US 3898081 A
A nickel base alloy, especially useful for high precision resistors, containing from about 6 to about 12% gallium, from about 7 to about 12% vanadium, and from about 6 to about 15% chromium, the combined content of vanadium and chromium being within a range of from about 18 to about 24% and the total content of vanadium, chromium and gallium being within a range of from about 28 to about 34%, the balance being nickel. Preferably, the alloy composition has a combined content of chromium and vanadium of not lower than 18%; a nickel content between 66 and 72%; a stoichiometric formula Ni2Me2/3 M1/3 where Me can be Cr, V, Re, W, Mo, Nb, Ti, Mn, Ta, Fe, Co, and/or Os and M can be Ga, Ge, Si, and/or Al; and a resistivity in the range of 1.7-2.2 mu ohm.m.
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Description (OCR text may contain errors)
United States Patent 1191 Kukhar [4 1 Aug.5, 1975 NICKEL BASE ALLOY FOR PRECISION RESISTORS  Inventor: Vasily Valentinovich Kukhar, 2
Murinsky prospekt, l5 kv. 34, Lenningrad, USSR,
 Filed: Dec. 13, 1973 ] Appl. No.1 424,6l0
 US. Cl 75/171; 148/32  Int. Cl. C22c l9/00  Field of Search 75/171, 170; 148/32, 325
 References Cited UNITED STATES PATENTS 3,134,670 5/1964 Prosen 75/l7l Primary E.mnu'nerR, Dean Atlorney. Agent, or FirmWaters, Schwartz & Nissen 5 7 1 ABSTRACT A nickel base alloy, especially useful for high precision resistors, containing from about 6 to about 12% gallium, from about 7 to about 12% vanadium, and from about 6 to about 15% chromium, the combined content of vanadium and chromium being within a range of from about 18 to about 24% and the total content of vanadium, chromium and gallium being within a range of from about 28 to about 34%, the balance being nickel. Preferably, the alloy composition has a combined content of chromium and vanadium of not lower than 18%; a nickel content between 66 and 72%; a stoichiometric formula Ni Me M where Me can be Cr, V, Re, W, Mo, Nb, Ti, Mn, Ta, Fe, Co, and/or Os and M can be Ga, Ge, Si, and/0r A]; and a resistivity in the range of l.72.2 uohmm.
8 Claims, N0 Drawings NICKEL BASE ALLOY FOR PRECISION RESISTORS BACKGROUND OF THE INVENTION The present invention relates to nickel base alloys, and, more particularly, it relates to alloys especially useful as high precision resistor material used in manufacturing resistors for various measurement circuits to control instrumentation.
An alloy for this kind of application should satisfy the following requirements (all of these requirements pertaining to the working range of temperatures);
1, The resistivity of the alloy should be sufficiently high, not lower than 0.30 0.35 [.LOhlTLm. Furthermore, the manufacture of resistors with high resistance values calls for alloys having resistivities not below 1.5 to 2.0 uOhmm.
2. The dependence of the resistivity of the alloy on temperature, if any, should be as small as possible.
3. The resistivity of the alloy should remain constant for a long period of time.
4. The thermoelectromotive force of the alloy versus copper should be as low as possible and, in any case, should not exceed pV/K. The expression K" whenever used herein, is intended to mean Kelvin, i.e., degree on the Kelvin thermometric scale" (a unit of temperature measurement adopted by the XIII Universal Conference on Weights and Measures in 1967). When used for expressing temperature differences, degrees Kelvin coincides with centigrade degrees (C).
5. The alloy should feature adequate corrosion resistance.
6. The alloy should be sufficiently plastic and strong to make it suitable for manufacture of sufficiently thin wires, bands, strips, and so forth.
Widely known in the art are three main groups of alloys satisfying the above requirements to a greater or lesser degree, namely, copper-manganese alloys (i.e., manganin type alloys), alloys based on noble metals, and nickel-chromium alloys (i.e., Nichrome type alloys).
Among the manganin type alloys i.e., copper base alloys to which manganese has been added intended for the manufacture of precision resistors, the above requirements are met to the greatest degree by an alloy described in the co-pending US. Application Ser. No. 399,199 filed Dec. 20, 1973 which is a continuation in part of US. Application Ser. No. 77,014 filed Sept. 30, I970 by joint inventors.
However, all the manganin type alloys fail to feature adequately high resistivity.
Alloys based on noble metals do not offer a combination of all the above-listed, required qualities. Moreover, a disadvantage of this kind of alloys is their high cost.
Among the Nichrome type alloys that are widely used in the art as a raw material for high precision resistors are alloys such as those known under the trade names of Evanohm, Karma, Nikrothal L, and so forth. These alloys contain 75% nickel, 17% to 21% chromium, the balance being: aluminum and copper (in the case of Evanohm); aluminum and iron (in the case of Karma); and silicon and manganese (in the case of Nikrothal L). However, the resistivity of these alloys does not exceed 1.4 p.Ohm.m. There is disclosed in US. Pat. Nos. 2,850,383 and 2,850,384 an alloy based on nickel and chromium to which vanadium and aluminum have been added. The resistivity of this alloy is somewhat higher and amounts to 950 Ohm/cmf, i.e., to 1.58 pOhm.m.
(In the preceding paragraph, as well as throughout the specification, all percentages given are in terms of percent by weight, unless specified otherwise).
Among the disadvantages of the known alloys are the relatively narrow range of working temperatures in which they can be used.
Although several attempts have already been made to develop Nichrome type alloys intended for the manufacture of high precision resistors with high resistance values (see, for example, U.S.S.R. Authors Certificate No. 241,677, issued August 27, 1969 and U.S.S.R. Authors Certificate No. 320,547, issued Jan. 7, 1972) the alloys disclosed in these publications do not offer a resistivity in excess of 1.6 uOhm.m.
SUMMARY OF THE INVENTION In accordance with the present invention, there is provided a nickel base alloy for the manufacture of precision resistors comprising in the combination of such additives as chromium, vanadium and gallium, said alloy having a resistivity of from 1.7 to 2.2 pOhmm. and being able to meet the rest of the abovelisted requirements under a broadened range of working temperatures.
DESCRIPTION OF THE PREFERRED EMBODIMENTS In a preferred embodiment of this invention, it has been found that replacing a part of the chromium in a nickel-chromium resistor alloy with vanadium and gallium, in combination, upgrades the resistivity of the alloy and at the same time decreases the dependence of the resistivity of the alloy upon temperature, while simultaneously increasing the strength of the alloy and the plasticity thereof, with the thermoelectromotive force vs. copper remaining within acceptable limits. It is preferable and advisable that the composition of the alloy substantially conform to a stoichiometric formula of Ni V Cr 63 This means that the alloy comprises 66.7 atomic nickel, l 1.1 atomic vanadium, l 1.1 atomic chromium, and l 1.] atomic gallium. In terms of weight percent this signifies that the alloy comprises 67.1% nickel, 13.3% gallium, 9.7 percent vanadium, 9.9 percent chromium.
The nickel content in the alloy cannot be substantially reduced, as compared with the content as set forth in the above stoichiometric formula (66.7 atomic since this would lead to separation of the second phase, i.e., to decomposition of the solid solution and to drastic changes in the properties of the alloy. However, a small reduction of the content of nickel, as small as l to 2%, is permissible. Any increase of the nickel content brings about a further increase in the stability of the alloy; however, with a nickel content in excess of 72 atomic the resistivity of the alloy drops below the required range of values. The total content of chromium and vanadium can vary from the value corresponding to the above stoichiometric formula (i.e., from 22.2 atomic viz, it can be increased by up to 5 atomic and it can be reduced by up to 2 atomic However, it is preferable that such reduction not exceed 1 atomic and that such increase not exceed 2 atomic The vanadium content should essentially not be below 8 atomic and preferably, should not be less than 9 atomic The content of gallium should not be substantially higher than the value derived from the above stoichiometric formula, i.e., higher than 1 1. 1 atomic however, it can be reduced, but not below 5 atomic Preferably, the gallium content lies within 5.5 atomic to 11.5 atomic In accordance with this invention, alloys having the required properties are those containing from 28 to 34 percent by weight chromium, vanadium and gallium, the balance consisting essentially of nickel and incidental impurities; however, such alloys must have a content of gallium of from 6% to 12%, a vanadium content of from 7 to 12%, and a chromium content of from 6 to 15%, the combined content of chromium and vanadium being from 18 to 24%. The ranges of vanadium and chromium expressed in terms of weight percent correspond to the following ranges in terms of atomic percent: vanadium from 8.0 to 13.7 atomic chromium from 6.7 to 16.8 atomic The above-specified upper limits of gallium, vanadium and chromium content in the alloy are close to the limits of solubility of each one of these elements in an alloy of nickel with the other two elements. Should the contents of any of these elements rise any further, the likelihood of separation of the second phase from the solid solution sharply increases, with a resulting reduction of the resistivity and deterioration of the other parameters of the alloy. Preferably, the content of gallium is from 8 to l 1% and that of vanadium from 8 to 10%.
The properties of the above-specified alloy would not be affected and in some respects would be even improved by addition into the alloy of small amounts of tungsten, rhenium, molybdenum and/or other (with the exception of chromium and vanadium) elements from A subgroups of IV to VII groups of the D. l. Mendeleev periodic table, or iron, cobalt and/or other (with the exception of nickel) elements of VI]! group of the periodic table, as well as of germanium, silicon and/or aluminum. These elements can be added to the alloy either separately or in combination. The total amount of the additives listed in the present paragraph should not exceed 10%, while the total amount of germanium, silicon and/or aluminum should not exceed 3%, the content of nickel in the alloy being not less than 66%. The content of each individual element should not substantially exceed the limit beyond which decomposition of the solid solution occurs. In other words, the content of each individual element should not exceed substantially the limit of solubility of such element in nickel (however, fully allowing for the influence of other elements in the alloy upon the said limit of solubility). The presence of the second phase in the alloy is permissible only in very small quantities, such very small quantities in some cases even being desirable.
In the present disclosure the expression elements from A subgroups of IV Vll groups of D. l. Mendeleev periodic table" is intended to embrace the elements with atomic numbers from 22 to 25, 40 to 43, 72 to 75, whereas the expression elements of Vlll group of the periodic table" is meant to embrace the elements with atomic numbers 26 to 28, 44 to 46 and 76 to 78 (See, for example, Physical Metallurgy, ed. by R. W. Cahn, Amsterdam, 1965, North-Holland Publishing Co., p. 40).
Addition into the alloy of elements (except chromium and vanadium) from A subgroups of 1V Vll groups of the D. l. Mendeleev periodic table within the above-described limits, in general, increases the resistivity of the alloy and usually causes a shift of the temperature coefficient of resistivity towards negative values, as well as a shift of the thermoelectromotive force vs. copper towards positive values. The above effect is the most pronounced when rhenium, tungsten, molybdenum and titanium are added. Addition of manganese and other elements from the said subgroups yields the same results, but to a lesser degree.
lt is advisable that the following elements from the said subgroups should be added to the alloy in the following quantities:
not more than about (percent) rhenium 5 .0; tungsten 5 .0; molybdenum niobium 1 .0; titanium I .0; manganese 4.0; tantalum 0.5.
Addition into the alloy of germanium, silicon and/or aluminum acts in about the same way as an increased content of gallium, viz. it increases the resistivity of the alloy and causes a shift of the thermoelectromotive force vs. copper towards negative values. It is preferable and advisable that the silicon content not be in excess of 2% and that the aluminum content not exceed 2%.
Addition into the alloy of the elements (except nickel) from the V111 group of periodic table in the above-specified quantities likewise increases the resistivity of the alloy. It is preferable and advisable that the following elements from Vll] group be added in quantities, as listed hereinbelow in percent by weight:
iron up to 7.0; cobalt up to 5.0; osmium up to 10.
Addition of iron and/or cobalt causes a shift of the thermoelectromotive force vs. copper towards negative values. It is not preferred and not advisable that the total content of iron and cobalt exceed 7%.
Some of the abovementioned additives, in addition to the above-specified influences upon the resistivity of the alloy, upon the thermal coefficient of resistivity thereof and upon the thermoelectromotive force vs. copper, also exert other types of influence upon the properties of the alloy. Iron and cobalt promote plasticity of the alloy. An addition of cobalt also improves the processing qualities of the alloy, minimizing adherence of the alloy to the walls of drawing dies. Small additives of elements with a strong metal bond (e.g., tungsten, rhenium, molybdenum, osmium), as well as of elements with a covalent bond (such as germanium, silicon) increase the mechanical strength of the alloy and ensure that the useful properties of the alloy, including high resistivity, are maintained in a very thin wire (10 um and less in diameter) made from the alloy. On the other hand, the presence of aluminum in the alloy could result in appearance of inclusions resisting drawing of the alloy into thin shapes.
The above considerations can be utilized in developing alloy compositions to meet specific demands. it should be noted that the value of the thermal coefficient of resistivity can to some extent be adjusted by varying the mode of thermal treatment of the alloy.
Preferred embodiments of the herein disclosed alloy can be described as those conforming substantially to the stoichiometric formula Ni Me M where Me is chromium, vanadium, rhenium, tungsten, molybdenum, niobium, titanium, manganese, tantalum, iron, cobalt, and/or osmium, the content of vanadium being not less than 8 atomic while M is gallium, germanium, silicon, and/or aluminum, the content of gallium being not less than 5 atomic provided that the content of each individual element in the alloy does not exceed substantially the limit beyond which there takes place decomposition of the solid solution. Preferably, the content of vanadium is not below 9 atomic the combined content of chromium and vanadium is not below 20 atomic and the content of gallium is not less than 5.5 atomic In order to improve the mechanical properties of the alloy, it is essential that the ready alloy have no cavities or blisters, as well as no inclusions that might affect the homogeneity of the alloy, e.g., hard oxides, nitrides, etc. To attain this, oxygen, nitrogen and other gases should be removed from the melt to the highest attainable degree. This function of removing the gases is performed to some extent by some of the above-listed additives, e.g., by germanium and silicon. However, the presence in the alloy of such highly active elements as vanadium in many cases renders the mere presence of the said elements in the alloy ineffective for attaining the aim of removing the unwanted inclusions. In such cases, it is preferable to add to, or include in, the melt some elements specifically intended to effect degassing, deoxidation, and/or denitrogenation of the metal. Among the elements which can be used to this end are boron, carbon, yttrium, scandium, calcium, lanthanum and lanthanides or rare earths. The total content of the last-mentioned elements should not exceed 0.2%; and the following maximum contents of the individual elements should not be exceeded: boron 0.0l%; carbon 0.0l%; calcium 0.03%; and scandium 0.03%;. During the course of the melting and thermal treatment of the alloy, a major part of these additives either burns away or goes into slags, mere traces of these elements remaining in the alloy. In any case, the content of the last-mentioned elements in the final alloy in the above quantities does not affect the properties of the alloy.
To prepare the alloy, the following initial components are utilized: nickel, chromium, vanadium, cobalt, manganese obtained in an electrolytic bath, gallium and aluminum with an impurity content not above 0.0l%, zone-purified germanium and silicon, metallic rhenium, iron obtained by decomposition of iron carbonyl or carboxide with subsequent sintering in vacuum, molybdenum, tungsten, niobium, titanium and the rest of the metals being of high purity.
It is advisable that the melting should be performed in a vacuum furnace in an aluminum oxide crucible,
tungsten carbide or through diamong drawing dies,
there can be produced thin wire of 10pm or even less in diameter. The alloy may be also worked into a strip as thin as 5 pm and even thinner. The process of cold forming (swaging, drawing, rolling) should be repeatlS edly interrupted to heat up the wire or the strip to l,lO0C 1,200C and then to cool it in water.
A wire or a strip manufactured from an alloy in accordance with the present invention can be used for the production of high precision resistors rated for operation at temperatures of from 60C to +400C and displaying within this range of working temperatures the following electric properties (after annealing at l,l00C to 850C);
electric resistivity p" from L7 to 2.2 pOhm.m, i.e.,
from 1020 to 1320 Ohm/cmf;
thermal coefficient of electric resistivity a=(dR/dt) not exceeding in absolute value 2'lO K thermoelectromotive force versus copper not in excess of 6 ,uV/K and within 2.5 to 3.5 uV/K in case of alloys containing iron (Examples Nos. 9, 15, l6, l7,
l8, I9, 28 herebelow.)
When the wire or strip, or the resistors made therefrom, are subjected to artificial aging, as is well known in the art, the above electric properties would not be practically affected by time. The stability of the electrical properties of the present alloy over a long period of time is not inferior to that of the best known resistor alloys of the Nichrome type. The present alloy is readily welded, and the mechanical properties thereof are as follows: tensile strength 1 2.10 N/m 100 to 200 kg/mm") and higher, ultimate elongation from 35 down to 6 percent The following table with examples serves to illustrate alloys according to the present invention, without, however, limiting the same thereto.
The table shows the composition of each alloy in percent by weight and gives the resistivity value p." The content of nickel, chromium, gallium and vanadium, as well as the total content of the major groups of elements is additionally given in atomic percent. Of course, many changes and variations in the amounts of the components of the new alloy may be made by those skilled in the art in accordance with the principles set forth hereinabove, without departing from the spirit and scope of the present invention, as defined in the appended claims.
Table Resi- Content, atomic '71 Content, 71 by weight sti- Gu Amvity,
ong 0th Among Ohm/ No Ni Ge them ers them Ni Cr V Ga Re W Mo Nb Ti Mn Ta Fe Co Y Pr Ge Si Al m Al V Cr Si Ga 1 3 4 5 7 8 9 H) il l2 l3 l4 l5 l6 l7 l8 19 20 'll 22 23 24 25 26 1 70.4 8.3 8.3 2L3 10.2 1].] 7| I0 9 10 1.76 2 69.7 8.4 8.4 21.9 l0.3 11.2 69.) It] 9 10 l 0.] 1.84 3 66.8 94 9.4 23.8 11.0 12.4 66.9 ll 95 ll 15 Ul 2.l0
Table-Continued Resi- Content. atomic 7: Content, 71 by weight sti- Ga Amvity' ong oth- Among ()h N N1 Ge them ers thegi Ni Cr V Ga Re W Mo Nb Ti Mn Ta Fe Co Y Pr Ge Si A] m A1 r Si Ga 1 2 3 4 5 6 7 8 9 10 ll l2 l3 14 16 l7 18 19 21 22 23 24 26 4 71.5 7.5 7.5 21.0 9.7 11.2 72.3 10 8.5 9 0.2 L74 5 71.6 7.5 7.5 20.9 9.7 11.1 72.4 10 8.5 9 0.1 L74 6 70.2 8.3 8.3 21.5 10.2 11.1 70.9 10 9 l0 0.1 L78 7 70.1 8.3 8.3 21.6 10.2 11.2 70.8 10 9 l0 02 L80 8 71.4 7.5 7.5 21.1 9.7 11.2 72.3 10 8.5 9 0.2 L74 9 69.0 7.1 7.1 23.9 10.2 11.2 70 10 9 8.5 2.5 1,74 10 70.1 7.5 7.5 22.4 10.2 11.2 71 10 9 9 l 1,80 11 69.4 9.1 8.3 21.5 10.3 11.2 70 10 9 10 1 105 12 70.1 8.5 8.3 21.4 10.2 11.2 70.9 10 9 l0 1),] L80 13 71.8 8.8 5.7 19.4 9.5 10.9 73 10 8.5 7 15170 14 66.5 9.7 8.9 23.8 11.0 12.4 66.8 11 9.5 10.5 1 0.2 I 210 15 69.0 6.7 6.4 24.3 10.3 10.] 69.9 9 9 7.7 0.7 0.1 3.4 0.1 0.1 1.94 16 69.0 6.0 5.8 25.0 10.3 11.2 69.8 10 9 7 0.7 0.2 3 0.2 1.90 17 66.7 8.2 5.7 25.1 10.1 11.0 68.15 10 9 7 0.8 0.1 0.1 005 0.4 0.1 2 l 0.2 0.1 l 1.85 18 68.5 7.6 7.1 23.9 10.3 11.2 69 10 9 8.5 1 2 0.4 (1.] 1,90 19 67.3 6.0 5.8 26.7 10.3 11.2 67.7 10 9 7 0.8 0.1 0.6 03 0.2 2 2 0.3 1.85 20 69.9 8.4 8.0 21.7 10.2 11.2 70 10 9 9.5 l 0.5 2.05 21 67.7 10.8 8.4 21.5 10.3 11.2 68 10 9 10 3 2 00 22 67.9 10.2 10.2 21.9 10.5 11.4 69 10 9 12 100 23 64.8 8.3 8.3 26.9 12.5 14.4 66 13 11 10 2,0 24 70.4 9.2 9.2 20.4 13.7 6.7 71 6 12 11 mlbdow 1.8 25 66.9 8.2 6.0 24.9 10.5 10.3 66 9 9 7 3 26 69.3 6.2 5.3 24.5 8.5 13.1 66 ll 7 6 5 4 l not below 1.7 27 65.4 7.9 5.8 26.7 11.4 8.9 66 8 10 7 l 4 1 28 66.3 5.8 5.0 27.9 10.3 10.1 67 9 9 6 l 7 I 29 70.6 5.0 5.0 24.4 7.9 16.6 72 15 7 6 What 1 claim is: 30 thanides is not in excess ofO.2%, the content of any one 1. A nickel base alloy particularly useful as material for high precision resistors, consisting essentially of between about 6% and about 12% gallium, between about 7 and about 12% vanadium, between about 6 and about 15% chromium, the combined content of vanadium and chromium being from about 18 to about 24%, the total content of vanadium, chromium and gallium being from about 28% to about 34%, and the balance nickel.
2. An alloy according to claim 1, wherein the gallium content is between about 8 and about 11%, the vanadium content is between about 8 and about 10% and the chromium content is between about 8 and about 3. A nickel base alloy especially useful as material for high precision resistors, consisting essentially of between about 6 and about 12% gallium; between about 7 and about 12% vanadium; between about 6 and about 15% chromium; chromium, vanadium and gallium being primary alloying components, and at least one additional secondary alloying component selected from the group consisting of titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, cobalt. ruthenium, rhodium, palladium, osmium, iridium, platinum, germanium, silicon, aluminum, boron, carbon, calcium, scandium, yttrium, lanthanum and lanthanides, the total content of said secondary alloying components not exceeding 10%; and the balance nickel, said alloy being essentially a solid solution of said primary and secondary alloying components in nickel wherein the combined content of chromium and vanadium is between about 18 and 24%, the combined content of germanium, silicon and/or aluminum is not in excess of 3%, the combined content of boron and/or carbon is not in excess of 0.02%, the combined content of calcium, scandium, yttrium, lanthanum and/or lanup to about (percent by weight) rhenium tungsten molybdenum niobium titanium manganese tantalum iron cobalt osmium germanium silicon aluminum boron carbon calcium scandium yttrium lanthanum and/or lanthanides the balance consisting essentially of nickel, the combined content of germanium, silicon and/or aluminum in said alloy not exceeding 3%, the combined content of calcium, scandium, yttrium, lanthanum, and/or lanthanides not exceeding 0.2%, the combined content of vanadium and chromium exceeding l8%, the combined content or iron and/or cobalt not exceeding 7%, the combined content of all said secondary alloying components not exceeding 10%, and the total content of gallium, vanadium, chromium and said secondary alloying components being between 28 and 34%.
5. An alloy especially useful as material for high precision resistors, consisting essentially of chromium, vanadium, gallium and nickel, the content of gallium being between about 5.5 atomic 70 and about I 1.5 atomic the content of nickel being between about 65 atomic and 72 atomic the combined content of chromium and vanadium being between about atomic and about atomic the content of vanadium being between about 8 atomic and about 13.7 atomic and the content of chromium between 6.7 atomic and l6.8 atomic 6. An alloy especially useful as material for high precision resistors, consisting essentially of a composition substantially conforming to the stoichiometric formula 2 'na im ma 7. An alloy especially useful as material for high precision resistors, consisting essentially of a composition substantially conforming to the stoichiometric formula Ni Me M where Me is at least one metal selected from the group consisting of chromium, vanadium, rhenium, tungsten, molybdenum, niobium, titanium, manganese, tantalum, iron, cobalt, osmium, and mixtures thereof and M is at least one element selected from the group consisting of gallium, germanium, silicon, aluminum, and mixtures thereof, said alloy being essentially a solid solution of all of the said components in nickel, the content of vanadium being between 8.0 and 13.7 atomic the content of chromium being between 6.7 and 16.8 atomic and the content of gallium being between 5 and l 1.5 atomic and the content of any of said components not substantially exceeding the limit beyond which decomposition of said solid solution occurs.
8. An alloy according to claim 7, wherein the combined content of chromium and vanadium is not less than 20 atomic the content of vanadium is not less than 9 atomic and the content of gallium is not less than 5.5 atomic UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,898,081 DATED August 5, 1975 INVENTOR(S) Kukhar It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Cover page, left-hand column, change "Lenningrad" to Leningrad Column 1, line 49, change the bold type for "1970" to regular type;
Column 2, line 62, the comma after "viz" should be changed to a period;
Column 6, line 16, change the bold type for "l,200C" to regular type;
In the table set out on the bottom of columns 5 and 6 and the top of columns 7 and 8, change "Oh/m to Ohm.m;
Claim 3, line 53, cancel "vanadium" and "chromium".
Signed and Scaled this Fourth Day of April 1978 [SPA H A mm.-
LHRELLE r. PARKER A (testing ()jficer PATENT NO.
DATED INVENTOR(S) I Column 1, line line line
Column 2, line line line
UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION August 5,
Page 1 of 2 1975 KUKHAR Cover page, right column, last line It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
change "uohm.m." to read uOhm.m.
delete "degrees" II) II amend "degrees" to read degree amend "Dec." to read Sept. and after "1973" (now U.S. Patent No. 3,847,602, dated November 12, 1974) after "inventors" insert including the insert inventor of the present invention change "Author's" to read Inventor's change "Au" to read Inchange "thor's" to read ventor's UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,898,081 Page 2 of 2 DATED I August 5, 1975 INVENTOR(S) KUKHAR It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Column 3, line 3 change to read Colunm 6, line 19 change "rated" to read destined line 23 change semicolon to a colon line 42 insert a period at the end of the sentence.
Columns 7 and 8, in the table under headings "Re", "C0", "Ge" and "Al", change "I" to l in each instance Signed and Scaled this First D a y 0 f January I 980 [SEAL] Arrest:
SIDNEY A. DIAMOND Arresting Oflicer Commissioner of Patents and Trademarks