SE431101B - AMORF METAL ALLOY - Google Patents

Description

7606842-s 2 At the time these amorphous alloys were discovered, they exhibited superior mechanical properties to the then known polycrystalline alloys. The superior mechanical properties included tensile strengths of up to 24.6 kp / mmz, hardness values of about 600-750 DPH and good ductility. Nevertheless, new applications, which require improved magnetic, physical and mechanical properties as well as higher thermal stability, have necessitated attempts to develop further specific compositions. In accordance with the present invention, amorphous iron group boron alloys have improved tensile strength and hardness and do not become brittle when heat treated at temperatures used in subsequent treatment steps. These amorphous metal alloys also have desirable magnetic properties. The amorphous alloys have essentially the composition MaM 'bcrchwdße where M is an element selected from iron, cobalt and nickel, M' is one or two elements selected from iron, cobalt, and nickel and which differs from M, M "is the least of the elements vanadium, manganese, molybdenum, tungsten, niobium and tantalum," a "varies from about 40 to 85 atomic%," b "varies from 0 to about 45 atomic%," c "and" d "each vary from 0 to about 20 atomic% and "e" ranges from about 15 to 25 atomic%. Preferably, chromium is present in an amount of about 4-16 atomic%, based on the total alloy composition, to achieve improved mechanical properties, improved Preferred compositions also include compositions in which M "is molybdenum, present in an amount of about 0.4 to 8 atomic%, based on the total alloy composition, to achieve increased hardness. For preferred compositions with desirable magnetic properties, "c" and "d" are both zero.

The alloys of the invention are at least 50% amorphous and at least 80% amorphous, and are most preferably about 100% amorphous, as determined by X-ray diffraction.

The amorphous alloys of the invention are prepared by a process which comprises forming a melt of the desired composition and quenching at a rate of about 105-106 ° C / s by casting the molten alloy on a cooling wheel or in a extinguishing fluid. Improved physical and mechanical properties, together with a higher degree of amorphousness, are achieved by casting the molten alloy on a cooling wheel in a partial vacuum with an absolute pressure of less than about 5.5 cm Hg. 'There are many applications, which require that an alloy has, among other things, a high tensile strength, high thermal stability and is easy to manufacture. For example, metal strips used in razor blades usually undergo a heat treatment at about 370 ° C for about 30 minutes to bond an applied coating of polytetrafluoroethylene to the metal. Similarly, metal strands used as a tire cord undergo a heat treatment at about 160-170 ° C for about 1 hour to bond the tire rubber to the metal.

When crystalline alloys are used, phase changes can occur during the heat treatment, which tend to impair the physical and mechanical properties. When amorphous alloys are used, a complete or partial conversion from the glassy state to a crystalline equilibrium state or metastable state can likewise occur during the heat treatment. As with inorganic oxide glasses, such a conversion impairs physical and mechanical properties, such as ductility, tensile strength, etc.

The thermal stability of an amorphous metal alloy is an important property in some applications. The thermal stability is characterized by the time-temperature conversion behavior of an alloy, and can be determined in part by DTA (differential thermal analysis). In the present context, relative thermal stability is also considered to be indicated by maintaining ductility in bending after heat treatment. Alloys that have a similar crystallization behavior, as observed by DTA, can exhibit different embrittlement behaviors when exposed to the same heat treatment cycle. By DTA measurement, crystallization temperatures, TC, can be accurately determined by slowly heating an amorphous alloy (at about 20-50 ° C / min) and noting whether excess heat develops within a limited temperature range (crystallization temperature) or whether excess heat is absorbed within a specific temperature range (glass transformation temperature). In general, the glass transformation temperature Tg is close to the lowest or first crystallization temperature Tel, and is by convention the temperature at which the viscosity varies from about 1013 to 1014 pois.

Most amorphous metal alloys, which contain iron, nickel, cobalt and chromium and which include phosphorus, among other metalloids, have tensile strength limits of about 185-245 kp / mm2 and crystallization t¿7ß @ aæe2-s e 4 temperatures.of about 400 -460 ° C. Thus, for example, an amorphous alloy having the composition Fe76P16C4Si2Al2 (the index refers to atomic%) has a tensile strength of about 220 kp / mm2 and a crystallization temperature of, about 460 ° C, an amorphous alloy having the composition Ee30Ni3oCo3O2 tensile strength of about 185 kp / mmz and a crystallization temperature of about 41 ° C, and an amorphous alloy having the composition Fe Cr PCB has a tensile strength of about 245 kp / mm 2 and a temperature of about 445 kp / mm 2: V 446 ° C {The thermal the stability of these compositions in the temperature range about 200-350 ° C is low, as evidenced by a tendency to embrittle after heat treatment, for example at 250 ° C for 1 hour or 30 ° C for ao min or 33 ° C for 5 my. New heat treatments are required in certain special applications, such as in curing a coating of polytetrafluoroethylene on razor blade edges or bonding tire rubber to metal wire strands.

In accordance with the invention, amorphous iron group boron alloys have improved tensile strength and hardness and do not embrittle in heat treatment at temperatures typically used in subsequent treatment steps. These amorphous metal alloys have essentially the composition 'MaM'bCrcM "dBe where M is an element of the iron group (iron, cobalt or nickel), M' is at least one of the remaining two elements of the iron group, M" is at least one of the elements vanadium, manganese, molybdenum, tungsten, niobium and tantalum, "a" varies from about 40 to 85 atomic%, "b" varies from 0 to about 45 atomic%, "c" and "d" each range from 0 to about 20%. atom%, and "e" varies from about 15 to 25 atom%. Examples of amorphous alloy compositions according to the invention include. grips Fe50Ni5Co7CrloMoloBl8, Fe40Ni2oColoCr10B20, 'I Ni46Fel3Col3Cr9Mo3Bl6, Co50Fel8Nil5Bl7, Fe65Vl5B2O and Ni58Mn20B22.

The purity of all the compositions is that found in normal commercial practice.

The amorphous metal alloys in accordance with the invention typically exhibit tensile yield strengths ranging from about 260 to 365 kp mm 2, hardness values ranging from about 925 to 1190 DPH; and crystallization temperatures, which range from about 370 to 10 ° C. e _ - e Å _Optimal resistance to corrosion and oxidation is obtained by: incorporating about 4-16 atomic% chromium into the alloy composition. Addition of such amounts of chromium generally also increases the crystallization temperature, the tensile strength and the thermal stability of the amorphous metal alloys. Below about 4 atomic%, insufficient corrosion-inhibiting behavior is observed, while more than about 16 atomic% chromium tends to reduce the resistance to embrittlement during heat treatment at elevated temperatures of the amorphous metal alloys. An increase in hardness and crystallization temperature is achieved when M "is molybdenum. Preferably about 0.4-8 atom% molybdenum is included in the alloy composition. Below about 0.4 atom% no significant increase in hardness is obtained. Above about 8 atom% it is reduced thermal stability, although increased hardness values are obtained, necessitating a balancing of desired properties.For many compositions, improved mechanical properties and increased crystallization temperatures are achieved at the expense of thermal stability, by incorporating about 4-8 atomic% molybdenum throughout the alloy composition.

For example, an amorphous metal alloy having the composition Fe67Ni5Co3Cr7B18 has a crystallization temperature of 488 ° C, a hardness of 1003 DPH and a tensile strength of 293 kp / mm 2, while an amorphous metal alloy having the composition Fe63Ni5Co3Cr7Mo4B8 DPH and a tensile strength limit of 351 kp / mmz. For some compositions, improved thermal stability and improved hardness are achieved unexpectedly by incorporating about 0.4-0.8 atomic% molybdenum into the alloy composition.

For comparison, an amorphous metal alloy having the composition Fe66Ni5Co4Cr8B17 has a hardness of 1038 DPH and remains ductile after heat treatment at 360 ° C for 30 minutes, but embrittles after heat treatment at 370 ° C for 30 minutes; an amorphous metal alloy with the composition Fe66Ni5Co3'2Cr8Moo'8Bl7 has a hardness of 1108 DPH and remains auctile after thermal bone analysis via a1o ° c for so min.

Many preferred composition ranges within the composition range of the invention may be indicated, depending on the particular improved properties desired.

For amorphous ferrous metal alloys, high strength and high hardness are obtained of alloys with compositions in the range Faso-70 (Ni '°°) 5-iscrs-16M ° o-sB1s ~ 22' Examples of such compositions include Fe54Ni6Co5Crl6Mo2Bl7f Fe60Ni7Bo4C43 Fe3Ni8Mo8Co3C. The tensile strength of such compositions typically varies in the range of about 290-350 kp / mm 2, the hardness values vary in the range of about 1025-1120 DPH, and the crystallization temperature varies in the range of about 480-555 ° C. Alloys within this composition range have been found to be particularly suitable for the production of tire cord filaments. High thermal stability is obtained in alloys with composition in the range of Peso-67Ni3-7 °° 3-7 ° ”7-1oM ° o, 4-o, sB17 '1 N. . . .

Examples of harps include Fe66Ni5Co3'6Cr8Mo0'4Bl7 and Fe66Ni5Co3,2Cr8Mo0'8Bl7. Such compositions generally remain. ductile for bending after heat treatment at 360-370 ° C for 0.5 h.

Alloys within this composition range have been found to be particularly suitable for the production of razor blade strips.

For amorphous nickel metal alloys, high hardness, moderately high strength, high thermal stability and corrosion resistance are obtained for alloys with a composition in the range g N14o-5øFe4-1sC ° s-zscrs-12 “° o-9315-22 'Examples include Ni40Fe5Co2oBlB6C4C4O44C420, Ni5OFe5Col7Cr9Mo3Bl6. The tensile strength of such compositions is typically about 280-290 kp / mm 2; the hardness values typically vary in the range of about 980-1055 DPH.

For amorphous cobalt metal alloys, high strength, high thermal stability and high hardness of alloys with a composition in the range °° 4o-soFes-2oNio-2o ° r4-15M ° o-9315-23 'are achieved. Examples of this include Co45Fel7Nil3Cr5Mo5Bo5MoFB Co46Fel8Nil5Mo4Bl7 and Co50Fel0Nil0Crl0B20. The hardness values for such compositions are typically about 1100 DPH.

Preferred amorphous metal alloys with desirable magnetic properties depend on the particular desired application. For such compositions, both "c" and "d" are zero. For high values of the saturation magnetization, eg about 13-17 kGauss, it is desirable that a relatively high content of cobalt and / or iron is present. Examples include Fe81Co3NilBl5 and Fe80Co5Bl5. For low coercive forces of less than about 0.5 Oe, it is desirable that a relatively high amount of nickel and / or iron be present. Examples include Ni50Fe32B18 and Fe50Ni20Col5B15. Suitable magnetic amorphous metal alloys have a composition in the range 7 7606842-8 Fe4o-so °° s-45315-25 ç ° 4o-soFes-45315-25 Fe4o-soNis-45315-25 Ni4o-soFes-45315-25 °° 4o-aoNis-45315-25 Ni4o-es °° 2o-45515-zs F84o-7oNi4-2sC ° 5-30315-25 N14o-7oFe5-2s °° s-25315-25 i C ° 4o-7oFes-2sN 5- 25315-25 'Examples of these include FeooCozoßzo, ComFeloßzo, Co40Fe40B2o, Ni7oFe12B1s' Fes2Ni3oB1a 'Fee2Ni2oB18' °° 72Ni1oB1s 'C ° 62Ni2oB1s' F ° 5N1 ° F7 '2 ° 1sB15 'Fe6oNi7C ° 12Bz1' Fe7oNi4 °° sB21 'NisoFe1s °° 1sB17' °° soF ° 1sNi1sB17 and C60Fel3Nil0Bl7.

Other suitable alloys according to the invention are Feasßiv 'Feaoßzo' Fevaßzz 'Fevvßzs' Fe7eB24 'Fevsßzs °° h C ° soB2o' The amorphous alloys are formed by cooling a melt at a rate of about 105-105 ° C / s. A variety of methods are available, as is well known in the art, for the manufacture of splash-cooled films and quick-cooled continuous tapes, wire, sheet, etc. Typically, a particular composition is selected, powders of the required elements (or materials which decompose to form the elements, such as ferroboron, ferrochrome, etc.) in the desired proportions are melted and homogenized, and the molten alloy is rapidly cooled either on a cooling surface, such as a rotating, cooled cylinder, or in a suitable fluid, such as a cooled brine.

The amorphous alloys can be formed in air. however, superior mechanical properties are achieved by forming the amorphous alloys in a partial vacuum with an absolute pressure of less than about 5.5 cm Hg, and preferably about 100 μm to 1 cm Hg, as described in U.S. Patent Application No. 552,673, filed on February 24, 1975.

The amorphous metal alloys are at least 50% amorphous, and preferably at least 80%, as determined by X-ray diffraction. However, a significant degree of amorphity approaching 100% is achieved by forming the amorphous metal alloys in a partial vacuum.

The ductility is thereby improved and such alloys, which possess a significant degree of amorphousness, are consequently preferred.

The amorphous metal alloys of the present invention exhibit superior manufacturing properties over prior art compositions. In addition to their improved resistance to embrittlement after heat treatment, these compositions tend to be more resistant to oxidation and corrosion than previously known compositions. The compositions remain amorphous under heat treatment conditions under which phosphorus-containing amorphous alloys tend to diffuse. Strips of the alloys are useful in applications which require relatively high thermal stability and increased mechanical strength.

Example 7 Rapid melting and production of amorphous strips or bands of uniform width and thickness from high melting (about 1100-1600 ° C), reactive alloys were performed under vacuum. The use of vacuum minimized oxidation and contamination of the alloy during melting or spraying and also eliminated surface damage (blisters, bubbles, etc.) commonly observed in tapes treated in air or inert gas at 1 atm. A copper cylinder was mounted vertically on the shaft for a vacuum rotation pass and placed in a stainless steel vacuum chamber. The vacuum chamber consisted of an I cylinder, which was flanged at two ends with two side openings and was connected to a diffusion pumping system. The copper cylinder was rotated by means of an electric motor with variable speed via the rotation passage. A crucible, surrounded by an induction coil assembly, was located above the rotating cylinder inside the chamber.

An induction power source was used to melt alloys present in crucibles of molten quartz, boron nitride, alumina, zirconia or beryllium oxide. The amorphous bands were prepared by melting the alloy in a suitable non-reactive crucible and spraying the melt by overpressuring argon through an opening in the bottom of the crucible on the surface of the rotating cylinder (about 1500-2000 rpm). The melting and spraying was carried out in a partial vacuum of about 10 "4 μm using an inert gas, such as argon, to adjust the vacuum pressure.

Using the vacuum melt casting apparatus described above, a number of different glass-forming iron m-6068 # 2-8 group boron alloys were cast and quenched as continuous strips of substantially uniform thickness and width. The thickness typically ranged from 0.025 to 0.076 mm and the width ranged from 1.3 to 3.0 mm. The bands were checked for amorphism by X-ray diffraction and DTA.

The hardness (in DPH) was measured by the diamond pyramid technique using a Vickers-type tip, which consisted of a diamond in the shape of a square-base pyramid and at an angle of 136 ° between opposite surfaces. Tensile tests to determine the tensile strength (in kp / mm2) were made using an Instron machine.

The mechanical behavior of amorphous metal alloys with a composition in accordance with the invention was determined as a function of heat treatment. All alloys were manufactured according to the above process. The amorphous bands of the alloys were all ductile in their cooled state. The straps were bent end to end to form a loop. The diameter of the loop was gradually reduced between the jaws by one micrometer. The straps were considered ductile if they could be bent to a radius of curvature of less than about 0.13 mm without breaking. If a band broke, it was considered brittle.

Example 1 'Alloys suitable for tire cord applications Alloys which would be suitable for tire cord applications, such as for metal strips in radial tires, must be able to withstand about 160-170 ° C for about 1 hour, which is the temperature commonly used. when curing a rubber tire. The alloys must also be resistant to sulfur corrosion and exhibit high mechanical strength.

Examples of alloy compositions suitable for tire cord applications and their crystallization temperature in ° C are given in Table 1. These alloys are described by the composition Feso-vo (NLCW s-1sCrs-16M ° o-sB1e-22 °. The alloys were prepared under the above described conditions.

All alloys remained ductile and completely amorphous after heat treatment at 200 ° C for 1 hour. After the previous heat treatment, these alloys maintained the values of hardness and mechanical strength noted for the cooled alloys. 0 'Éó fl šéßlä-Z-ß 10 Table 1 Thermal and mechanical properties of some amorphous iron group boron compositions suitable for tire cord applications Alloy composition Hardness Crystallization ~ Tensile strength §atomZ) (DPH) temperature (° C) (kp / mm2) Fe3N7 1083 488 293 reæniscoscrfao 41318 1043 szs ii I 350 Fe6èNí7Co7Cr8Bl8 1025 481 U 343 Fesgm 5c ° 3cr7u ° 8n1l8 1120 _ 533, 624 290 Fe55Ni10Co5Cr10B20 1048 487 335 Fe55Ní6B 106 55 '56 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 Co Cr Mo B 1033 508 312 S3, 6 5 16 3 17 Alloys suitable for razor blade applications Alloys which must be suitable for razor blade applications must be able to withstand about 370 ° C for about 30 minutes, which are the treatment conditions which required to apply a coating of polytetrafluoroethylene to the cutting edge. Such alloys should be able to remain ductile and completely amorphous and maintain high hardness and corrosion resistance after the previous heat treatment. Table 2 lists some typical compositions which are suitable for use as razor blades. These alloys are included in the general composition Feö0¿67Ni3_7Co3_7Cr7_lOMo0,4_O'8Bl7.

All alloys remained ductile and completely amorphous after heat treatment at 370 ° C for 30 minutes. After the previous heat treatment, these alloys retained the hardness and corrosion resistance observed in the cooled alloys. u "zfsoeaaz-s Table 2 Thermal and mechanical properties of some amorphous iron group boron compositions suitable for razor blade applications Composition Hardness Crystallisation (atomZ) (DPH) temperature (° C) _ Fe66Ní5Co3,6Cr8Mo0,4B17 1108 487 Ni Co Cr Mo 1101 '494 Feea- s 3,4 so, sB17 Fe66Ni5Co3 * 2Cr8Mo0,8B17 1105 498 Example 3 Alloys having high values of strength and hardness Other alloys having high hardness and high crystallization temperature are given in Table 3. These alloys are included in the general composition M40_85M'0_45Cr0_20MoO_2oBl5_25.Such alloys are useful, for example, in structural applications.

Table 3 Thermal and mechanical properties of some amorphous iron group boron alloys Alloy composition Hardness Crystallisation (atomñ) (DPH) temperature (° C) Fe2Ní4Co3Cr5B16 1086. 440, 492 Fe66Ní5Co4Cr8B17 Fe65Ni5Co3Crl0Bl7 1088 486 1096 478 1130 Fe65Ni2Co2Cr¿Mol0B17 _ * 547 485 Feesvlsßzo re63c ° 10cr7m ° 2ßl8 '1130 512 1115 530 Fe62Ní5Co3Cr7Mo5B18 Feöomiscolocrsßzo loose Fe60Ni5Co3Cr5Mol0Bl7 0475 1120 518 1099 495 Fe60Col0Cr10B20 Fe58Mn22B20 Fe55Ní5Co3Gr7Mo12B18 483 1136 581 ~ ws cr \ c: > QS; eo .sf s »> I 12 Table 3 (continued) Thermal and mechanical properties of some amorphous iron group boron alloys Alloy composition (atomZ) Fe Ni CO Cr so 10 10 ioßzo Fe Co Cr -Mb B 50 15 15 4 16 Fe - Ni Co Cr B 4; 15 1o 10 zo 'Fe4oNí2o °° 1o ° ”1oB20 Fe4oNí8Co5Crl0Mb20Bl7 NïasV1sB2o NíssM“ zoB2z Ni Cr Mo °° 4sF ° 11 13 s 3317' Exemgel 4 Amorphous nickel metal alloys Hardness (DPatur 10 C8 ° 10) C ) 483 sz9, .ssa asa 481 sov, 671 sos 511 540, 628 Table 4 shows the composition, hardness and crystallization temperature of some amorphous nickel alloys containing boron. These alloys have also been found to have high mechanical strength.

The alloys are included in the composition Co Fe Ni40-so 4-15 5-zscra-12M ° o-9315-23 '13 _' rßusaaz-a Table 4 Thermal and mechanical properties of some amorphous nickel alloys with boron I Alloy composition Hardness Tensile strength Crystallization (awmz ) (m) (ip / MZ) temperature (° C) 977 432 Ni50Fe5Co17Cr9Mo3Bl6 Ni47Fe4Co23Cr9Mo1Bl6 982-400, 473, 575 Ni46Fe4Co23Cr9Mo2B16 _ 981,420, 500 Ni¿6Fel0Co2OCr8B16 980,400, 470, 580 Ní46Fe13Col3Cr9Mo3B16 995,439, 542 Ni45Fe5Co20Cr10Mo¿B16 - 1033 278 _ 463, 560 Ni4¿Fe2oCo5Crl0Mo¿Bl7 1024 422, 608 Ni44Fe5Co24Crl0B17 1001 425, 463, 615 Näorwecozocrunoóßló 1033 278 '478, 641 NiaoFesCozoCrloliska properties6, 29 reversible in magnetic applications, is given in Table 5. For some alloys, the saturation magnetization (Ms) at room temperature is given as 1 kGauss or the coercive force (Hc) in Oe for a band under direct current conditions.

Example 6 Corrosion Resistant Alloys - A number of amorphous ferrous boron metal alloys were immersed in a solution of 10% by weight NaCl in water at room temperature for 450 hours and then visually inspected for corrosion or oxidation. The results are given in Table 6. The amorphous alloys, which contained chromium, showed excellent resistance to corrosion or oxidation. 4? ÊD6842-8 Table 5 Thermal properties of some magnetic alloys Alloy composition (atomZ) Feao-ao °° s-45315-25 * Feso °° sB1s F ° 7o ° 1oBzo Ca Faso 3oB2o 4 Fe4o °° 4oB2o °° 4o ~ soFes -45315-25 * °° eoF ° 2oBzo Nino-soFes-45315-25 * Ní7oFe1zB1s 4NíßoF ° 22B1s NísoF ° s2B1s F ° 4o-7oNí4-2s °° s-30315-25 * Fe7oNí4Co5B2l, F ° 7oN s “1s Fe65Ní7Co7B2l FesoNí7 °° 12Bz1 FesoNizo °° 1sB1s FesoNísC ° zaB17 Fe4o“ í1s °° 2sB2o Níao-7oFes-2s °° 5-25315-25 * Ní60Fel3Co10B17 °4? Ns? -25315-25 * °° ssFe7, sNí7, sB17 °° eoF ° 13Ní1oB17 Saturation magnetization (Ms) or coercive force (Hc) MS = l5.6 kGauss Hc = 0.059 Oe _ H = o, o29 and C Ms = 1s; 1 kcauss Ms = 13.45 kGauss uc = o, o3s oe 'Crystallization temperature (° C) 465 493 492 483 435 444 456 455 435, 504 465 472 422, 458 450, 492 473 373 405 423 432 _ 442 15? 6068ë2 ~ 8 Table 5 (continued) Thermal properties of some magnetic alloys Alloy composition (atomß) ° 4ø ~ 7oF ° s-2sNís-25315-25 * °° soF ° 1sNí1sB17 C ° 4oFe2oNi17B23 Other: Fe81Co3Ní1B15 Measures tnadamagnetization (Ms) or coercive force (Mc) Crystallization temperature (° ç) 437, 450 462 Ms = l5, l kGauss - Table 6 Results of corrosion tests for some amorphous iron, nickel and cobalt alloys with boron Fe66Ní5Co3,6Cr8Mo0, 4B17 Fe65Ni5Co3CrloBl7 Fe63Ni5Co3Cr7Mo¿B18 Fe55Ni8Co5Crl5Bl7 Fe5¿Ní6Co5Crl5Mo2B18 FesoNí1o °° 1oC "1oBzo Co. Fe4oNí1s 25320 Ní44Fe20Co5Crl0Mo4B17 Ní¿oFe5CoZ0Cr1OMo9B16 °° SOF ° 1sNí1sB17 Exemgel 7 Thermal aging of alloys a number of amorphous iron group-bormetallegeringar was aged thermally at a temperature of 250-375 ° C in air below 0.5-lh and evaluated no corrosion, oxidation or discoloration corroded and matt no corrosion, oxidation or discoloration corroded and matt with respect to embrittlement. The heat treated strips were raised to .7606842-8 'in 16 to form a loop. The diameter of the loop was gradually reduced between the jaws of a micrometer until breakage occurred. The average fracture diameter of the amorphous alloy strip obtained from the micrometer readings indicates the ductility. A low value indicates good ductility. For example, the value zero means that the amorphous band is completely ductile. The results are given in Tables 7 and 8.

Table 8 Results of embrittlement studies on amorphous nickel-boron metal alloys Mean breaking diameter (μm) Alloy composition _ Thickness 325 ° C 340 ° C 355 ° C 360 ° C 375 ° C (atømñ) (μm)> 1/2 h> 1/2 h> 1 / 2 h> 1/2 h> 1/2 h N145re5c ° 20cr10m ° 4B16 38,1 o U oloo I o Ni44Fe5c ° 2¿crl0Bl7 34,3 ooo _ o 381 Ni50Fe5c ° l7cr9m ° 3B16 30,5 ooo sos Ni46Fe4c ° 23cr9M ° 2ßl6 35,6 olo 0 635 Ni46Fe1UCo20Cr8Bl6 30,5 _ 0 0 381 ui46re13c ° 13cr9M ° 3Bl6 35,6 Q l 254 Ni40Fe6c ° 2ocrl2M ° 6ßl6 35,6 o 381 Ni40Fe5Co2Bl6MM 35 www noe nä .. wow ßwe www www .www wße wwQ owQ æmq ßæw wme Auov Hnumum fl muu. IWEOMUNWHH AMUMMHM QQQ _ Q ~ .QQ QQQQQQQQQQQQQQQQQQQQQ NQN QQ Q.Qm QQQ QzQQ ~ ~ ~ Q QmQQQQzQQ NQQ QQ Q.QQ QQQQQQzQ .q ~ ~ »Q QQ QQQ Q.Qm QNQNQQQQZQQQQ QQQ QQ Q.QQ QQQQQQQQQQQNQQNQQQQQQ QQQQ QQQ QQQ QQ m .QQ QQQQQQQQQQQQZQQQQ QQQQ Q ~ QQQ Q.QQ QQQQQQQQQQQzmQQQ QQQ QQQ Q.QQ QNQQQQQQQQQQQQQQQQQ QQQH QQQQ QQQ Q.Qm QQQQQQQQQQQQQQQQQQQ QQQ QQQQQ Q.Qm QQQQQQQQQNQzQQQQ QQQ qqqqqq ~ .QQ QQQQQQQQQQQQQQQQQ QQQ QQQQ .QQ ~ .mQ QQQNQQQQQQQZQQQQ QQQ qqqqqq m.QQ QQQQQQQ ° QQQzQQ «Q QQN QQQQQQ Q.mQ ~ QQ ~ .QQzQ» QQ.QQQmQzQQ@QQQQQQQQQ QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ \ Q ^ Q ~ \ Q ^ QQQQQQQQ QQQQ ANQQQQQ QQQNQ QQQQQ QQQQQ QQQNQ QQQQQ QQQQQQ. QQQQN QQQQQQQQQQQQQ Hw »waQQQQQoQnQwQws ß HHmQßB mm fl nuum wømšnwwmws fl nwwwq

Claims (12)

? 6Û6842-8 18 PATENT REQUIREMENTS 1. l. Amorphous metal alloy which is at least 50% amorphous, characterized in that the alloy has essentially the composition MaM'bCrcM 'dBe, where M is an element of the iron group, M' is at least one of the remaining two elements from the iron group, M "is at least one of the elements vanadium, manganese, molybdenum, tungsten, niobium and tantalum," a "varies from about 40 to 85 atomic%," b "varies from 0 to about 45 atomic%," c "and "d" each varies from 0 to about 20 atomic%, and "e" varies from about 15 to 25 atomic%, where since M is nickel "b", "c" and "d" not all can be 0. at the same time. Amorphous metal alloy according to claim 1, characterized in that "e" varies from about 17 to 22 atomic%. 3. An amorphous metal alloy according to claim 1, characterized in that "c" varies from about 4 to 16 atomic%. Amorphous metal alloy according to claim 1, characterized in that M "is molybdenum, and that" d "varies from about 0.4 to about atom. Amorphous metal alloy according to claim 4, characterized in that "d" varies from about 0.4 to 0.8 atomic%. Amorphous metal alloy according to claim 4, characterized in that "d" varies from about 4 to 8 atomic%. 7. An amorphous metal alloy according to claim 1, characterized in that it has substantially the composition Feso <10 (Ni '°°) s-lscrs-1sM ° o-sB16-22'. 8. An amorphous metal alloy according to claim 1, characterized in that it has substantially the composition Eeeo-67Ní3-7 °° 3-7 ° r7-1oM ° o, 4-o, sB17-zo ' 9. An amorphous metal alloy according to claim 1, characterized in that it has substantially the composition N14o-soFe4-1o °° s-2sera-12M ° o-9315-22 '. 10. An amorphous metal alloy according to claim 1, characterized in that it has substantially the composition °° 4o-soFes-20oNio-zo ° "4-1sM ° o-9515-23 '. 11. ll. Amorphous metal alloy according to claim 1, characterized in that the alloy has essentially a composition, nails being selected from Fe831al7, Fesoßzo, Fenßzz, Fe771a2'3, Fewßu, Fe75B25 and CQBOBZO. Amorphous metal alloy according to claim 1, characterized in that the alloy is at least 80% amorphous.