Bulk nickel-phosphorus-boron glasses bearing manganese
09816166 · 2017-11-14
Assignee
Inventors
- Jong Hyun Na (Pasadena, CA)
- Michael Floyd (Pasadena, CA, US)
- Marios D. Demetriou (West Hollywood, CA)
- William L. Johnson (San Marino, CA)
- Glenn Garrett (Pasadena, CA)
- Maximilien Launey (Pasadena, CA, US)
- Danielle Duggins (Garden Grove, CA, US)
Cpc classification
C22C45/04
CHEMISTRY; METALLURGY
International classification
C22C45/04
CHEMISTRY; METALLURGY
Abstract
The disclosure is directed to Ni—P—B alloys bearing Mn and optionally Cr and Mo that are capable of forming a metallic glass, and more particularly metallic glass rods with diameters at least 1 mm and as large as 5 mm or larger. The disclosure is further directed to Ni—Mn—Cr—Mo—P—B alloys capable of demonstrating a good combination of glass forming ability, strength, toughness, bending ductility, and corrosion resistance.
Claims
1. An alloy comprising at least Ni, Mn, X, P and B represented by the following formula (subscripts denote atomic percentages):
Ni.sub.(100-a-b-c)Mn.sub.aX.sub.bP.sub.c-dB.sub.d (1) where: a is between 0.5 and 10, b is up to 15, c is between 14 and 24, d is between 1 and 8, and wherein X is Cr and/or Mo, the balance is Ni, and the alloy is capable of forming a metallic glass, wherein the alloy has a critical rod diameter is at least 1 mm.
2. The alloy according to claim 1, wherein b is at least 1, and wherein the alloy also comprises at least one of Nb or Ta at a combined atomic concentration of less than 1 percent.
3. The alloy according to claim 1, wherein b is 0, and wherein the alloy also comprises at least one of Nb or Ta at a combined atomic concentration of less than 0.5 percent.
4. The alloy according to claim 1, wherein up to 1 atomic percent of P is substituted by Si.
5. The alloy according to claim 1, wherein Ni is substituted in accordance with at least one of the following: up to 50 atomic percent of Ni is substituted by Co, up to 30 atomic percent of Ni is substituted by Fe, or up to 10 atomic percent of Ni is substituted by Cu.
6. A metallic glass formed of the alloy according to claim 1.
7. The alloy according to claim 1, wherein b=0, a is at least 2 and up to 9.5, c is between 16.5 and 21.5, and d is between 1 and 6.5.
8. An alloy according to claim 7, wherein a is between 3 and 8 and the critical rod diameter is at least 2 mm.
9. An alloy according to claim 7, wherein a is between 6 and 7.5 and the critical rod diameter is at least 3 mm.
10. An alloy according to claim 7, wherein c is between 17.25 and 20.75 and the critical rod diameter is at least 2 mm.
11. An alloy according to claim 7, wherein c is between 18.5 and 20.25 and the critical rod diameter is at least 3 mm.
12. An alloy according to claim 7, wherein d is between 1.75 and 5.75 and the critical rod diameter is at least 2 mm.
13. An alloy according to claim 7, wherein d is between 2.5 and 3.75 and the critical rod diameter is at least 3 mm.
14. An alloy represented by the formula (subscripts denote atomic percentages):
Ni.sub.(100-a-b1-b2-c-d)Mn.sub.aCr.sub.b1Mo.sub.b2P.sub.cB.sub.d (2) where: a is between 1 and 5, b1 is between 4 and 11, b2 is up to 3, c is between 15 and 19, and d is between 1 and 5, wherein the alloy has a critical rod diameter is at least 2 mm.
15. An alloy according to claim 14, wherein a is between 2.25 and 3.75, b1 is between 5 and 10, b2 is up to 2, c is between 15.75 to 18, d is between 1.5 and 4.5, and the critical rod diameter is at least 2 mm.
16. An alloy according to claim 14, wherein a is between 2.5 and 3.5, b1 is between 6 and 9, b2 is up to 1.5, c is between 16 to 17.75, d is between 2.25 and 3.75, and the critical rod diameter is at least 3 mm.
17. An alloy according to claim 14, wherein a is between 2.75 and 3.25, b1 is between 6 and 8, b2 is between 0.75 and 1.25, c is between 16 to 17.25, d is between 2.5 and 3.5, and the critical rod diameter is at least 4 mm.
18. An alloy according to claim 14, wherein the sum of c and d is between 18.5 and 20.5.
19. A metallic glass formed of the alloy according to claim 14.
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.
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DETAILED DESCRIPTION
(33) 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.
(34) Description of Alloy Compositions
(35) In accordance with the provided disclosure and drawings, Ni—Mn—P—B alloys optionally containing Cr and Mo are capable of forming metallic glasses. In some aspects, the alloys have glass-forming ability comparable to the Ni—Cr—Nb—P—B, Ni—Cr—Ta—P—B, and Ni—Mo—Nb—P—B alloys. Specifically, in one aspect, the disclosure is directed to alloys and/or metallic glasses represented by the following formula (subscripts denote atomic percentages):
Ni.sub.(100-a-b-c)Mn.sub.aX.sub.bP.sub.c-dB.sub.d (1)
where: a is between 0.5 and 10 b is up to 15 c is between 14 and 24 d is between 1 and 8 wherein X can be Cr and/or Mo.
(36) In various aspects, the critical rod diameter of the alloy is at least 1 mm.
(37) In another aspect, the alloys can be Ni-based alloys with a Mn content of between 0.5 and 10 atomic percent, a total metalloid content (i.e. the sum of P and B atomic concentrations) of between 14 and 24 atomic percent, and B content of between 1 and 6.5 atomic percent. In further aspects, the alloys have a Mn content of about 6 to 7.5 atomic percent, P content of about 16 to 16.5 atomic percent, and B content of about 3 atomic percent.
(38) In the present disclosure, the glass-forming ability of each alloy can be quantified by the “critical rod diameter”, defined as largest rod diameter in which the amorphous phase (i.e. the metallic glass) can be formed when processed by the method of water quenching a quartz tube with 0.5 mm thick wall containing a molten alloy.
(39) In the present disclosure, the term “entirely free” of an element means not more than trace amounts of the element found in naturally occurring trace amounts.
(40) The notch toughness, defined as the stress intensity factor at crack initiation K.sub.q, 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.
(41) The compressive yield strength, σ.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 σ.sub.y ensures that the material will be strong.
(42) 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.
(43) Sample metallic glasses 1-10 showing the effect of substituting Ni by Mn, according to the formula Ni.sub.80.5-xMn.sub.xP.sub.16.5B.sub.3, are presented in Table 1 and
(44) Differential calorimetry scans for sample metallic glasses in which Ni is substituted by Mn are presented in
(45) TABLE-US-00001 TABLE 1 Sample metallic glasses demonstrating the effect of substituting Ni by Mn on the glass forming ability of the Ni—Mn—P—B alloys Critical Rod Diameter Example Composition [mm] 1 Ni.sub.78.5Mn.sub.2P.sub.16.5B.sub.3 1 2 Ni.sub.78Mn.sub.2.5P.sub.16.5B.sub.3 1 3 Ni.sub.77Mn.sub.3.5P.sub.16.5B.sub.3 2 4 Ni.sub.75.5Mn.sub.5P.sub.16.5B.sub.3 2 5 Ni.sub.74.5Mn.sub.6P.sub.16.5B.sub.3 2 6 Ni.sub.74Mn.sub.6.5P.sub.16.5B.sub.3 4 7 Ni.sub.73.5Mn.sub.7P.sub.16.5B.sub.3 4 8 Ni.sub.73Mn.sub.7.5P.sub.16.5B.sub.3 2 9 Ni.sub.72.5Mn.sub.8P.sub.16.5B.sub.3 1 10 Ni.sub.71.5Mn.sub.9P.sub.16.5B.sub.3 1
(46) Sample metallic glasses 7 and 11-19 showing the effect of substituting P by B, according to the formula Ni.sub.73.5Mn.sub.7P.sub.19.5-xB.sub.x, are presented in Table 2 and
(47) Differential calorimetry scans for several sample metallic glasses in which P is substituted by B are presented in
(48) TABLE-US-00002 TABLE 2 Sample metallic glasses demonstrating the effect of substituting P by B on the glass forming ability of the Ni—Mn—P—B alloys Critical Rod Diameter Example Composition [mm] 11 Ni.sub.73.5Mn.sub.7P.sub.18B.sub.1.5 1 12 Ni.sub.73.5Mn.sub.7P.sub.17.5B.sub.2 2 13 Ni.sub.73.5Mn.sub.7P.sub.17B.sub.2.5 2 7 Ni.sub.73.5Mn.sub.7P.sub.16.5B.sub.3 4 14 Ni.sub.73.5Mn.sub.7P.sub.16B.sub.3.5 3 15 Ni.sub.73.5Mn.sub.7P.sub.15.5B.sub.4 2 16 Ni.sub.73.5Mn.sub.7P.sub.15B.sub.4.5 2 17 Ni.sub.73.5Mn.sub.7P.sub.14.5B.sub.5 2 18 Ni.sub.73.5Mn.sub.7P.sub.14B.sub.5.5 2 19 Ni.sub.73.5Mn.sub.7P.sub.13.5B.sub.6 1
(49) Sample metallic glasses 7 and 20-28 showing the effect of varying the metal to metalloid ratio, according to the formula (Ni.sub.0.913Mn.sub.0.087).sub.100-x(P.sub.0.846B.sub.0.154).sub.x, are presented in Table 3 and
(50) Differential calorimetry scans for several sample metallic glasses in which the metal to metalloid ratio is varied are presented in
(51) TABLE-US-00003 TABLE 3 Sample metallic glasses demonstrating the effect of increasing the total metalloid concentration at the expense of metals on the glass forming ability of the Ni—Mn—P—B alloys Critical Rod Diameter Example Composition [mm] 20 Ni.sub.75.78Mn.sub.7.22P.sub.14.38B.sub.2.62 1 21 Ni.sub.75.33Mn.sub.7.17P.sub.14.81B.sub.2.69 2 22 Ni.sub.74.87Mn.sub.7.13P.sub.15.23B.sub.2.77 2 23 Ni.sub.74.41Mn.sub.7.09P.sub.15.65B.sub.2.85 2 24 Ni.sub.73.96Mn.sub.7.04P.sub.16.08B.sub.2.92 4 25 Ni.sub.73.73Mn.sub.7.02P.sub.16.29B.sub.2.96 5 7 Ni.sub.73.5Mn.sub.7P.sub.16.5B.sub.3 4 26 Ni.sub.73.04Mn.sub.6.96P.sub.16.92B.sub.3.08 3 27 Ni.sub.72.59Mn.sub.6.91P.sub.17.35B.sub.3.15 2 28 Ni.sub.72.13Mn.sub.6.87P.sub.17.77B.sub.3.23 1
(52) An image of a 5 mm metallic glass rod of example alloy Ni.sub.73.73Mn.sub.7.02P.sub.7.02B.sub.2.96 is presented in
(53) The measured notch toughness and yield strength of sample metallic glass Ni.sub.73.73Mn.sub.7.02P.sub.16.29B.sub.2.96 are listed along with the critical rod diameter in Table 4. The stress-strain diagram for sample metallic glass Ni.sub.73.73Mn.sub.7.02P.sub.16.29B.sub.2.96 is presented in
(54) TABLE-US-00004 TABLE 4 Critical rod diameter, notch toughness, and yield strength of metallic glass Ni.sub.73.73Mn.sub.7.02P.sub.16.29B.sub.2.96 Critical Rod Notch Yield Diameter Toughness Strength Example Composition [mm] [MPa m.sup.1/2] [MPa] 25 Ni.sub.73.73Mn.sub.7.02P.sub.16.29B.sub.2.96 5 102.1 ± 1.1 2215
(55) In various embodiments, the metallic glasses according to the disclosure demonstrate bending ductility. Specifically, under an applied bending load, the metallic glasses are capable of undergoing plastic bending in the absence of fracture for diameters up to at least 1 mm. Optical images of plastically bent metallic glass rods at 1-mm diameter section of sample metallic glass Ni.sub.73.73Mn.sub.7.02P.sub.16.29B.sub.2.96 is presented in
(56) In other aspects of the present disclosure, Ni—Mn—P—B alloys containing Cr and optionally a very small fraction of Mo, are capable of forming metallic glasses, and in some aspects bulk metallic glasses having glass-forming ability comparable to the Ni—Cr—Nb—P—B and Ni—Cr—Ta—P—B alloys. In some aspects, the disclosure is directed to a metallic glass comprising an alloy represented by the following formula (subscripts denote atomic percent):
Ni.sub.(100-a-b1-b2-c-d)Mn.sub.aCr.sub.b1Mo.sub.b2P.sub.cB.sub.d (2)
where: a is between 1 and 5 b1 is between 4 and 11 b2 is up to 3 c is between 15 and 19 d is between 1 and 5.
(57) In certain variations, Ni-based compositions with a Mn content of about 3 atomic percent, Cr content of between 6 and 9 atomic percent, Mo content of up to 2 atomic percent, B content of about 3 atomic percent, and P content of about 16.5 atomic percent, are capable of forming bulk metallic glass rods with diameters of at least 1 mm, 2 mm, 3 mm, 4 mm, and as large as 5 mm or larger.
(58) Sample metallic glasses 29-33 showing the effect of substituting P by B, according to the formula Ni.sub.69Cr.sub.8.5Mn.sub.3P.sub.19.5-xB.sub.x, are presented in Table 5 and
(59) Differential calorimetry scans for sample metallic glasses in which P is substituted by B are presented in
(60) TABLE-US-00005 TABLE 5 Sample metallic glasses demonstrating the effect of increasing the B atomic concentration at the expense of P on the glass forming ability of the Ni—Cr—Mn—P—B alloy. Critical Rod Example Composition Diameter [mm] 29 Ni.sub.69Cr.sub.8.5Mn.sub.3P.sub.17.5B.sub.2 2 30 Ni.sub.69Cr.sub.8.5Mn.sub.3P.sub.17B.sub.2.5 3 31 Ni.sub.69Cr.sub.8.5Mn.sub.3P.sub.16.5B.sub.3 3 32 Ni.sub.69Cr.sub.8.5Mn.sub.3P.sub.16B.sub.3.5 3 33 Ni.sub.69Cr.sub.8.5Mn.sub.3P.sub.15.5B.sub.4 2
(61) Sample metallic glasses 31 and 34-38 showing the effect of substituting Ni by Cr, according to the formula Ni.sub.77.5-xCr.sub.xMn.sub.3P.sub.16.5B.sub.3, are presented in Table 6 and
(62) Differential calorimetry scans for several sample metallic glasses in which Ni is substituted by Cr are presented in
(63) TABLE-US-00006 TABLE 6 Sample metallic glasses demonstrating the effect of increasing the Cr atomic concentration at the expense of Ni on the glass forming ability of the Ni—Cr—Mn—P—B alloys Critical Rod Example Composition Diameter [mm] 34 Ni.sub.72Cr.sub.5.5Mn.sub.3P.sub.16.5B.sub.3 2 35 Ni.sub.71Cr.sub.6.5Mn.sub.3P.sub.16.5B.sub.3 3 36 Ni.sub.70Cr.sub.7.5Mn.sub.3P.sub.16.5B.sub.3 3 37 Ni.sub.69.5Cr.sub.8Mn.sub.3P.sub.16.5B.sub.3 3 31 Ni.sub.69Cr.sub.8.5Mn.sub.3P.sub.16.5B.sub.3 3 38 Ni.sub.68Cr.sub.9.5Mn.sub.3P.sub.16.5B.sub.3 2
(64) Sample metallic glasses 31, and 39-42 showing the effect of substituting Cr by Mn, according to the formula Ni.sub.69Cr.sub.11.5-xMn.sub.xP.sub.16.5B.sub.3, are presented in Table 7 and
(65) Differential calorimetry scans for several sample metallic glasses in which Cr is substituted by Mn are presented in
(66) TABLE-US-00007 TABLE 7 Sample metallic glasses demonstrating the effect of increasing the Mn atomic concentration at the expense of Cr on the glass forming ability of the Ni—Cr—Mn—P—B alloys. Critical Rod Example Composition Diameter [mm] 39 Ni.sub.69Cr.sub.9Mn.sub.2.5P.sub.16.5B.sub.3 2 40 Ni.sub.69Cr.sub.8.75Mn.sub.2.75P.sub.16.5B.sub.3 2 31 Ni.sub.69Cr.sub.8.5Mn.sub.3P.sub.16.5B.sub.3 3 41 Ni.sub.69Cr.sub.8.25Mn.sub.3.25P.sub.16.5B.sub.3 3 42 Ni.sub.69Cr.sub.8Mn.sub.3.5P.sub.16.5B.sub.3 2
(67) Sample metallic glasses 31 and 43-45 showing the effect of substituting Ni by P, according to the formula Ni.sub.85.5-xCr.sub.8.5Mn.sub.3P.sub.xB.sub.3, are presented in Table 8 and
(68) An optical image of an amorphous 4 mm rod of example alloy Ni.sub.68.5Cr.sub.8.5Mn.sub.3P.sub.17B.sub.3 is presented in
(69) Differential calorimetry scans for sample metallic glasses in which Ni is substituted by P are presented in
(70) TABLE-US-00008 TABLE 8 Sample metallic glasses demonstrating the effect of increasing the P atomic concentration at the expense of Ni on the glass forming ability of the Ni—Cr—Mn—P—B alloys. Critical Rod Example Composition Diameter [mm] 43 Ni.sub.69.5Cr.sub.8.5Mn.sub.3P.sub.16B.sub.3 2 31 Ni.sub.69Cr.sub.8.5Mn.sub.3P.sub.16.5B.sub.3 3 44 Ni.sub.68.5Cr.sub.8.5Mn.sub.3P.sub.17B.sub.3 4 45 Ni.sub.68Cr.sub.8.5Mn.sub.3P.sub.17.5B.sub.3 3
(71) The critical rod diameters for sample metallic glasses showing the effect of substituting Ni by both Cr and Mn, according to the formula Ni.sub.80.5-x-yCr.sub.xMn.sub.yP.sub.16.5B.sub.3, are presented in a contour plot in
(72) TABLE-US-00009 TABLE 9 Sample metallic glasses demonstrating the effect of increasing the Cr and Mn atomic concentration at the expense of Ni on the glass forming ability of the Ni—Cr—Mn—P—B alloys. Critical Rod Example Composition Diameter [mm] 46 Ni.sub.71Cr.sub.6.5Mn.sub.3.5P.sub.16.5B.sub.3 2 47 Ni.sub.70.25Cr.sub.7Mn.sub.3.25P.sub.16.5B.sub.3 3 48 Ni.sub.69.83Cr.sub.7.5Mn.sub.3.17P.sub.16.5B.sub.3 2 49 Ni.sub.69.42Cr.sub.8Mn.sub.3.08P.sub.16.5B.sub.3 3 50 Ni.sub.69.6Cr.sub.8Mn.sub.2.9P.sub.16.5B.sub.3 3
(73) Sample metallic glasses 31 and 51-54 showing the effect of varying the metal to metalloid ratio, according to the formula (Ni.sub.0.857Cr.sub.0.106Mn.sub.0.037).sub.100-x(P.sub.0.846B.sub.0.154).sub.x, are presented in Table 10 and
(74) Differential calorimetry scans for metallic glasses in which the metal to metalloid ratio is varied are presented in
(75) TABLE-US-00010 TABLE 10 Sample metallic glasses demonstrating the effect of increasing the total metalloid concentration at the expense of metals on the glass forming ability of the Ni—Cr—Mn—P—B alloys. Critical Rod Example Composition Diameter [mm] 51 Ni.sub.69.86Cr.sub.8.61Mn.sub.3.04P.sub.15.65B.sub.2.85 1 52 Ni.sub.69.43Cr.sub.8.55Mn.sub.3.02P.sub.16.08B.sub.2.92 3 31 Ni.sub.69Cr.sub.8.5Mn.sub.3P.sub.16.5B.sub.3 3 53 Ni.sub.68.57Cr.sub.8.45Mn.sub.2.98P.sub.16.92B.sub.3.08 3 54 Ni.sub.68.14Cr.sub.8.39Mn.sub.2.96P.sub.17.35B.sub.3.15 2
(76) Sample metallic glasses 31 and 55-58 showing the effect of substituting Cr by Mo, according to the formula Ni.sub.69Cr.sub.8.5-xMn.sub.3Mo.sub.xP.sub.16.5B.sub.3, are presented in Table 11 and
(77) Differential calorimetry scans for example metallic glasses in which Cr is substituted by Mo are presented in
(78) An image of a 5 mm metallic glass rod of example alloy Ni.sub.69Cr.sub.7.5Mn.sub.3Mo.sub.1P.sub.16.5B.sub.3 is presented in
(79) TABLE-US-00011 TABLE 11 Sample metallic glasses demonstrating the effect of increasing the Mo atomic concentration at the expense of Cr on the glass forming ability of the Ni—Cr—Mn—Mo—P—B alloys. Critical Rod Example Composition Diameter [mm] 31 Ni.sub.69Cr.sub.8.5Mn.sub.3P.sub.16.5B.sub.3 3 55 Ni.sub.69Cr.sub.8Mn.sub.3Mo.sub.0.5P.sub.16.5B.sub.3 3 56 Ni.sub.69Cr.sub.7.5Mn.sub.3Mo.sub.1P.sub.16.5B.sub.3 5 57 Ni.sub.69Cr.sub.7Mn.sub.3Mo.sub.1.5P.sub.16.5B.sub.3 3 58 Ni.sub.69Cr.sub.6.5Mn.sub.3Mo.sub.2P.sub.16.5B.sub.3 2
(80) Sample metallic glasses 31 and 59-60 showing the effect of substituting P by Si, according to the formula Ni.sub.69Cr.sub.8.5Mn.sub.3P.sub.16.5-xB.sub.3Si.sub.x, are listed in Table 12. As shown, Si substitution of P up to about 1% slightly degrades the glass forming ability of Ni—Cr—Mn—P—B alloys.
(81) TABLE-US-00012 TABLE 12 Sample metallic glasses of the Ni—Cr—Mn—P—B—Si alloys Critical Rod Example Composition Diameter [mm] 31 Ni.sub.69Cr.sub.8.5Mn.sub.3P.sub.16.5B.sub.3 3 59 Ni.sub.69Cr.sub.8.5Mn.sub.3P.sub.16B.sub.3Si.sub.0.5 2 60 Ni.sub.69Cr.sub.8.5Mn.sub.3P.sub.15.5B.sub.3Si.sub.1 2
(82) The measured notch toughness and yield strength of sample metallic glasses Ni.sub.68.5Cr.sub.8.5Mn.sub.3P.sub.17B.sub.3 and Ni.sub.69Cr.sub.7.5Mn.sub.3Mo.sub.1P.sub.16.5B.sub.3 are listed along with the critical rod diameter in Table 13. The stress-strain diagrams for sample metallic glasses Ni.sub.68.5Cr.sub.8.5Mn.sub.3P.sub.17B.sub.3 Ni.sub.69Cr.sub.7.5Mn.sub.3Mo.sub.1P.sub.16.5B.sub.3 are presented in
(83) TABLE-US-00013 TABLE 13 Critical rod diameter, notch toughness, and yield strength of sample metallic glasses of the Ni—Cr—Mn—P—B and Ni—Cr—Mn—Mo—P—B alloys Critical Rod Notch Yield Diameter Toughness Strength Example Composition [mm] [MPa m.sup.1/2] [MPa] 44 Ni.sub.68.5Cr.sub.8.5Mn.sub.3P.sub.17B.sub.3 4 92 ± 3 2285 56 Ni.sub.69Cr.sub.7.5Mn.sub.3Mo.sub.1P.sub.16.5B.sub.3 5 87 ± 3 2275
(84) The metallic glasses demonstrate bending ductility. Specifically, under an applied bending load, the metallic glasses are capable of undergoing plastic bending in the absence of fracture for diameters up to at least 1 mm. Optical images of amorphous plastically bent rods at 1-mm diameter section of example metallic glasses Ni.sub.68.5Cr.sub.8.5Mn.sub.3P.sub.17B.sub.3 (composition 44) and Ni.sub.69Cr.sub.7.5Mn.sub.3Mo.sub.1P.sub.16.5B.sub.3 (composition 56) are presented in
(85) Lastly, the metallic glasses, Ni—Mn—Cr—Mo—P—B, also exhibit a remarkable corrosion resistance. The corrosion resistance of example metallic glass Ni.sub.69Cr.sub.7.5Mn.sub.3Mo.sub.1P.sub.16.5B.sub.3 (composition 56) is evaluated by immersion test in 6M HCl. A plot of the corrosion depth versus time is presented in
(86) Description of Methods of Processing the Sample Alloys
(87) A method for producing the metallic glasses 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%, Cr 99.996%, Mo 99.95%, Mn 99.9998%, Si 99.9999%, 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 1100° C. or higher, and particularly between 1200° C. 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 1100° C. or higher, and particularly between 1200° C. 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 1100° C. or higher, and particularly between 1200° C. and 1400° C., under inert atmosphere, and injecting or pouring the molten alloy into a metal mold, particularly 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 a time period of 1000 seconds at a temperature of about 1100° C. or higher, and subsequently water quenching.
(88) Test Methodology for Measuring Notch Toughness
(89) The notch toughness 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 μm 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)).
(90) Test Methodology for Measuring Yield Strength
(91) Compression testing of sample 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.
(92) Test Methodology for Measuring Corrosion Resistance
(93) The corrosion resistance of sample metallic glasses was evaluated by immersion tests in hydrochloric acid (HCl). A rod of metallic glass sample with initial diameter of 2.97 mm, and a length of 14.77 mm was immersed in a bath of 6M HCl at room temperature. The density of the metallic glass rod was measured using the Archimedes method to be 7.751 g/cc. The corrosion depth at various stages during the immersion was estimated by measuring the mass change with an accuracy of ±0.01 mg. The corrosion rate was estimated assuming linear kinetics.
(94) 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. 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. Additionally, a number of well-known processes and elements have not been described in order to avoid unnecessarily obscuring the disclosure. 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.