JP2012162805A - Zirconium based amorphous alloy and use thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an alloy in which the glass formability is excellent, the compatibility with a living body is improved; and to provide especially an alloy that does not emit nickel even if contacting with a body fluid.SOLUTION: The alloy includes an amorphous phase and is shown by general formula [Zr(Fe)(AlG)]Z. In the formula, a, b, x, and y are a real number indicating an atomic percent; 70≤a≤90, x≥50, y>0, 0≤b≤6 are satisfied; G denotes at least one element chosen from the group consisting of platinum and palladium; Z is a component comprising at least one element; and all component of G and Z are each different and are not zirconium, iron, and aluminum; and the alloy does not substantially includes copper and nickel.

Description

  The invention relates to an alloy having the features of the preamble of claims 1 to 19 and to its use. The present invention also relates to a molded article produced from the alloy, particularly an implant such as an artificial organ.

Many alloys can be brought into a vitreous state, i.e., an amorphous structure, by rapid quenching, for example, at a very high cooling rate of 10 < ⁶ > K / sec. However, most of these alloys cannot be cast into bulk glassy structures at cooling rates much lower than the cooling rates by casting.

  In recent years, many bulk metallic glass forming liquids have been found that are sufficient for vitrification if the cooling rate is less than 1000 K / sec. In the present specification, “bulk metallic glass” means when cooling from a temperature above the melting point of the amorphous phase to a temperature below the glass transition temperature at a cooling rate of 1000 K / sec or less, preferably 100 K / sec or less. , Refers to an alloy that at least partially exhibits an amorphous structure. Cooling rates in this range are common in bulk casting operations.

  Bulk metallic glasses generally have better mechanical properties than their crystalline bodies. Due to the lack of dislocation mechanisms for plastic deformation, bulk metallic glasses often have high yield strength and elastic limits. In addition, many bulk metallic glasses have good fracture toughness, corrosion resistance, and fatigue properties. See, for example, Johnson WL, MRS Bull, 24, 42 (1999) and Loffler JF, Intermetallics 11, 529 (2003) for an overview of the properties and applications of such materials. Reference is explicitly made to the disclosure of these documents and the incorporated examples teaching the properties of the glass-forming metal alloys cited in these documents and the methods for determining the properties of the glass-forming metal alloys. Application of bulk metallic glass to the industrial field is described, for example, in Buchanan O, MRS Bull. 27, 850 (2002).

Currently, only zirconium-based bulk metallic glasses (and some of the platinum-based glasses for gems) have found their application. The following documents relating to the prior art relate to zirconium-based glass-forming alloys.
US Pat. No. 5,740,854 discloses an alloy of composition Zr ₆₅ Al _7.5 Ni ₁₀ Cu _17.5 .
US Pat. No. 5,288,344 discloses an alloy of general composition Zr—Ti—Cu—Ni—Be. In particular, the alloy Zr _41.2 Ti _13.8 Cu _12.5 Ni ₁₀ Be _22.5 known under the trade name Vitreloy 1 or Vit 1 and the alloy Zr _46.75 Ti _8.8 Ni ₁₀ Cu known under the trade name Vitreloy 4 or Vit4. _7.5 Be _27.5 is disclosed in this document.
US Pat. No. 5,737,975 discloses an alloy of general composition Zr—Cu—Ni—Al—Nb. In particular, an alloy of the composition Zr ₅₇ Cu _15.4 Ni _12.6 Al ₁₀ Nb ₅ known under the trade name Vitreloy 106 or Vit 106 is disclosed in this document.
-Lin X H, Johnson WL, Rhim W K, Mater. Trans. JIM 38, 473 (1997) discloses the alloy Zr _52.2 Ti ₅ Cu _17.9 Ni _14.6 Al ₁₀ known as Vit105.
-Loffler JF, Bossuit S, Grade SC,
Johnson WL, Wagner W, Thiagaarajan P, Appl. Phys. Lett. 77, 525 (2000) and Loffler JF, Johnson WL, Appl.
Phys. Lett. 76, 3394 (2000) describes comparative considerations of Vit1, Vit105 and Vit106.
-Kundig AA, Loffler JF, Johnson WL, Ugowitzer PJ, Thiayagarajan P, Scr. material. 44, 1269 (2001) describes an alloy of the general formula Zr _52.5 Cu _17.9 Ni _14.6 Al _10-x Ti _{5 + x} , that is, an alloy composition changed near the composition of Vit105.
-Inoue A, Shibata T .; and Zhang T. , Mater. Trans. JIM 36, 1426 (1995) discloses an alloy of composition Zr _65-x Ti _x Al ₁₀ Cu ₁₅ Ni ₁₀ .
-Zhang T, Inoue A, Mater. Trans. The JIM 39, 1230 (1998), an alloy of composition _{Zr 70-x-y Ti x} Al y Cu 20 Ni 10 is disclosed.
-Xing LQ, Ochin P, Harmelin et al, Mat. Sci. Eng. A220, the 155 (1996), among others, alloys and other Zr-Cu-Al-Ni- Ti -based alloy composition _{Zr 57 Cu 20 Al 10 Ni 8} Ti 5 is disclosed.
-Loffler JF, Thiagaarajan P, Johnson WL, J. MoI. Appl. Cryst. 33, 500 (2000) discloses a Zr—Ti—Cu—Ni—Be alloy whose (Zr, Ti) and (Cu, Be) contents vary between the compositions of Vit1 and Vit4.
-Inoue A, Zhang T, Nishiyama N, Ohba K, Masamoto T, Mater. Trans. JIM 34, 1234 (1993) discloses an alloy of composition Zr ₆₅ Al _7.5 Cu _17.5 Ni ₁₀ .

According to the following literature, it was thought that adding iron to a Zr—Al—Ni—Cu alloy would not even improve the glass forming ability, but even decrease it.
-Inoue A, Shibata T, Zhang T, Mater. Trans. JIM 36, 1420 (1995)
-Eckert J, Kubler A, Reger-Leonhard A et al, Mater. Trans. JIM 41, 1415 (2000)
-Mattern N, Roth S, Kuhn U et al, Mater. Trans. JIM 42, 1509 (2001)

  Due to its favorable mechanical properties, bulk metallic glasses are promising for use in biomedical applications. However, the most well-known glass forming alloys, especially zirconium-based alloys, contain a significant proportion of nickel (Ni). Exposure to nickel is known to cause allergies in some cases. Therefore, these alloys are not well suited for medical applications where the alloy contacts body fluids, skin, cells, or other body parts. In particular, these alloys cause an allergic reaction because they tend to release a small amount of nickel upon prolonged contact with the body. If not as nickel, copper (Cu) is also problematic.

  Fan C, Inoue A, Mater. Trans. JIM 38, 1040 (1997) describes that mechanical properties can be improved by precipitating nano-unit compound particles in a Zr-Cu-Pd-Al amorphous alloy. However, these alloys are not bulk metallic glasses and are amorphous only when performing melt spinning or ultra-quenching.

  An object of the present invention is to provide an alloy having good glass forming ability and improved compatibility with a living body, particularly an alloy that does not release nickel even when it comes into contact with a body fluid.

  This object is achieved by an alloy having the features of claim 1.

  Another object of the present invention is to provide an alloy having good glass forming ability and improved compatibility with a living body, particularly an alloy substantially free of both copper and nickel.

  This object is achieved by an alloy having the features of claim 19.

  Thus, an alloy containing at least four components A, D, E and G is provided. If necessary, a fifth component Z may be present. This alloy preferably has a bulk structure comprising at least one amorphous phase. That is, a volume fraction of at least 10%, preferably 50% of the alloy is amorphous. In the context of this document, a structure is considered to be completely amorphous if a material having this structure does not show a clear Bragg peak in the X-ray diffraction pattern. Therefore, the volume fraction of the amorphous phase in the mixed phase material can be estimated by integrating the intensity of the Bragg peak and comparing it with the intensity of the non-Bragg characteristic.

  Preferably, the amorphous phase is obtained by cooling at a cooling rate of 1000 K / sec or less from a temperature above the melting point of the amorphous phase and below the glass transition temperature. That is, the alloy is a bulk metallic glass. More preferably, the amorphous phase is obtained at a cooling rate of 100 K / second or less. This allows the material to be formed by casting, in particular casting using a copper mold. In other words, the alloy having at least one amorphous phase is in a shape having a dimension of at least 0.1 millimeter, preferably at least 0.5 millimeter, more preferably at least 1 millimeter in any direction of space. can get. This is not possible with alloys that have an amorphous structure only at the cooling rate achieved by ultra-quenching or melt spinning.

  Component A is composed of at least one element selected from the group consisting of zirconium, hafnium, titanium, niobium, lanthanum, palladium, and platinum. The other components D, E, G, and, if necessary, Z are different from each other and different from the component A. Each of these components may consist of a plurality of elements as long as all the elements of all the components are different. Preferably, components D, E and G are each composed of a single element. The composition of the alloy follows the “80:20 diagram”. That is, the ratio of the total atomic content of components A and D to the total atomic content of components E and G is approximately 80:20 with a range of plus or minus 10, preferably plus or minus 5, especially plus or minus 2. It is.

The alloy of the present invention is represented by the following chemical formula.
_{[(A x D 100-x} ) a (E Y G 100-y) 100-a] 100-b Z b
(Wherein x, y, a and b are independent numbers selected from zero and a positive real number indicating atomic percent, and 70 ≦ a ≦ 90, preferably 75 ≦ a ≦ 85, more preferably 78. The following example (≦ a ≦ 82) is intended to illustrate the meaning of atomic percent. Divide the index inside the brackets by 100 before multiplying the index inside and outside the brackets. For example, (Zr _72.5 Cu _27.5 ) ₈₀ (Fe ₄₀ Al ₆₀ ) ₂₀ becomes Zr ₅₈ Cu ₂₂ Fe ₈ Al ₁₂ . With all parentheses removed, each index represents the number of elements contributing to the formula unit of the alloy. In this example, 58 elements of zirconium are combined with 22 elements of copper, 8 elements of iron, and 12 elements of aluminum to form one formula unit. In other words, if one number is "atomic percent", this shows the chemical equivalence theory understood in normal chemistry when divided by 100.

  Component A is the main component in the alloy of the present invention in the sense of x ≧ 50. In order to make the content of the component D effective, preferably x ≦ 95, more preferably x ≦ 90. Advantageously, the content of component G relative to component E is not too low, preferably y ≧ 5, more preferably y ≧ 10. On the other hand, the content should not be too high. Preferably, y ≦ 95, more preferably y ≦ 90. If a fifth component Z is present, that component is present only in a very small proportion. In terms of numbers, 0 ≦ b ≦ 6, preferably 0 ≦ b ≦ 4, and more preferably 0 ≦ b ≦ 2. The numbers x, y, a and b are usually independent of each other.

  It is important that the alloys of the present invention are substantially free of nickel. As used herein, “substantially free of nickel” means that the total nickel content of the alloy is less than 1 atomic percent, preferably less than 0.1 atomic percent. For medical applications, the nickel content is required to be below 10 atomic ppm. In particular, none of components A, D, E, G or Z is required to contain nickel.

  Preferably, components A and E are miscible over a wide composition and temperature range. “Wide composition and temperature range” means “a temperature range that extends beyond a temperature range of at least 600 K” and any component that is liquid and below the liquid temperature in the phase diagram of the AE phase. “Composition range extending beyond 60 atomic percent”. In this example, a broad composition range means, for example, that component A is 20 atomic percent to 80 atomic percent in a binary mixture from A to E.

More preferably, Component A and Component E can form a deep eutectic composition in the absence of other components. “A deep eutectic composition can be formed” means that when A and E are mixed in the molten state in the absence of other components, there is a composition in which A and E are miscible up to the liquidus temperature. It means that the liquidus temperature of the mixture with respect to the product has a local minimum as a function of the composition. In other words, when the composition is changed in the vicinity of the deep eutectic composition, the liquidus temperature is higher than the temperature in the composition of the deep eutectic itself. Often, the binary liquid phase temperature in a deep eutectic composition is even lower than the melting point of each component. As an example of the deep eutectic composition, when the component A is zirconium, the melting point T _m (Zr) is 2128K, when the component E is iron, the melting point T _m (Fe) is 1811K, and the eutectic is 1201K = 0. .66 T _m (Fe). Similarly, when T _m (Au) = 1337K and T _m (Si) = 1687K, the eutectic is 636K = 0.47T _m (Au).

Preferably, a deep eutectic composition of the mixture of components A to E occurs with composition A _{a ′} E _{100-a ′} (in this case 70 ≦ a ′ ≦ 90, preferably 75 ≦ a ′ ≦ 85). Select ingredients. The number a is then preferably set so that the absolute value of the difference between a and a ′ is less than or equal to 10 (ie | a−a ′ | ≦ 10, preferably | a−a ′ | ≦ 5). )select.

Preferably, components A and D are miscible over a wide temperature range and composition range. More preferably, components A and D can form deep eutectic compositions when mixed in a binary system. If components A and D form a deep eutectic composition with A _{x ′} D _{100-x ′} , x is preferably | x−x ′ | ≦ 10, more preferably | x−x ′ | ≦ Is selected to be 5.

  Preferably, component G is miscible with component E over a wide temperature range and composition range, particularly when component E is at least one element selected from the group consisting of transition metals, particularly iron and cobalt. And preferably, component G forms a deep eutectic composition with component A.

More preferably, components G and E can form a deep eutectic composition with E _{y ′} G _{100-y ′} . And y is preferably selected to satisfy | y−y ′ | ≦ 10, more preferably | y−y ′ | ≦ 5. Alternatively or additionally, it is preferred that A and G preferably form a deep eutectic composition.

  Preferably, the gold schmidt atomic radius of each element of component A is relatively large, at least 0.137 nanometers, preferably at least 0.147 nanometers, more preferably at least 0.159 nanometers. In particular, when the gold Schmidt atomic radius of each element of component A is at least 0.159 nanometers, it is preferably 70 ≦ a ≦ 90. If this radius is at least 0.147 nanometers, preferably 75 ≦ a ≦ 85. If this radius is at least 0.137 nanometers, preferably 78 ≦ a ≦ 82. In particular, in the case of zirconium, hafnium, and lanthanum alloys, it preferably means that 70 ≦ a ≦ 90. In the case of titanium and niobium alloys, preferably 75 ≦ a ≦ 85. In the case of platinum and palladium based alloys, preferably 78 ≦ a ≦ 82.

  Components A, D, E and G may have similar atomic radii and atomic properties. However, the atomic radius of each element in component E is preferably smaller than the atomic radius of each element in component A.

  A table summarizing the atomic (Gold Schmid) radii of the elements can be found in standard textbooks or in the 2004 edition of Goodfellow Catalog published by Goodfellow, Huntingdon, England. See Table 1 below for particularly selected elements.

  In general, component D is preferably at least one element selected from the group consisting of copper, beryllium, silver, and gold. In particular, when component A is at least one element selected from the group consisting of lanthanum, palladium, and platinum, component D is preferably copper. When component A is at least one element selected from the group consisting of zirconium, hafnium, and titanium, component D is preferably copper or beryllium. Both copper and beryllium have deep eutectic compositions with zirconium, hafnium, and titanium.

  In general, component E is preferably at least one metal selected from the group consisting of transition metals excluding nickel. In particular, scandium, titanium, vanadium, chromium, manganese, iron, cobalt, zinc, yttrium, morbidene, tantalum, and tungsten. A transition metal is defined as any of 30 chemical elements with atomic numbers 21 to 30, 39 to 48, 71 to 80. These metals are preferred because of their tendency to form deep eutectic compositions with component A and their special electronic properties. In particular, component E is preferably at least one metal selected from iron and cobalt. It has been found empirically that these metals are preferred.

  Component G is preferably at least one element selected from the group consisting of aluminum, zirconium, phosphorus, carbon, gallium, indium, and metalloid. In particular, boron, silicon, and germanium. Known metalloids include boron, silicon, germanium, arsenic, antimony, tellurium, and polonium. It is believed that the unique electronic properties of these elements have a positive effect on glass forming ability. In addition, boron, phosphorus, carbon, and silicon have particularly small atomic sizes (≦ 0.117 nanometers), which contributes to the large differences in component A and component G sizes. In particular, when component E is iron, component G is preferably selected from the group consisting of aluminum, zirconium, phosphorus, boron, silicon, and carbon. More preferably, when component E is iron, component G is aluminum. In this case, y is preferably selected to be in the range of approximately 30 to 50, in particular approximately 40. Alternatively, when component E is cobalt, component G is preferably at least one element selected from zirconium, aluminum, boron, silicon, germanium, gallium and indium.

  In a preferred embodiment, component A is zirconium or zirconium and a mixture of either hafnium or titanium, or both, and at least 80 atomic percent of component A is zirconium. Component D is preferably copper. It has been found empirically that this combination has an excellent glass-forming ability.

When component A is zirconium and component D is copper, x is preferably selected from between 62 and 83 (ie, 62 ≦ x ≦ 83). Preferably 68 ≦ x ≦ 77, particularly preferably x is approximately 72.5. More preferably, when component A is zirconium and component D is copper, component E is iron and component G is aluminum. In this case, y is preferably selected in the range of approximately 30 to approximately 50. Particularly preferably, y is approximately 40. It has been found by the inventors that an alloy having this composition, in particular, an alloy having a composition close to that of Zr ₅₈ Cu ₂₂ Fe ₈ Al ₁₂ has the most excellent glass forming ability so far.

  When the fifth component Z is present, this component is preferably at least one element selected from the group consisting of titanium, niobium, hafnium. Or component Z is preferably at least one element selected from the group consisting of transition metals, or component Z is preferably selected from the group consisting of beryllium, yttrium, palladium, silver, platinum, tin At least one element. In general, it is preferred that component Z, together with component A, can form a deep eutectic composition.

  The alloys of the present invention can have a structure comprising at least one amorphous phase and at least one crystalline phase. The volume fraction of the amorphous phase is preferably at least 10 percent. The amorphous phase and the crystalline phase must not be separated macroscopically. Such a structure can be generated by different means. As one method, a composite comprising crystals embedded in an amorphous matrix can be produced by heat treating the alloy at a temperature above the glass transition temperature. For details, see the description of preferred embodiments below. As another method, for example, Holland TB, Loffler JF, Munir ZA, J. et al. Appl. Phys. 95, 2896 (2004), there is a method of passing an electric current through the alloy of the present invention. It describes the crystallization of metallic glass under the influence of high-density direct current. As yet another method, there is a method of selecting an alloy composition in a molten state so that it is initially outside the glass forming region. Upon cooling, crystals begin to form inside the melt. As a result, the composition of the mixture remaining in the melt changes to the glass forming region. Upon further cooling, a glassy matrix with embedded crystals is formed. For details, see Hays CC, Kim CP, Johnson WL, Phys Rev. Lett. 84, 2901 (2000). As yet another method, there is a method of promoting crystal growth in an amorphous matrix by selecting an appropriate fifth component Z. Suitable component Z is preferably at least one element selected from the group consisting of titanium, niobium, tantalum or transition metals, or at least one element selected from the group consisting of beryllium and palladium. For details, see, for example, He G, Eckert J, Loser W, Schultz L, Nature Materials 2, 33 (2003).

  In a preferred embodiment, component A is zirconium and component D is selected from the group consisting of copper and iron. In particular, component A is preferably zirconium, component D is copper, and component E is selected from the group consisting of iron and cobalt. The component G is preferably at least one element selected from the group consisting of aluminum and metalloid. A particularly preferred system is the Zr—Cu—Fe—Al system. That is, component A is zirconium, component D is copper, component E is iron, and component G is aluminum. It has been found that alloys of this composition have favorable glass forming properties according to the 80:20 concept described above.

  When component A is zirconium and component D is copper, these ratios are preferably selected according to 62 ≦ x ≦ 83. When component E is iron and component F is aluminum, these ratios are preferably selected according to 30 ≦ y ≦ 50. The combination of these ranges, along with the general 80:20 concept, determines the range of quaternary compounds with very good glass forming properties.

In particular, the alloys of the present invention are substantially represented by the formula (Zr _x Cu _100-x ) ₈₀ (Fe ₄₀ Al ₆₀ ) ₂₀ . Here, x is 62 ≦ x ≦ 83. In particular, x is represented by 62, 64, 66, 68, 72.5, 77, 79, 81 or 83, or any of the following formulas. (Zr ₉₅ Ti ₅ ) ₇₂ Cu ₁₃ Fe ₁₃ Al ₂ , Zr ₇₀ Cu ₁₃ Fe ₁₃ Al ₃ Sn ₁ , Zr ₇₀ Cu ₁₃ Fe ₁₃ Al ₂ Cr ₂ , Zr ₇₀ Cu ₁₃ Fe ₁₃ Al ₂ Nb ₂ , Zr ₇₀ Cu _{13 Fe 13 Al 2 Zn 2,} (Zr 72 Cu 13 Fe 13 Al 2) 98 Mo 2, (Zr 72 Cu 13 Fe 13 Al 2) 98 P 2, (Z 95 Hf 5) 72 Cu 13 Fe 13 Al 2, _{Zr 70 Cu 11 Fe 11 Al 8} , Zr 71 Cu 11 Fe 10 Al 8, (Zr 74 Cu 13 Fe 13) 90 Al 10, Zr 72 Cu 13 Fe 13 Al 2, (Zr 74 Cu 13 Fe 13) 98 Al 2 _{, Zr 73 Cu 13 Fe 13 Al} 1, Zr 72 Cu 13 Fe 13 A _{2, Zr 71 Cu 13 Fe 13} Al 3, Zr 72 Cu 12 Fe 12 Al 4, Zr 70 Cu 13 Fe 13 Al 4, Zr 72 Cu 11 Fe 11 Al 6, Zr 72 Cu 11.5 Fe 11 Al 5.5 _{, Zr 73 Cu 11 Fe 11 Al} 5, Zr 71 Cu 11 Fe 11 Al 7, Zr 69 Cu 11 Fe 11 Al 9, Zr 70 Cu 10.5 Fe 10.5 Al 9, Zr 70 Cu 10 Fe 11 Al 9, _{Zr 70 Cu 11 Fe 10 Al 9} , Zr 69 Cu 10 Fe 10 Al 11, Zr 69 Cu 10 Fe 11 Al 10, Zr 70 Cu 13 Fe 13 Al 2 Sn 2, Zr 72 Cu 13 Fe 13 Sn 2, (Zr 74 _{Cu 13 Fe 13) 98 Sn 2} , (Zr 79 Cu 21) 8 _{(Fe 40 Al 60) 20,} (Zr 81 Cu 19) 80 (Fe 40 Al 60) 20, (Zr 83 Cu 17) 80 (Fe 40 Al 60) 20, (Zr 66 Cu 34) 80 (Fe 40 Al 60 ) ₂₀ , (Zr ₆₄ Cu ₃₆ ) ₈₀ (Fe ₄₀ Al ₆₀ ) ₂₀ , and (Zr ₆₂ Cu ₃₈ ) ₈₀ (Fe ₄₀ Al ₆₀ ) ₂₀ .

  Another system that has excellent glass forming properties when following the 80:20 concept is the Zr-Fe-Al- (Pd / Pt) system. This system is further advantageous in that it does not contain copper. In other words, preferably component A is zirconium, component D is iron, component E is aluminum, and component G is one or both elements selected from palladium and platinum. In particular, it has been found that when component G is palladium, the glass-forming ability is increased, while the biocompatibility is slightly improved when palladium is totally or partially replaced with platinum. In this context, palladium and platinum belong to the same group of the periodic table and have similar (shell) electronic structures, almost the same Gold Schmid radius and similar chemical behavior. Please pay attention. Therefore, even if platinum is used instead of palladium, it is expected that the glass forming ability of the alloy will not change greatly. In these systems, it is advantageous if the atomic percent of iron and aluminum is substantially equal. It was found that the glass forming ability is high when 68 ≦ x ≦ 89 and 73 ≦ a ≦ 87. Particularly good results have been obtained for 81 ≦ x ≦ 85, 80 ≦ a ≦ 83, and 65 ≦ y ≦ 80, especially when component G is palladium. The ratio of aluminum to palladium / platinum is selected according to 40 ≦ y ≦ 82.

  In general, it is preferred that only a small amount of additional elements be present. That is, it is preferable that 0 ≦ b ≦ 2. In particular, b = 0 is preferable. That is, it is preferred that substantially only a very small amount of additional elements be present. If such an element is present, ie if b> 0, Z is preferably titanium, hafnium, vanadium, niobium, yttrium, chromium, molybdenum, iron, copper, tin, zinc, phosphorus, palladium, silver , At least one element selected from the group consisting of gold and platinum.

Stated differently, Zr-Fe-Al-Pd / Pt system if it meets the general formula _{Zr i (Fe 50 + ε Al} 50-ε) j X k, having a good glass forming ability. Where X is one or both elements selected from palladium, platinum, a, b, c, and ε are zero or positive real numbers indicating atomic percent, ε ≦ 10, i ≧ 50, j ≧ 19, k ≧ 0.5, and i + j + k = 100. In the example where X is palladium, good glass forming ability was achieved. On the other hand, when palladium is partially or wholly replaced with platinum having characteristics very similar to palladium, it is expected that biocompatibility may be slightly improved. Preferred ranges (independently or in combination) are 62 ≦ i ≦ 77, 19 ≦ j ≦ 34, and ε ≦ 2. Preferably, ε is substantially zero, that is, the atomic percent of iron and aluminum is approximately equal. For the best glass-forming alloys found in this system, ε is substantially zero, with 66 ≦ i ≦ 70, 25 ≦ j ≦ 29, and 4 ≦ k ≦ 7. The best glass-forming alloy of this system conforms to the 80:20 concept described above.

In particular, an alloy substantially represented by one of the following formulas has a high glass forming ability. Zr ₆₇ Fe _13.2 Al _13.2 Pd _6.6 , Zr _69.7 Fe _12.95 Al _12.95 Pd _4.4, Zr _66.7 Fe _14.45 Al _14.45 Pd _4.4 , Zr _68.3 Fe _13.4 Al _13.4 Pd _4.9 , Zr _65.4 Fe _14.85 Al _14.85 Pd _4.9 , Zr _62.3 Fe _16.7 Al _16.7 Pd _4.3 , Zr _59.2 Fe _18.3 Al _18.3 Pd _4.2 , Zr ₇₂ Fe _11.5 Al _11.5 Pd _5, Zr _73.4 Fe _10.9 Al _10.9 Pd _4.8 , Zr _{75. 2} Fe _10.2 Al _10.2 Pd _4.3 , Zr ₇₇ Fe _9.5 Al _9.5 Pd ₄ , Zr _67.9 Fe _11.8 Al _11.8 Pd _8.5 , Zr ₆₅ Fe _11.4 Al _11.4 P _{12.2, Zr} 62.5 _Fe 10.75 _Al 10.75 alloy represented by any one of _{Pd 16,} wherein _{Zr i (Fe 50 Al 50)} 30 Pd 70-i (62 ≦ i ≦ 69.5) In particular, the formula Zr _69.5 Fe ₁₅ Al ₁₅ Pd _0.5, Zr ₆₉ Fe ₁₅ Al ₁₅ Pd _0.5 , Zr ₆₈ Fe ₁₅ Al ₁₅ Pd ₂ , Zr ₆₇ Fe ₁₅ Al ₁₅ Pd ₃ , Zr ₆₆ Fe ₁₅ An alloy represented by any one of Al ₁₅ Pd ₄ , Zr ₆₅ Fe ₁₅ Al ₁₅ Pd ₅ , Zr ₆₄ Fe ₁₅ Al ₁₅ Pd ₆ , Zr ₆₃ Fe ₁₅ Al ₁₅ Pd ₇ , Zr ₆₂ Fe ₁₅ Al ₁₅ Pd ₈ , or _{, Zr 71 Fe 12 Al 12 Pd} 5, Zr 69 Fe 12.85 Al 12.85 Pd 5.3, Zr 66.8 Fe 13. _{Al 13.7 Pd 5.8, Zr 65 Fe} 14.5 Al 14.5 Pd 6, Zr 61.9 Fe 16.2 Al 16.2 Pd 5.7, Zr 50 Fe 12 Al 12 Pd 26, Zr 53 _.2 Fe _12.6 Al _12.6 Pd _21.6 , Zr _57.6 Fe _13.95 Al _13.95 Pd _14.5 , Zr ₆₀ Fe _14.3 Al _14.3 Pd _11.4 It is an alloy represented.

  Preferably, the alloy has a structure comprising at least one amorphous phase and at least one crystalline phase. Said at least one amorphous phase is preferably obtained by cooling at a cooling rate of 1000 K / sec or less from a temperature above the melting point of the alloy to a temperature below the glass transition temperature of the amorphous phase. That is, the alloy of the present invention is preferably a bulk metallic glass.

The present invention further relates to a method for producing the above-described alloy of the present invention. The method is
-Preparing an aliquot melt of components A, D, E, G and optionally component Z; and-bringing the melt from a temperature above the melting point to a glass transition temperature of the amorphous phase. Cooling to a lower temperature at a cooling rate of 1000 K / sec or less to obtain a solid substance.

Alternatively, the alloys of the present invention can be obtained, for example, from Eckert J, Mater. Sci. Eng. A 226-228, 364 (1997):
It can also be produced by mechanical methods such as those described in Mechanical alloying of high processable glassy alloys. The mechanical method means that an alloy or a solid component is mechanically processed and does not go through a liquid state. In particular, an amorphous metal alloy may be obtained by mechanically alloying crystal grains, for example. A suitable mechanical method includes, but is not limited to, ball milling. For details, reference is made explicitly to the teachings of Eckert's paper mentioned above.

  The method of the present invention can further include processing the alloy above the glass transition temperature, for example, to obtain a mixed phase material. In particular, the method of the invention heat treats the solidified material at a temperature below the initial crystallization temperature for a few minutes to 15 hours, or at a temperature above the initial crystallization temperature for a few seconds to 2 hours. Process. The initial crystallization temperature is the temperature of the first exothermic characteristic in the DTA scan of the amorphous alloy when the temperature is raised above the glass transition temperature. Heat treatment at a relatively low temperature moderates the reaction rate. A slow reaction rate is thought to lead to the formation of small crystals. For details, see the preferred embodiments described below.

  To obtain materials with special surface properties, see, for example, Kundig AA, Cucinelli M, Uggowitzer PJ, Dominmann A, Microelect. Eng. 67, 405 (2003): “Formation of high-aspect-ratio surface microstructure using zirconium-based bulk metallic glass” or the method described in patent application PCT / CH2004 / 000401. What is necessary is just to make it. The contents of these documents are incorporated herein in their entirety for reference. Refinement can be achieved by pouring a liquid alloy into a mold that itself has a microstructure. For details, refer to the above-mentioned paper by Kundig et al. And PCT / CH2004 / 000401. In another embodiment, the already solidified alloy is brought to a superplastic state, i.e., easy to process, by heating it to a temperature above the glass transition temperature and pressed against the refined matrix. Refer to PCT / CH2004 / 000401 for details. In a preferred embodiment, the microstructured matrix is a silicon wafer that has been etched to provide a microstructure and is well known in the art. In yet another aspect, the liquid alloy is drawn into the capillary system by the capillary effect and rapidly solidifies within the capillary. For details, the teaching of PCT / CH2004 / 000401 is helpful.

  The invention also relates to the use of the alloys according to the invention in the manufacture of molded articles that come into contact with the human or animal body. In particular, the invention relates to the use of the alloys according to the invention for the production of surgical instruments, jewelry, in particular watch cases and prostheses, in particular prostheses called so-called stents. A stent is an artificial organ that is inserted into a blood vessel, and lines the inner surface of the blood vessel. Stents are used in particular to ensure sufficient blood flow in blood vessels or to stabilize blood vessels for the purpose of preventing aneurysms. Other implants in which the alloys of the invention can be used can be used in the field of osteosynthesis. For example, hip implants, artificial knees and the like. The invention also relates to artificial organs, in particular stents, made from the alloys of the invention.

  The alloy of the present invention is particularly suitable for such biomedical applications because of its high biocompatibility, high strength and high elasticity. In particular, the alloys according to the invention represented by the general composition Zr—Cu—Fe—Al or Zr—Fe—Al—Pd are very suitable for these purposes.

FIG. 1 is a very simplified schematic phase diagram of a binary alloy of zirconium and iron. FIG. 2 is a very simplified schematic phase diagram of a binary alloy of copper and zirconium. FIG. 3 is a very simplified schematic phase diagram of a binary alloy of iron and aluminum and the ε phase. FIG. 4 shows an alloy of composition Zr _54.4 Cu _25.6 Fe ₈ , Al ₁₂ Zr ₅₈ Cu ₂₂ Fe ₈ Al ₁₂ and Zr _61.6 Cu _18.4 Fe ₈ Al ₁₂ cast to 1 mm × 1 cm 2 ( It is an XRD pattern of an as-cast alloy. FIG. 5 shows the composition Zr _54.4 Cu _25.6 Fe ₈ Al ₁₂ , Zr ₅₈ Cu ₂₂ Fe ₈ Al ₁₂ and Zr _61.6 Cu _18.4 Fe ₈ cast as 1 mm × 1 cm 2 (as cast). Small angle neutron scattering intensity data for an alloy of Al ₁₂ (wave number Q = 4πsin θ / l, θ is half the scattering angle, and l is the wavelength of the neutron). 6 shows Zr _54.4 Cu _25.6 Fe ₈ Al ₁₂ , Zr ₅₈ Cu ₂₂ Fe ₈ Al ₁₂ , Zr _61.6 Cu _18.4 Fe ₈ Al ₁₂ and Zr ₆₅ Al _7.5 Ni ₁₀ Cu _{17. 5} is a DTA scan of a sample having a composition of ₅ performed at a heating rate of 20 K / min (T _g is the glass transition and T _x1 is the initial crystallization temperature). FIG. 7 is a DTA scan of Zr ₅₈ Cu ₂₂ Fe ₈ Al _{12 performed} at a heating rate of 20 K / min. FIG. 8 is a photograph showing a cast sample having a composition of Zr ₅₈ Cu ₂₂ Fe ₈ Al ₁₂ with a ruler indicating the actual size. FIG. 9 is an XRD pattern of Zr ₅₈ Cu ₂₂ Fe ₈ Al ₁₂ cast into 5 mm, 7 and 8 mm diameter cylindrical rods and a 1 mm thick (inset) plate. FIG. 10 is a DTA scan of Zr ₅₈ Cu ₂₂ Fe ₈ Al ₁₂ cast on cylindrical rods with a diameter of 5, 7, and 8 millimeters (heating rate 20 K / min). FIG. 11 is an XRD pattern of Zr _54.4 Cu _25.6 Fe ₈ Al ₁₂ cast into a 6 mm outer diameter cone. FIG. 12 is a DTA scan of Zr _61.6 Cu _18.4 Fe ₈ Al ₁₂ performed at a heating rate of 20 K / min. FIG. 13 is an SEM image of a fracture surface of vitreous Zr _61.6 Cu _18.4 Fe ₈ Al ₁₂ . FIG. 14 shows a room temperature tensile-strain curve of Zr ₅₈ Cu ₂₂ Fe ₈ Al ₁₂ cast (as-cast) into a 5 mm diameter cylinder. FIG. 15 shows the XRD pattern of Zr ₅₈ Cu ₂₂ Fe ₈ Al ₁₂ after fabrication and after several hours of annealing. FIG. 16 shows the XRD pattern (72 hour scan) of Zr ₅₈ Cu ₂₂ Fe ₈ Al ₁₂ after annealing at 708 K for 12 hours. The index indicates the presence of an icosahedral phase with a lattice constant of 4.76 angstroms. FIG. 17 shows a DTA scan of Zr ₅₈ Cu ₂₂ Fe ₈ Al ₁₂ immediately after manufacture and after annealing for several hours at different temperatures as shown (heating rate is 20 K / min). FIG. 18 is a result of small-angle neutron scattering measurement at a normal position of Zr ₅₈ Cu ₂₂ Fe ₈ Al ₁₂ carried out at a temperature of 708 K at different times. FIG. 19 shows the change in grain size and wrinkle of Zr ₅₈ Cu ₂₂ Fe ₈ Al ₁₂ using the Guinea approximation. FIG. 20 is a pseudo-ternary mixing diagram. FIG. 21 is a DTA scan of alloy Zr _68.3 (Fe _0.5 Al _0.5 ) _26.8 Pd _4.9 cast to a thickness of 1 millimeter. FIG. 22 is an X-ray diffraction pattern of alloy Zr _68.3 (Fe _0.5 Al _0.5 ) _26.8 Pd _4.9 cast to a thickness of 1 millimeter.

  Before describing specific examples and characteristics of the alloy of the present invention, the concept leading to the development of the alloy of the present invention will be described and illustrated.

Many binary alloys that form metallic glass when ultra-quenched have the composition A ₈₀ X ₂₀ . Here, the atomic radius of component A is considerably larger than the atomic radius of component X. The glass forming ability of alloys having such a large size ratio is explained by the topology effect. In the present invention, this “80-20 concept” has been generalized to quaternary or larger component alloys and has been successfully applied to the development of nickel-free bulk metallic glasses. Surprisingly, it has been found that an alloy with exceptionally good glass-forming ability is formed according to the principle described in claim 1. In the art, the presence of nickel improves the glass forming ability of alloys, particularly zirconium-based alloys, and therefore nickel is considered an essential component of many quaternary bulk glass-forming alloys, particularly zirconium-based alloys. Yes. On the other hand, the present inventors have found that nickel can be omitted by the principle of the present invention described below while obtaining an alloy having excellent glass forming ability.

  The present invention is not limited to the special compositions described below, but the principles underlying the present invention are illustrated below for alloys having the general composition Zr-Cu-Fe-Al. Of the four components present in such alloys, zirconium has the largest atomic size (radius = 0.160 nanometers). Together with iron (radius = 0.128 nanometers), zirconium forms a deep eutectic composition with iron close to 20 atomic percent (at.%). This is shown in FIG. This is very schematic, but shows a portion of the phase diagram for a binary Zr-Fe alloy. The movement between the various solid phases is omitted in this figure, but it only shows the liquidus where the phase diagram was expected, ie the liquidus temperature as a function of composition, to make the figure easier to understand. (S = solid, L = liquid). A deep eutectic feature at 24 atomic percent iron is clearly seen. This deep eutectic can be explained qualitatively by topologies.

  Zirconium and copper also have a eutectic composition, but as shown in FIG. 2, one of them occurs at 72.5% zirconium. This phase diagram is also shown very schematically, but shows the liquidus. Several other eutectics are expected at various compositions between 38.2 atomic percent and 72.5 atomic percent.

The fourth component of the general composition described above is aluminum. FIG. 3 is also shown very schematically, showing a portion of the phase diagram of a binary Al—Fe alloy. The movement between the various solid phases is also shown in this figure. In particular, a high temperature phase, the so-called ε phase 301, is present near the composition Al ₆ Fe ₄ . This phase prevents the presence of deep eutectics near 60 atomic percent of the Al-Fe phase diagram. If this deep eutectic is not prevented, it will occur by extrapolation, as shown by the dotted line in FIG. However, because the eutectic of Zr ₇₆ Fe ₂₄ and Zr _72.5 Cu _27.5 is already below 1000 ° C., the high temperature ε phase spanning 1102 degrees Celsius and 1232 degrees Celsius is no longer generated in quaternary alloys. .

These considerations led to the development of the composition (Zr _72.5 Cu _27.5 ) ₈₀ (Fe ₄₀ Al ₆₀ ) ₂₀ . This is the starting point for further observation, detailed below. This alloy exhibits excellent glass forming ability without further purification of the composition. Furthermore, it has been found that the composition of this alloy varies and retains good glass forming ability over a wide range of compositions.

  This indicates that the “80:20 concept” is successfully generalized to quaternary alloys. This concept is generally applicable and is not limited to the specific Zr—Cu—Fe—Al system described above. In particular, similar considerations may be applied to alloys based on titanium, hafnium, niobium, lanthanum, palladium, or platinum. Instead of copper, other elements having a deep eutectic together with the main component may be used. Particularly preferred are beryllium, silver and gold. Instead of the iron component, one or more transition metals other than nickel, such as cobalt, may be used. Instead of the aluminum component, for example zirconium or one or more metalloids may be used.

  Examples of the production method and characterization of the alloy of the present invention will be given below.

Example 1
Preparation and Characterization of Amorphous (Zr _x Cu _100-x ) ₈₀ (Fe ₄₀ Al ₆₀ ) ₂₀ Samples Several zirconium-based alloys (Zr _x Cu _100-x ) ₈₀ (Fe ₄₀ Al ₆₀ that do not contain nickel) ₂₀ was produced. Here, x is 60, 62, 64, 66, 68, 72.5, 77, 79, 81, 83, and 85. An ingot was produced by purging the components (purity> 99.9%) in an argon atmosphere gettered with titanium (purity: 99.9999%). Using a heating induction coil, the ingot was remelted with a quartz tube (vacuum ≈10 ⁻⁵ mbar) and injection cast into a copper mold with high purity argon. The sample was cast into a plate having a thickness of 0.5 mm, a width of 5 mm, and a length of 10 mm. In order to determine the critical casting thickness, some samples were additionally or alternatively cast into various rods and cones in the range up to 10 millimeters in diameter. In addition, some samples were made with a thickness of 1 millimeter and a cross section of 1 cm x 4 cm. These samples are then cut into various 1 cm long pieces, as deemed appropriate, and X-ray diffraction (XRD), small angle neutron scattering equipment (SANS), differential thermal analysis (DTA) and / or hardness. Observed by measurement. XRD was performed with a Scintag XDS-2000 X-ray diffractometer using a parallel beam monochromatic CuKα X-ray source. Thermophysical properties were observed using a Netzsch Proteus C550 DTA, SANS was performed at the Paul Scherrer Society in Switzerland, the wavelength used was λ = 6 Å, and the distance between sample and detector was 1.8. Meters, 6 meters and 20 meters.

FIG. 4 shows the composition Zr _54.4 Cu _25.6 Fe ₈ Al ₁₂ , Zr ₅₈ Cu ₂₂ Fe ₈ Al ₁₂ , and Zr _61.6 Cu _18.4 Fe ₈ Al ₁₂ , ie, x = 68, 72.5, The XRD pattern of an as-cast alloy of (Zr _x Cu _100-x ) ₈₀ (Fe ₄₀ Al ₆₀ ) ₂₀ that is 77 and 77. All samples show a typical XRD pattern with an amorphous structure without a Bragg peak. The amorphous nature was also confirmed by SANS. As is apparent from FIG. 5, the same sample does not show small angle scattering over a wide Q range. This proves the presence of a uniform amorphous structure.

From the DTA scan shown in FIG. 6 performed at a heating rate of 20 K / min, for all three alloys, there was an apparent glass transition followed by an extended undercooled liquid range followed by an exothermic crystallization peak. You can see that it exists. For comparison, an alloy Zr ₆₅ Al _7.5 Ni ₁₀ Cu _17.5 containing nickel was also observed with DTA. The results are shown in FIG. 6 for comparison. Furthermore, although the DTA scan shown in FIG. 7 was performed in a wider temperature range, it shows an exothermic melting peak of Zr ₅₈ Cu ₂₂ Fe ₈ Al ₁₂ .

Table 2 shows the feature values extracted from the DTA scan, similar to those in FIGS. The glass transition temperature T _g is extracted from the beginning of the endothermic event in FIG. 6 (upward arrow), and the initial crystallization temperature T _x1 is obtained from the beginning of the exothermic peak (downward arrow). The start of melting T _m and the end of melting T ₁ were obtained from a scan as shown in FIG. The new nickel-free alloy has an undercooled liquid range ΔT _x = T _x1 -T _{g of} 78 to 86K and a reduced glass transition temperature T _g / T _l between 0.56 and 0.57. Show. Table 2 _shows the ratio of _T g / T _m. This is because in many publications this ratio is used as the reduced glass transition temperature. The value of T _g / _{T m} is 0.62 from 0.59 for the new alloy containing no _nickel, significantly greater than the value of _{Zr 65 Al 7.5 Ni 10 Cu 17.5} .

Table 3 shows the Vickers hardness HV of alloys not containing nickel, measured at a load of 500 g. From these measurements, an approximate yield strength of 1.56 to 1.68 GPa is obtained using the similarity relationship σy = 3HV. That is, a detailed tensile strength test revealed that the alloy Zr ₅₈ Cu ₂₂ Fe ₈ Al _{12 had} a yield strength σy = 1.71 GPa and an elastic limit of 2.25%.

Detailed casting experiments have been performed on these nickel-free alloys. And these are the same experimental conditions as Zr ₆₅ Al _7.5 Ni ₁₀ Cu _17.5 and Zr _52.5 Ti ₅ Cu _17.9 Ni _14.6 Al ₁₀ (Vit105 (registered trademark)). Compared below. The alloy Zr ₅₈ Cu ₂₂ Fe ₈ Al ₁₂ (x = 72.5) could be cast into a completely amorphous state up to a rod diameter of 7 millimeters. FIG. 8 shows some examples of such cast samples. These examples demonstrate that molded articles used in actual applications can be produced from the alloys of the present invention. The wedge-shaped sample is completely amorphous up to a diameter of 7 millimeters.

FIG. 9 shows the X-ray diffraction pattern of Zr ₅₈ Cu ₂₂ Fe ₈ Al ₁₂ cast on cylindrical rods with diameters of 5, 7, and 8 millimeters and a 1 millimeter thick plate (inset). No obvious Bragg peak can be observed in either the 5 millimeter rod sample or the 1 millimeter plate, and only a very weak Bragg peak is seen in the 7 millimeter rod sample. In contrast, a clear crystalline component is present in the 8 millimeter rod sample, as evidenced by the strong Bragg peak.

  These findings are consistent with the DTA scan shown in FIG. This DTA scan was performed on 5 millimeter, 7 millimeter, and 8 millimeter rod samples. A clear exothermic crystallization peak is observed in the 5 and 7 millimeter samples, but not in the 8 millimeter sample.

  Similarly, an alloy with x = 68, 77 can be cast in the form of a rod having an amorphous structure and a diameter of at least 5 millimeters.

FIG. 11 shows the XRD pattern of Zr _54.4 Cu _25.6 Fe ₈ Al ₁₂ (x = 68) cast into a cone with a maximum outer diameter of 6 millimeters. An XRD scan was performed on a 0.5 millimeter thick plate cut perpendicular to the longitudinal axis of the cone. The average diameter of these plates is illustrated. The XRD pattern of plates with a diameter of 5 millimeters or less shows a typical amorphous structure, and a plate with a diameter of 6 millimeters has several Bragg peaks that show a very small volume fraction of crystals within the amorphous matrix. Looks like it shows. This is in complete agreement with the finding for rods with a uniform diameter.

FIG. 12 shows a DTA scan of Zr _61.6 Cu _18.4 Fe ₈ Al ₁₂ (x = 77) performed at a heating rate of 20 K / min. Obvious glass transition, crystallization and melting properties are observed. FIG. 13 is an SEM image showing a fracture surface of vitreous Zr _61.6 Cu _18.4 Fe ₈ Al ₁₂ (x = 77) typical of amorphous glass. These findings prove that Zr _61.6 Cu _18.4 Fe ₈ Al ₁₂ (x = 77) has an excellent glass forming ability.

In summary, of the three alloys with x = 68, 72.5, and 77, the alloy Zr ₅₈ Cu ₂₂ Fe ₈ Al ₁₂ (x = 72.5) is the largest glass comparable to Vit105®. Has ability to form. The next best glass forming ability is Zr _61.6 Cu _18.4 Fe ₈ Al ₁₂ and Zr _54.4 Cu _25.6 Fe ₈ Al ₁₂ , followed by conventional alloys Zr ₆₅ Al _7.5 Ni ₁₀ Cu _17.5 . These experimental results are shown in Turnbull theory (D. Turnbull, Contemp. Phys. 10, 473 (1969), F. Spapen and D. Turnbull, Proc. Sec. Int. Conf. On Rapid. On Rapid. M.I.T. Press, 1976), pp. 205-229) and are well matched, the best glass-forming ability is expected to be obtained in the alloy with the highest ratio of _T g / _{T l} The

FIG. 14 shows the tensile stress-strain curve for an as-cast cylindrical sample Zr ₅₈ Cu ₂₂ Fe ₈ Al ₁₂ (x = 72.5) with a diameter of 5 millimeters. Hook's law applies well for strains up to 2.25%. The excellent elastic modulus and high tensile strength evident from this figure are just one example of the excellent mechanical properties of the alloys of the present invention.

  Alloys where x = 60, 62, 64, 66, 79, 81, 83, 85 were also observed in a similar manner selected. Alloys where x is between 62 and 81 are amorphous when cast to a thickness of 0.5 millimeters. When cast to a thickness of 0.5 millimeters, the alloy with x = 60 is crystalline, the alloy with x = 83 is partially amorphous, and the alloy with x = 85 is crystalline.

  As is apparent from this example, the composition of the material can be varied over a wide range without compromising the glass forming ability. In particular, changes that occur in the composition with respect to other component elements, and moderate changes that occur in the numbers of a and y do not significantly change the glass forming ability. Furthermore, the addition of a small amount of additional components does not adversely affect or improve the glass forming ability of the alloy of the present invention. On the other hand, certain desirable characteristics may be improved.

Example 2
Preparation of mixed phase sample A sample having a mixed phase structure was prepared as follows. A completely amorphous sample Zr ₅₈ Cu ₂₂ Fe ₈ Al ₁₂ was prepared in the same manner as in Example 1. Samples were heat treated at various temperatures for 12 hours (annealed, indicated as ann in FIG. 15). XRD patterns and DTA scans were recorded for the heat treated samples. FIG. 15 shows the XRD pattern of the fabricated state (bottom trace) and the sample immediately after annealing. The XRD pattern shows a typical amorphous structure up to an annealing temperature of 683K. At higher annealing temperatures, a clear Bragg peak derived from the icosahedral phase (IP) is observed. At higher temperatures, a peak typical of the Zr ₂ Fe structure is observed. FIG. 16 shows in more detail the XRD pattern of a sample annealed at 708K for 12 hours. The index indicates the presence of an icosahedral phase with a lattice constant of 0.476 nanometers. FIG. 17 shows a DTA scan of the same sample as shown in FIG. This DTA scan is consistent with the development of a glassy and crystalline structure.

For better characterize the structure after annealing, the small angle neutron scattering (SANS) experiments in normal position, the _Zr 58 _Cu 22 _Fe 8 _{Al 12} was the first fully _amorphous, in annealing at a temperature 708K Implemented. The results are shown in FIG. The total annealing time is as shown. From this result, it is shown that a crystalline region is first developed in a completely amorphous sample. Its typical size is only a few nanometers. These data were analyzed applying the Guinier approximation. FIG. 19 shows the change with time of the particle diameter に お け る in this approximation. This clearly demonstrates the expression of nanocrystals in a vitreous matrix. The production of such nanocrystals is facilitated by keeping the annealing temperature slightly above the experimental glass transition temperature. In particular, it is facilitated by keeping it in the range of 0 to 150 K above the experimental glass transition temperature. The glass transition temperature at the experimental level is considered to be the glass transition temperature determined using DSC (Differential Scanning Calorimetry) at a typical heating rate of 20 K / min. Higher annealing temperatures often lead to the deposition of larger crystals, for example from 0.1 to 20 microns.

  Such mixed phase materials have somewhat different mechanical properties than completely glassy materials. In particular, ductility often improves. It can be explained by the fact that, due to shear forces, the shear bands that develop during production and lead to the destruction of the material are broken up by the crystals. These properties are particularly advantageous in applications where the material must be processed and deformed during manufacture of the final product.

Example 3
Compositional changes Samples with a very wide range of compositions were made and observed. When the composition in the table below is cast into a plate of 1 millimeter thickness (Table 4), 0.5 millimeter thickness (Table 5), or 0.2 millimeter thickness (Table 6), at least partially It was proved to be amorphous.

  For comparison, binary, ternary, or nickel-containing alloys shown in Table 7 were also observed, and at least partially developed an amorphous structure when cast to a thickness of 0.2 millimeters. .

In particular, this list shows that ternary, nickel-free alloys have good glass-forming ability when formulated according to the “80:20 scheme”. In particular, this list shows that _a ternary alloy having the composition (Zr _x D _100-x ) _a Fe _100-a has good glass forming ability when the number a is in the range of about 70 to about 90, especially around 80. It shows that it has. Here, D is preferably copper, niobium, aluminum or tin.

The alloys of Table 8 were also made and found to be completely amorphous when superquenched at a high cooling rate of approximately 10 ⁶ K / sec at a thickness of 20 microns. These alloys may be considered candidates for bulk metallic glasses, and casting experiments are necessary to prove which of these are bulk metallic glasses.

  It was also found that the ternary and binary alloys listed in Table 9 were completely amorphous when supercooled. These are listed for comparison purposes.

  A wide range of alloys according to the present invention investigated in these experiments have been shown to be able to vary in composition over a wide range without losing glass forming ability.

Example 4
Examples of the alloy containing no nickel was developed biocompatibility testing new, to determine the cytotoxicity of the alloy _{Zr 58 Cu 22 Fe 8 Al 12} . The effect of surface change due to passivation in diluted nitric acid was also investigated.

  Surface analysis using XPS revealed that a natural oxide layer consisting of mostly zirconium oxide with a thickness of 7-8 nanometers was formed on the surface of the glass. This layer protects the fibroblasts of research mice from toxic metals, especially copper, present in the bulk and promotes good cell growth for the alloy. Indirect testing has shown that this layer is stable in PBS (phosphate buffer) for weeks and is not affected by toxicity due to the high ion concentration diffusing into the medium.

  The thickness of the zirconia layer increased slightly with nitric acid passivation. However, this treatment clearly improved the surface layer quality. This increases anticorrosion and reduces the diffusion of bulk elements into the medium, resulting in improved biocompatibility. After passivation treatment, the alloy exhibits cell growth comparable to that on polystyrene, which is used here as a negative control.

  In conclusion, the cytotoxic properties of the metallic glass of the present invention are very promising and show very good biocompatibility.

Example 5
Copper and Nickel-Free Alloys Copper has been problematic in many medical applications, and studies have been conducted on alloys that do not contain copper. Beginning with the Zr-Cu-Fe-Al bulk metallic glass of the previous example, palladium has proven to be a promising metal to replace copper in such alloys. In order to systematically study bulk metal alloys, pseudo-ternary Zr— (Fe _0.5 Al _0.5 ) —Pd alloys have been mentioned. Initially, the amount of palladium is 0% and approximately 22% along the (Fe _0.5 Al _0.5 ) ₃₀ line in the pseudo-ternary system Zr— (Fe _0.5 Al _0.5 ) —Pd system. Will be changed between. On the other hand, the ratio of the sum of atomic percentages of Zr and Fe and the sum of atomic percentages of Al and Pd was selected according to the concept of 80:20. In this way, a number of initial alloy compositions having favorable glass forming ability have been identified. The composition changed near these initial compositions in repetitions in the range of pseudobinary Zr— (Fe _0.5 Al _0.5 ) —Pd compositions.

  The table below summarizes the results found in these observations.

  The examples of Tables 10, 11 and 12 are shown as black squares in the pseudo-ternary mixing diagram of FIG. From this figure, an alloy containing at least 50 atomic percent zirconium, at least 0.5 atomic percent palladium, and a mixture of at least 19 atomic percent iron and aluminum in approximately equal atomic ratios is expected to have excellent glass-forming ability. Is done. This is also true for such alloys containing at least about 59 atomic percent zirconium, up to about 36 atomic percent iron and aluminum mixtures, and / or at least 4 atomic percent palladium. In particular, in FIG. 20, it can be reasonably expected that all alloys in the region indicated by the trapezoid have excellent glass forming ability. A slight change in the relative ratio of iron to aluminum within a few percent, ie between 60:40 and 40:60, or more preferably between 55:45 and 45:55 has a strong influence on the glass forming ability. Is not expected to affect

  In particular, all alloys in Tables 10 and 11 and most alloys in Table 12 correspond to the 80:20 principle in the following sense: The meaning is that the ratio of the sum of atomic percent of zirconium and iron to the sum of atomic percent of aluminum and palladium is approximately 80:20. In the examples of Tables 10 and 11, the ratio of the Zr + Fe atom content to the Al + Pd atom content varies between approximately 73:27 and approximately 87:13. The 80:20 principle is well realized for the alloys shown in Table 10, ie all alloy compositions found to have the highest critical cast thickness. Here, the corresponding ratio varies between approximately 80:20 and approximately 83:17.

  With respect to changes in the Zr-Fe subsystem, in the preferred compositions of Tables 10 and 11, the ratio of atomic percent zirconium to atomic percent iron is between approximately 76:24 and approximately 89:11. This seems to be the preferred range. In particular, in the example of Table 10, this ratio varies between approximately 81:19 and approximately 85:15. In contrast, the aluminum to palladium ratio clearly varies over a wider range without adversely affecting the glass forming ability of the alloy. In the examples of Tables 10 and 11, the ratio of atomic percent of aluminum to atomic percent of palladium varies between approximately 40:60 and 82:18. In particular, in the example of Table 10, this ratio varies between approximately 65:35 and approximately 78:22.

  In the above example, replacing palladium partially or completely with platinum further improves biocompatibility. Platinum has properties very similar to palladium, such as the external electronic structure, and as a result, has a similar gold schmidt radius. Therefore, partial or complete replacement of palladium with platinum will not have a strong effect on the mechanical properties or glass forming ability of the alloy.

As an example of measurements performed on an alloy containing no copper, FIG. 21 shows a DTA scan of Zr _68.3 (Fe _0.5 Al _0.5 ) _26.8 Pd _4.9 cast to 1 millimeter, 22 shows an X-ray diffraction pattern when Co-Kα is used as the X-ray source. The DTA scan shows a clear glass transition and a second crystallization phenomenon. On the other hand, the X-ray diffraction pattern shows a broad hump indicating the presence of an amorphous material.

The following alloys containing no copper were also found to be at least partially amorphous when cast to 0.5 millimeters.
Zr ₆₉ Fe ₁₅ Al ₁₅ Y _1, Zr _68.5 Fe ₁₅ Al ₁₅ Y _1.5.
In these examples, palladium is completely replaced by yttrium.

A further example of an alloy that was found to be at least partially amorphous when cast to 0.2 millimeters is Zr ₇₀ Fe ₂₈ Nb ₁ Sn ₁ .

  The above examples are merely illustrative and the present invention is not limited to these examples.

at% atomic percent XRD X-ray diffraction SEM scanning electron microscope SANS small angle neutron neutron scattering DTA differential temperature analysis DSC differential scanning calorimetry T _g glass transition temperature T _x1 initial crystallization temperature ΔT _x undercooled liquid region T ₁ end of melting (Liquidus temperature)
T _m Melting start T Temperature σ _y Yield strength HV Vicker hardness S Solid L Liquid 2θ Scattering angle Int Strength a. u. Arbitrary unit Q Wave number S (Q) Scattering intensity q Heat transfer cps Count per second σ Tensile stress ε Strain IP Regular icosahedron phase ann. Annealed Φ Particle size

Claims (18)

Includes an amorphous phase, the general formula _{[Zr x Fe 100-x)} a (Al y G 100-y) 100-a] represented by _{100-b Z b,} where, a, b, x, y are A real number indicating atomic percent, 70 ≦ a ≦ 90, x ≧ 50, y> 0, 0 ≦ b ≦ 6, G is at least one element selected from the group consisting of platinum and palladium, and Z Is a component composed of at least one element, and all elements of G and Z are different from each other and are not zirconium, iron, and aluminum, and the alloy is substantially free of copper and nickel .   The alloy according to claim 1, characterized in that G is palladium.   Alloy according to claim 1 or 2, characterized in that the atomic percentages of iron and aluminum are equal.   The alloy according to claim 1, wherein 68 ≦ x ≦ 89 and 73 ≦ a ≦ 87.   The alloy according to claim 1, wherein 40 ≦ y ≦ 82.   The alloy according to claim 1, wherein 81 ≦ x ≦ 85, 80 ≦ a ≦ 83, and 65 ≦ y ≦ 80.   The alloy according to claim 1, wherein 0 ≦ b ≦ 2.   b> 0, and Z is at least one selected from the group consisting of titanium, hafnium, vanadium, niobium, yttrium, chromium, molybdenum, iron, cobalt, tin, zinc, phosphorus, palladium, silver, gold, and platinum The alloy according to claim 1, wherein the alloy is an element.   The alloy according to claim 1, wherein b = 0. An alloy comprising an amorphous phase and represented by the general formula Zr _i (Fe _{50 + ε} Al _50-ε ) _j X _k (X is one or more elements selected from the group consisting of palladium and platinum; j, k, and ε are real numbers representing atomic percent, and −10 ≦ ε ≦ 10, i ≧ 50, j ≧ 19, k ≧ 0.5, i + j + k = 100).   11. Alloy according to claim 10, characterized in that X is palladium.   The alloy according to claim 10, wherein 62 ≦ i ≦ 77.   The alloy according to claim 10, wherein 19 ≦ j ≦ 34.   The alloy according to claim 10, wherein −2 ≦ ε ≦ 2.   14. Alloy according to claim 10, characterized in that ε is zero and 66 ≦ i ≦ 70, 25 ≦ j ≦ 29 and 4 ≦ k ≦ 7. The alloy has the following formula: Zr ₆₇ Fe _13.2 Al _13.2 Pd _6.6 , Zr _69.7 Fe _12.95 Al _12.95 Pd _4.4 , Zr _66.7 Fe _14.45 Al _{14. 45} Pd _4.4 , Zr _68.3 Fe _13.4 Al _13.4 Pd _4.9 , Zr _65.4 Fe _14.85 Al _14.85 Pd _4.9 , Zr _62.3 Fe _16.7 Al _{16 .7} Pd _4.3 , Zr _59.2 Fe _18.3 Al _18.3 Pd _4.2 , Zr ₇₂ Fe _11.5 Al _11.5 Pd ₅ , Zr _73.4 Fe _10.9 Al _10.9 Pd _4.8 , Zr _75.2 Fe _10.2 Al _10.2 Pd _4.3 , Zr ₇₇ Fe _9.5 Al _9.5 Pd ₄ , Zr _67.9 Fe _11.8 Al _11.8 Pd _8.5 , _Zr 65 _{Fe 11 4 Al 11.4 Pd 12.2, Zr 62.5} Fe 10.75 either _Al 10.75 _{Pd 16,} wherein _{Zr i (Fe 50 Al 50)} 30 Pd 70-i (62 ≦ i ≦ 69.5 ), In particular the formula Zr _69.5 Fe ₁₅ Al ₁₅ Pd _0.5 , Zr ₆₉ Fe ₁₅ Al ₁₅ Pd _0.5 , Zr ₆₈ Fe ₁₅ Al ₁₅ Pd ₂ , Zr ₆₇ Fe ₁₅ Al ₁₅ Pd ₃ , Zr ₆₆ Fe ₁₅ Al ₁₅ Pd ₄ , Zr ₆₅ Fe ₁₅ Al ₁₅ Pd ₅ , Zr ₆₄ Fe ₁₅ Al ₁₅ Pd ₆ , Zr ₆₃ Fe ₁₅ Al ₁₅ Pd ₇ , Zr ₆₂ Fe ₁₅ Al ₁₅ Pd ₈ , or Zr ₇₁ Fe _{12 Al 12 Pd 5, Zr 69} Fe 12.85 Al 12.85 Pd 5.3, Zr 66.8 Fe 13.7 Al _{3.7 Pd 5.8, Zr 65 Fe 14.5} Al 14.5 Pd 6, Zr 61.9 Fe 16.2 Al 16.2 Pd 5.7, Zr 50 Fe 12 Al 12 Pd 26, Zr 53. ₂ Fe _12.6 Al _12.6 Pd _21.6 , Zr _57.6 Fe _13.95 Al _13.95 Pd _14.5 , Zr ₆₀ Fe _14.3 Al _14.3 Pd _11.4 The alloy according to any one of claims 1 to 15, characterized in that:   The alloy according to claim 1, comprising an amorphous phase and a crystalline phase. The amorphous phase is obtained by cooling at a cooling rate of 1000 K / sec or less from a temperature above the melting point of the alloy to a temperature below the glass transition temperature of the amorphous phase. 18. The alloy according to any one of 17.

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