HK1232922B - Nickel-free zirconium and/or hafnium-based bulk amorphous alloy - Google Patents

Description

Nickel-free zirconium and/or hafnium-based bulk amorphous alloys

Technical Field

The present invention relates to bulk amorphous alloys.

The invention further relates to a timepiece component made from an alloy of this type.

The invention also relates to a watch comprising at least one such assembly.

The invention relates to the fields of watchmaking and jewellery, and in particular to the following structures: watch cases, case middles, main plates, bezels, push buttons, crowns, buckles, bracelets, rings, earrings and the like.

Background Art

Amorphous alloys are increasingly used in the watchmaking and jewelry sectors, particularly in the following structures: watch cases, case middles, main plates, bezels, buttons, crowns, buckles, bracelets, rings, earrings, etc.

Particularly due to the toxicity or sensitizing effects of some metals, particularly beryllium and nickel, externally applied components that come into contact with the user's skin must adhere to certain restrictions. Despite the inherent properties of these metals, efforts are underway to commercialize alloys that contain little or no beryllium or nickel, at least for components that are likely to come into contact with the user's skin.

Zirconium-based bulk amorphous alloys have been known since the 1990s. The following publications deal with such alloys:

[1] Zhang et al., Amorphous Zr-Al-TM (TM=Co, Ni, Cu) Alloys with SignificantSupercooled Liquid Region of Over 100K, Materials Transactions, JIM, Vol. 32, No. 11 (1991) pp. 1005-1010.

[2] Lin et al., Effect of Oxygen Impurity on Crystallization of an Undercooled Bulk Glass Forming Zr-Ti-Cu-Ni-Al Alloy, Materials Transactions, JIM, Vol. 38, No. 5 (1997) pp. 473-477.

[3]U.S. Patent No. 6,592,689.

[4] Inoue et al., Formation, Thermal Stability and MechanicalProperties ofBulk Glassy Alloys with a Diameter of 20mm in Zr-(Ti,Nb)-Al-Ni-Cu System, Materials Transactions, JIM, Vol. 50, No. 2 (2009) pp. 388-394.

Amorphous alloys with optimal glass forming ability, known and hereinafter referred to as "GFA" and associated with a critical diameter D _c *, exist in the following systems:

-Zr-Ti-Cu-Ni-Be,

- and Zr-Cu-Ni-Al.

The compositions of the most commonly used/characterized alloys are listed below (in atomic %):

-Zr44Ti11Cu9.8Ni10.2Be25(LM1b)

-Zr65Cu17.5Ni10Al7.5[1]

-Zr52.5Cu17.9Ni14.6Al10Ti5(Vit105)[2]

-Zr57Cu15.4Ni12.6Al10Nb5(Vit106) and Zr58.5Cu15.6Ni12.8Al10.3Nb2.8(Vit106a)[3]

-Zr61Cu17.5Ni10Al7.5Ti2Nb2[4]

Nickel's sensitizing potential precludes the use of these alloys in applications involving skin contact, such as watch exteriors. Furthermore, due to beryllium's toxicity, the manufacture and machining of some of these alloys require special precautions. This is unfortunate, as both elements stabilize the amorphous phase and make it easier to obtain alloys with a high critical diameter, D _c *. Furthermore, nickel has a positive effect on the corrosion resistance of zirconium-based amorphous alloys.

However, the critical diameter of nickel- and beryllium-free zirconium-based amorphous alloys is generally lower than that of alloys containing nickel and beryllium, which is not conducive to the manufacture of solid components. Therefore, it is necessary to develop alloys with sufficient critical diameter D _c *.

Summary of the Invention

The present invention proposes the production of nickel-free or both nickel-free and beryllium-free zirconium-based and/or hafnium-based bulk amorphous alloys for horological applications.

The present invention proposes to increase the critical diameter of zirconium-based and/or hafnium-based amorphous alloys that are at least nickel-free or both nickel-free and beryllium-free while maintaining a high ΔTx value (the difference between the crystallization temperature Tx and the glass transition temperature Tg).

The present invention relates to a nickel-free zirconium-based and/or hafnium-based bulk amorphous alloy according to claim 1, to which other elements are added in order to increase the critical diameter.

The invention also relates to a timepiece or jewelry component made from an alloy of this type.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will become apparent upon reading the following detailed description with reference to the accompanying drawings, in which:

- Figure 1 shows a schematic diagram of the measurement of the critical diameter D _c * in a conical sample;

- Figure 2 shows a schematic diagram of a timepiece made from the alloy of the invention.

DETAILED DESCRIPTION

The invention relates to the fields of watchmaking and jewellery, and in particular to the following structures: watch cases, case middles, main plates, bezels, push buttons, crowns, buckles, bracelets, rings, earrings and the like.

The present invention proposes to produce nickel-free or both nickel-free and beryllium-free zirconium- and/or hafnium-based bulk amorphous alloys for horological applications, these alloys according to the invention being designed to have properties similar to amorphous alloys containing nickel or nickel and beryllium.

The present invention proposes to increase the critical diameter of a zirconium-based and/or hafnium-based amorphous alloy that is at least nickel-free or both nickel-free and beryllium-free while maintaining a high ΔTx value.

"Z-free" means that the Z content in the alloy is preferably zero or very low, like an impurity, and is preferably less than or equal to 0.1%.

"Nickel-free alloy" herein refers to an alloy that does not contain nickel, ie, contains less than 0.1 atomic % nickel, and "nickel-free and beryllium-free alloy" refers to an alloy that contains less than 0.1 atomic % nickel and less than 0.1 atomic % beryllium.

The present invention therefore concerns the development of alloys comprising elements that replace nickel or replace nickel and beryllium, which do not cause problems in contact with the skin and have high values of the critical diameter D _c * and high values of ΔTx.

The present invention therefore relates to nickel-free zirconium-based and/or hafnium-based bulk amorphous alloys, to which specific components are added in order to increase the critical diameter D _c *.

In fact, experiments conducted on the present invention have determined that the probability of obtaining a high-quality external timepiece component made of an amorphous alloy with a given thickness E is closely related to the critical diameter D _c * of the amorphous alloy. In a particularly advantageous embodiment, the advantages of the critical diameter D _c * are maximized. The critical diameter D _c * is preferably greater than 1.8 times the thickness E. More specifically, the critical diameter D _c * is close to twice the thickness E, in particular between 1.8E and 2.2E.

Various families of nickel-free compositions are known in the literature, but have low critical diameters and/or poor corrosion resistance.

A family of zirconium alloys comprising at least copper and aluminum, particularly Zr-Cu-Al and Zr-Cu-Al-Ag, is disclosed in the document "Mater Trans, Vol. 48, No. ₇ (2007) 1626-1630." Their known property is that the critical diameter can be increased from 8 mm _{to 12 mm by adding silver to the alloy, for example, by converting a Zr46Cu46Al8 alloy into a Zr42Cu42Al8Ag8 alloy . Due to the} high percentage of copper (ratio Cu/Zr≈1), this family of alloys has very poor corrosion resistance, and these compositions tend to discolor or darken over time, even at ambient temperature. These compositions do not contain iron.

US Patent 2013032252 discloses a family of zirconium-based alloys comprising at least titanium, copper, and aluminum, particularly Zr-Ti-Cu-Al and Zr-Ti-Nb-Cu-Al. The following alloys are particularly known: Zr _45-69 Ti _0.25-8 Cu _21-35 Al _7.5-15 and _{Zr 45-69} (Nb, Ti) _0.25-15 Cu _21-35 Al _7.5-13 , where 0.25 ≤ Ti ≤ 8. These compositions contain no iron. The critical diameters disclosed are less than 10 mm. It should be emphasized that the values shown in this document do not always correspond to reality. For example, in US Patent 2013032252, the optimal composition is found around Zr 60-62 Ti 2 Cu 24-28 Al 10-12. In contrast, the Zr61Ti2Cu26Al11 alloy, which should have a critical diameter of 10 mm, produced an embodiment of the invention during the experimental process according to the operating mode described below, with a critical diameter D _c * of only 4.5 mm. This casts deep doubt on the very optimistic results presented in some prior art documents.

A family of zirconium alloys of the Zr-Cu-Pd-Al type comprising at least palladium, copper and aluminum is known from WO patent application No. 2004022118, which discloses compositions containing 10% palladium, which are therefore very expensive. The critical diameter is still quite small. The composition does not contain iron.

WO Patent Application No. 013075829 discloses a family of zirconium alloys of the Zr-Nb-Cu-Al type, comprising at least niobium, copper, and aluminum. This family allows the production of amorphous alloys using less-than-perfect elements, such as technical zirconium instead of pure zirconium. Consequently, the composition also includes trace amounts of Fe, Co, Hf, and O: Zr _64.2-72, Hf _0.01-3.3 (Fe, Co), Nb _{1.3-2.4, O 0.01-0.13,} Cu _{23.3-25.5 ,} Al _3.4-4.2 (mass percentages). The critical diameter is approximately 5 mm.

The document "J Mech Behav Biomed, Vol. 13 (2012) 166-173" discloses a family of zirconium-based alloys of the Zr-Nb-Cu-Pd-Al type, comprising at least niobium, copper, palladium, and aluminum. This document relates to the development of amorphous alloys in the Zr _45+x Cu _40-x Al ₇ Pd ₅ Nb ₃ system. These compositions contain no iron. Tests conducted during the development of the present invention have demonstrated that these Zr-Nb-Cu-Pd-Al compositions are not corrosion-resistant.

The document "MSEA, Vol. 527 (2010) 1444-1447" discloses a family of zirconium-based alloys of the Zr-Cu-Fe-Al-Ag type, comprising at least copper, iron, aluminum, and silver. The document studies the effect of Fe on the thermophysical properties of an alloy (Zr ₄₆ Cu _39.2 Ag _7.8 Al ₇ ) _100-y Fe _y ) with 0 < y < 7. The high Cu/Zr ratio results in poor corrosion resistance.

A family of zirconium-based alloys of the Zr-Cu-Fe-Al-X type comprising at least copper, aluminum and silver is known from WO patent application No 2006026882, wherein X is at least one element from the group consisting of Ti, Hf, V, Nb, Y, Cr, Mo, Fe, Co, Sn, Zn, P, Pd, Ag, Au, Pt, which relates to the alloy Zr _33-81 Cu _6-45 (Fe,Co) _3-15 Al _5-21 -X _0-6 .

The same family is also known from Chinese patent document No 102534439, which more particularly relates to _{the alloy Zr 60-70 Ti 1-2.5} Nb _0-2.5 Cu _5-15 Fe _5-15 Ag _0-10 Pd _0-10 Al _7.5-12.5 .

In view of the limitations mentioned in the various literature disclosures, the development of the present invention required extensive experimental activities to improve the properties, especially the critical diameter, of nickel-free and beryllium-free nickel-free amorphous alloys.

Despite the theoretical prohibitive teachings regarding alloys of the Zr-Cu-Fe-Al-Ag or Zr-Cu-Fe-Al-X type that are incompatible with the regulations (especially with regard to the corrosion resistance that must be perfected for external timepiece components), the process of the present invention seeks to verify whether the specific role played by iron (by virtue of its favorable effect on the thermophysical properties of the alloy) can serve as the basis for determining a specific alloy composition having a critical diameter D _c * preferably greater than or equal to 9 mm, very good corrosion resistance and excellent color stability over time.

For this reason, the present invention only includes alloys containing at least 0.5% iron.

In practice, the Zr-Cu-Fe-Al system was chosen as a starting point because the literature teaches that this system has a relatively high glass forming ability (GFA) (higher than ternary Zr-Cu-Al alloys). Iron was chosen primarily for the following reasons:

- The fact of having four elements (Zr-Cu-Al+Fe) increases the complexity of the alloy (more difficult to form an ordered structure) and therefore increases its GFA;

Typically, the optimal composition is found near the deep eutectic point in the phase diagram. Iron is known to form a deep eutectic with Zr, and thermodynamic calculations have confirmed that iron lowers the liquidus in this quaternary system. The deep eutectic point is near Zr60Cu25Fe5Al10 and Zr62.5Cu22.5Fe5Al10;

- In addition, in order to increase the GFA, the energy of the mixture between the main elements must be negative (this is the case of Zr-Fe and Al-Fe).

However, the critical diameter of the Zr-Cu-Fe-Al quaternary alloy is not large enough to form solid external watch components such as case middles. The target of a critical diameter D _c * close to 9 mm or larger takes into account the fact that case middles, at least in high-end watchmaking, are typically close to 5 mm thick.

The experimental strategy consists in adding additional elements to the initial quaternary alloy to increase the critical diameter using the following main steps:

1. A zirconium and/or hafnium base material is provided, preferably formed from a Zr-Cu-Fe-Al quaternary alloy, for example: Zr ₅₈ Cu ₂₇ Fe ₅ Al ₁₀ . Zirconium can be replaced by hafnium or a zirconium-hafnium mixture.

2. Select at least two (or more) elements X selected from Ti, V, Nb, Y, Cr, Mo, Co, Sn, Zn, P, Pd, Ag, Au, Pt, Ta, Ru, Rh, Ir, Os and Hf (when the base material does not contain them) and Zr (when the base material does not contain them); in the term Xa, "a" represents the cumulative percentage of all X-type elements.

3. If the selected X element belongs to (Ti, Nb, Ta), it replaces Zr. In fact, the elements (Ti, Nb, Ta) are chemically close to Zr because they are adjacent to Zr in the periodic table and easily form solid solutions with Zr, so they are used to replace Zr.

4. If the X element belongs to (Pd, Pt, Ag, Au, Ru, Rh, Ir, Os) and is therefore also chemically close to Cu, it replaces Cu.

5. Maintain the alloy composition thus obtained. For example: X1 = Nb, and X2 = Ag; the selected alloy is Zr _{58- X1} Nb _X1 Cu _{25- X2} Ag _X2 Fe ₅ Al ₁₂

6. Make alloys with different X1 and X2 contents. For example, X1 = 2% and 3%, and X2 = 3.5% and 4.5%

7. Measure the properties of the alloy, especially the critical diameter D _c *, and identify the optimal composition. For example, Zr ₅₆ Nb ₂ Cu _22.5 Ag _4.5 Fe ₅ Al ₁₀ .

For each experimental alloy, an approximately 70-gram charge of alloy was prepared in an electric arc furnace using pure elements (greater than 99.95% purity). The prealloy was then remelted in a centrifugal caster using a silica crucible under an argon atmosphere and cast in a conical copper mold (approximately 11 mm thick, 20 mm wide, and 6.3° opening angle). A metallographic section was made in the middle of each cone to measure the critical diameter D _c *, which corresponds to the thickness of the cone at the beginning of the crystalline zone as seen in FIG1 .

The following table summarizes the experiments carried out in the Zr-Cu-Fe-Al-X system, where X is at least one element selected from Ti, Hf, V, Nb, Y, Cr, Mo, Fe, Co, Sn, Zn, P, Pd, Ag, Au, Pt, Ta, Ru, Rh, Ir, Os.

Compositions 1 and 2 are known, do not include the additional component X and correspond to the teaching of WO patent application No 2006026882.

Compositions 3 and 4 relate to compositions not disclosed in the literature, but are covered by some of the ranges disclosed in WO Patent Application No. 2006026882. Composition 3 includes a single additional component, X, silver, and has a critical diameter that is superior to Compositions 1 and 2, but insufficient to meet the specifications of the present invention. Composition 4 includes two additional X components, niobium and silver, with a total percentage of 6, and has a critical diameter of the same order as that of Sample 3.

The test campaign confirmed that the only means of significantly increasing the critical diameter D _c * is to provide a percentage higher than or equal to 6.3.

Compositions 5 to 12 are completely new and do not overlap with the prior art. They include compositions 5 to 11 having a critical diameter D _c * greater than or equal to 9.5 mm. Composition 12 demonstrates that above a certain value (in this case, 10 atomic %), the cumulative percentage "a" of the X component has no beneficial effect, and may even have the opposite effect, since the critical diameter D _c * is significantly lower than the previous ones.

The results show that the addition of X elements increases the critical diameter D _c * and ideally at least two X elements should be added to maximize their effect. Experiments show that the critical diameter D _c * is maximized when the cumulative percentage "a" of X elements is 6 to 10%.

Experiments have also confirmed that the addition of a small amount of rare earth elements is beneficial to reducing the adverse effects of oxygen present in the alloy (oxygen scavenger).

Therefore, the present invention relates to a second bulk amorphous alloy, characterized in that it is nickel-free and consists of the following composition in atomic % values:

- a base material formed of zirconium and/or hafnium, the content of which constitutes the balance, the total zirconium and hafnium value being greater than or equal to 52.0 and less than or equal to 62.0;

- Copper: greater than or equal to 16.0 and less than or equal to 28.0;

- Iron: greater than or equal to 0.5 and less than or equal to 10.0;

- Aluminum: greater than or equal to 7.0 and less than or equal to 13.0;

- at least a first additional metal and a second additional metal, referred to as X, selected from the group consisting of Ti, V, Nb, Y, Cr, Mo, Co, Sn, Zn, P, Pd, Ag, Au, Pt, Ta, Ru, Rh, Ir, Os, and Hf (when the base material is free of them) and Zr (when the base material is free of them), the cumulative atomic percentage "a" of the at least two additional metals being greater than 6.0 and less than or equal to 10.0.

Preferably, when the alloy includes Y, its content is greater than 0.5.

More particularly, the first additional metal and the second additional metal are selected from Ti, Nb, Pd, Ag, Au, Pt, Ta, Ru, Rh, Ir, Os and Hf (when the base material does not contain them) and Zr (when the base material does not contain them), and the cumulative atomic percentage of the at least two additional metals is greater than 6.0 and less than or equal to 10.0.

More particularly, the first additional metal and the second additional metal are selected from Ti, Nb, Pd, Ag, Au, Pt, Ta, Ru, Rh, Ir, Os, and the cumulative atomic percentage of the at least two additional metals is greater than 6.0 and less than or equal to 10.0.

In a particular variant, the alloy of the invention contains only zirconium and no hafnium.

In another particular variant, the alloy of the invention contains only hafnium and no zirconium.

More particularly, the alloys of the present invention are both nickel-free and beryllium-free.

The best results obtained so far are achieved as follows:

-X＝Ag+Nb；

-X＝Ag+Ti;

-X＝Nb+Ag+Pd.

In an advantageous variant, the alloy further comprises 0.1-1% of at least one rare earth element chosen from scandium, yttrium and lanthanides with atomic numbers from 57 to 71, the total amount of these rare earth elements being greater than or equal to 0.01 and less than or equal to 1.0.

Among these rare earth elements, more particularly but not limitatively, Sc, Y, Nd, and Gd are most commonly used.

Still more particularly, the alloys of the present invention are cobalt-free and/or chromium-free.

In short, the alloys of the present invention are corrosion resistant and have stable color (no tarnish or discoloration during wear).

The following list contains various alloys according to the present invention:

Zr52Hf4Nb2Cu21.5Ag5.5Fe5Al10

Zr60Hf2Ta3Cu16Ag5Fe7Al7

Zr56Hf2Ti2Cu21Pd2Fe6Al11

Zr50Hf6Nb2Cu21.5Ag5.5Fe5Al10

Zr40Hf16Nb2Cu21.5Ag5.5Fe5Al10

Zr56Nb1.5Cu21.5Ag3.5Pd1.5Fe3Al13

Zr55Nb3Cu21Ag4.5Pd2.5Fe5Al9

Zr52Ti3.5Nb3.5Cu28Fe5Al8

Zr54Ti5Nb3Cu16Fe10Al12

Zr58.5Ti3.5Ta3Cu20Fe4.5Al10.5

Zr57Ti4.5Cu28Ag2Fe0.5Al8

Zr62Ti2Ta1Cu16Ag4Fe5Al10

Zr54Y2Cu28Ag5Fe3.5Al7.5

Zr54Y1Nb2Cu21.5Ag4.5Pd2Fe5Al10

Zr55Nb2Cu21.5Ag4.5Pt2Fe5Al10

Zr58Cu22.5Ag5Pt2Fe3Co2Al7.5

Zr53Ta3Cu22.5Ag3Au3Fe6Al9.5

Zr57Nb3Cu20Pd3Au2Fe5Al10

Zr58Nb3Cu19Ag2Ru2Fe4.5Al11.5

Zr53Nb2.5Cu24.5Rh4Fe6Al10

Zr56Ti2Cu23Ag3.5Ir1.5Fe3Al11

Zr52Ta2.5Cu24.5Ag3.5Os2.5Fe5Al10

Zr56Nb2Cu21.5Ag5.5Fe5Al8Sn2

Zr55Nb2Cu22.5Ag3.5Pd2Fe4.5Al9Sn1.5

Zr54Ti2.5Cu21Ag5.5Fe5Al10.5Zn1.5

Zr61Nb2Cu16.5Pd2.5Fe8Al8Zn2

Zr54Nb2.5Cu18.5Ag4.5Fe9Al10P1.5

Zr56Nb2Cu21.5Ag3.5Pd2Fe5Al8P2

Zr60Nb3Cu17.5Ag3Fe4Cr2Al10.5

Zr53Nb2Cu24.5Ag2.5Pd2Fe4Cr2Al10

Zr57Ta3Cu20Ag2Fe5Co3Al10

Zr55Ti2.5Nb2.5Cu24.5Fe3.5Co2.5Al9.5

Zr59Nb2Cu18Pd3Fe4.5V2.5Al11

Zr56Ti3Cu22.5Ag4.5Fe2.5V1.5Al10

Zr55Ti2.5Cu24Ag2.5Fe3.5Mo2.5Al10

Zr52Nb2Cu26Ag4.5Fe4Mo1.5Al9Sn1

The invention also relates to a timepiece or jewelry component made of such an amorphous alloy.

More specifically, the critical diameter D _c * of the amorphous alloy of the present invention forming such an assembly is greater than 1.8 times the maximum thickness E of the assembly 1 .

The invention also relates to a watch 2 comprising at least one such external assembly 1 .

More particularly, watch 2 comprises an exterior component 1 made of such an amorphous alloy having a critical diameter D _c * greater than 8 mm and a case middle with a maximum thickness E of 4.0 to 5.0 mm.

Claims (12)

1. A bulk amorphous alloy, characterized in that the alloy is nickel-free and consists of the following components in atomic percent: - A base material composed of zirconium and/or hafnium, the content of which constitutes the balance, with a total zirconium and hafnium value greater than or equal to 52.0 and less than or equal to 62.0; - Copper: Greater than or equal to 16.0 and less than or equal to 28.0; - Iron: greater than or equal to 0.5 and less than or equal to 10.0; - Aluminum: Greater than or equal to 7.0 and less than or equal to 13.0; - At least a first and a second additional metal, referred to as X, selected from Ti, V, Nb, Y, Cr, Mo, Co, Sn, Zn, P, Pd, Ag, Au, Pt, Ta, Ru, Rh, Ir, and Os, wherein the cumulative atomic percentage of said at least two additional metals is greater than 6.0 and less than or equal to 10.0. Where X includes Ag+Nb, or X includes Ag+Ti, or X includes Nb+Ag+Pd. The critical diameter _Dc * of the amorphous alloy is greater than 1.8 times the maximum thickness E of the external components of watches or jewelry made from the amorphous alloy. 2. The bulk amorphous alloy according to claim 1, wherein the first additional metal and the second additional metal are selected from Ti, Nb, Pd, Ag, Au, Pt, Ta, Ru, Rh, Ir, and Os, and the cumulative atomic percentage of the at least two additional metals is greater than 6.0 and less than or equal to 10.0. 3. The bulk amorphous alloy according to claim 1, characterized in that the alloy comprises, in atomic percent, at least one rare earth element selected from scandium and yttrium, in an amount greater than or equal to 0.01 and less than or equal to 1.0. 4. The bulk amorphous alloy according to claim 1, characterized in that the alloy is free of cobalt and/or chromium. 5. The bulk amorphous alloy according to claim 1, characterized in that when the alloy includes yttrium, its content is greater than 0.5%. 6. The bulk amorphous alloy according to claim 1, characterized in that the alloy composition is one of the following: Zr58Cu22Fe8Al10 (Zr58Cu22Fe8Al10)0.95Ag5 Zr56Nb2Cu21Ag4Fe5Al12 Zr55.9Nb2.1Cu22.8Ag2.1Pd2.1Fe4Al11 Zr56Ti2Cu22.5Ag4.5Fe5Al10 Zr56Nb2Cu22.5Ag4.5Fe5Al10 Zr56Cu22.5Ag4.5Pd2Fe5Al10 Zr56Nb2Cu21.5Ag5.5Fe5Al10 Zr55Nb2Cu21.5Ag4.5Pd2Fe5Al10 Zr57.5Nb3.5Cu20Ag3.5Pd2Fe3Al10.5 Zr52Hf4Nb2Cu21.5Ag5.5Fe5Al10 Zr60Hf2Ta3Cu16Ag5Fe7Al7 Zr50Hf6Nb2Cu21.5Ag5.5Fe5Al10 Zr40Hf16Nb2Cu21.5Ag5.5Fe5Al10 Zr56Nb1.5Cu21.5Ag3.5Pd1.5Fe3Al13 Zr55Nb3Cu21Ag4.5Pd2.5Fe5Al9 Zr52Ti3.5Nb3.5Cu28Fe5Al8 Zr54Ti5Nb3Cu16Fe10Al12 Zr 58.5Ti 3.5Ta 3Cu 20Fe 4.5Al 10.5 Zr57Ti4.5Cu28Ag2Fe0.5Al8 Zr62Ti2Ta1Cu16Ag4Fe5Al10 Zr54Y2Cu28Ag5Fe3.5Al7.5 Zr54Y1Nb2Cu21.5Ag4.5Pd2Fe5Al10 Zr55Nb2Cu21.5Ag4.5Pt2Fe5Al10 Zr58Cu22.5Ag5Pt2Fe3Co2Al7.5 Zr53Ta3Cu22.5Ag3Au3Fe6Al9.5 Zr57Nb3Cu20Pd3Au2Fe5Al10 Zr58Nb3Cu19Ag2Ru2Fe4.5Al11.5 Zr53Nb2.5Cu24.5Rh4Fe6Al10 Zr56Ti2Cu23Ag3.5Ir1.5Fe3Al11 Zr52Ta2.5Cu24.5Ag3.5Os2.5Fe5Al10 Zr56Nb2Cu21.5Ag5.5Fe5Al8Sn2 Zr55Nb2Cu22.5Ag3.5Pd2Fe4.5Al9Sn1.5 Zr54Ti2.5Cu21Ag5.5Fe5Al10.5Zn1.5 Zr61Nb2Cu16.5Pd2.5Fe8Al8Zn2 Zr54Nb2.5Cu18.5Ag4.5Fe9Al10P1.5 Zr56Nb2Cu21.5Ag3.5Pd2Fe5Al8P2 Zr60Nb3Cu17.5Ag3Fe4Cr2Al10.5 Zr53Nb2Cu24.5Ag2.5Pd2Fe4Cr2Al10 Zr57Ta3Cu20Ag2Fe5Co3Al10 Zr55Ti2.5Nb2.5Cu24.5Fe3.5Co2.5Al9.5 Zr59Nb2Cu18Pd3Fe4.5V2.5Al11 Zr56Ti3Cu22.5Ag4.5Fe2.5V1.5Al10 Zr55Ti2.5Cu24Ag2.5Fe3.5Mo2.5Al10 Zr52Nb2Cu26Ag4.5Fe4Mo1.5Al9Sn1. 7. The bulk amorphous alloy according to claim 1, characterized in that the composition of the alloy is: Zr60Cu25Fe5Al10 Zr58Cu27Fe5Al10 Zr56Nb2Cu22.5Ag4.5Fe5Al10 Zr55.9Nb2.1Cu22.8Ag2.1Pd2.1Fe4Al11 Zr56Cu22.5Ag4.5Pd2Fe5Al10 Zr55Nb2Cu21.5Ag4.5Pd2Fe5Al10 Zr56Nb1.5Cu21.5Ag3.5Pd1.5Fe3Al13 Zr55Nb3Cu21Ag4.5Pd2.5Fe5Al9 Zr54Y1Nb2Cu21.5Ag4.5Pd2Fe5Al10 Zr55Nb2Cu22.5Ag3.5Pd2Fe4.5Al9Sn1.5 Zr56Nb2Cu21.5Ag3.5Pd2Fe5Al8P2 Zr53Nb2Cu24.5Ag2.5Pd2Fe4Cr2Al10. 8. The bulk amorphous alloy according to claim 1, characterized in that X = Ag + Nb, or X = Ag + Ti, or X = Nb + Ag + Pd. 9. A watch or jewelry exterior component (1) made of an amorphous alloy according to claim 1. 10. The component (1) according to claim 9, wherein the critical diameter _Dc * of the amorphous alloy forming the external component (1) is greater than 1.8 times the maximum thickness E of the external component. 11. A watch (2) comprising at least one external component (1) according to claim 9 or 10. 12. The watch (2) according to claim 11, characterized in that the watch (2) includes the external component (1), which is a case center made of an amorphous alloy according to claim 1 with a maximum thickness E of 4.0 to 5.0 mm and a critical diameter _Dc * greater than 8 mm.