is 5 kg/m
m' is insufficient, and the molding pressure required to obtain sufficient strength is No.

From the experimental data of 20.21, it is thought to be 10 kg/am2 or more.

Judging from the experimental results of Nos. 29 to 33, it is necessary to increase the molding pressure in the case of cold forming, and the molding pressure is 50 kg/
It must be pressure molded at a pressure of mi2 or higher. No again. From the experimental results of No. 35 to No. 39, a heat treatment temperature of 550°C after cold forming is insufficient (No. No. 36 has a strength of 13 kg/1 m' and a B too of 4800 gaus).
s), No. whose heat treatment temperature is 600 to 800°C,
Compared to the strength of 34.35, 37.38 (20 kg/am”) and B+oo (5100 gauss),
Its value is clearly inferior. Also, the heat treatment temperature is 830℃
No. 39 has no problem in terms of strength, but it contains Fe, which contributes to improving magnetic performance, and C, which contributes to improving electrical conductivity.
Magnetic performance CB+ because u are dissolved in solid solution with each other and are worn out. . )
and the increase in electrical resistance (that is, the decrease in electrical conductivity) are large.

From the above results, in the case of cold forming, the forming pressure should be 50 kg/
mi2 or higher, and the heat treatment temperature must be set at 800 to 800°C.

The magnetic Cu alloys according to the present invention are No. 27 and No. 27.

13-17 or No, 28 and No, 22 or N
As can be seen by comparing No. 42 and No. 40, when the same ferromagnetic material is used, better performance can be obtained in all aspects of magnetic performance, electrical conductivity, and strength than when AI is used as a matrix. can.

[Effects of the Invention] The present invention is configured as described above, and has a magnetic performance of 1! compared to the conventional magnetic A1 alloy. A magnetic alloy excellent in all aspects of air conductivity and strength can be obtained. In this way, we have succeeded in providing a magnetic Cu alloy that exhibits high performance in the field of induction motors, including linear motors, and in the field of electromagnetic shielding.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the relationship between ferromagnetic material volume fraction and magnetic performance, and FIG. 2 is a graph showing the relationship between hot forming temperature and various properties.

Claims (3)

[Claims] (1) It is characterized by containing 10 to 85% by volume of fine particles of ferromagnetic metal, and the ferromagnetic metal is integrated with Cu or Cu alloy by metallic bonding without forming an intermetallic compound. Magnetic Cu alloy. (2) A mixture containing ferromagnetic metal particles of 10 to 85% by volume and the remainder being Cu or Cu alloy is 600 to 85% by volume.
A method for manufacturing a magnetic Cu alloy, characterized by solidifying and forming it at a temperature of 00°C and applying a pressure of 10 kg/mm^2 or more. (3) A mixture containing 10 to 85% by volume of ferromagnetic metal particles, with the remainder being Cu or Cu alloy, was heated at room temperature for 5
After compacting at a pressure of 0 kg/mm^2 or more, 600
A method for producing a magnetic Cu alloy, characterized by heat treatment at ~800°C.