LOW MAGNETOSTRICTION AMORPHOUS METAL ALLOYS

Abstract: Cobalt rich amorphous metal alloys have a value of magnetostriction of about -6 x 10⁻⁶ to +4 x 10⁻⁶ and a saturation induction of about 0.1 to 1.0T. The alloys, especially suited for soft magnetic applications, have the formula (Co 1-x T x ) 100-b (B 1-y Y y ) b , where 7 is at least one of Cr and V, Y is at least one of carbon and silicon, B is boron, x ranges from about .05 to .25, y ranges from about 0 to .75 and b ranges from about 14 to 28.

Description: DESCRIPTION LOW 1 AGNETOSTRICTION AMORPHOUS METAL ALLOYS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to amorphous metal alloys and, more particularly, to cobalt rich amorphous metal alloys that include certain transition metal and metalloid elements. 2. Description of the Prior Art There are three physical parameters which can inhibit the easy magnetization and demagnetization of magnetic materials: strong anisotropy, non-zero magnetostriction and, at high frequencies, low resistivity. Metallic glasses generally show resistivities greater than 100 micro ohm cm, whereas crystalline and polycrystalline magnetic metals generally show resistivities below 50 micro ohm cm. Also, because of their randomly disordered structures, metallic glasses are typically.isotropic in their physical properties, including their magnetization. Because of these two characteristics, metallic glasses have an initial advantage over conventional magnetic metals. However, metallic glasses do not generally show zero magnetostriction. When zero magnetostriction glasses can be found they are generally good soft magnetic metals tR.C. O1Handley, B.A. Nesbitt, and L.I. Mendelsohn, IEEE Trans híag-12, p. 942, 1976, U.S. Patents Nos. 4,038,073 and 4,150,981), because they satisfy the three approved criteria. For this reason, interest in zero magnetostriction glasses has been intense as indicated by the many publications on low magnetostriction metallic glasses (A.W. Simpson and W.G. Clements, IEEE Trans Mag-ll, p. 1338, 1975; N. Tsuya, K.I. Arai, Y. Shiraga and T. Masumoto, Phys. Lett. A51, p. 121, 1975; H.A. Brooks, Jour. Appl. Phys. 47, s. 334, 1975; T. Egami, P.J. Flanders and C.D. Graham, Jr., Appl. Phys. Lett. 26, p. 128, 1975 and AIP Conf. Proc. No. 24, p. 697, 1975; R.C. Sherwood, E.M. Gyorgy, H.S. Chen, S.D. Ferris, G. Norman and H.J. Leamy, AIP Conf. Proc. No. 24, p. 745, 1975; n. Fujimori, K.I. Arai, H. Shiraga, M. Yamada, T. Masumoto and l5. Tsuya, Japan, Jour. Appl. Phys. 15, p. 705, 1976; L. Kraus and J. Schneider, phys. stat. sol. a39, p. K161, 1977; R.C. O'Handley in Amorphous Magnetism, edited by R. Levy and R. Hasegawa (Plenum Press, New York 1977), p. 379; R.C. O'Handley, Solid State Communications 21, p. 1119, 1977; R.C. O'Handley, Solid State Communications 22, p. 458, 1977; R.C. O'Handley, Phys. Rev. 18, p. 930, 1978; H.S. Chen, E.M. Gory, H.J. Learnt and R.C. Sherwood, U.S. Patent No. 4,056,411, Nov. 1, 1977). The existence of a zero in the magnetostric- tion of C0-Mn-B glasses has been observed by H. Hiltzinger of Vacuumschmeltze A.G., Hanau, Germany. Reference to Co-rich glasses containing 6 atom percent of Cr is made by N. Heiman, R.D. Hempstead and N. Kazama in Journal of Applied Physics, Vol. 49, p. 5663, 1978. Their interest was in improving the corrosion resistance of Co-B thin films. No reference to magnetostriction is made in that article. Saturation moments and Curie temperatures of CO80-xT xP10B10 glasses (T = Mn, Cr, or V) were recently reported by T Mizoguchi in the Supplement to the Scientific Reports of RITU (Research Institutes of Tonoku University), A June 1978, p. 117. No reference to their magnetostrictive properties was reported. In Journal of Applied Physics, Vol. 50, p. 7597, 1979, S. Ohnuma and . Nasumoto outline their studies of magnetization and magnetostriction in Co-Fe-B-Si glasses with light transition metal (Mn, Cr, V, W, Ta, Mo and Nb) substitutions. They show that the coercivity decreases and the effective permeability increases in the composition range near zero magnetostriction. New applications requiring improved soft zeromagnetic materials that are easily fabricated and have excellent stability have necessitated efforts to develop further specific compositions. SUMMARY OF THE INVEt4TIOll The present invention provides low magnetostriction and zero magnetostriction glassy alloys that are easy to fabricate and thermally stable. The alloys are at least about 50 percent glassy and consist essentially of compositions defined by the formula: (CO1-xTx)100-b(B1-yYy)b, where m is at least one of Cr and V, Y is at least one of carbon and silicon, B is boron, x ranges from about .05 to .25, y ranges from about 0 to .75, and b ranges from about 14 to 28 atom percent. The alloys of the invention have a value of magnetostriction ranging from about -6 x 10 6 to 4 x 10 6 and a saturation induction of about 0.2 to 1OT. In addition, the invention provides cobaltiron-nickel base and nickel-rich magnetic alloys that are easily fabricated and thermally stable. The cobaltiron-nickel base alloys are at least 50 percent glassy and consist essentially of compositions defined by the formula: (Co1-x-y-zFexNixTz)100-b(B1-wMw)b, where T is at least one of Mn, Cr, V, Ti, Mo, Nb and 1S, M is at least one of Si, P, C and Ge, B is boron, x ranges from about .05 to .25, y ranges from about .05 to .80, z ranges from about 0 to .25, b ranges from about 12 to 30 atom percent, w ranges up to .75 when M is Si or Ge and up to .5 when M is C or P. These alloys have a value of magnetostriction of about -7 x 10-6 and +5 x 10-6 and a saturation induction of about 0.2 to 1.4T. The nickelrich alloys are at least 50 percent glassy and consist essentially of compositions defined by the formula: (Ni5Co5-xTx)100-bBb, where T is at least one of Mn, Cr and V, B is at least one of B, Si, P, C and Ge, x is less than 0.25, and b ranges from 17 to 22 atom percent. The nickel-rich alloys have a value of magnetostrlction of about -8 x 10 to +2 x 10 and a saturation induction of about 0.3 to 0.8 T. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be more fully understood and further advantages will become apparent when reference is made to the following detailed description of the preferred embodiments of the invention and the accompanying drawings, in which Figure 1 is a graph showing saturation magnetization for compositions defined by the formula Co80-xTxB20, where T is at least one of Fe, Mn, Cr and V and x ranges up to about 16 atom percent; Figure 2 is a graph showing Curie temperatures of compositions for which T is below the crystalliza c tion temperature vex; Figure 3 is a graph showing the relationships between saturation nagnetostriction and composition for selected alloys of the invention; ; Figure ss is a graph showing the relationships between temperature and magnetostriction values for selected alloys of the invention; Figure 5 shows the cobalt-rich corners of triangular diagrams for compositions defined by the formula (Co1y Fe T ) where T is at least one of x y 80B20, V, Cr, Mn, Fe, Co and Ni; and Figure 6 is a triangular Fe-Co-Ni diagram showing regions of positive and negative magnetostriction, the dotted line isolating therefrom the region of nickel-rich compositions wherein amorphous metals are difficult to form and thermally unstable. DESCRIPTION OF THE PREFERRED EMBODIMENTS In accordance with the invention, there is provided a magnetic alloy that is at least 50 percent glassy and consists essentially of the composition: (Co1-xTx)100-b(B1-yYy)b, where T is at least one of chromium and vanadium, Y is at least one of carbon and silicon, x ranges frorn about .05 to .25, y ranges from about 0 to .75, and b ranges from about 14 to 28 atom percent. The glassy alloy has a value of magnetostriction of about -6 x 10 to 4 x 10-6 and a saturation induction of about U.2 to i.0T. The purity of the above composition is that found in normal commercial practice. However, it will be appreciated that the alloys of the invention may contain, based on total composition, up to about 5 atom percent of at least one other transition metal element, such as Fe, Co, Ni, Cu, Zn, Mn, Cr, V, Ti, Zr, b, Ta, Mo, W, Ru, Rh and Pd, and up to about 2 atom percent based on total composition of at least one other metalloid element, such as B, C, Si, P, Ge, Al, N, 0 and S, without significantly degrading the desirable magnetic properties of these glassy alloys. The amorphous alloys of the invention can be formed by cooling a melt of the composition at a rate of at least about 10 50C/sec. A variety of techniques are available, as is now well-known in the art, for fabricating splat-quenched foils and rapid-quenched continuous ribbons, wire, sheet, etc. Typically, a particular composition is selected, powders of the requisite elements (or of materials that decompose to form the elements, such as nickel-borides, etc.) in the desired proportions are melted and homogenized, and the molten alloy is rapidly quenched either on a chill surface, such as a rotating cooled cylinder, or in a suitable fluid medium, such as a chilled brine solution. The amorphous alloys may be formed in air. However, superior mechanical properties are achieved by forming these amorous alloys in a partial vacuum with absolute pressure less than about 5.5 ci of Hg, and preferably about 100 m to 1 crll of Hg, as disclose in U.S. Patent No. 4,154,283 to Ray et al. The amorphous metal alloys are at least 50 percent amorphous, and preferably at least 80 percent amorphous, as measured by X-ray diffraction. However, a substantial degree of amorphousness approaching 100 percent amorphous is obtained by foring these amorphous metal alloys in a partial vacuum. Ductility is thereby improved, and such alloys possessing a substantial degree of amorphousness are accordingly preferred. Ribbons of these alloys find use in soft magnetic applications and in applications requiring low magnetostriction, high thermal stability (e.g., stable up to about 100 C) and excellent fabricability. The following example is presented to provide a more complete understanding of the invention. The specific techniques, conditions, materials, proportions and reported data set forth to illustrate the principles and practice of the invention are exemplary and should not be construed as limiting the scope of the invention. E.vAMPLE An alloy melt of known composition was rapidly quenched to form non-crystalline ribbons, presumably of the same conposition as the melt. The ribbons, typically 40 micrometers (um) by 2 mm in cross section, were cut into squares for vibration-sample magnetometer measurements of specific magnetization a(4.2K, 9 KOe) and a(T, 9 ROe) with 295 K < T < Tx, the crystallization temperature. Curie temperatures were obtained from the inflection points in the a(T, 9 KOe) curves. The magnetostriction measurements were made in fields up to 4 KOe with metal foil strain gauges (as reported in more detail by R.C. O1Handley in Solid State Communications, Vol. 22, p. 485, 1977). The accuracy of these measurements is considered to be within 10 percent of full strain and their strain sensitivity is on the order of 10 7. Composition variations of the room temperature specific saturation magentizations o(295 R, 9 KOe) as functions of composition x for Co80-xTxB20 (T = Fe, Mn, Cr, V) glasses are shown in Figure 1. The trends in Figure 1 reflect the variations of both the saturation moments nB and the Curie temperatures TC of these alloys. The Curie temperatures of Co-rich glasses are generally well above the temperatures for crystallization Tx but fall below Tx for sufficiently large additions of Cr or V (Figure 2). In order to be useful in magnetic devices, materials should show appreciable magnetization. Commercial zero magnetostriction crystalline metallic alloys of the class exemplified by Permalloy ((Ni82Fe18)1-xXx with x = Mo or Cu and x < .04) have saturation inductions B5 = H + 4 Tt Ms = 4 Tr Ms of about 0.6 to 0.8 tesla (6 to 8 kGauss). The specific magne- tizations in Figure 1 can be converted to tesla by multiplying by the mass density times 4 @/10,00. Densities for the glasses studied here can be estimated fro the measured densities for Co80B20, Feg0B20 and Co70Fe10 B20 glasses and the known densities of crstalline Co, Fe, Mn, Cr and V. Defining Px to be the mass density of the crystalline material X and pg to be that of the glassy material X80E2Q, the ratios of the measured quantities Pg/PX were found to be 0.92 and 0.94 for Co80B20 and Fe80B20 glasses. A similar trend holds for the hypothetical X80B20 glasses listed in Table I. The estimated densities of X80B20 (X = Mn, Cr, V) glasses are also set forth in Table I. The densities of CO70X101320 glasses were calculated by linearly combining the densities of Co80B20 and X80B20. The value so obtained for Co70Fe10B20 is less than 1 percent larger than the measured density for that glass. TABLE I Densities and Saturation Inductions for CO70 X10B20 Glasses Crystalline X X80B20 Glass Co70X10 B20 Glass Px P Pg/Px Saturation Density Density Density Induction 3 3 3 X (gm/cm ) (gm/cm3) (gm/cm ) (tesla) Co 8.90 8.22 (a) .92 8.22 (a) 1.14 (a) Fe 7.86 7.41 (a) .94 8.12 (b) 1.25 (c) 8.06 (a) 1.24 (a) Mn 7.a3 7.06 (b) .95 8.06 (b) 1.11 (c) Cr 7.19 6.90 (b) .96 8.04 (b) 0.59 (c) V 6.00 5.82 (b) .97 7.92 (b) 0.43 (c) (a) measured (b) estimated (c) measured specific magnetization, estimated density. In Figure 3, there is shown the effects of Fe, Nn, Cr and V substitutions on the saturation magnetostriction of Cog0E20 glass. As is the case with the Fe substitutions for Co disclosed by U.S. Patent No. 4,038,073 to O'Handley et al., the lighter transition metals cause X to increase through zero, positive below 5 T for Mn and Cr substitutions and go to zero for V sub c stitutions. In the case of Co66V14B20 glass, Tc = 300 K (Fig. 2). Thus, the room temperature magneto striction is zero probably because of the low T c Co80-xVxB20 glasses with x > 14 may show positive magnetostriction at 4.2 K (see Fig. 4). These Co-Mn-B and Co-Cr-B glasses are, therefore, non-magnetostrictive alloys. Co74Fe6B20 and related glasses are non-magneto- strictive alloys that have approximately two times the magnetization of the permalloys for which A 0. Co71MnOB20 glass is in the same category, with X= 0 and o(295 K = 111 emu/gm (4#M = 11 kGauss). The temperature dependence of As is shown in Figure 4 for selected alloys. The sign of X was ob S served to change in two of the glasses. Such compen sation temperatures have not previbusly been observed in metallic glasses. The vanadium containing glasses either become paramagnetic or they crystallize before any compensation can be realized. Thus, the negative magnetostriction glasses shown in Figure 3 may be used in applications requiring As = 0 at some elevated tem- perature (up to approximately 2000C above room temperature, which is not uncommon in many electronic devices). The new low magnetostriction metallic glasses disclosed herein (Co-Cr-B and Co-V-B) show relatively low 4#MS (Fig. 1). As a result, their utility is limited to applications requiring superior mechanical properties or improved corrosion resistance relative to permalloys or other A = 0 crystalline or non-crystal 5 line materials. Co-rich glass compositions with positive and negative magnetostriction can be added linearly to give zero magnetostriction. For example, A5 for Co70Fe10B20 and Co80B20 glasses are +4 and -4 x 10 6, respectively. A 50-50 percent mixture of these glasses gives Co75Fe5B20 which does in fact show A5 = 0 (O'Handley et al., IEEE Trans Mag-12, p. 942, 1976). Similarly, for Co40Ni40B40 X = -7 x 10-6 while for Fe8cB20 A5 = 32 x 10 6. A linear mixture having X = 0 would be 0.18 x (Fe80B20) + 0*82 x (Co40Ni40B20) = Co33Ni33Fe14B20 which is very close to the observed = O composizion, Co@ Ni@ Fe@ B@ 5 The rule of linear combination of opposing magnetostrictions (LCOM) has been applied to develop additional zero magnetostriction glasses fron those measured and shown in Figure 3. Table II lists several such glasses and Figure 5 shows where they fall in the Co-Rich corner of a triangular composition diagram. The lines connecting these newly developed A = 0 5 cortpositions closely follow the observations of Ohnuna and Masumoto (cited above) for (Co Fe X)78B14Si8 glasses (with X = Mn, Cr, V) despite the different metalloids used in the two cases. TABLE II Some Near-zero Magnetostriction Cobalt-rich Glasses Developed b the LCOM Method Co73Fe4.5Mn2.5B20 Co73Fe2Mn5B20 Co73Fe 5Mn4 .5B20 Co73Fe5Cr2B20 Co71Fe4.5Cr4.5B20 Co70Fe2.5Cr7.5B20 Co73Fe3.5V3.5B20 Co71Fe3V6B20 Co70.5Fe2.5V7B20 Co72.3Fe4.3V3.4B20 Co70Mn5V5B20 Co69Mn5Cr6B20 Co66Cr8V6B20 The magnetostriction of Co-rich glasses is small because of the near-cancellation of two independent mechanisms for the magnetostriction, a positive two-ion interaction and a negative single-tN-ion term (O'Handley, Phys. Rev. B 18, p. 930, 1978). As a re sult, the TM makeup for X = 0 is nearly independent of S TM/M ratio. That is, because # = 0 for (Co 94Fe .06)80B20, is nearly zero for other compositions (Co.94Fe.06)100-xBx such that 12 < x < 28 atom percent. An improvement on this approximation can be realized by taking into account the fact that the strength of the negative single-ion term varies linearly with the concentration of magnetic ions, i.e., at (100-x). The two-ion term should vary as the number of TM pairs at short range. However, observed trends in Co100-xBx glasses (K. Narita, J. Yamasaki, and H. Fukunaga, Jour. Appl. Phys. Vol. 50, p. 7591, 1979 and J. Aboaf and E. Klokholm, ICM Munich Sept. 1979 to appear in Jour. Magnetism and Magnetic Materials), are best described by assuming the number of nearest neighbor TM pairs to be independent of x. is implies that the nearestneighbor coordination of cobalt atoms by cobalt atoms does not vary strongly with x. Thus the compositional dependence of magnetostriction in Co-rich glasses is well described at room temperature b: As + 6.8 x 10 6 - 10.2 x 10 x (100-x)/80 where the first term is the observed two-ion component of magnetostriction (independent of composition x) and the second is the single-ion component of magnetostriction (which varies linearly with the TM concentration). Thus the magnetostriction becomes less negative as metalloid content increases, the change in # being +0.13 x 10-6 per atom percent more metalloid. Alternatively, the zero magnetostriction composition is shifted to glasses richer in iron as 100-x increases, the shift being approxiriately +0.23 percent Fe per 1 percent decrease in x. As a result, the Co-Fe-T ratios (T = Mn, Cr, V) for As = O in Figure 5 hold approximately for other S TM/M ratios in the glass-forming range 12 < x < 28 atom percent. . first order correction shifts the As = O S lines toward Fe by approximately 1 percent for every 4 percent decrease in x. Metalloid type has little effect on the magni- tude or sign of magnetostriction in Co-rich glasses (O'Handley in Amorphous Magnetism eds. R. Levy and R. Hasegawa, Plenum Press 1977, p. 379). Hence, the compositions in Table II and Figure 5 will still be of near-zero magnetostriction if B is replaced by P, C, Si or some combination of these metaloids. The rule of linear conbination of opposing magnetostrictions (LCOM) can also be applied across the Co-Ni side of the Fe-Co-Ni triangular nagnetostriction diagram shown in Figure 6 (see also U.S. Patent No. 4,150,981 to O'Handley). Table III sets forth some typical near-zero magnetostriction compositions. TABLE III New Co-Ni Base Glassy Alloys or Near-zero Magnetostriction Developed by LCOM Method. Co66Mn9Ni5B20 Co68.4Mn8.3Ni3.3B20 Co53.7Ni15.3Fe5.5Mn5.5B20 Co52Ni18Fe8Mn2B20 Co41Ni30Fe5Mn4B20 Ni45Co26.5Fe7.5Mn1B20 Co58Ni12Fe6Mn4B20 Co51Ni18Fe8Cr3B20 Co39Ni30Cr6Fe5B20 Co56Ni12Fe6Cr6B20 Co51Ni18Fe9Cr2B20 Co40Ni30Fe5V5B20 Co59Ni12Fe6V5B20 Referring to Figure 6, a region of difficult to fabricate and relatively unstable glasses exists in the 7, rich corner of the triangular Fe-Co-ni diagram. Yet, glassy alloys of zero or low magnetostriction exist there with potential for various applications. Ni-rich glasses are more easily made and are more stable if the "late" transition metal ni is balanced to a certain extent by an "early" Ti, e.g., Mn, Cr, V. Examples of such glasses include lli50Mn30B20, Ni60Cr20B20, or Ni70V10B20. Based on the evidence of A5 = 0 alloys set forth above and the known stabilizing effects of light TM's on Ni-rich glasses7 new low magnetostriction glasses rich in Ni have been developed in the region below or near the A = 0 line in Figure 8 (i.e., glasses S initially showing X < 0) by the addition of Mn, Cr, and/or V. Thus, for example, (Co 25Ni.75)80B20 can be rendered more fabricable and more stable in the glassy state, and its negative magnetostriction can be increased to near zero by substituting Mn, Cr or V for Co: (Ni.75Co.25-xTx)80B20. Having thus described the invention in rather full detail, it will be understood that such detail need not be strictly adhered to but that various changes and modifications may suggest thertlselves to one skilled in the art, all falling within the scope of the invention as defined by the subjoined claims.

Claims: We claim: 1. A magnetic alloy that is at least about 50 percent glassy, haviny the formula where T is at least one of chromium and vanadiurn, Y is carbon, silicon, phosphorus and germanium, x ranges from about .05 to .25, y ranges from about 0 to .75, and b ranges from about I4 to 28 atom percent, said alloy containing, as transition metal impurities, up to 5 atom percent of the total alloy of at least one of Fe, Co, Ni, Cu, Zn, Mn, Cr, V, Ti, r, Nb, Ta, Mo, W, Ru, Rh and Pd, ana, as metalloid impurities, up to 2 atom percent of the total alloy of at least one of B, C, Si, P, Ge, Al, N, O and S, having a value of magnetostriction of about -6 x 10 6 to 4 x 10 6 and saturation induction of about 0.2 to 1.0T. 2. h magnetic alloy, as recited in claim 1, wherein x ranges from about .05 to .15, y ranges from about 0 to .25 ana b ranges from about 17 to 22 atom percent said alloy having G value of magnetostriction of about -3 x 10 -6 to +1 x 10-6 an d saturation induction of about 0.3 to 0.6T. 3. A magnetic alloy that is at least 50 percent glassy, having the formula (Co1-xTx)100-bBb, where T is at least one of chromium and vanadium, b ranges from about 18 to 22 atom percent and x ranges from 2 to 16 atom percent, said alloy further contain- ing, as transition metal impurities, up to 5 atom per cent of the total alloy of at least one of Fe, Co, Ri, Cu, Zn, Mn, Cr, V, Ti, Zr, Nb, Ta, Mo, W, Ru, Rn and Pd, and, as metalloid impurities, up to 2 atom percent of the total alloy of at least one of B, C, Si, P, Ge, Al, N, 0 and S. 4. A magnetic alioy that is least 50 per cent glassy, naving the formula (Co1-x-y-zFexNiyTz)100-b(B1-wNw)b, where T is at least one of Mn, Cr, V, Ti, rlo, Nb and , N is at least one of Si, P, C and Ge, b is boron, x ranges fro about .05 to .25, y ranges from about .05 to .80, ranges from about 0 to .25, b ranges from about 12 to 80 atoll percent, w ranges up to .75 when i. is Si or Ge ari up to .5 when M is C or P, said alloy naving a value o; magnetostriction of about -7 x 10-6 and +5 x 10 6 ana saturation induction of auout 0.2 to 1.4T. 5. A magnetic ailoy, as recited in claim 4, wherein y ranges fro about 0.3 to 0.6 or between 0.60 to 0.80 and z is respectively less than 0.2 or less that 0.15 when T is more that 50 percent of dt least one of Cr and V, said alloy having value of magnetostric- tion of about -6 x 10 6 to +4 x 10-6 and a saturation induction of about 0.1 to 0.9T. 6. A magnetic alloy that is at least 50 percent glassy, having the formula (Ni.5Co5-xTx)100-bBb, where T is at least one ol Mn, Cr and V, B is at least one of B, Si, P, C and Ge, x is less than 0.25, and b ranges from 17 to 22 atom percent, said alloy naving value of magnetostriction of about -8 x 10-6 to +2 x 10-6 and a saturation induction of about 0.3 to 0.85?. 7. A magnetic alloy that is at least 50 percent glassy, said alloy having the formula (Wi.75Co25-xTx)100-bMb, where T is at least one of Mn, Cr aiiu V, M is at least one of B, bi, , P, t and Ge x ranges up to about 0.25, anU b ranges fro about 17 tu 22 atom percent, said alloy having a value of magnetostriction of about -6 x 10-6 to +2 x 10-6 ano a saturation induction of about 0.1 to 0.7T. 8. A magnetic alloy, as recited in either claim 6 or 7, wherein ii is essentially boron anti sdid alloy contains, as metalloid impurities, up to 2 ato. percent of at least one of , Si, P, C and e. 9. A magnetic alloy having a composition selected from the consisting of Co73Fe4.5Mn2.5B20, Co73Fe2.5Mn4.5B20, Co73Fe5Cr2B20, Co70Fe2.5Cr7.5B20, Co73Fe3.5V3.5B20, Co70.5Fe2.5V7B20, Co70Mn5V5B20, Co66Cr8V6B20, Co73Fe2Mn5B20, Co71Fe4.5Cr4.5B20, Co71Fe3V6B20, Co72.3Fe4.3V3.4B20 and Co69Mn5Cr6B20. 10. A magnetic alloy having a composition selected from the group consisting of Co66Mn9Ni5B20, Co53.7Ni15.3Fe5.5Mn5.5B20, Co41Ni30Fe5Mn4B20, Co58Ni12Fe6Mn4B20, Co58Ni12Fe6Mn4B20, Co51Ni18Fe6Cr3B20, Co56Ni12Fe6Cr6B20, Co40Ni30Fe5V5B20, Co68.4Mn8.3Ni3.3B20, Co52Ni18Fe8Mn2B20, Ni45Co26.5Fe7.5Mn1B20, Co39Ni30Cr6Fe5B20, Co51Ni18Fe9Cr2B20 and Co59Ni12Fe6V5B20. 11. A magnetic alloy tnat is at least 50 percent glassy, said alloy having tne formula Co80-xTxB20, where T is at least one of Cr and V, B is boron, and x ranges from about 0 to 16 atom percent.

Inventors: O'HANDLEY, ROBERT CHARLES
Applicants: ALLIED CORPORATION
Application year: 1981
Main classification: C22C19
IPC codes: C22C45, H01F1