US3374123A - Method of manufacturing non-magnetic, elastic articles having a small change of vibration and deflection for temperature change - Google Patents

Description

March 19, 1968 HAKARU MASUMOTO ETAL 3,374,123

METHOD OF MANUFACTURING NONMAGNETIC, ELASTIC ARTICLES HAVING A SMALL CHANGE OF VIBRATION AND DEFLECTION FOR TEMPERATURE CHANGE C5 Sheets-Sheet 1 Filed March 5, 1965 mmm4mwmmm Fig.

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b---96% cold-waged state c--stute after heotin so le b at 560C for l5 h0 2 INVENTORS ATTORNEY 3,374,123 TIC, ELASTIC ARTICLES F VIBRATION AND ERATURE CHANGE March 19. 1968 HAKARU MASUMOTO ETAL METHOD OF MANUFACTURING NONMAGNE HAVING A SMALL CHANGE O DEFLECTION FOR TEMP 5 Sheets-Sheet 2 Filed March 5, 1965 O v A O 2 w 8 .WW I 5 4 4 8 u M A... A I 7 2 I M M am. Q a 5 5 Q I N H -00 I A v 2 .m F w 0 ow .I A o 0 w 0 w 0 m 0 Q Q a ABY JAM-$2M ATTORNEY March 1968 HAKARU MASUMOTO ETAL' 3,374,123

METHOD OF MANUFACTURING NONMAGNETIC, ELASTIC ARTICLES HAVING A SMALL CHANGE OF VIBRATION AND DEFLECTION FOR TEMPERATURE CHANGE Filed March 3, 1965 6 Sheets-Sheet 5 Fig.3.

Pd48%, Au 52% Pa 546.0- 3 3 545.0 5' 526.0- g Pd52k,Au48% g 0 I0 so 40 so so Temperature ('6) Z INVENTORS m/mez/ MASUMfiTO 74 A/EO K054 V4860 BY JM M ATTORNEY United States Patent 3,374,123 .METHOD OF MANUFACTURING NON-MAG- N ETIC, ELASTIC ARTICLES HAVING A SMALL CHANGE OF VIBRATION AND DE- FLECTION F R TEMPERATURE CHANGE Hakaru Masumoto, Sendai, and Takeo Kobayashi, Natori,

Japan, assignors to The Foundation, The Research Institute of Electric and Magnetic Alloys, Sendai, Japan Filed Mar. 3, 1965, Ser. No. 436,902 laims priority, application Japan, Mar. 4, 1964,

39/ 11,779 3 Claims. (Cl. 148-11.5)

ABSTRACT OF THE DISCLOSURE A method of manufacturing non-magneticand elastic 7 articles having little change in Youngs modulus with change in temperature, which comprises annealing an alloy consisting essentially of about 50% gold and about 50% palladium by heating said alloy at a temperature above 600 C. for at least one minute, and then heat treating said alloy by a suitable combination of quenching, cold working, and tempering.

In conventional methods of manufacturing elastic articles having a-small temperature change of vibration and deflection, elinvar type alloys (Fe-Ni alloys added with other elements) and co-elinvar type alloys (Fe-Co alloys added with other elements) have been used.

All the above known alloys, however, show not only ferromagnetic properties but also' have disadvantage of causing corrosions when exposed to, an acidic or alkaline vapour or solution or to a solution of salts.-Accordingly,

hitherto conventional alloys are not suitable for certain applications. 7 f

As a result of a number of investigations and experiments to obviate the. above disadvantage of conventional alloys, the-inventors discovered that palladium-gold-alloys sion but also non-magnetic properties as well as-a hardness of 'various degrees- Alloys of the invention obviate the disadvantage'inherentto conventional elastic alloys.

. A process of manufacturing the elastic articles accordand about 50% by weight of goldis subjected to one of .ing to the invention is characterized in that a binary alloy consisting essentially of about by weight of palladium is quenched by rapidly cooling it at a rate faster than 1 C./second andthen heated at a comparatively low temperature, such as 200 to 550 C.;

(2)An a'l'loytannealed'ata temperature above 600. C.

is cold worked to reduce the sectional area more'than 20% at room temperature and then heated at a:com-

paratively low temperature, 'such as 200'to 550 C.;

(3)An alloy annealed at a temperature above 600 C.

is first'qu'enched by rapidly cooling it at a rate faster 3,374,123 Patented Mar. 19, 1968 lastly heated at a comparatively low temperature, such as 200 to 550 C. The article thus obtained has an arbitrary value of temperature coefficient of Youngs modulus (or rigidity modulus) ranging from an ordinary negative value to a positive value and different values of hardness.

' The principles of the invention will now be explained further in detail. According to the invention, at first, a mixture consisting of a proper amount of palladium and gold or in addition suitable amount of said sub-ingredients is melted in air, in vacuo, or in an inert gas by means of a suitable furnace, then degassed by adding a small quantity of degassing agent (element) such as manganese, silicon aluminum, titanium, etc., and stirred thoroughly to produce a melted alloy having homogeneous structure. Then the melted alloy is poured into a mould of suitable size and shape to obtain a sound ingot, and the ingot thus prepared can be forged, rolled, swaged or drawn at room tempreature or at an elevated temperature lower than 1400 C. to provide a product having desired shape and size.

Thereafter, the product is heated for more than 1 minute, say 1 hour, at a temperature higher than 600 C.

but lower than the melting point of the alloy and then gradually cooled. If desired, the mechanical strength of the product can be increased by several means for instance by quenching from a temperature higher than 400 C. but lower than the melting point of the alloy or by cold working at a reduction ratio more than about 20% or by applying both quenching and cold working. If further stabilizationof characteristics is desired, the product can be heated at a temperature higher than 200 C. but

lower than 550 C. for at least one minute after the above quenching or cold working or application of both quenching and cold working. The final product thus obtained shows an arbitrary value of temperature coefiicient of Youngs modulus (or rigidity modulus) ranging from 'an ordinary negative value to a positive value.

v For a better understanding of the invention reference is made to the accompanying drawings,.in which FIG. 1 is a diagram illustrating densities (at 20 C.),

.Youngs moduli (at 20 C.), mean temperature coeffi- ,cients (0-40 C.) of Youngs modulus (040 C.) and mean thermal expansion coeficients (0-40 C.) of palladium-gold alloys for different concentration of palladium in saidalloys;

FIG. 2 is a diagram illustrating mean temperature coefficients of Youngs modulus (040 C.) of three kinds of alloys which were processed through cold swaging at a reduction ratio of 96%, for different annealing term 50 have not only-high resistances against oxidation and corrofirst melted in an alumina crucible of about 10; mm.

inside dia. by means of a Tammann furnace (electric resistance furnace) while passing hydrogen gas, then the mixture was stirred thoroughly and cooled in said crucible.

Then the ingot Was'made into a bar of about 2 mm. dia.

by swaging at a reduction ratio of 96% at room temperature, and a portion of the bar, about 10 cm. long, was cut offto provide a sample to determine-behaviours in the state -of cold working. The sample was then heated at various temperatures for 15 hours and cooled to take measurements. At last, the sample was annealed at 1000" C. for one hour and then measurements were made.

.Youngs .moduli were determined by measuring at first natural frequencies of the sample bars by means of a device, based on principles of an electrostatic vibrator controlled oscillator, and then by calculation from the ditions, that is to say the conditions when the sample bars being gradually cooled at a rate of 300 C. per hour after heated at 1000 C. for one hour. The curve b indicates the values for conditions after processed through cold swaging at a reduction ratio of 96%, and the curve for conditions after heating the sample bars of the curve b at 360 C. for 15 hours.

FIG. 2 illustrates how the mean temperature coefficients of Youngs modulus in the range of 0 to 40 C. vary for the different annealing temperatures. FIG. 3 illustrates how natural frequencies of three kinds of Pd-Au alloys annealed at 360 C. for 15 hours following cold working vary for different measuring temperatures.

As shown in FIG. 1, the temperature coefficients of Youngs modulus of annealed alloys consisting essentially of 30 to 70% of palladium and 70 to 30% of gold lie within a range of from 18.0 10- to 3.0 when the temperature of the alloy is in the neighbourhood of room temperature, especially said coefficient of the alloys consisting essentially of 57 to 37% of palladium and 43 to 63% of gold is substantially small.

As shown in FIG. 1, the temperature coefiicients of Youngs modulus of alloys of the invention after processed through cold working are larger in negative domain than those of said alloys under annealed conditions, however, when said cold worked samples are annealed once again at a temperature approximately 360 C. for hours the negative values of said coefficients are substantially reduced, especially said coefficient of the alloy consisting essentially of 50% of palladium and 50% of gold becomes +2.8 10 Besides, after the additional annealing. following cold working, the natural frequencies of the alloys of the present invention vary in a substantially linear relationship with temperatures as shown in FIG. 3

aslong as the temperature lies in the neighbourhood of room temperature, which is also a salient feature of the alloys of the invention compared with conventional elinvar type alloys showing a considerable non-linear variation of characteristic frequencies when temperature varies in the neighbourhood of room temperature (see FIG. 3).

The alloys of the invention are also characterized in having non-magnetic properties. Non-magnetic materials having constant values of Youngs modulus for the temperature change have never been invented heretofore, and the alloys of the present invention are the first of the kind. In addition, the alloys of the invention have substantially strong resistances against oxidation and corrosion. I Elfects of the sub-ingredients on the properties of pal ladium-gold alloys are shown in Table 1. It is apparent from Table 1 that additions of other elements into palladium-gold alloys generally result in a substantial increase in hardness both under the annealed condition and under the condition when heated at 360 C. following cold swaging, irrespective of the fact that the temperature coefficients of Youngs modulus are caused to increase in the negative domain by said additions. The increase in hardness means the increase in yield point, which is very preferable for application of the alloys to springs Itcan be emphasized here that applicationof quenching from an elevated temperature or, a combination of TABLE 1 As annealed As heated at 360 C.

at 1,000C.' for 15 hrs. after [or 1 hour 96% cold-reduction Alloys, 50% 5 1 150% Au alloy Temperature Micro- Temperature Microcoeliicient Vickers coeflicient Vlekers of Youngs hardness of Youngs hardness modulus (20 0.), 89 modulus (20 0.), 184 I (040 0.), (040 C Atoresaid alloy 21th addition 3. 0% PL... 9. 8 116 7. 5 212 1. 0% 111.... 11. 0 138 4. 7 249 3. 0% In- 11. 5 100 9. 9 245 3. 0% Ta. 13. 1 128 9. 3 258 3. 0% Ag 10. 5 100 9. 5 210 3. 0% Fe. 15. 0 126 10. 2 278 3.0 0 Ni. -14. 0 144 6. 7 268 3. 0 0 00.... 11. 1 123 9.9 273 1.0% CL..- 13. 5 101 11.2 260 3.0 0 Mn... 10.0 112 8.0 212 3.0% Cu... 11.0 93 7.3 241 1.0 V... 10.0 118 7.3 269 3.0% Mo--. 13.0 143 8. 5 291 3. 0% W 14.0 134 11. 0 263 0.2% 14.0 127 9. 8 277 3. 0% 8. 0 124 5. 5 289 3. 0% 13. 0 107 --5. 6 261 3. 0% -13. 5 109 6. 5 242 0.2% T1 11.0 122 6.0 248 0. 17 10. 0 132 6. 7 267 1. 0%; 9. 0 140 7. 4 233 0. 5% 14. 7 128 -11. 1 267 0.5% 11.0 117 6.0 250 0.1% -15. 5 112 --11.0 216 1. 0% -15.0 105 5. 4 216 As shown in the foregoing descriptions, temperature coefficients of Youngs modulus of the alloys of the invention are not only small but also practically constant at different temperatures in the neighbourhood of room tempcrature. Furthermore, the alloys of the invention have nonmagnetic properties and substantially high resistances against oxidation and corrosion. Therefore, the alloys of the invention are most suitable to devices which require constant frequencies regardless of ambient temperature variation and non-magnetic 1 properties, such as hair springs of chronometers, standard tuning forks, etc.

In order to obtain a sound ingot, better forgeability and better mechanical properties of materials according to the invention, the alloys consisting essentially of palladium and gold can be added with 0 to 3% of one or more elements selected from the group consisting of platinum, iridium, indium, tantalum, silver, iron, nickel, cobalt, chromium, manganese, copper, vanadium, molybdenum, tungsten, aluminium, antimony, tin and zinc and 0 to 2% of more thanone elements selected from the group consisting of titanium, silicon, cadmium, beryllium, zirconium, boron and niobium as sub-ingredients.

What we claim is:

'1. A method of manufacturing nonmagnetic and elastic articles having little variation in Youngs modulus upon temperature change, comprising the steps of annealing a gold-palladium alloy consisting essentially of about 50% by weight of gold and about 50% by weight of palladium' by heating it at a temperature higher than 400 C.

but lower than themelting point of the alloy for more than one minute, quenching by cooling it at a rate faster than 1 C. per second, and tempering by further heating by heating it at a temperature higher than 400 C. but lower than the melting point of the alloy for more than one minute, then working it at room temperature to re- 5 6 duce its cross-sectional area by more than about 20%, OTHER REFERENCES and tempering by further heatmg It at a tempefamre The Platinum Metals and Their Alloy s, Vines, 1941, pp. tween 200 C. and 550 C. for at least one mmute.

34-42, 110-112. References Cited 5 DAVID L C P E UNITED STATES PATENTS 2,780,543 2/1957 Schneider et a1. 7s 172 SAITO Amid"! Exammer-

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