JP7635112B2 - Non-magnetic member and method of manufacturing same - Google Patents

Description

The present invention relates to non-magnetic members and the like that are used in alternating magnetic fields.

There are various types of equipment that utilize electromagnetism (simply referred to as "electromagnetic equipment"), such as electric motors (including generators as well as motors) and actuators, and many of these use alternating magnetic fields. In order to save energy, it is necessary to reduce high-frequency losses in such electromagnetic equipment when they are used in an alternating magnetic field. In particular, in electric motors that rotate at (ultra) high speeds, it is highly necessary to reduce eddy current losses, which increase in proportion to the square of the rotation speed (frequency of the alternating magnetic field). For example, the rotor core and stator core of a motor are often constructed by laminating electromagnetic steel sheets coated with an insulating layer in order to suppress eddy currents that occur in a direction perpendicular to the alternating magnetic field.

However, for some components (called "electromagnetic components") that are used in alternating magnetic fields, it is difficult to adopt such a configuration. In such cases, it is necessary to construct the electromagnetic components from a material with high electrical resistivity (simply called "resistivity") to reduce eddy current loss.

The electromagnetic components disposed in the magnetic circuit are not limited to magnetic materials, and may be non-magnetic. Furthermore, electromagnetic components may be required to satisfy not only electrical characteristics (e.g., resistivity) and magnetic characteristics (e.g., magnetic permeability), but also certain mechanical characteristics (rigidity, strength, ductility, etc.). The following patent documents contain descriptions related to such electromagnetic components.

JP2001-339886 Patent Publication 2008-29153 Patent Publication No. 2020-43746 JP 5-5142 A Patent No. 3712614 (WO2000/005425) JP2005-320618A Patent Publication No. 2005-524774 (WO2003/095690) U.S. Pat. No. 4,731,115

Patent Documents 1 and 2 describe a protective tube (sleeve) made of carbon fiber reinforced plastic (CFRP) as an example of an electromagnetic component made of a non-magnetic material (referred to as a "non-magnetic component"). The protective tube is fitted over the outer periphery of a cylindrical permanent magnet provided on the outer periphery of the rotor shaft (rotating shaft) of the motor. The protective tube prevents damage to the permanent magnet, which is subjected to large centrifugal forces at high speeds. However, when the rotation speed is further increased, the mechanical properties of a protective tube made of CFRP are not necessarily sufficient.

Patent Document 3 proposes a non-magnetic member made of a titanium-based composite material. The titanium-based composite material is made by dispersing reinforcing particles made of TiCy (0<y<1) in which some of the C is missing in a matrix made of Ti-6%Al-4%V, etc. This non-magnetic member has high resistivity, high strength, and high rigidity.

Incidentally, Patent Documents 4 to 8 also contain descriptions of titanium alloys or titanium-based composites, but there is no specific description of electromagnetic components or their resistivity, etc.

The present invention was made in consideration of these circumstances, and aims to provide non-magnetic components and the like that use titanium alloys that are different from conventional ones.

As a result of intensive research conducted by the inventors to solve this problem, they succeeded in obtaining a titanium alloy with a different composition from conventional ones, which exhibits high resistivity and high strength. By expanding on this result, they have completed the present invention, which is described below.

<Non-magnetic member>
(1) The present invention is a non-magnetic member used in an alternating magnetic field, comprising a titanium alloy containing, in terms of mass ratio relative to the entire alloy, an α-phase stabilizing element having an Al equivalent of 5.5 to 11 and a β-phase stabilizing element having a Mo equivalent of 6 to 17, wherein the β-phase stabilizing element contains Fe and Mn.

(2) The non-magnetic member (electromagnetic member) of the present invention comprises a titanium alloy that exhibits high resistivity and high strength. Therefore, even when used in an alternating magnetic field in the high frequency range (e.g., high rotation speed), the eddy current loss generated in the non-magnetic member is reduced. In addition, even when large forces (centrifugal forces, inertial forces, etc.) may act due to high-speed motion (rotation, reciprocation, etc.), the non-magnetic member can be made thinner, lighter, smaller, etc.

The reason why the titanium alloy according to the present invention exhibits high resistivity and high strength is not entirely clear. At present, it is believed that the α-phase stabilizing element with a high Al equivalent and the β-phase stabilizing element with a high Mo equivalent act synergistically to obtain a titanium alloy that combines high resistivity and strength. In particular, it is believed that the magnetic element Fe is dissolved in Ti to improve the resistivity of the non-magnetic titanium alloy. Also, assuming that the Al equivalent and Mo equivalent are within a specified range, it is believed that the strength of the titanium alloy is significantly improved by the inclusion of Mn.

<Production Method>
The present invention can also be understood as a method for manufacturing the above-mentioned non-magnetic member and titanium alloy. For example, when the titanium alloy is made of a sintered material, the non-magnetic member is obtained by a sintering process for obtaining a sintered body from powder and a processing process for forming the sintered body into a desired shape according to the non-magnetic member. Furthermore, the titanium alloy made of the sintered material can exhibit excellent high resistivity and high strength even if it is not necessarily subjected to a special heat treatment (e.g., solution treatment or aging treatment) after the processing process. Of course, the titanium alloy according to the present invention is not limited to a sintered material, and may be a melt-cast material.

"others"
(1) The α-phase stabilizing element in this specification is an alloying element that increases the allotropic transformation temperature (about 885°C) of pure titanium and expands the α-phase region. The β-phase stabilizing element is an alloying element that decreases the allotropic transformation temperature and expands the β-phase region. In other words, the α-phase stabilizing element is an element that appears in the calculation formula for the Al equivalent, and the β-phase stabilizing element is an element that appears in the calculation formula for the Mo equivalent. In this specification, even alloying elements (Sn, Zr, etc.) that are generally considered to be neutral elements (completely soluble elements) are treated as α-phase stabilizing elements or β-phase stabilizing elements as long as they are alloying elements that affect the allotropic transformation temperature or equivalent. Of course, the titanium alloy according to the present invention may further contain neutral elements (alloying elements that do not affect the allotropic transformation temperature) that do not affect the allotropic transformation temperature or equivalent.

The degree of "non-magnetic" (magnetic permeability) referred to in this specification may be within a range that does not short-circuit the magnetic circuit of an electromagnetic device. In this specification, electromagnetic components that contain a non-magnetic titanium alloy and are used in an alternating magnetic field are referred to as non-magnetic components. A non-magnetic component does not have to be entirely made of a titanium alloy, and does not necessarily have to be entirely non-magnetic. In short, the non-magnetic component of the present invention only needs to have at least a portion made of a titanium alloy.

(2) Unless otherwise specified, "x to y" in this specification includes a lower limit of x and an upper limit of y. Any numerical value included in the various numerical values or numerical ranges described in this specification may be used as a new lower limit or upper limit to create a new range such as "a to b." Additionally, "x to y μΩm" in this specification means x μΩm to y μΩm. The same applies to other units (MPa, GPa, etc.).

1 is a structural photograph (SEM image) of the titanium alloy of sample 2. This is an enlarged photograph (SEM image) of the structure. 1 is a structural photograph (SEM image) of the titanium alloy of sample 3. FIG. 2 is an explanatory diagram showing a method for measuring resistivity.

One or more components selected from this specification may be added to the components of the present invention described above. The contents described in this specification apply not only to non-magnetic members, but also to their manufacturing methods. They may also be method-related components or product-related components. Which embodiment is best depends on the target, required performance, etc.

Titanium alloy
(1) Composition The titanium alloy may contain an α-phase stabilizing element with an Al equivalent of 5.5 to 11, 6 to 10, 7 to 9.5, or even 8 to 9 (or less), and a β-phase stabilizing element with an Mo equivalent of 6 to 17, 6.5 to 15, 7 to 12, or even 8 to 11.5. If the Al equivalent is too small, the resistivity will be insufficient, and if it is too large, the elongation will be small. If the Mo equivalent is too small, the strength will be insufficient, and if it is too large, the elongation will be small.

Here, the Al equivalent ([Al”eq) and Mo equivalent ([Mo”eq) are calculated as follows (Source: Light Metals, Vol. 55, No. 2 (2005), pp. 97-102):
[Al” eq=[Al]+[Zr]/6+[Sn]/3+10[O]+16.4[N]+11.7[C]
[Mo” eq=[Mo]+[Ta]/5+[Nb]/3.5+[W]/2.5+[V]/1.5+1.25[Cr]
+1.25[Ni]+1.7[Mn]+1.7[Co]+2.5[Fe]
However, in the present invention, unless otherwise specified, the Al equivalent is defined based on Al, Zr, and Sn, which are the main α-phase stabilizing elements ([Al] eq = [Al] + [Zr]/6 + [Sn]/3).

Unless otherwise specified, the composition ratio (concentration) referred to in this specification is a mass ratio (mass%) and is simply indicated as "%". The brackets [ ] in the above calculation formula indicate the mass ratio (%) of each alloy element to the entire titanium alloy. In the case of a titanium-based composite material in which reinforcing particles (e.g., TiC, TiB, etc.) are included in the titanium alloy (matrix), the Al equivalent and Mo equivalent are calculated as the mass ratio to the entire matrix.

The α-phase stabilizing element may be, for example, Zr, Sn (neutral element), etc., in addition to Al. A representative example is Al, which may be contained in an amount of, for example, 7 to 10% or even 8 to 9% of the entire titanium alloy (100% by mass).

Beta phase stabilizing elements include, for example, Mo, V, Mn, Fe, etc. A typical example of Mo is 1-5% or even 1.5-4% of the total titanium alloy, and V may be 4-8% or even 5-7%.

The titanium alloy may also contain 0.5-3.5%, 0.9-3%, or even 1-2.5% Fe, which contributes to improving resistivity, and 0.2-3%, 0.4-2.5%, or even 0.5-1.5% Mn, which contributes to improving strength.

Furthermore, the titanium alloy may contain 0.1-1%, 0.2-0.7%, or even 0.3-0.5% S, which contributes to improving machinability, relative to the entire titanium alloy. Although S is not essential, the inclusion of S can improve machinability. However, excessive S can embrittle the titanium alloy.

Titanium alloys contain impurities (e.g., O, N, etc.) that are technically and economically difficult to remove or unavoidable. For example, O may be contained in an amount of about 0.1 to 0.7%, or even 0.2 to 0.5%, relative to the total amount of the titanium alloy.

(2) Structure The metal structure of a titanium alloy (simply referred to as "structure") can change depending on the manufacturing process and heat treatment. The structure differs depending on whether the material is melt-cast or sintered, and even in the case of sintered materials, it differs depending on the presence or absence of heat treatment and the heat treatment conditions. However, since the titanium alloy according to the present invention has a sufficiently large Al equivalent and Mo equivalent, it is likely to have a metal structure in which α phase and β phase are mixed, regardless of the specific form.

As an example, in a titanium alloy made of sintered material, a composite structure is obtained in which a hexagonal close-packed lattice structure (referred to as "hcp structure") is distributed in islands in a body centered cubic lattice structure (referred to as "bcc structure") (see FIG. 1A). The bcc structure is mainly composed of β phase, and the hcp structure is mainly composed of α phase. More specifically, the bcc structure is mainly composed of Ti, which is a base element, and one or more β phase stabilizing elements (Mo, Fe, V, etc.). The hcp structure is mainly composed of Ti, which is a base element, and one or more α phase stabilizing elements (Al, etc.). The bcc structure may contain one or more α phase stabilizing elements. Similarly, the hcp structure may contain one or more β phase stabilizing elements.

The hcp structure accounts for, for example, 30-70%, 37-67%, or even 43-60% by volume of the entire composite structure. Incidentally, the hcp structure is, for example, an aggregate of needle-like or granular ultrafine structures. For example, each ultrafine structure has a maximum length of 2 μm or less, or even 1 μm or less, and an aspect ratio (maximum length/minimum length) of 3-20 or even 5-10. The volume fraction, size, and aspect ratio of each structure (phase) are determined by analyzing (calculating) two-dimensional optical microscope photographs (images) using analysis software: ImageJ (an open source program).

The composite structure described above is a structure not seen in conventional titanium alloys. However, the correlation between the structure of titanium alloys and their properties (resistivity, strength, etc.) is currently unclear.

(3) Characteristics Titanium alloys exhibit excellent electrical and mechanical characteristics. For example, they exhibit resistivities of 2 to 5 μΩm, 2.1 μΩm to 4 μΩm, and even 2.2 μΩm to 3 μΩm. Such resistivities are far greater than the resistivity of pure Ti (about 0.4 μΩm) and the resistivity of a typical titanium alloy (Ti-6%Al-4%V) (about 1.7 μΩm). In this specification, the resistivity is determined by measuring a sample (bulk material) of a given size using a DC four-terminal method (see FIG. 3), unless otherwise specified.

Titanium alloys can exhibit high strength, for example, a tensile strength (breaking strength) of 1200 to 1700 MPa, 1250 to 1650 MPa, or even 1350 to 1550 MPa, and a 0.2% yield strength of 1150 to 1600 MPa or even 1200 to 1500 MPa. Titanium alloys can also exhibit high rigidity, for example, a Young's modulus of 115 to 135 GPa or even 120 to 130 GPa.

Furthermore, titanium alloys have an elongation of, for example, 0.2 to 2% or even 0.4 to 1.5%, and can be plastically processed into non-magnetic components.

<Production Method>
The titanium alloy (non-magnetic member) can be manufactured by, for example, a sintering method, a melting method, a (powder) additive manufacturing method (so-called 3D printer), etc. As an example, the case of manufacturing a titanium alloy by a sintering method will be described below.

The sintering method is a method in which a powder compact is heated to obtain a sintered body. If the compact or sintered body is close to the shape of a non-magnetic material (i.e., near-net shape), post-processing can be reduced. Of course, the sintered body may be subjected to plastic processing such as forging or pressing in a cold or hot state.

(1) Powder Generally, a mixed powder obtained by blending (weighing) a plurality of kinds of raw material powders is used for molding and sintering. In addition to simple substance powder, alloy powder, compound powder, etc. are used as the raw material powder. For example, Ti source powder (pure Ti powder) is an example of the simple substance powder. For example, Al-V powder, Ti-Al powder, Fe-Mo powder (ferromolybdenum powder), etc. are examples of the alloy powder. For example, Mn-S powder (manganese sulfide powder), Fe-Mn powder (ferromanganese powder), etc. are examples of the compound powder. Note that even powders of the same type with the same alloy elements have various composition ratios. An appropriate raw material powder may be selected according to the desired blend composition. In any case, by using alloy powder or compound powder rather than simple substance powder, it is possible to reduce raw material costs and to homogenize and stabilize the structure.

The average particle size (median diameter: D50) of each powder may be, for example, 1 to 20 μm, or even 3 to 15 μm. The mixed powder is prepared using a V-type mixer, a ball mill, a vibration mill, or the like (mixing process).

(2) Molding process The mixed powder is molded in a die, CIP (Cold Isostatic Pressing), RIP (Rubber Isostatic Pressing), or the like to form a molded body of a desired shape. The shape of the molded body may be close to the shape of the final member (non-magnetic member), or may be a billet shape (intermediate material shape) when processing is performed after the sintering process. The molding pressure can be adjusted as appropriate, but is preferably, for example, 200 to 600 MPa, or further 300 to 400 MPa.

(3) Sintering process The compact is heated in a vacuum or in an inert gas to become a sintered body. The sintering temperature is, for example, 1150°C to 1400°C, or 1200°C to 1350°C. The sintering time is, for example, 3 to 25 hours, or 10 to 20 hours. By using an appropriate sintering temperature and sintering time, a titanium alloy with high properties can be efficiently obtained. The above-mentioned molding process and sintering process may be performed simultaneously by HIP (Hot Isostatic Pressing) molding.

(4) Cooling process After the sintering process, the material may be cooled by furnace cooling or forced cooling (by introducing an inert gas, etc.) at a rate of, for example, 0.1 to 10°C/s. The structure and properties of the titanium alloy may be adjusted by controlling the cooling rate.

(5) Processing step The sintered body may be used as a non-magnetic member as it is, or may be processed into a non-magnetic member by plastic processing, cutting, or the like. The plastic processing may be cold processing or hot processing. Hot processing can prevent cracks and the like and allows the production of non-magnetic members with a high yield. Cooling after hot processing may be furnace cooling, but air cooling is also sufficient.

The titanium alloy according to the present invention can exhibit the desired structure and characteristics without the need for heat treatment such as solution treatment or aging treatment. Such non-heat-treatable titanium alloys contribute to reducing the manufacturing costs of non-magnetic components.

<Non-magnetic parts/electric devices>
The non-magnetic member of the present invention has high resistivity, high strength, and low magnetic permeability, and is therefore suitable as an electromagnetic member used in an alternating magnetic field. Its specific use does not matter, but it can be used, for example, as a protective member (protective tube, protective case) for a permanent magnet (field source) incorporated in an electric motor (electromagnetic device, electric device) (see JP 2020-43746 A, mentioned above). An example of such an electric motor is a centrifugal compressor that requires high rotation. Such a compressor is used, for example, in an engine supercharger or an air compressor for a fuel cell.

Various samples (sintered titanium alloys) with different component compositions were produced, and their electrical properties (resistivity) and mechanical properties (tensile strength, 0.2% yield strength, Young's modulus, elongation) were evaluated. The present invention will be described in more detail below, using these specific examples.

<Sample Preparation>
(1) Raw Powder The Ti powder used was a commercially available hydrogenated/dehydrogenated powder (manufactured by Toho Tech Co., Ltd.) that had been classified using a sieve (#350, average particle size 75 μm).

As the alloy powders serving as the alloying element sources, one or more of the following powders were used.
(a) Al-40% V powder (average particle size: 9 μm/Kinsei Matec Co., Ltd.)
(b) Ti-36% Al powder (average particle size: 9 μm/manufactured by Daido Steel Co., Ltd.)
(c) Fe-60%Mo powder (average particle size: 45 μm/manufactured by Taiyo Koko Co., Ltd.)
(d) MnS powder (average particle size: 9 μm/manufactured by Fukuda Metals Co., Ltd.)
(e) Fe-78% Mn powder (average particle size: 10 μm/manufactured by Fukuda Metals Co., Ltd.)

Unless otherwise specified, the compositions shown in this example are the mass percentages (mass%) of each raw material powder or mixed powder relative to the total, and are simply indicated as "%". The average particle size of each powder was determined using a laser diffraction/scattering type particle size distribution measuring device (MT3300EX/manufactured by Nikkiso Co., Ltd.). Each powder may contain a small amount of oxygen (impurity) that is inevitably adsorbed or bonded to the particle surface.

(2) Mixing step Each raw material powder was weighed and mixed so as to obtain the overall composition (Al equivalent, Mo equivalent) shown in Table 1 (excluding samples C4 and C5). Each mixed powder was mixed in a V-type mixer for 1 hour to obtain a mixed powder for each sample.

(3) Molding Step Each mixed powder was placed in a polyvinyl chloride tube (PVC) and molded by CIP to obtain a round bar-shaped molded body (approximately φ16 mm×150 mm) under a molding pressure of 4 t/cm ² (392 MPa).

(4) Sintering step Each compact was sintered by heating (1300°C x 16 hours) in a vacuum (1 x ^10-5 torr). The heating rate up to the sintering temperature was about 5°C/min, and the cooling rate after the sintering time was 10°C/s.

(5) Processing step Furthermore, the sintered bodies of each sample were hot worked (forged) in an air atmosphere. The heating temperature was 1200°C, and the working ratio was 56%. The working ratio was calculated by the reduction in area (Aw/Ao). Aw is the cross-sectional area after working, and Ao is the cross-sectional area before working.

After hot working, the sintered bodies (worked products) were cooled in the air to lower the temperature, and no heat treatment was performed after air cooling. Various measurements and observations were performed using each test material (billet) obtained in this way.

(6) Ingot material (Comparative example)
For samples C4 and C5 shown in Table 1, commercially available ingots (manufactured by Daido Steel Co., Ltd.) were used as test materials as they were.

"measurement"
(1) Electrical properties (resistivity)
The resistivity of each sample was determined as shown in FIG. 3. Specifically, first, electrodes were formed on a prism (3.014 mm (t) × 3.014 mm (w) × 20 mm) made from each test material as follows. The center part of each prism (voltage electrode interval (L): 10 mm) was masked with masking tape. Terminal wires (silver wire: φ0.20 mm) were wound around the masked end parts and the two outer parts, which are four places (see FIG. 3). Silver paste (Dotite D-550, manufactured by Fujikura Kasei Co., Ltd.) was applied to the parts where the terminal wires were wound and to both end faces of the prism. After application, the prism was heated in the air at 100°C for 12 hours to dry. In this way, a test piece equipped with a current electrode and a voltage electrode was prepared.

The resistivity (electrical resistivity) of each sample was calculated from the voltage (V) and current (I) values measured for each test piece by the DC four-terminal method at room temperature and the cross-sectional shape (S = t x w) of the test piece (rectangular column) (see formula (1) in Figure 3). The resistivity (measured value) of each sample thus obtained is also shown in Table 1.

(2) Mechanical properties (Young's modulus, tensile strength, elongation)
A tensile test was carried out using a round bar tensile test piece (parallel part diameter: φ2.4 mm, gauge length: 14 mm) made from the test material, with an autograph (AUTOGRAPH AG-1 50 kN, manufactured by Shimadzu Corporation).

The tensile test was carried out at room temperature in air at a strain rate of 5×10 ^-4 /s. The mechanical properties of each sample were determined based on the stress-strain relationship calculated from the load-stroke diagram obtained from the load cell and video extensometer in this tensile test (see JIS Z 2241:2011). The results are also shown in Table 1. The tensile strength was calculated based on the load at break and the initial shape of the test piece. The elongation is the strain of the test piece at break.

"observation"
(1) The structure of the test material before the tensile test was observed by a SEM (Scanning Electron Microscope). As an example, the observation image (SEM image) of Sample 2 is shown in Fig. 1A and Fig. 1B. Also, the SEM image of Sample 3 is shown in Fig. 2. Both Fig. 1B and Fig. 2 show an enlarged island structure.

(2) SEM images of the structures before the tensile tests were analyzed using ImageJ to determine the proportion of island structures in each sample. The results are shown in Table 1.

(3) X-ray diffraction The structure before the tensile test was subjected to X-ray diffraction analysis (XRD/Cu-Kα). As a result, it was found that the island structure was a hcp structure with a hexagonal close-packed lattice structure, and the base structure surrounding it was a bcc structure with a body-centered cubic lattice structure.

"evaluation"
(1) Characteristics As is apparent from Table 1, the titanium alloys of Samples 1 to 5, which had both an Al equivalent and Mo equivalent within the prescribed range and contained Fe and Mn, had high resistivity and high strength.

Furthermore, titanium alloys that do not contain S, such as sample 5, have high resistivity, high strength, and high ductility even without heat treatment. Specifically, the titanium alloy exhibits a tensile strength of 1600 MPa or more and an elongation of 1% or more, achieving a high level of compatibility between strength and elongation, which are generally in a trade-off relationship.

On the other hand, samples C1 and C2, which had a small Mo equivalent, had insufficient strength. Samples C4 and C5, which had a small Al equivalent, had at least insufficient resistivity. Furthermore, sample C3 had high resistivity because the Al equivalent and Mo equivalent were within the specified range, but because it did not contain Mn, its strength (especially 0.2% yield strength) was insufficient.

(2) Structure As is clear from Figure 1A and Table 1, it was found that samples 1 to 5 have a composite structure in which many island-shaped hcp structures (simply referred to as "island structures") are surrounded by bcc structures. Also, as can be seen from Figure 1B and Figure 2, it was found that the island structures are composed of an aggregate of needle-shaped or fibrous (ultra) fine structures. It was also found from the SEM images that each fine structure has a maximum length of 2 μm or less and an aspect ratio of 5 or more.

In addition, it was confirmed through actual machining that the titanium alloys of samples 1 to 4 all have better machinability than the titanium alloys of samples C1 to C5.

From the above, it was found that titanium alloys containing Fe and Mn, with both the Al equivalent and Mo equivalent within the specified range, have high resistivity and high strength, and are suitable for non-magnetic electromagnetic components (non-magnetic components). It was also found that such titanium alloys have a unique structure in which a hcp structure (island structure) consisting of a collection of fine structures is dispersed in a bcc structure.

Claims (10)

A non-magnetic member used in an alternating magnetic field,
A non-magnetic member comprising a titanium alloy containing an α-phase stabilizing element having an Al equivalent of 7 to 11 and a β-phase stabilizing element having a Mo equivalent of 6 to 17 , the composition ratio being as follows, in terms of mass ratio relative to the entire alloy:
Al: 7 to 10%,
Mo: 1 to 5%,
Fe: 0.5-3.5%,
Mn: 0.2-3%,
The balance is Ti and impurities. 2. The non-magnetic member according to claim 1, wherein the titanium alloy further contains 4 to 8% V by mass relative to the total mass of the titanium alloy. The non-magnetic member according to claim 1 or 2, wherein the titanium alloy further contains 0.1 to 1% S by mass relative to the total mass of the titanium alloy. The non-magnetic member according to any one of claims 1 to 3, wherein the titanium alloy is a composite structure in which a hexagonal close-packed lattice structure (referred to as an "hcp structure") is distributed in islands within a body-centered cubic lattice structure (referred to as an "bcc structure"). The non-magnetic member according to claim 4, wherein the hcp structure is 30 to 70 volume % of the entire composite structure. The non-magnetic member according to any one of claims 1 to 5, wherein the titanium alloy has a resistivity of 2 μΩm or more. The non-magnetic member according to any one of claims 1 to 6, wherein the titanium alloy has a 0.2% yield strength of 1150 MPa or more. The non-magnetic member according to any one of claims 1 to 7, wherein the titanium alloy is made of a sintered material. 9. A method for producing a non-magnetic member according to claim 8, comprising the steps of:
a sintering step for obtaining a sintered body from the powder;
and a processing step of forming the sintered body into a desired shape corresponding to the non-magnetic member.
The method for producing a non-magnetic member includes obtaining the titanium alloy without at least performing a solution treatment after the processing step. The method for manufacturing a non-magnetic member according to claim 9, wherein the powder contains at least ferromolybdenum powder and manganese sulfide powder.