Bulk nickel-phosphorus-boron glasses bearing manganese, niobium and tantalum

Abstract

The present disclosure is directed to NiPB alloys and glasses containing small fractions of Nb and Ta and optionally Mn. Over a specific range, the alloys are capable of forming bulk metallic glasses having critical casting thickness in excess of 1 mm. In one embodiment, compositions with a Mn content of between 3 and 4 atomic percent, Nb content of about 3 atomic percent, B content of about 3 atomic percent, and P content of about 16.5 atomic percent, where the balance in Ni, were capable of forming bulk metallic glass rods with diameters as large as 5 mm or larger. In another embodiment, Ni-based compositions with a Mn content of between 5 and 7 atomic percent, Ta content of between 1 and 2 atomic percent, B content of about 3 atomic percent, and P content of about 16.5 atomic percent, where the balance in Ni, were capable of forming bulk metallic glass rods with diameters as large as 5 mm or larger.

Claims

1. An alloy capable of forming a metallic glass represented by the following formula (subscripts denote atomic percentages):
Ni.sub.(100-a-b-c-d)Mn.sub.aX.sub.bP.sub.cB.sub.d(1) where: a is 0.25 to 15 b is between 0.5 and 10 c is between 12 and 21 d is between 1 and 6 wherein X is at least one of Nb and Ta, wherein the alloy has a critical rod diameter of at least 1 mm.

2. The alloy of claim 1, wherein the sum of c and d is between 18.5 and 20.5.

3. The alloy of claim 1, wherein the sum of c and d is between 19 and 20.

4. The alloy of claim 1, wherein X is Nb, a is between 0.25 and 5, b is between 1.5 and 4.5, c is between 15.25 to 17.75, and d is between 1.5 and 4.5.

5. The alloy of claim 1, wherein X is Nb, a is between 0.5 and 4.5, b is between 2 and 4, c is between 15.5 to 17.5, and d is between 2 and 4, and wherein the critical rod diameter is at least 2 mm.

6. The alloy of claim 1, wherein X is Nb, a is between 1 and 4, b is between 2 and 4, c is between 16 to 17, and d is between 2.25 and 3.75, and wherein the critical rod diameter is at least 3 mm.

7. The alloy of claim 1, wherein X is Nb, a is between 2.5 and 3.75, b is between 2.5 and 3.5, c is between 16.25 to 16.75, and d is between 2.5 and 3.5, and wherein the critical rod diameter is at least 4 mm.

8. The alloy of claim 1, wherein X is Ta, a is between 3 and 9, b is between 0.5 and 4.5, c is between 15.25 to 17.75, and d is between 1.5 and 4.5.

9. The alloy of claim 1, wherein X is Ta, a is between 4 and 8, b is between 0.5 and 4, c is between 15.5 to 17.5, and d is between 2 and 4, and wherein the critical rod diameter is at least 2 mm.

10. The alloy of claim 1, wherein X is Ta, a is between 4.25 and 7.75, b is between 0.5 and 3.5, c is between 16 to 17, and d is between 2.25 and 3.75, and wherein the critical rod diameter is at least 3 mm.

11. The alloy of claim 1, wherein X is Ta, a is between 4.5 and 7.5, b is between 0.5 and 3.25, c is between 16.25 to 16.75, and d is between 2.5 and 3.5, and wherein the critical rod diameter is at least 4 mm.

12. A metallic glass comprising an alloy of claim 1.

13. The metallic glass of claim 12, wherein the metallic glass has a notch toughness of at least 60 MPa m.sup.1/2.

14. The metallic glass of claim 12, wherein the metallic glass has a yield strength of at least 2150 MPa.

15. A method of producing the metallic glass of claim 12 comprising: melting the alloy into a molten state to form a melt; and quenching the melt at a cooling rate sufficiently rapid to prevent crystallization of the alloy.

16. The method of claim 15, further comprising fluxing the melt with a reducing agent prior to quenching.

17. The method of claim 15, wherein the reducing agent is boron oxide.

18. The method of claim 15, wherein the melt prior to quenching is heated to at least 1200 C.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The description will be more fully understood with reference to the following figures and data graphs, which are presented as various embodiments of the disclosure and should not be construed as a complete recitation of the scope of the disclosure.

(2) FIG. 1 provides a plot showing the effect of substituting Ni by Mn on the glass forming ability of Ni.sub.77.5-xMn.sub.xNb.sub.3P.sub.16.5B.sub.3 alloy, in accordance with embodiments of the present disclosure.

(3) FIG. 2 provides a plot showing calorimetry scans at a heating rate of 20 K/min for sample metallic glasses Ni.sub.77.5-xMn.sub.xNb.sub.3P.sub.16.5B.sub.3, in accordance with embodiments of the present disclosure. Arrows from left to right designate the glass-transition and liquidus temperatures, respectively.

(4) FIG. 3 provides a plot showing the effect of substituting Nb by Mn on the glass forming ability of Ni.sub.74Mn.sub.xNb.sub.6.5-xP.sub.16.5B.sub.3 alloys, in accordance with embodiments of the present disclosure.

(5) FIG. 4 provides a plot showing calorimetry scans at a heating rate of 20 K/min for sample metallic glasses Ni.sub.74Mn.sub.xNb.sub.6.5-xP.sub.16.5B.sub.3, in accordance with embodiments of the present disclosure. Arrows from left to right designate the glass-transition and liquidus temperatures, respectively.

(6) FIG. 5 provides a plot showing the effect of substituting Ni by Nb on the glass forming ability of Ni.sub.77-xMn.sub.3.5Nb.sub.xP.sub.16.5B.sub.3 alloys, in accordance with embodiments of the present disclosure.

(7) FIG. 6 provides a plot showing calorimetry scans at a heating rate of 20 K/min for sample metallic glasses Ni.sub.77-xMn.sub.3.5Nb.sub.xP.sub.16.5B.sub.3, in accordance with embodiments of the present disclosure. Arrows from left to right designate the glass-transition and liquidus temperatures, respectively.

(8) FIG. 7 provides a plot showing the effect of substituting P by B on the glass forming ability of Ni.sub.74Mn.sub.3.5Nb.sub.3P.sub.19.5-xB.sub.x alloys, in accordance with embodiments of the present disclosure.

(9) FIG. 8 provides a plot showing calorimetry scans at a heating rate of 20 K/min for sample metallic glasses Ni.sub.74Mn.sub.3.5Nb.sub.3P.sub.19.5-xB.sub.x, in accordance with embodiments of the present disclosure. Arrows from left to right designate the glass-transition and liquidus temperatures, respectively.

(10) FIG. 9 provides a plot showing the effect of varying the metal to metalloid ratio, according to the formula (Ni.sub.0.919Mn.sub.0.043Nb.sub.0.037).sub.100-x(P.sub.0.846B.sub.0.154).sub.x, in accordance with embodiments of the present disclosure.

(11) FIG. 10 provides a plot showing calorimetry scans at a heating rate of 20 K/min for sample metallic glasses (Ni.sub.0.919Mn.sub.0.043Nb.sub.0.037).sub.100-x(P.sub.0.846B.sub.0.154).sub.x, in accordance with embodiments of the present disclosure. Arrows from left to right designate the glass-transition and liquidus temperatures, respectively.

(12) FIG. 11 provides an image of an amorphous 5 mm rod of sample metallic glass Ni.sub.74Mn.sub.3.5Nb.sub.3P.sub.16.5B.sub.3, in accordance with an embodiment of the present disclosure.

(13) FIG. 12 provides an x-ray diffractogram verifying the amorphous structure of a 5 mm rod of sample metallic glass Ni.sub.74Mn.sub.3.5Nb.sub.3P.sub.16.5B.sub.3, in accordance with an embodiment an the present disclosure.

(14) FIG. 13 provides a compressive stress-strain diagram for sample metallic glass Ni.sub.74Mn.sub.3.5Nb.sub.3P.sub.16.5B.sub.3, in accordance with an embodiment of the present disclosure.

(15) FIG. 14 provides a plot showing the effect of substituting Mn by Ta on the glass forming ability of Ni.sub.74Mn.sub.6.5-xTa.sub.xP.sub.16.5B.sub.3 alloy, in accordance with embodiments of the present disclosure.

(16) FIG. 15 provides a plot showing calorimetry scans at a heating rate of 20 K/min for sample metallic glasses Ni.sub.74Mn.sub.6.5-xTa.sub.xP.sub.16.5B.sub.3, in accordance with embodiments of the present disclosure. Arrows from left to right designate the glass-transition and liquidus temperatures, respectively.

(17) FIG. 16 provides a plot showing the effect of substituting Ni by Mn on the glass forming ability of Ni.sub.79-xMn.sub.xTa.sub.1.5P.sub.16.5B.sub.3 alloys, in accordance with embodiments of the present disclosure.

(18) FIG. 17 provides a plot showing calorimetry scans at a heating rate of 20 K/min for sample metallic glasses Ni.sub.79-xMn.sub.xTa.sub.1.5P.sub.16.5B.sub.3, in accordance with embodiments of the present disclosure. Arrows from left to right designate the glass-transition and liquidus temperatures, respectively.

(19) FIG. 18 provides a plot showing the effect of substituting Ni by Mn on the glass forming ability of Ni.sub.74.5-xMn.sub.6Ta.sub.xP.sub.16.5B.sub.3 alloys, in accordance with embodiments of the present disclosure.

(20) FIG. 19 provides a plot showing calorimetry scans at a heating rate of 20 K/min for sample metallic glasses Ni.sub.74.5-xMn.sub.6Ta.sub.xP.sub.16.5B.sub.3, in accordance with embodiments of the present disclosure. Arrows from left to right designate the glass-transition and liquidus temperatures, respectively.

(21) FIG. 20 provides an image of an amorphous 5 mm rod of sample metallic glass Ni.sub.73Mn.sub.6Ta.sub.1.5P.sub.16.5B.sub.3, in accordance with an embodiment of the present disclosure.

(22) FIG. 21 provides an x-ray diffractogram verifying the amorphous structure of a 5 mm rod of sample metallic glass Ni.sub.73Mn.sub.6Ta.sub.1.5P.sub.16.5B.sub.3, in accordance with an embodiment of the present disclosure.

(23) FIG. 22 provides a compressive stress-strain diagram for sample metallic glass Ni.sub.73Mn.sub.6Ta.sub.1.5P.sub.16.5B.sub.3, in accordance with an embodiment of the present disclosure.

(24) FIG. 23 provides an image of a plastically bent 1 mm amorphous rod of example metallic glass Ni.sub.74Mn.sub.3.5Nb.sub.3P.sub.16.5B.sub.3.

DETAILED DESCRIPTION

(25) The present disclosure is directed to alloys, metallic glasses, and methods of making and using the same. In some aspects, the alloys are described as capable of forming metallic glasses having certain characteristics. It is intended, and will be understood by those skilled in the art, that the disclosure is also directed to metallic glasses formed of the disclosed alloys described herein.

(26) Definitions

(27) In the present disclosure, the term entirely free of an element means not more than amounts of the element found in naturally occurring trace amounts.

(28) The glass-forming ability of each alloy can be quantified by the critical rod diameter, defined as the largest rod diameter in which the amorphous phase (i.e. the metallic glass) can be formed when processed with a method of water quenching a quartz tube with 0.5 mm thick wall containing a molten alloy.

(29) The notch toughness is defined as the stress intensity factor at crack initiation K.sub.q when measured on a 3 mm diameter rod containing a notch with length ranging from 1 to 2 mm and root radius ranging from 0.1 to 0.15 mm. Notch toughness is the measure of the material's ability to resist fracture in the presence of a notch. The notch toughness is a measure of the work required to propagate a crack originating from a notch. A high K.sub.q ensures that the material will be tough in the presence of defects.

(30) The compressive yield strength, .sub.y, is the measure of the material's ability to resist non-elastic yielding. The yield strength is the stress at which the material yields plastically. A high .sub.y ensures that the material will be strong.

(31) Bending ductility is a measure of the material's ability to deform plastically and resist fracture in bending in the absence of a notch or a pre-crack. A high bending ductility ensures that the material will be ductile in a bending overload.

(32) Description of Metallic Glasses and Alloy Compositions

(33) The toughness of Ni-based metallic glasses bearing P and B may obey a correlation with the Ni content. For example, as shown in U.S. patent application Ser. No. 14/067,521, the notch toughness of P and B bearing Ni-based metallic glasses with Ni content below 70 atomic percent (e.g. samples 8-10 in Table 1) are lower than those with higher Ni content (e.g. samples 1-7 in Table 1). Hence discovering bulk P and B bearing Ni-based glasses having Ni content in excess of 70 atomic percent may enable better combinations of glass forming ability and toughness.

(34) In certain embodiments of the present disclosure, it was found that NiPB alloys containing small fractions of Nb and Ta and optionally Mn and being entirely free of Cr or Mo, demonstrate critical rod diameters comparable to the NiCrNbPB and NiCrTaPB alloys. For example, in some embodiments, Ni-based compositions with a Mn content of between 3 and 4 atomic percent, Nb content of about 3 atomic percent, B content of about 3 atomic percent, and P content of about 16.5 atomic percent have critical rod diameters as large as 5 mm or larger. In other embodiments, Ni-based compositions with a Mn content of between 5 and 7 atomic percent, Ta content of between 1 and 2 atomic percent, B content of about 3 atomic percent, and P content of about 16.5 atomic percent have critical rod diameters as large as 5 mm or larger.

(35) It will be understood to those of skill in the art that description of the atomic percent of elements in alloys described herein also describe metallic glasses, as described herein.

(36) NiMnNbPB alloys

(37) Sample metallic glasses 1-9 showing the effect of substituting Ni by Mn, according to the formula Ni.sub.77.5-xMn.sub.xNb.sub.3P.sub.16.5B.sub.3, are presented in Table 1 and FIG. 1. As shown, when the Mn atomic percent is between 0.25 and 5, the critical rod diameter is at least 1 mm, when it is between 0.5 and 4.5 the critical rod diameter is greater than 2 mm. When the Mn atomic percent is between 1 and 4, the critical rod diameter is greater than 3 mm. When the Mn atomic percent is between 2.5 and 3.75, the critical rod diameter is greater than 4 mm. And, when the Mn atomic percent is between 3.25 and 3.75, the critical rod diameter is 5 mm. Differential calorimetry scans for several sample metallic glasses in which Ni is substituted by Mn are presented in FIG. 2.

(38) TABLE-US-00001 TABLE 1 Sample metallic glasses demonstrating the effect of increasing the Mn atomic concentration at the expense of Ni on the glass forming ability of NiMnNbPB alloys Critical Rod Diameter Sample Composition [mm] 1 Ni.sub.77.5Nb.sub.3P.sub.16.5B.sub.3 1 2 Ni.sub.77Mn.sub.0.5Nb.sub.3P.sub.16.5B.sub.3 2 3 Ni.sub.76.5Mn.sub.1Nb.sub.3P.sub.16.5B.sub.3 2 4 Ni.sub.76Mn.sub.1.5Nb.sub.3P.sub.16.5B.sub.3 3 5 Ni.sub.75.5Mn.sub.2Nb.sub.3P.sub.16.5B.sub.3 3 6 Ni.sub.75Mn.sub.2.5Nb.sub.3P.sub.16.5B.sub.3 3 7 Ni.sub.74.5Mn.sub.3Nb.sub.3P.sub.16.5B.sub.3 4 8 Ni.sub.74Mn.sub.3.5Nb.sub.3P.sub.16.5B.sub.3 5 9 Ni.sub.73.5Mn.sub.4Nb.sub.3P.sub.16.5B.sub.3 2 10 Ni.sub.73Mn.sub.4.5Nb.sub.3P.sub.16.5B.sub.3 2 11 Ni.sub.72.5Mn.sub.5Nb.sub.3P.sub.16.5B.sub.3 1

(39) Sample metallic glasses 8, 12 and 13 showing the effect of substituting Nb by Mn, according to the formula Ni.sub.74Mn.sub.xNb.sub.6.5-xP.sub.16.5B.sub.3, are presented in Table 2 and FIG. 3. As shown, when the Mn atomic percent is between 3 and 4, the critical rod diameter is at least 3 mm, while when the Mn atomic percent is between 3.25 and 3.75, the critical rod diameter is at least 4, and in some embodiments at least 5 mm. Differential calorimetry scans for several sample metallic glasses in which Nb is substituted by Mn are presented in FIG. 4.

(40) TABLE-US-00002 TABLE 2 Sample metallic glasses demonstrating the effect of increasing the Mn atomic concentration at the expense of Nb on the glass forming ability of NiMnNbPB alloys Critical Rod Diameter Sample Composition [mm] 12 Ni.sub.74Mn.sub.3Nb.sub.3.5P.sub.16.5B.sub.3 3 8 Ni.sub.74Mn.sub.3.5Nb.sub.3P.sub.16.5B.sub.3 5 13 Ni.sub.74Mn.sub.4Nb.sub.2.5P.sub.16.5B.sub.3 3

(41) Sample metallic glasses 8, 14 and 15 showing the effect of substituting Ni by Nb, according to the formula Ni.sub.77-xMn.sub.3.5Nb.sub.xP.sub.16.5B.sub.3, are presented in Table 3 and FIG. 5. As shown, when the Nb atomic percent is between 2.5 and 3.5, the critical rod diameter is at least 3 mm, while when the Nb atomic percent is between 2.75 and 3.25, the critical rod diameter is at least 4 mm, and in some embodiments at least 5 mm. Differential calorimetry scans for several sample metallic glasses in which Ni is substituted by Nb are presented in FIG. 6.

(42) TABLE-US-00003 TABLE 3 Sample metallic glasses demonstrating the effect of increasing the Nb atomic concentration at the expense of Ni on the glass forming ability of NiMnNbPB alloys Critical Rod Diameter Sample Composition [mm] 14 Ni.sub.74.5Mn.sub.3.5Nb.sub.2.5P.sub.16.5B.sub.3 3 8 Ni.sub.74Mn.sub.3.5Nb.sub.3P.sub.16.5B.sub.3 5 15 Ni.sub.73.5Mn.sub.3.5Nb.sub.3.5P.sub.16.5B.sub.3 3

(43) Sample metallic glasses 8, 16 and 17 showing the effect of substituting P by B, according to the formula Ni.sub.74Mn.sub.3.5Nb.sub.3P.sub.19.5-xB.sub.x, are presented in Table 4 and FIG. 7. As shown, when the B atomic percent is between 2.5 and 3.5, the critical rod diameter is at least 2 mm, while when the B atomic percent is between 2.75 and 3.25, the critical rod diameter is at least 4 mm, and in some embodiments at least 5 mm. Differential calorimetry scans for several sample metallic glasses in which P is substituted by B are presented in FIG. 8.

(44) TABLE-US-00004 TABLE 4 Sample metallic glasses demonstrating the effect of increasing the B atomic concentration at the expense of P on the glass forming ability of NiMnNbPB alloys Critical Rod Diameter Sample Composition [mm] 16 Ni.sub.74Mn.sub.3.5Nb.sub.3P.sub.17B.sub.2.5 3 8 Ni.sub.74Mn.sub.3.5Nb.sub.3P.sub.16.5B.sub.3 5 17 Ni.sub.74Mn.sub.3.5Nb.sub.3P.sub.16B.sub.3.5 2

(45) Sample metallic glasses showing the effect of varying the metal to metalloid ratio, according to the formula (Ni.sub.0.919Mn.sub.0.043Nb.sub.0.037).sub.100-x(P.sub.0.846B.sub.0.154).sub.x, are presented in Table 5 and FIG. 9. As shown, when the metalloid atomic percent x is between 19 and 20, the critical rod diameter is at least 4 mm, while when the metalloid atomic percent is between 19.5 and 19.75, the critical rod diameter is at least 4 mm, and in some embodiments, at least 5 mm. Differential calorimetry scans for example metallic glasses in which the metal to metalloid ratio is varied are presented in FIG. 10.

(46) TABLE-US-00005 TABLE 5 Sample metallic glasses demonstrating the effect of increasing the total metalloid concentration at the expense of metals on the glass forming ability of NiMnNbPB alloys Critical Rod Diameter Sample Composition [mm] 18 Ni.sub.74.46Mn.sub.3.52Nb.sub.3.02P.sub.16.08B.sub.2.92 4 8 Ni.sub.74Mn.sub.3.5Nb.sub.3P.sub.16.5B.sub.3 5 19 Ni.sub.73.54Mn.sub.3.48Nb.sub.2.98P.sub.16.92B.sub.3.08 4

(47) Most sample metallic glasses in Tables 1-5 have nickel composition equal to or higher than 73.5 atomic percent, which is higher than the nickel composition in almost all the P and B Ni-based metallic glasses disclosed in the earlier disclosures (e.g., U.S. patent application Ser. No. 13/592,095 and U.S. patent application Ser. No. 14/067,521). The higher nickel concentration may enable a higher toughness.

(48) Among the alloy compositions investigated in this disclosure, the alloy exhibiting the highest glass-forming ability is Example 8, having composition Ni.sub.74Mn.sub.3.5Nb.sub.3P.sub.16.5B.sub.3, which demonstrates a critical rod diameter of 5 mm. The measured notch toughness and yield strength of sample metallic glass Ni.sub.74Mn.sub.3.5Nb.sub.3P.sub.16.5B.sub.3 are listed along with the critical rod diameter in Table 6. Example 8 provides a good combination of high toughness, high strength, and good glass forming ability. The notch toughness of the metallic glasses according to the disclosure is expected to be at least 60 MPa m.sup.1/2, and the yield strength at least 2150 MPa m.sup.1/2.

(49) An image of a 5 mm diameter amorphous Ni.sub.74Mn.sub.3.5Nb.sub.3P.sub.16.5B.sub.3 rod is shown in FIG. 11. An x-ray diffractogram taken on the cross section of a 5 mm diameter Ni.sub.74Mn.sub.3.5Nb.sub.3P.sub.16.5B.sub.3 rod verifying its amorphous structure is shown in FIG. 12. The stress-strain diagram for sample metallic glass Ni.sub.74Mn.sub.3.5Nb.sub.3P.sub.16.5B.sub.3 is presented in FIG. 13.

(50) TABLE-US-00006 TABLE 6 Critical rod diameter, notch toughness, and yield strength of Ni.sub.74Mn.sub.3.5Nb.sub.3P.sub.16.5B.sub.3 metallic glass. Critical Rod Notch Yield Diameter Toughness Strength Sample Composition [mm] [MPa m.sup.1/2] [MPa] 8 Ni.sub.74Mn.sub.3.5Nb.sub.3P.sub.16.5B.sub.3 5 84.3 3.8 2220

(51) NiMnTaPB alloys

(52) Sample metallic glasses showing the effect of substituting Mn by Ta, according to the formula Ni.sub.74Mn.sub.6.5-xTa.sub.xP.sub.16.5B.sub.3, are presented in Table 7 and FIG. 14. As shown, when the Ta atomic percent is between 0.5 and 4, the critical rod diameter is at least 1 mm, when it is between 0.5 and 3.5 the critical rod diameter is at least 2 mm, when it is between 0.5 and 3.25 the critical rod diameter is at least 3 mm, while when it is between 1 and 3 the critical rod diameter is at least 4 mm. Differential calorimetry scans for example metallic glasses in which Mn is substituted by Ta are presented in FIG. 15.

(53) TABLE-US-00007 TABLE 7 Sample metallic glasses demonstrating the effect of increasing the Ta atomic concentration at the expense of Mn on the glass forming ability of the NiMnTaPB alloy Critical Rod Diameter Example Composition [mm] 20 Ni.sub.74Mn.sub.6.5P.sub.16.5B.sub.3 4 21 Ni.sub.74Mn.sub.6Ta.sub.0.5P.sub.16.5B.sub.3 3 22 Ni.sub.74Mn.sub.5.5Ta.sub.1P.sub.16.5B.sub.3 4 23 Ni.sub.74Mn.sub.5Ta.sub.1.5P.sub.16.5B.sub.3 4 24 Ni.sub.74Mn.sub.4.5Ta.sub.2P.sub.16.5B.sub.3 4 25 Ni.sub.74Mn.sub.4Ta.sub.2.5P.sub.16.5B.sub.3 4 26 Ni.sub.74Mn.sub.3.5Ta.sub.3P.sub.16.5B.sub.3 4 27 Ni.sub.74Mn.sub.3Ta.sub.3.5P.sub.16.5B.sub.3 2 28 Ni.sub.74Mn.sub.2.5Ta.sub.4P.sub.16.5B.sub.3 1

(54) Sample metallic glasses showing the effect of substituting Ni by Mn, according to the formula Ni.sub.79-xMn.sub.xTa.sub.1.5P.sub.16.5B.sub.3, are presented in Table 8 and FIG. 16. As shown, when the Mn atomic percent is between 3.5 and 8.5, the critical rod diameter is at least 1 mm, when it is between 4.5 and 7.5 the critical rod diameter is at least 4 mm, while when the Mn atomic percent is between 5.25 and 6.75, the critical rod diameter is at least 4 mm, and in some embodiments at least 5 mm. Differential calorimetry scans for example metallic glasses in which Ni is substituted by Mn are presented in FIG. 17.

(55) TABLE-US-00008 TABLE 8 Sample metallic glasses demonstrating the effect of increasing the Mn atomic concentration at the expense of Ni on the glass forming ability of the NiMnTaPB alloy Critical Rod Diameter Example Composition [mm] 29 Ni.sub.75Mn.sub.4Ta.sub.1.5P.sub.16.5B.sub.3 1 23 Ni.sub.74Mn.sub.5Ta.sub.1.5P.sub.16.5B.sub.3 4 30 Ni.sub.73Mn.sub.6Ta.sub.1.5P.sub.16.5B.sub.3 5 31 Ni.sub.72Mn.sub.7Ta.sub.1.5P.sub.16.5B.sub.3 4 32 Ni.sub.71Mn.sub.8Ta.sub.1.5P.sub.16.5B.sub.3 1

(56) Sample metallic glasses showing the effect of substituting Ni by Ta, according to the formula Ni.sub.74.5-xMn.sub.6Ta.sub.xP.sub.16.5B.sub.3, are presented in Table 9 and FIG. 18. As shown, when the Ta atomic percent is between 0.5 and 3, the critical rod diameter is at least 1 mm, when it is between 0.5 and 2.5 the critical rod diameter is at least 3 mm, when it is between 1 and 2.25 the critical rod diameter is at least 4 mm, while when it is between 1.25 and 2 the critical rod diameter is at least 4 mm, and in some embodiments at least 5 mm. Differential calorimetry scans for example metallic glasses in which Ni is substituted by Ta are presented in FIG. 19.

(57) TABLE-US-00009 TABLE 9 Sample metallic glasses demonstrating the effect of increasing the Ta atomic concentration at the expense of Ni on the glass forming ability of the NiMnTaPB alloy Critical Rod Diameter Example Composition [mm] 33 Ni.sub.74.5Mn.sub.6P.sub.16.5B.sub.3 2 34 Ni.sub.74Mn.sub.6Ta.sub.0.5P.sub.16.5B.sub.3 3 35 Ni.sub.73.5Mn.sub.6Ta.sub.1P.sub.16.5B.sub.3 4 30 Ni.sub.73Mn.sub.6Ta.sub.1.5P.sub.16.5B.sub.3 5 36 Ni.sub.72.5Mn.sub.6Ta.sub.2P.sub.16.5B.sub.3 4 37 Ni.sub.72Mn.sub.6Ta.sub.2.5P.sub.16.5B.sub.3 3 38 Ni.sub.71.5Mn.sub.6Ta.sub.3P.sub.16.5B.sub.3 1

(58) Many sample metallic glasses in Tables 7-9 have nickel compositions equal to or higher than 73.5 atomic percent, which is higher than the nickel composition in almost all the P and B Ni-based metallic glasses disclosed in the earlier disclosures (e.g., U.S. patent application Ser. No. 13/592,095 and U.S. patent application Ser. No. 14/067,521). The higher nickel concentration may enable a higher toughness.

(59) Among the alloy compositions investigated in this disclosure, the alloy exhibiting the highest glass-forming ability is Example 30, having composition Ni.sub.73Mn.sub.6Ta.sub.1.5P.sub.16.5B.sub.3, which demonstrates a critical rod diameter of 5 mm. The measured notch toughness and yield strength of sample metallic glass Ni.sub.73Mn.sub.6Ta.sub.1.5P.sub.16.5B.sub.3 are listed along with the critical rod diameter in Table 10. Example 30 provides a good combination of high toughness and good glass forming ability.

(60) An image of a 5 mm diameter amorphous Ni.sub.73Mn.sub.6Ta.sub.1.5P.sub.16.5B.sub.3 rod is shown in FIG. 20. An x-ray diffractogram taken on the cross section of a 5 mm diameter Ni.sub.73Mn.sub.6Ta.sub.1.5P.sub.16.5B.sub.3 rod verifying its amorphous structure is shown in FIG. 21. The stress-strain diagram for sample metallic glass Ni.sub.73Mn.sub.6Ta.sub.1.5P.sub.16.5B.sub.3 is presented in FIG. 22.

(61) TABLE-US-00010 TABLE 10 Critical rod diameter, notch toughness, and yield strength of Ni.sub.73Mn.sub.6Ta.sub.1.5P.sub.16.5B.sub.3 amorphous alloy Critical Rod Notch Yield Diameter Toughness Strength Example Composition [mm] [MPa m.sup.1/2] [MPa] 30 Ni.sub.73Mn.sub.6Ta.sub.1.5P.sub.16.5B.sub.3 5 86.8 4.9 2315

(62) Lastly, the alloys of the present disclosure exhibit a remarkable bending ductility. Specifically, under an applied bending load, the alloys are capable of undergoing plastic bending in the absence of fracture for diameters up to at least 1 mm. Images of amorphous plastically bent rods at 1-mm diameter section of example metallic glass Ni.sub.74Mn.sub.3.5Nb.sub.3P.sub.16.5B.sub.3 are presented in FIG. 23.

(63) Description of Methods of Processing the Sample Alloys

(64) A method for producing the alloys involves inductive melting of the appropriate amounts of elemental constituents in a quartz tube under inert atmosphere. The purity levels of the constituent elements were as follows: Ni 99.995%, Mn 99.9998%, Nb 99.95%, P 99.9999%, and B 99.5%. A method for producing metallic glass rods from the alloy ingots involves re-melting the ingots in quartz tubes of 0.5-mm thick walls in a furnace at 1200 C. or higher, or more specifically between 1300 and 1400 C., under high purity argon and rapidly quenching in a room-temperature water bath. In general, amorphous articles from the alloy of the present disclosure can be produced by (1) re-melting the alloy ingots in quartz tubes of 0.5-mm thick walls, holding the melt at a temperature of about 1200 C. or higher, or more specifically between 1300 and 1400 C., under inert atmosphere, and rapidly quenching in a liquid bath; (2) re-melting the alloy ingots, holding the melt at a temperature of about 1200 C. or higher, or more specifically between 1300 and 1400 C., under inert atmosphere, and injecting or pouring the molten alloy into a metal mold. In a particular embodiment, the metal mold can be made of copper, brass, or steel. Optionally, prior to producing an amorphous article, the alloyed ingots can be fluxed with a reducing agent by re-melting the ingots in a quartz tube under inert atmosphere, bringing the alloy melt in contact with the molten reducing agent and allowing the two melts to interact for about 1200 C. or higher, or more specifically between 1300 and 1400 C., and subsequently water quenching.

(65) Test Methodology for Measuring Notch Toughness

(66) The notch toughness testing of sample metallic glasses was performed on 3-mm diameter rods. The rods were notched using a wire saw with a root radius of between 0.10 and 0.13 m to a depth of approximately half the rod diameter. The notched specimens were placed on a 3-point bending fixture with span distance of 12.7 mm and carefully aligned with the notched side facing downward. The critical fracture load was measured by applying a monotonically increasing load at constant cross-head speed of 0.001 mm/s using a screw-driven testing frame. At least three tests were performed, and the variance between tests is included in the notch toughness plots. The stress intensity factor for the geometrical configuration employed here was evaluated using the analysis by Murakimi (Y. Murakami, Stress Intensity Factors Handbook, Vol. 2, Oxford: Pergamon Press, p. 666 (1987)).

(67) Test Methodology for Measuring Yield Strength

(68) Compression testing of exemplary metallic glasses was performed on cylindrical specimens 3 mm in diameter and 6 mm in length by applying a monotonically increasing load at constant cross-head speed of 0.001 mm/s using a screw-driven testing frame. The strain was measured using a linear variable differential transformer. The compressive yield strength was estimated using the 0.2% proof stress criterion.

(69) The metallic glasses described herein can be valuable in the fabrication of electronic devices. An electronic device herein can refer to any electronic device known in the art. For example, it can be a telephone, such as a mobile phone, and a land-line phone, or any communication device, such as a smart phone, including, for example an iPhone, and an electronic email sending/receiving device. It can be a part of a display, such as a digital display, a TV monitor, an electronic-book reader, a portable web-browser (e.g., iPad), and a computer monitor. It can also be an entertainment device, including a portable DVD player, conventional DVD player, Blue-Ray disk player, video game console, music player, such as a portable music player (e.g., iPod), etc. It can also be a part of a device that provides control, such as controlling the streaming of images, videos, sounds (e.g., Apple TV), or it can be a remote control for an electronic device. It can be a part of a computer or its accessories, such as the hard drive tower housing or casing, laptop housing, laptop keyboard, laptop track pad, desktop keyboard, mouse, and speaker. The article can also be applied to a device such as a watch or a clock.

(70) Having described several embodiments, it will be recognized by those skilled in the art that various modifications, alternative constructions, and equivalents may be used without departing from the spirit of the disclosure. Additionally, a number of well-known processes and elements have not been described in order to avoid unnecessarily obscuring the embodiments disclosed herein. Accordingly, the above description should not be taken as limiting the scope of the document.

(71) Those skilled in the art will appreciate that the presently disclosed embodiments teach by way of example and not by limitation. Therefore, the matter contained in the above description or shown in the accompanying drawings should be interpreted as illustrative and not in a limiting sense. The following claims are intended to cover all generic and specific features described herein, as well as all statements of the scope of the present method and system, which, as a matter of language, might be said to fall therebetween.