WO1999049095A1

WO1999049095A1 - Titanium-based amorphous alloy

Info

Publication number: WO1999049095A1
Application number: PCT/JP1999/001469
Authority: WO
Inventors: Akihisa Inoue
Original assignee: Japan Science And Technology Corporation
Priority date: 1998-03-25
Filing date: 1999-03-24
Publication date: 1999-09-30
Also published as: JP3933713B2

Abstract

A titanium-based amorphous alloy which has a composition represented by the formula Ti¿100-a-b-c?ZraTMbMc (wherein TM represents at least one element selected from the group consisting of Fe, Co, Ni, and Cu; M represents at least one element selected from the group consisting of Al, Si, Sn, and Sb; and a, b, and c respectively are numbers in at.% satisfying the relationships 0≤a≤20, 30≤b≤70, 0∫c≤10, and 30≤a+b+c≤70) and has a wide range where a supercooled liquid having an amorphous-phase content of 90 vol.% or higher is present. It has an excellent tensile strength.

Description

Description Ti-based amorphous alloy Technical field

The present invention relates to a Ti-based amorphous alloy having a wide supercooled liquid region and excellent tensile strength. Background art

It is well known that an amorphous metal material having various shapes such as a ribbon shape, a filament shape, and a granular material shape can be obtained by rapidly cooling a molten alloy. Amorphous alloy ribbons can be easily manufactured by a single-roll method, twin-roll method, spinning in liquid spinning method, etc., which can provide a large cooling rate. Numerous amorphous alloys have been obtained for Co, Pd, Cu, Zr and Ti alloys, revealing the unique properties of amorphous alloys such as high corrosion resistance and high strength. It has been. Above all, Ti-based amorphous alloys have much better corrosion resistance than other amorphous alloys and are less harmful to the human body. It is expected to be applied to fields such as medical materials and chemical materials. However, amorphous alloys obtained by the above-described manufacturing method are limited to ribbons and thin wires, and it is difficult to process them into a final product shape using them. Was quite limited.

On the other hand, when an amorphous alloy is heated, the supercooled liquid It is known that the state changes to a viscous state and shows a sharp decrease in viscosity. For example, it has been reported that a Zr—A1-Ni1-Cu amorphous alloy can exist as a supercooled liquid region at a heating rate of 40 ° C per minute for about 120 ° C before crystallization. Trans. J IM, Vol. 32 (1991) 1005). In such a supercooled liquid state, since the viscosity of the alloy is reduced, it is possible to produce an amorphous alloy compact having an arbitrary shape by a method such as closed forging, and is made of an amorphous alloy. Gears are also manufactured (see Nikkan Kogyo Shimbun, January 12, 1999, January 12). Therefore, it can be said that an amorphous alloy having a wide supercooled liquid region has excellent workability. Among such amorphous alloys having a supercooled liquid region, Ti-Ni-Cu alloy has a temperature range of a supercooled liquid region of 50 ° C or more, and has excellent practicality such as excellent corrosion resistance. It was considered to be a highly amorphous alloy (see the 110th Abstract of the Annual Meeting of the Japan Institute of Metals (1992), paragraph 273). In addition, the workability and mechanical properties of these amorphous alloys have been improved, and the Ti-Ni-Cu- () has a supercooled liquid region of 50 ° C or higher and a strength exceeding 100 OMPa. Fe, Co, Zr, and Hf) -based amorphous alloys have been developed and are known (JP-A-6-264199 and JP-A-6-264200). Disclosure of the invention

(Problems to be solved by the invention)

The aforementioned Ti-Ni-Cu-based and Ti-Ni-Cu- (Fe, Co, Zr, Hi) -based amorphous alloys have a supercooled liquid region above 30 ° C. 00 Amorphous alloy shape obtained because of its low amorphous forming ability, although having strength exceeding OMPa However, they were limited to ribbons, filaments, and powders, and could not be said to have dimensions that could be applied to general industrial materials.

(Means to solve the problem)

In order to solve the above-described problems, the present inventors have developed an amorphous material that can achieve practical strength and dimensions that can be applied to industrial materials without impairing the temperature range of the supercooled liquid region. As a result of diligent research aimed at providing a Ti-based amorphous alloy material having both forming ability, a Ti-TM system having a specific composition [TM _: a group consisting of FeCoNi and Cu One or two or more elements selected from the group consisting of 特定 1 ", ぴ 1 Si S n and S b By melting the alloy and rapidly solidifying it from the liquid state, it was found that a Ti-based amorphous alloy having both practical strength and large amorphous forming ability was obtained, and completed the present invention. Reached.

That is, the present invention provides a compound represented by the formula: TiZra TMb Mc wherein TM is one or more elements selected from the group consisting of FeCoNi and Cu, and M is A l is one or more elements selected from the group consisting of S i S n and S b, ab and c each represent atomic%, 0≤a≤20 30≤b≤70, 0 < c≤10, 30≤a + b + c≤70] is provided. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of the present invention will be described.

In the Ti-based amorphous alloy according to the present invention, TM is FeCoNiCuCu. is one or more elements selected Ri _chi, the content of this element group 3 0 Nuclear ^_0/0 or 7 0 atomic% or less, preferably 35 atomic% or more 6 5 atomic% It is as follows. If the content of this element group is less than 30 at% and more than 70 at%, no amorphous phase is formed even by a single roll method with a high cooling rate. If the content of this element group is less than _{35 c at} % and more than 75 at%, a supercooled liquid region is not exhibited, and workability is deteriorated. Μ is one or more element group selected from Al, Si, Sn and Sb. When the content of this element group is 0 atomic%, the single-roll method with a large cooling rate Although an amorphous phase is formed, the ability to form an amorphous phase is not improved, and an amorphous alloy block cannot be obtained by other methods such as mold construction. On the other hand, if it exceeds 10 atomic%, the supercooled liquid region 0 will not be exhibited. Although Zr is not necessarily an essential element, the alloy of the present invention can improve the ability to form an amorphous phase by adding Zr.

The term “supercooled liquid region” in this specification is defined as the difference between the glass transition temperature and the crystallization temperature obtained by performing differential scanning calorimetry at a heating rate of 40 ° C. per minute. The “converted vitrification temperature” is defined as a value obtained by dividing the glass transition temperature obtained by the above calorimetric analysis by the melting point of the total metal. The “supercooled liquid region” is a numerical value indicating workability, and the “converted vitrification temperature” is a numerical value indicating the easiness of becoming amorphous. The alloy of the present invention has a supercooled liquid region of 30 ° C or higher and a reduced vitrification temperature of 0.55 or higher.

The Ti-based amorphous alloy of the present invention is cooled and solidified from the molten state by various methods such as a single roll method, a twin roll method, a spinning method in a rotating liquid 0, an atomizing method, etc. A body-shaped amorphous solid can be obtained. However, since the amorphous solid is inferior to other amorphous alloys in the ability to form an amorphous phase, an amorphous solid of the above-mentioned form can be obtained. ! Gold bullion could not be made. Since the alloy of the present invention has a remarkable improvement in the ability to form an amorphous phase from a conventional Ti-based amorphous alloy, preferably, the molten alloy is filled in a mold so that the cross section is circular. A columnar amorphous alloy ingot having a diameter of 0.8 mm, that is, a cross-sectional area of 0.5 mm ² can be obtained. Further, by changing the mold shape, an amorphous alloy lump having a cross-sectional area of 0.5 mm ² or more of an arbitrary shape can be obtained.

For example, typical in the mold铸造method, filling the alloy was melted in an argon atmosphere in a quartz tube, the molten alloy jet pressure 0. 5~2. 0 k gZc m ² in copper mold By solidifying, an amorphous alloy lump can be obtained.

Further, by making the Ti-based amorphous alloy into a molten state and atomizing it, it is possible to obtain an amorphous single-phase powder having a particle size of 750 μιη or less. By extruding the Ti-based amorphous alloy powder at a temperature 20 to 3 OK higher than the glass transition temperature (Tg), a Ti-based amorphous alloy lump can be obtained. If the extrusion temperature is higher than this, extrusion becomes difficult.

(Examples 1 to 11, Comparative Examples 1 to 4)

5 Examples of the present invention will be described below.

An alloy composition shown in Table 1 material (Example 1 one 1 1, Comparative Examples 1 to 5) and the single-ended Lumpur method and mold錶造method to produce an alloy ingot sample in the ribbon-shaped and the diameter 1 mm _c The glass transition temperature (Tg), crystallization onset temperature (Tx), and melting point (Tm) of the ribbon-shaped sample were measured by differential scanning calorimetry. From these values, the supercooled liquid region (Tx-T 0 g) and the reduced vitrification temperature (Tg / Tm) were calculated. In addition, the confirmation of the amorphization of the 1-mm-diameter alloy ingot produced by the die-casting method was performed by X-ray diffraction and optical microscope observation of the sample cross section. In addition, the volume fraction of the amorphous phase contained in the sample (V f-amo) was evaluated for its calorific value during crystallization using differential scanning calorimetry with that of a single-aperture foil strip that was completely amorphized. Further, a tensile test piece was prepared by machining, and the breaking strength (σ f) was evaluated by a tensile test.

As is clear from Table 1, the amorphous alloys of Examples 1 to 11 show a supercooled liquid region of 30 ° C or more, a reduced vitrification temperature of 0.55 or more, and a non- The crystalline alloy ¾ also has a strength exceeding 180 OMPa.

(table 1)

On the other hand, since the alloy of Comparative Example 1 does not contain the elements of Group M, the amorphous volume fraction is not only less than 90%, but also has a strength of only 163 OMPa. Comparative Example 2 In alloys No. 3 and No. 3, since the elements in Group M exceed 10 atomic%, the supercooled liquid region has a force of less than 30 ° C and the volume fraction of the amorphous phase in the ribbon shape by the single roll method is low. Only about 65% can be obtained. In the alloy of Comparative Example 4, since the total content of the elements in the M group and the TM group exceeds 70 atomic%, the volume fraction of the amorphous phase contained in the alloy lump having a diameter of 1 mm is less than 60%. Since the alloy ingot is brittle and cannot be subjected to a tensile test, it has no mechanical properties that can withstand practical use.

(Example 12)

The Ti-based amorphous alloy was melted at 1600 K and atomized with He gas at a gas pressure of 9.8 MPa to obtain an amorphous single-phase powder having a particle size of 75 / zm or less. The alloy composition of this powder is Ti ₄₅ Zr ₅ Cu ₂₅ Ni ₂ . S n ₅ (same as in Example 2). This powder was sealed in a copper can with an outer diameter of 23 mm and an inner diameter of 20 mm, and after vacuum degassing, the extrusion temperature: Tg (= 705 K) + 20K = 725Κ, the extrusion speed: 0.5 mmZs Extrusion molding was performed at each extrusion ratio shown in Table 2. Table 2 shows the results. The extrusion ratio 1 was obtained by hot pressing a 20 mm φ compact at 1 GPa. As can be seen from these results, extrusion ratios of 4 and 5 are preferred.

(Table 2)

Extrusion ratio 1 2 3 4 5 6 Density 99.2 99.4 99.5 99.7 99.8

V f — a m o 1 00 1 0 0 1 00 1 00 1 0 0

σ f / MP a 480 1 3 2 0 1 8 00 1 880 1 9 00

(Example 13)

Extrusion molding was performed under the same conditions as in Example 12, except that the extrusion temperature was set to Tg 705K) + 30K = 735K. Table 3 shows the results. As can be seen from this result, an extrusion ratio of 4 is preferable.

(Table 3)

(Comparative Example 5)

Extrusion molding: Extrusion molding was performed under the same conditions as in Examples 12 and 13, except that Tg (= 705K) + 40K = 745K. In this case, extrusion was not possible. Industrial applicability The Ti-based amorphous alloy of the present invention exhibits a supercooled liquid region of 30 ° C. or more, a reduced vitrification temperature of 0.55 or more, and 180 MPa of amorphous alloy ingot having a diameter of 1 mm. It shows a strength exceeding. For these reasons, it can be used for various applications as a Ti-based amorphous alloy having excellent glass-forming ability, workability, and mechanical strength.

Claims

The scope of the claims

1. Formula: T i loo-abc Z ra TMb Mc [where TM is one or more elements selected from the group consisting of Fe, Co, Ni, and Cu, and M is A l, S

1. One or more elements selected from the group consisting of Sn and Sb, where a, b and c represent atomic%, respectively, 0≤a≤20, 30≤b≤70, 0

<c≤l0, 30≤a + b + c≤70], and a Ti-based amorphous alloy containing 90% or more by volume fraction of an amorphous phase.

2. The supercooled liquid region [indicated by the difference between the crystallization onset temperature and the glass transition temperature] of 30 or more and the reduced vitrification temperature [glass transition temperature / no melting point] of 0.55 or more. The described Ti-based amorphous alloy.

3. The Ti-based amorphous alloy ingot according to claim 1, having a cross-sectional area of 0.5 mm ² or more and a tensile strength of 180 OMPa or more.

4. The Ti-based amorphous alloy according to any one of claims 1 to 3, wherein the Ti-based amorphous alloy is manufactured by extruding a Fen alloy.