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    • 专利摘要:
    Alloy for the manufacture of jewelery or watch components with minimum gold concentrations of 75% by weight, copper between 5% and 21%, silver between 0% and 21%, iron between 0.5% and 4% and vanadium between 0.1% and 2.0%, in order to increase the resistance to tarnishing of alloys with a minimum gold content of 75% by weight in environments where sulfur and chlorine compounds are present.
    公开号:CH709207B1
    申请号:CH00790/15
    申请日:2013-12-02
    公开日:2018-08-15
    发明作者:Arnaboldi Sergio；Nauer Marco；Ghiringhelli Stefano
    申请人:Argor Heraeus Sa；
    IPC主号:
    专利说明:

    Description
    Field of the art The present invention relates to an alloy for making jewels and / or watch components and / or the like, with a minimum concentration of 75% gold by weight, a concentration of copper between 5% in weight and 23% by weight, a concentration of silver between 0% by weight and 21% by weight, an iron concentration between 0.5% by weight and 4% by weight, a concentration of vanadium between 0.1% by weight and 2.0% by weight of iridium between 0% by weight and 0.05% by weight. In a particular embodiment of the invention, the alloy comprises palladium contents ranging from 0.5% by weight to 4% by weight.
    State of the art [0002] Thanks to the high ductility, excellent thermal and electrical conductivity or high chemical inertia, gold has always been used in different fields of application and where these properties have important technological functions. In particular, the peculiar optical and color properties of this element have been exploited since ancient times for the creation of decorative objects.
    [0003] Furthermore, over the last few years, numerous gold alloys have been developed with defined functional properties. Even today, many of the studies conducted on gold alloys are aimed at identifying particular and innovative chemical compositions, able to satisfy the increasingly diversified demands of the watch industry or jewelery manufacturers. In the industrial field, in fact, increasingly specific requirements have made the synthesis of compositions with innovative color properties indispensable. The color of a generic metal alloy is strictly dependent on its chemical composition, since the modes of interaction between the incident light and the metal are a function of the alloying elements and the levels with which they are present in the alloy. For example, gold alloys with shades varying from green, yellow or pink (gold-colored alloys) typically contain silver and copper, while elements such as palladium, platinum, nickel or manganese are added gold for the production of white alloys.
    [0004] Thanks to recent developments in spectrophotometric techniques, the color of a generic metal can be quantitatively and uniquely defined in the three-dimensional domain CI E 1976 L * a * b *, note the values of the Cartesian coordinates L *, a * and b * ( ISO 7224 standard). The L * parameter identifies the brightness and takes values between 0 (black) and 100 (white), while a * and b * represent the chromaticity coordinates. In this space, therefore, the achromatic scale of the grays is identified by the points from the L * axis, where a * = b * = 0, while a * and b * identify the color. Positive a * values indicate red, negative a * values indicate green, positive b * values indicate yellow and negative b * values indicate blue. This color evaluation system also allows the estimation of the difference ΔΕ * (L *, a *, b *) = (AL * 2 + Aa * 2 + Ab * 2) 172 between two different shades of color. AL *, Aa * and Ab * represent the arithmetic differences between the values of the coordinates L *, a *, b * that identify in the space CIE 1976 L * a * b * the two tonalities considered. In general, the human eye is able to distinguish two different shades of color if ΔΕ * (L *, a *, b *)> 1.
    [0005] Gold alloys can undergo undesirable superficial discolorations over time, due to the chemical / physical interactions that can occur between the metal and aggressive environments capable of promoting corrosion or tarnishing phenomena. According to technical literature ("Tarnish resistance, corrosion and stress corrosion cracking of gold alloys"; Gold Bulletin, 29 (2) pp. 61-68, 1996; "Chemical stability of Gold dentai alloys"; Gold Bulletin, 17 (2 ), pp. 46-54, 1984) the phenomenon of corrosion is defined as a gradual chemical or electrochemical attack, following which there is a continuous dissolution of metal. In contrast, the tarnishing phenomenon represents a specific form of corrosion. In this case, the reactions that accompany this phenomenon lead to the formation of thin layers of oxides, sulphides or chlorides, capable of modifying the color and surface gloss of gold alloys. These variations in surface color properties can be quantified by evaluating the AE parameter (L *, a *, b *) over time, calculated with respect to the conditions prior to the onset of corrosive phenomena.
    [0006] 18-karat gold alloys are traditionally considered to be free from corrosion and suitable for the manufacture of jewelery or watch components. In fact, recent studies and observations do not seem to confirm these considerations and show that even high levels of gold or other noble elements do not guarantee adequate chemical stability in different conditions of use over time.
    [0007] For example, a standard 5N ISO 8654 18-carat alloy with a copper content of 20.5% and silver at 4.5% by weight shows a clear chemical instability even if it is simply exposed to the action of a generic atmosphere environment. At a temperature of 25 ° C, the interactions that take place between the metal and the ambient atmosphere are able to change the surface color of the gold alloy considered. These color variations are a function of the time t of exposure to the aggressive action of the ambient atmosphere and can be quantified by performing spectrophotometric measurements of the L *, a * coordinate values on the surface of a sample of 5N ISO 8654 18-carat alloy * b. The values of the CI E 1976 L * a * b * coordinates, measured at defined time intervals, allow to analyze the decolourization kinetics of the surface of the sample under examination, evaluating over time the parameter ΔΕ * (L *, a *, b * ) = [(L * -L * 0) 2 + (a * -a * 0) 2 + (b * -b * 0)] 1 / 2. This parameter is calculated with respect to the coordinates L * o, a * 0 , b * 0, of the alloy under examination, measured immediately after a polishing and a subsequent polishing of the surface of the sample under examination. This preparation of the sample surface is carried out until a constant reflection factor has been reached. A similar preparation of the surface of the sample being analyzed is indispensable and is carried out to remove the traces of any compounds (eg oxides) that can vary the surface composition of the alloy, its real color and can therefore distort the experimental measurements. The results of these tests allow to obtain experimental curves AE * (L *, a *, b *) vs time, as shown in fig. 1. The curve shown here can thus be analyzed. The time t = 0 corresponds to the conditions immediately following the polishing and therefore the value of AE * (L *, a *, b *, t = 0) is null. The value of this parameter tends to vary considerably during the first days of testing. In fact, after about 5 days from the start of the test, the material undergoes a perceptible variation of color AE * (L *, a *, b *)> 1. Beyond this time interval, the value of the parameter AE * (L * , a *, b *) continues to increase, but the speed with which the color changes over time decreases, until the parameter AE * (L *, a *, b *) is almost asymptotically lower than 2.5.
    [0008] The ways in which corrosive phenomena occur in gold alloys are closely linked to their composition. As the levels of silver, copper or other elements able to degrade the typical chemical stability of gold increase, the chances of triggering corrosive phenomena of different nature increase. In the same way, the kinetics of the chemical or electrochemical reactions that accompany the variation of the surface properties of the artefacts will also be favored. The ways in which tarnishing or corrosion manifest themselves can also be linked to the microstructural characteristics of gold alloys. From a metallurgical point of view, any microstructural inhomogeneities can generate differences in electrical potential within the material and reduce its chemical stability. For this reason, homogeneous solid solutions generally have a greater chemical stability to corrosive phenomena than alloys whose microstructures consist of multiple immiscible phases or different structural components. Furthermore, grain boundaries may represent preferential sites for triggering corrosive phenomena. The size of the crystalline grain (ISO 643 standard) influences the chemical stability of a gold alloy, since when the average size of the crystalline grains decreases there is an increase in grain energy. This energy, defined as the excess of free energy of the polycrystalline structure with respect to the perfect lattice, can cause a decrease in the chemical stability of the alloy, increasing the differences in electrochemical potential that are established between the alloy elements or between the segregated phases. Finally, the presence of any residual stresses generated by the volumetric shrinkage in the solidification phase or by the processing by cold plastic deformation of the material, can give rise to stress corrosion phenomena and lead to undesired fractures of the material.
    [0009] The environments capable of promoting the corrosive phenomena of gold alloys are multiple and linked to their applications. In the field of jewelery and the watch industry, color alloys containing silver or copper appear to be particularly prone to tarnishing phenomena. Solutions containing chlorides such as sea water or in which surfactants are present, can trigger unwanted variations in the surface color of this type of gold alloy in a short time. Likewise, humidity, organic vapors, oxygen compounds and especially sulfur compounds such as hydrogen sulfide H2S present in the ambient atmosphere are able to trigger tarnishing phenomena. Finally, the same problems can arise from the interaction with organic solutions such as sweat, where mainly salts such as sodium chloride, electrolytes, fatty acids, uric acid, ammonia and urea are dissolved.
    [0010] Gold colored alloys, characterized by shades varying from green, yellow or pink and typically used for the production of jewelery or watch components, can therefore be characterized by inadequate chemical stability and suffer in time unwanted changes in surface color properties. The present invention aims to improve the chemical stability of the currently available commercially available gold alloys. In particular, the goal is to increase the resistance to tarnishing of alloys with a minimum gold content of 75% by weight in environments where sulfur or chlorine compounds are present.
    [0011] The technical literature reports different chemical compositions, in which elements such as germanium, indium, cobalt, gallium, manganese, zinc, tin or iron are added to the gold-silver base ternary system copper to obtain particular physical or functional properties. All the following compositions are expressed in weight.
    [0012] Document JP 2008 179 890 A (2008) considers germanium as an element capable of increasing the corrosion resistance of 18 carat gold alloys. In particular, compositions with germanium contents between 0.01% and 10% are considered.
    [0013] Also the document JP 2002 105 558 A (2002) shows concentrations of germanium between 3% and 5%, in compositions characterized by at least 75% of gold, from copper contents between 12% and 13% and silver to balance. In this case, germanium is not considered to improve the chemical stability of 18 carat pink alloys, but simply to achieve desired color properties.
    [0014] Document CA 2 670 604 A1 (2011) contains compositions with gold contents between 33.3% and 83%, of indium between 0.67% and 4.67%, tin up to 0.9%, manganese up 0.42%, silicon up to 0.04% and copper in the balance sheet. In this case, indium is used to obtain gold alloys, with colors similar to those of bronzes.
    [0015] Otherwise, document US 7 413 505 (2008) proposes 14-carat pink gold alloys, in which in addition to copper, silver and zinc, cobalt levels are present between 3% and 4%, added in alloy to obtain specific hardness values. The same document reports similar 18-karat alloys, whose compositions are not claimed, however. To obtain hardness and corrosion resistance higher than those of the standard alloys used in dentistry, the document JP 2009 228 088 A (2009) proposes gallium additions ranging from 0.5% to 6%, in alloys characterized by gold levels higher than 75% , of platinum between 0.5%, palladium between 0.5% and 6% and budget copper. The document JP 2001 335 861 (2001) claims instead the addition of manganese in contents between 2% and 10%, in alloys with a minimum gold content of 75%, of copper between 10% and 30%, silver between 0.5% and 3%, zinc between 0.5% and 3% and indium between 0.2 and 2%.
    [0016] Finally, the document GB 227 966 A (1985) alloys with gold contents between 33% and 90%, of iron between 0.1% and 2.5%, silver between 0.01% and 62.5%, copper between 0.01% and 62.5%, zinc between 0.01% and 25% and characterized by hardnesses between 100 HV and 280 HV. Again, JP 2008 308 757 (2008) considers the addition of 0.5% -5% tin to gold alloys containing copper contents ranging from 14.5% to 36.5% and indium between 0.5% and 6%. In this case, the invention simply claims the possibility of obtaining rose gold alloys, avoiding the use of elements such as nickel, manganese and palladium and the disadvantages that their use entails. In fact, as known, nickel can cause allergies, manganese, in addition to reducing workability due to cold plastic deformation, involves the use of advanced production technologies, while palladium causes a reduction in surface brightness.
    [0017] As previously stated, palladium is an element typically added to gold due to the synthesis of white alloys. Some documents report the use of this chemical element also in gold alloys of color, since, even if it generates dark and lackluster surfaces, in reality it is able to increase resistance to corrosive phenomena.
    [0018] In fact, palladium contents less than 3% by weight ("Effect of palladium addition on the tarnishing of dental gold alloys"; J Mater Sci-Mater, 1 (3), pp. 140-145,1990; " Effect of palladium on sulfide tarnishing of noble metal alloys "; J Biomed Mater Res, 19 (8), pp. 317-934, 1985), minimize the effects of tarnishing generated by environments in which sulfur compounds are present above all. In this case, palladium is able to reduce the growth of the surface layer formed mainly by silver sulphides (Ag2S). Contrary to what happens for silver, there is no surface enrichment of palladium, but statistically it is possible to observe an increase in the content of this element in the layer immediately below the outer layer of sulphides. This localized increase in palladium reduces the diffusion of S2 ions "from the surface area to the core area of the artifacts and consequently reduces the growth of the sulfide layer and the surface color variation of the gold alloys in which it is contained.
    [0019] For example, document JP 60 258 435 A (1985) considers palladium as an element capable of improving the chemical stability of 18 carat gold alloys, characterized by copper contents between 15% and 30% and of silver between 5% and 25%. In this case, the invention reports palladium additions ranging from 4% to 7%. JP 10 245 646 A (1998) also proposes additions of palladium ranging from 0.3% to 5% in rose gold alloys (L * = 86-87, a * = 8-10 a * and b * = 17- 22) with gold contents between 75% and 75.3%, copper between 15% and 23% and silver in the balance sheet. This invention does not consider palladium as an element capable of increasing resistance to corrosive phenomena, but its use is reported to increase the castability and toughness of the material.
    [0020] Finally, also EP 1 512 765 A1 (2005), among the various claims, reports palladium additions lower than 4%. In addition to the same purpose, it also considers additions of platinum between 0.5% and 4%, in alloys with gold contents higher than 75%, copper content between 6% and 22% and in which minimal additions of silver may be present , cadmium, chromium, cobalt, iron, indium, manganese, nickel or zinc lower than 0.5%. These compositions have been developed for the synthesis of rose gold alloys with high resistance to surface color variation, in environments where chlorine compounds may be present.
    [0021] Different documents (WO 2009 092 920, DE 3 211 703, EP2 251 444, DE 10 2004 050 594, DE 10 027 605 A1, EP 0 381 994, US 4 820 487) report additions of vanadium or other elements such as iron, chromium, zirconium, hafnium, titanium or tantalum in white gold alloys. In the cited documents however, similar additions are considered exclusively to improve the mechanical characteristics of the claimed compositions or to obtain particular color properties.
    Description of the invention The present invention aims to improve the chemical stability of the currently available commercially available gold alloys. The goal is to increase the resistance to tarnishing of alloys with a minimum gold content of 75% by weight in environments where sulfur or chlorine compounds are present.
    [0023] In particular, the present invention aims to increase the chemical stability of high carat weight color alloys, considering the addition of iron and vanadium to the gold-silver-copper base system. In particular, the invention reports the compositions of alloys with concentrations of gold greater than 75% by weight of copper between 5% and 23%, of silver between 5% and 21%, of iron comprised between 0.5% and 4% and vanadium between 0.1% and 2.
    Description of the tables and figures [0024] TABLE 1 shows the compositions and the main physical characteristics of the alloys considered in this document. For each composition, the values shown in the L * or, at * 0, b * 0, columns are evaluated using a Konica Minolta CM-3610d spectrophotometer. These measurements are carried out in reflectivity condition, using a D65-6504K light source, an 8 ° di / d observation angle and an 8 mm measurement area (MAV). Measurements are made on samples immediately after carefully preparing the surfaces. The preparation of the sample surfaces of the different compositions shown, involves a sanding with abrasive papers and a subsequent polishing. Sanding is carried out with abrasive papers, while polishing with diamond paste, up to a granulometry of 1 pm. This preparation is carried out until a constant reflection factor has been reached. A similar preparation is indispensable and is carried out to remove the traces of any compounds that can change the surface composition of the alloy, its real color and can therefore distort the experimental measurements. The hardness values reported, are measured after a work hardening for flat lamination of the material equal to 70% (column «Inerudito 70%»), after an annealing treatment at 680 ° C («Ricotto» column) and after a heat treatment of hardening carried out at a temperature of 300 ° C ("Aged" column). The hardness tests are conducted with an applied load of 9.8 N (HV1) and maintained for 15 seconds, as specified by the ISO 6507-1 standard.
    [0025] TABLE 2 reports the values of AE (L *, a *, b *) measured after 150 hours of exposure to thioacetamide vapors (column "exposure to thioacetamide vapors [150 hours]") and after 175 hours of immersion in the saturated solution of neutral ph sodium chloride and thermostated at 35 ° C (column "Immersion in a NaCI saturated aqueous solution [175 h]"). The values of the AE parameters (L *, a *, b *) reported, are relative to spectrophotometric measurements of the values of the coordinates L *, a *, b * carried out at defined time intervals. The values of the CIE 1976 L * a * b * coordinates, thus obtained, allow to quantify the decolourization kinetics of the surface of the sample under examination, evaluating over time the parameter AE * (L *, a *, b *) = [( L * -L * 0) 2 + (a * -a * 0) 2 + (b * -b * 02)] 1/2 · This parameter is calculated with respect to the values of the coordinates L * o, a * 0, b * 0, of the alloy in question (values shown in table 1).
    [0026] Fig. 1 shows the changes in the surface color of a 5N ISO 8654 alloy during exposure to a generic ambient atmosphere at 25 ° C.
    [0027] Fig. 2 shows the color variations AE (L *, a *, b *) of the compositions 5N ISO 8654, of the composition L11 and of the composition L01, evaluated during the tests carried out according to the ISO 4538 standard.
    [0028] Fig. 3 shows the color variations AE (L *, a *, b *) of the compositions L01, L02, L03 and L04, evaluated during the tests carried out according to the ISO 4538 standard.
    [0029] Fig. 4 shows the color variations AE (L *, a *, b *) of the compositions 3N ISO 8654 and L05, evaluated during the tests carried out according to the ISO 4538 standard.
    [0030] Fig. 5 shows the color variations AE (L *, a *, b *) of the compositions 5N ISO 8654, of the composition L11 and of the composition L01, evaluated during the tests conducted by immersing the different samples in a saturated solution of sodium chloride, neutral pH and thermostated at 35 ° C.
    [0031] Fig. 6 shows the color variations AE (L *, a *, b *) of the compositions L01, L03 and L06, evaluated during the tests conducted by immersing the different samples in a saturated solution of sodium chloride NaCl a neutral pH and thermostat at 35 ° C.
    [0032] Fig. 7 shows the color variations AE (L *, a *, b *) of the compositions L01, L03 and L06 evaluated during the tests carried out according to the ISO 4538 standard.
    Detailed description of the invention [0033] The different compositions reported in the present invention are fused by an induction furnace equipped with a graphite crucible and cast into graphite brackets of rectangular section. The homogeneity of the bath during fusion is ensured by the stirring generated by electromagnetic induction. The pure elements (Au 99.999%, Cu 99.999%, Pd 99.95%, Fe 99.99%, Ag 99.99%, V> 99.5%) are melted and cast in a controlled atmosphere. In particular, the fusion operations are carried out only after having conducted at least 3 conditioning cycles of the atmosphere of the fusion chamber. This conditioning involves reaching a vacuum level up to pressures below 1 x 10-2 mbar and a subsequent partial saturation with argon at 500 mbar. During melting, the argon pressure is maintained at pressure levels between 500 mbar and 800 mbar. Once the pure elements have completely melted, the liquid is overheated to a temperature of about 1250 ° C, in order to homogenize the chemical composition of the metallic bath. During overheating, a vacuum level lower than 1 x 10-2 mbar is reached again, useful for eliminating part of the slag produced during the melting of the pure elements. At this point, the molten material is poured inside the graphite bracket, after having partially pressurized again the argon melting chamber at 800 mbar. Once solidification has taken place, the melts obtained are extracted from the bracket, rapidly cooled in water to avoid phase variations in the solid state and then plastically deformed by cold rolling flat.
    [0034] During the cold plastic processing process, the different compositions synthesized according to the previously described casting procedure, are deformed up to 70%, then subjected to an annealing heat treatment at temperatures higher than 680 ° C and subsequently rapidly cooled in water to avoid phase change in the solid state. During the entire manufacturing process, all the compositions reported are subjected to hardness and annealed hardness tests. Further hardness measurements are made after a hardening heat treatment carried out at a temperature of 300 ° C. The hardness tests are conducted with an applied load of 9.8 N (HV1) and maintained for 15 seconds, as specified by the ISO 6507-1 standard.
    [0035] From the materials processed by the previously described processing procedures, i.e. after melting, rolling, annealing heat treatment and subsequent rapid cooling, samples are taken to be subjected to metallographic analysis. These samples are sanded, polished and analyzed to evaluate the microstructural properties of the synthesized compositions. In the same way, further material samples are taken from the processed materials by the previously described processing procedures and subjected to color measurements and accelerated corrosion tests.
    [0036] The surface of the samples subjected to color measurements and to the accelerated corrosion tests are carefully smoothed with abrasive papers and subsequently polished with diamond paste with grain size up to 1 pm, until a constant reflection factor has been reached. A similar preparation of the surface of the samples is indispensable and is carried out to remove the traces of any compounds that can pollute the surface composition of the alloy, its real color and distort the experimental measurements.
    [0037] Color measurements are made using a Konica Minolta CM-3610d spectrophotometer, immediately after sample preparation and during different corrosion tests. These measurements are carried out in reflectivity condition, using a D65-6504K light source, an 8 ° di / d observation angle and an 8 mm measurement area (MAV).
    [0038] The resistance to the superficial color variation of the different compositions proposed is evaluated according to the test methods prescribed by the ISO 4538 standard. This standard establishes the equipment and the procedure for the evaluation of the corrosion and oxidation resistance of metal surfaces , in an atmosphere containing volatile sulphides. For this purpose, the specimens are exposed to the thioacetamide CH3CSNH2 vapors in an atmosphere with a relative humidity of 75%, maintained through the presence of a saturated solution of sodium acetate CH3COONa 3H2O trihydrate.
    [0039] Furthermore, to evaluate the resistance to surface color variation in environments characterized by the presence of chlorides, further tests are conducted by immersing the samples in a saturated solution of neutral pH, thermostated at 35 ° C.
    [0040] The color variations suffered by the compositions analyzed in the accelerated corrosion tests are a function of the time t of exposure to the aggressive action of the test environments. These variations can be evaluated experimentally by performing spectrophotometric measurements of the L *, a *, and b * coordinate values at defined time intervals on the surface of the samples. The values of the CIE coordinates 1976 L * a * b *, thus obtained, allow to quantify the kinetics of discoloration of the surface of the material under examination, evaluating over time the parameter ΔΕ * (L *, a *, b *) = [( L * -L * 0) 2 + (a * -a * 0) 2 + (b * -b02)] 1/2. This parameter must be evaluated with respect to the coordinates L * or, at * 0, b * 0, of the material under examination, measured immediately after sanding with abrasive papers and a subsequent polishing with diamond paste with grain size up to 1 pm. These operations are carried out until a constant reflection factor has been reached. A similar preparation of the sample surface is indispensable and is carried out to remove the traces of any compounds that may vary the surface composition of the alloy, its real color and can therefore distort the experimental measurements. The results of these tests allow to obtain experimental AE * curves (L *, a *, b *) vs time, indispensable for analyzing the color variation kinetics of the analyzed compositions and then quantitatively assessing their chemical stability in the test environments considered .
    [0041] The compositions and the main physical characteristics of the alloys considered in this document are reported in Table 1. For the analyzed compositions, Table 2 instead shows the values of AE (L *, a *, b *) measured after 150 hours exposure to thioacetamide vapors and after 175 hours immersion in the sodium chloride containing solution.
    [0042] Additions of iron and vanadium higher than 1% and 0.1% by weight respectively, allow to reduce the variation of surface color in an atmosphere containing volatile sulphides. In this way, palladium additions capable of improving the chemical stability of the analyzed compositions are not considered and the decrease in surface brightness, linked to the alloy presence of this element, is avoided. Likewise, platinum additions are not considered expensive.
    [0043] The curves shown in fig. 2 can thus be analyzed. The time t = 0 corresponds to the conditions immediately following the polishing of the samples 5N ISO 8654, L11, L01 and therefore the value of AE * (L *, a *, b *, t = 0) for the three different compositions shown is zero . As it is possible to observe, after 150 hours of exposure to thioacetamide vapors, for an alloy with an iron content equal to 1.8% by weight and vanadium equal to 0.4% by weight (L01) the change in color AE (L *, a *, b *) is equal to 2.9. In the same conditions a 5N ISO 8654 alloy undergoes a variation equal to 5.6, while for an alloy (L11) according to the document EP 1 512 765 A1 this parameter has a value equal to 4.1.
    [0044] Furthermore, for alloys with a composition included in this embodiment of the invention, the bleaching kinetics during the test differs with respect to the two compositions taken as reference. As you can always see in fig. 2, as regards the 5N ISO 8654 alloy, there is a rapid variation of the color in the first 24 hours of testing. Subsequently, the kinetics of color variation decreases, but the parameter AE (L *, a *, b *) continues to increase in all the 150 hours of tests analyzed. Also the L11 alloy shows an analogous behavior, but after about 120 hours of exposure to the thioacetamide vapors the values of the parameter AE (L *, a *, b *) related to this composition are at about constant values. Otherwise, the L01 composition stabilizes its color change after only 80 hours of testing.
    [0045] Again, the presence of iron in the composition of the alloy allows an increase in the miscibility of vanadium in gold. Maintaining a ratio between the iron and vanadium content of more than 4, it is possible to obtain solid solutions and avoid the separation of second phases.
    [0046] The curves shown in fig. 3 can thus be analyzed. The time t = 0 corresponds to the conditions immediately following the polishing of the samples L01, L02, L03, L04 and therefore the value of AE * (L *, a *, b *, t = 0) for the four different compositions shown is zero . Compositions in which palladium is substituted for iron show less resistance to color change in environments characterized by the presence of volatile sulphides. An alloy with 1.8% palladium by weight and 0.4% by weight of vanadium (L03) after 150 hours of exposure to thioacetamide vapors, undergoes an AE variation (L *, a *, b *) equal to 4.1 and therefore shows a surface color variation comparable to the L11 composition. In this case however (fig. 3), for the composition L03 it is not possible to observe a stabilization of the parameter AE (L *, a *, b *) in the first 150 hours of testing.
    [0047] Furthermore, the addition of vanadium is essential for increasing the chemical stability of the compositions considered. In atmospheres containing volatile sulphides, a simple addition of iron equal to 1.8% by weight (L02), results in a color variation completely equivalent to that shown by the reference alloy 5N ISO 8654 (fig. 3). If palladium is replaced by iron, the effects generated by the presence of vanadium are less evident. As always shown in fig. 3, a composition characterized simply by a palladium content equal to 1.8% by weight (L04), after 150 hours of exposure to the thioacetamide vapors, undergoes a color change AE (L *, a *, b *) equal to 3.8 . For a composition in which vanadium is also present, this parameter has a value of 4.1. In this case the presence of vanadium does not influence the chemical stability of the gold-silver-copper-palladium quaternary system. Furthermore, the compositions L03 and L04 are not characterized simply by the same chemical stability, but also by the same kinetics of color evolution over the entire test interval.
    [0048] In the case in which the palladium is present in the alloy in substitution of the iron, the effect of the vanadium becomes appreciable only following the increase of the silver content and the decrease of the copper content. This is the case of an alloy with silver contents between 5% and 16% by weight, palladium ranging from 0.2% to 5% by weight and vanadium between 0.2% and 1.5% by weight. The curves shown in fig. 4 can thus be analyzed. The time t = 0 corresponds to the conditions immediately following the polishing of samples 3N ISO 8654, L05 and therefore the value of AE * (L *, a *, b *, t = 0) for the two different compositions shown is zero. For example (Fig. 4), an alloy with silver and copper contents equal to 12.5% by weight and additions of palladium and vanadium, respectively equal to 1.8% and 0.4% by weight (L05), after 150 hours of exposure to vapors of thioacetamide, shows a change in color AE (L *, a *, b *) equal to 3.6. A standard 3N ISO 8654 alloy undergoes a change of 4.8 in the same conditions. In this particular realization of the invention, the additions of palladium allow the increase of the miscibility of vanadium in gold.
    [0049] The tests conducted by immersing the samples in the sodium chloride solution (Fig. 5) confirm the chemical stability of the L11 alloy reported in EP 1 512 765 A1. After 175 hours of immersion in the solution containing chlorides, this composition undergoes a change in color AE (L *, a *, b *) equal to 1.9, while for a composition 5N ISO 8654 this parameter has a value of 3.6. Under the same conditions, the composition L01 undergoes a variation equal to 2.7. Therefore simple additions of iron or vanadium do not allow the optimization of the resistance of gold alloys in solutions in which chlorides are dissolved.
    [0050] For this purpose, a further embodiment of the invention considers additions of palladium ranging from 0.5% to 2% by weight of iron comprised between 0.5% and 2% by weight and vanadium comprised between 0.1% and 1.5% in weight.
    [0051] An alloy characterized by 0.9% iron by weight, by 0.9% palladium by weight and by 0.4% by weight of vanadium (L06), after 175 hours of immersion in the solution containing chlorides, undergoes a change in color AE ( L *, a *, b *) equal to 2.1. The curves shown in fig. 6 can thus be analyzed. The time t = 0 corresponds to the conditions immediately following the polishing of the samples L01, L03, L06 and therefore the value of AE * (L *, a *, b *, t = 0) for the three different compositions shown is zero. As can be seen in fig. 6, the variation of the color of the L11 alloy undergoes a rapid variation in the first 48 hours of testing and after about 150 hours of immersion, the values of the AE parameter (L *, a *, b *) stand at almost constant values. Differently, the composition L06 undergoes a rapid color variation in the first 24 hours and, similarly to what happens for the composition L11, the parameter AE (L *, a *, b *) of the composition L06 also stabilizes after about 150 hours of testing.
    [0052] This further embodiment of the invention allows to increase the resistance to color variation in solutions in which chlorides are dissolved. At the same time, however, chemical stability is maintained in environments containing volatile sulphides. The curves shown in fig. 7 can thus be analyzed. The time t = 0 corresponds to the conditions immediately following the polishing of the samples L01, L03.L06 and therefore the value of AE * (L *, a *, b *, t = 0) for the three different compositions shown is zero. As reported in fig. 7 after 150 hours of exposure to thiocatamide vapors, the composition L06 undergoes a change in color AE (L *, a *, b *) equal to 3.3. This color change is based on intermediate values relative to those relating to composition L01 and L03.
    [0053] Still, compositions in which the ratio between the sum of the concentrations of iron and palladium and the concentration of vanadium is higher than 4, are homogeneous solid solutions, without second phases.
    [0054] By replacing the iron with the palladium, it is possible to obtain brighter surfaces. As shown in table 1, the composition L01 is characterized by a parameter L * equal to 86.66, while for the composition L04 this parameter takes values lower and equal to 85.21. By partially replacing the palladium iron as occurs in the composition L06, intermediate L * values are obtained with respect to those just reported.
    [0055] Iron and vanadium are chemical elements capable of reducing the saturation of the hue of gold alloys. As the concentration of these elements increases, the values of the coordinates a * and b * decrease and more and more achromatic colors are obtained.
    [0056] To overcome this problem a further embodiment of the invention contains compositions in which silver may not be present, in which there are copper contents ranging from 16% to 23% by weight, of iron between 0.5% and 4% in weight and vanadium between 0.1% and 1% by weight. For example, the composition L07 in which the iron is present with a concentration equal to 2.5% by weight and the vanadium content is equal to 0.6% by weight, it is possible to obtain a value of a * equal to 6.45, similarly to what reported for the composition L01. However, the lack of silver causes a decrease in the parameter b * (yellow). In fact, the composition L07 is characterized by a value of b * equal to 12.90, while for the composition L01 this parameter takes the value of 15.49. Also in this particular embodiment of the invention, considering compositions in which the ratio between the concentrations of iron and vanadium is greater than 4, homogeneous solid solutions without second phases are obtained.
    [0057] Furthermore, the presence of iron produces an increase in surface brightness. An alloy with 2.5% by weight of palladium (L09) is characterized by an L * value of 83.77. The composition L07 in which the iron is present in a content equal to 2.5% by weight is characterized by a value of L * equal to 86.09. By increasing the iron content to 3.1% by weight, even in the absence of vanadium (L08), the parameter L * assumes a value equal to 86.33.
    [0058] A last embodiment of the invention can comprise iridium contents lower than 0.05% by weight. These additions allow an refinement of the crystalline structure of the considered compositions. Fig. 8 shows the microstructure of an alloy with an iron content of 1.8% by weight of vanadium equal to 0.4% by weight and of iridium equal to 0.01% by weight, plastically deformed to cold up to 70% and ricotta at 680 ° C . The composition is characterized by a grain size of 7 according to the ISO 643 standard. A similar grain size allows a good polishing of the surfaces of the manufactured articles. Higher iridium additions can further increase the grain size index and have negative effects on the chemical stability of the alloy.
    CIE color Σ ~
    The Composition [% in L * a * b * __ ur 22 _ p6S °] | _ * 0 a * 0 b * 0 'Π <7Γ0% ίθ Aged Ricotto
    . n. Au75 Ag4.1 Cu18.7 Fe1.8 86.8 6.4 15.4 9C7 9CC LQ1 VQ.4__6__5__9 267 170 265 L02 Au75 Ag4.2 Cu19.0 Fe1.8 888 θ 4 1θ5 261 162 273 7Ξ Au75Ag4.1 Cu18.7Pd1.8 85 ^ TT 14.1 9KR 7Z ΣΣ L03 VO 4 4 2 7 256 285 L04 Au75 Ag4.2Cu19.0 Pd18 88'2 8θ2 14'4 254 156 298 ~ Au75Ag11.4 Cui 1.4 Pd1.8 87.2 ΊΓΓ 17.3 “~ ~ LU0 V0 .4 7 6 0 Zóy θ'4 Z 0
    . nc Au75 Ag3.6 Cui 9.2 Pd0.9 85.7 6.8 14.1 97Q 97C 106 Fe0.9 V0.4__7__5__0 273 165 275 L07 Au75 Cu21.9 Fe2.5 V0.6 88-0 8C4 12 9 295 192 323 ___9 or u____ L08 Au75Cu21 .9Fe3.1 88-3 5θ7 12 7 272 163 302 L09 Au75 Cu22.5 Pd25 83.7 8'1 114 245 163 286
    Mn Au75Ag4.1 Cu18.7Fe1.8 86.8 6.4 15.4 9RJ- .7_ 9Rn L1 ° V0.4lr0.01 0 3 9 285 172 280 84 5 9 1 13 1 L11 Au76Pt3Cu21 0 0 270 185 300 5N ISO Λ -, c Λ Λ cr 'c 86.9 9.6 17.5 oon
    Au75 Ag4.5 Cu20.5. n 230 230 325 8654_____4 0 0____ 3θθ ^ ° Au75 Agl2.5 Cui2.5 δθ3 5θ8 2 | 4 220 145 230
    Table 1
    权利要求:
    Claims (10)
    [1]

    AE (L *, a *, b *) Lega Composizione [/> in Esposizione ai vapori di immersion in soluzione pesoJ tioacetammide (150 acquosa satura NaCI ___ ore) __ (175 ore) _ L01 Au75 Ag4.1 Cu18.7 Fe1.8 2g 2.7 L02 Au75 Ag4.2Cu19.0 Fe1.8 4.7 2.9 L03 Au75 Ag4.1 Cu18.7 Pd1.8 ~ L04 Au75 Ag4.2 Cu19.0 Pd18 3.3 2.4, nc Au75 Agl 1.4 Cui 1.4 Pd1.8 "R L05 V0.4 3 · 6 20, Au75 Ag3.6 Cui 9.2 Pd0.9 "" ". LUt> Fe0.9 V0.4 _______ L07 Au75 Cu21.9 Fe2.5 V0.6 4.2 2.6 L08 Au75Cu21.9Fe3.1 4.4 3.0 L09 Au75 Cu22.5 Pd25 4.7 2.0 L11 Au76Pt3Cu21 4.1 1.9 5g6lf4 ° Au75 Ag4.5 Cu20.5 5.6 3.6 ^ 54 ° Au75 Ag12.5 Cu12.5 4.8 3.3 Tabella 2 Rivendicazioni
    1. Lega d'oro per la fabbricazione di gioielli o componenti di orologi caratterizzata dal fatto di comprendere almeno i seguenti elementi con le seguenti concentrazioni percentuali in peso; l'oro uguale o superiore al 75% in peso, il rame tra 5% e 23%, l'argento tra 0% e 21%, il ferro tra 0.5% e 4% e il vanadio tra 0.1% e 2%.
    [2]
    2. Lego d'oro secondo rivendicazione 1, in cui l'argento è present with tenori compresi fra 5% e 16% in peso, il vanadio tra 0.1% e 2% in peso, caratterizzata dal fatto che è anche presente del palladio tra 0.1% e 5%.
    [3]
    3. Lega d'oro con tenori secondo rivendicazione 1, in cui il ferro è presente in tenori compresi fra 0.5% e 2% in peso, il vanadio fra 0.2% e 1.5% in peso ed č anche presente palladio fra 0.5% e 2% in pesos.
    [4]
    4. Lega d'oro secondo le rivendicazioni 2 o 3, in cui il rapporto fra la somma delle concentrazione di ferro e palladio and the concentrazione di vanadio è superiore a 4.
    [5]
    5. Lega d'oro secondo rivendicazione 1, in cui il rame è presente in tenori compresi fra 16% e 23% in peso, il ferro fra 0.5% e 4% in peso ed il vanadio fra 0.1% ed 1% in peso ,
    [6]
    6. Lega d'oro secondo le rivendicazioni 1.5 in cui il rapporto fra il tenore di ferro e di vanadio è superiore a 4.
    [7]
    7. Lega d'oro secondo rivendicazioni precedenti, caratterizzata dal fatto di comprendere anche dell'iridio con tenori inferiori allo 0.05% in peso.
    [8]
    8. Procedimento per produrre una lega d'oro secondo una qualsiasi delle precedenti rivendicazioni caratterizzato dal fatto di comprendere le fasi di; a) fusione sotto agitazione, mediante un forno ad induction equipaggiato con crogiolo di graphite, elemental puri Au 99.999%, Cu 99.999%, Pd 99.95%, Fe 99.99%, Ag 99.99%, V> 99.5 % in atmosfera controllata di argon da 500 mbar a 800 mbar all'interno di un'apposita camera of fusion, quest'ultima essendo previamente sottoposta ad almeno tre cicli di condizionamento, detto condizionamento prevedendo il raggiungi-mento di un vuoto inferiore a 1 x 10 "2 mbar ed una successiva saturazione parziale con argon preferibilmente a 500 mbar; b) Surriscaldamento del fuso omogeneizzato ad una temperatura di circa 1250 ° C e a una pressione residua inferiore a 1 x 10 "2 mbar; c) Colata in atmosfera controllata, dei metalli fusi, staff di grafite di sezione rettangolare, previa pressurizzazione, in camera di fusione, con argon a 800 mbar; d) Estrazione dalla staffa dei lingotti di lega rapidamente raffreddati, detto raffreddamento rapido avvenendo in acqua; e) Deformazione fino al 70% dei lingotti di lega, secondo le precedenti rivendicazioni, indotta per lavorazione plastica a freddo, detta lavorazione plastica prevedendo la laminazione piana dei lingotti, la loro ricottura a temperature superiori a 680 ° C ed il successivo rapido raffreddamento dei lingotti in acqua.
    [9]
    9. Procedimento secondo precedente rivendicazione comprendente l'escuzione di prove durezza, durante tutte le fasi secondo la precedente rivendicazione, it proves the durezza avvenendo allo stato incrudito, ricotto ed ano dopo un ulteriore trattamento termico effettuato a 300 ° C, utilizzando un carico applicato pari ad almeno 9.8 N per un tempo di 15 secondi.
    [10]
    10. Procedimento secondo le rivendicazioni 8 e 9 comprendente la levigatura, la lucidatura, e l'analisi dei materiali processati detti materiali processati essendo accuratamente levigati mediante carte abrasive e successivamente lucidati con paste diamantate di granulometria pari a 1 pm, fino al raggiungimento di un fattore di riflessione costante.
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    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    GB227966A|1924-09-10|1925-01-29|Giovanni Della Coletta|Improvements in hydraulic bituminous cement in powder and process for its production|
    BE621400A|1961-08-15|
    DE3211703C2|1982-03-30|1984-01-12|C. Hafner GmbH + Co., 7530 Pforzheim|Use of low-gold precious metal alloys for dental purposes|
    JPS60258435A|1984-06-06|1985-12-20|Citizen Watch Co Ltd|Corrosion resistant, hard and golden gold alloy|
    GB2184457B|1985-12-06|1989-03-30|Vittorio Antoniazzi|Gold alloy|
    JPH0723529B2|1986-07-17|1995-03-15|三菱マテリアル株式会社|Decorative Au alloy member having surface hardened layer|
    EP0381994B1|1989-02-09|1995-09-27|C. HAFNER GmbH &amp; Co.|Alloy with a high gold content for ornamental uses|
    CN1017633B|1990-01-05|1992-07-29|中山大学|Gold marmen able to be shaped and process for manufacturing same|
    JPH04183836A|1990-11-19|1992-06-30|Seiko Instr Inc|Surface hardened colored gold alloy|
    JPH0717974B2|1990-11-28|1995-03-01|工業技術院長|Gold alloy with shiny grey-black and black coloring and its coloring method|
    GB9314292D0|1993-07-10|1993-08-25|Johnson Matthey Plc|Gold alloy|
    JPH08325656A|1995-06-01|1996-12-10|Kuwayama Kikinzoku:Kk|Pinkish gold alloy for decoration|
    JPH0967628A|1995-08-31|1997-03-11|Shosuke Otsuka|Dental gold-titanium alloy|
    JPH10245646A|1997-03-07|1998-09-14|Seiko Epson Corp|Gold alloy, ornamental member, portable watch and production of ornamental member|
    EP0904765A2|1997-09-25|1999-03-31|Ivoclar Ag|Gold coloured dental alloy|
    JPH11335755A|1998-05-27|1999-12-07|Ijima Kingin Kogyo Kk|Alloy for eye glass|
    JP2000245514A|1998-12-28|2000-09-12|Yoshihiro Hosaka|Earring|
    DE19958800A1|1999-06-30|2001-01-04|Wieland Edelmetalle|White gold jewelry alloy for all jewelry purposes contains alloying additions of silver and iron|
    JP2001335861A|2000-05-26|2001-12-04|Tokuriki Honten Co Ltd|Gold alloy for ornament|
    DE10027605A1|2000-06-06|2001-12-20|Hafner C Gmbh & Co|Alloy used in the production of jewelry, coins or medallions contains gold and chromium|
    JP2002105558A|2000-09-29|2002-04-10|Shoei Shokai:Kk|Gold alloy for personal ornament|
    EP1227166B1|2001-01-26|2010-04-28|Metalor Technologies International SA|Grey gold alloy|
    EP1512766A1|2003-09-04|2005-03-09|Rolex Sa|Article of watch or jewelry having color resistance|
    DE60310555T2|2003-09-04|2007-12-27|Rolex Sa|Decolorative clock or jewelry|
    JP2005082890A|2003-09-08|2005-03-31|Ijima Kingin Kogyo Kk|Gold alloy for accessory|
    DE102004050594A1|2004-10-16|2005-06-30|Degudent Gmbh|Palladium-free, copper-free, high-gold dental alloy, useful for producing dental prostheses, contains added specified high-melting elements|
    JP2006118029A|2004-10-25|2006-05-11|Mikimoto Soshingu:Kk|White gold alloy and method for thermally hardening the same|
    US7413705B2|2005-05-09|2008-08-19|Leach & Garner Company|Rose-colored gold alloy compositions with reversible hardness characteristics|
    JP4554666B2|2006-12-27|2010-09-29|株式会社シュプレーム|A noble metal alloy for jewelry and a jewelry made of the noble metal alloy for jewelry|
    US7413505B1|2007-02-12|2008-08-19|Rowlen Jr Michael A|Pipe and shaft sander|
    JP4058101B1|2007-05-15|2008-03-05|株式会社ラーピス|Decorative and dental gold alloys|
    FR2923492A1|2007-11-12|2009-05-15|Gerard Bienvenu|White gold alloy, useful to prepare materials for optoelectronics and in jewelry, where the gold is combined with at least one refractory metal of IVB, VB and VIB column of periodic table|
    KR100925845B1|2008-01-15|2009-11-09|주식회사 예스바이오|Alloy composition for dental prosthesis comprising silicon|
    JP4231092B1|2008-03-25|2009-02-25|株式会社ラーピス|Gold alloys for dental, decorative and industrial products that age harden as cast.|
    EP2251444A1|2009-05-06|2010-11-17|Rolex Sa|Grey gold alloy with no nickel and no copper|
    CA2670604A1|2009-07-06|2011-01-06|Stanislaw Cieslukowski|Brown gold alloy|
    CN105008561B|2012-12-03|2018-07-03|Argor-Heraeus股份有限公司|The billon of anti-colour fading|
    WO2014122234A1|2013-02-06|2014-08-14|Rolex Sa|Timepiece made from rose gold alloy|CN105008561B|2012-12-03|2018-07-03|Argor-Heraeus股份有限公司|The billon of anti-colour fading|
    CN108085630A|2018-01-11|2018-05-29|广州优妮凯珠宝有限公司|A kind of preparation method of silver jeweleries|
    EP3527678B1|2018-02-15|2021-06-02|Richemont International S.A.|Alloy of gold and copper, method for preparing same and use thereof|
    IT201800003593A1|2018-03-15|2019-09-15|Argor Heraeus Sa|GOLD ALLOY RESISTANT TO BLEACHING AND PRODUCTION METHOD OF THE SAME|
    CH714785A1|2018-03-15|2019-09-30|Argor Heraeus Sa|Gold alloy resistant to discoloration and its production method.|
    EP3553192B1|2018-04-12|2021-07-14|Argor-Heraeus S.A.|Tarnishing resistant gold alloy at 14k and method of production thereof|
    IT201800004444A1|2018-04-12|2019-10-12|14K GOLD ALLOY RESISTANT TO TARNISHING AND PRODUCTION METHOD OF THE SAME|
    EP3575421A1|2018-06-01|2019-12-04|Omega SA|Piece of watchmaking or jewellery made of an alloy based on gold|
    CN109136625A|2018-09-14|2019-01-04|深圳市品越珠宝有限公司|A kind of high hardness alloy and preparation method thereof|
    CH715727A1|2019-01-11|2020-07-15|Richemont Int Sa|Process for obtaining a micromechanical component made of an 18-carat gold alloy.|
    CH715728A1|2019-01-11|2020-07-15|Richemont Int Sa|Process for obtaining an 18-carat gold component for watch and jewelery dressing applications.|
    CN110029244A|2019-05-22|2019-07-19|北京有色金属与稀土应用研究所|High-performance gold-vanadium alloy material and its preparation method and application|
    EP3862445A1|2020-02-07|2021-08-11|Richemont International S.A.|Gold alloy and method for manufacturing same|
    CN113215431A|2021-05-18|2021-08-06|沈阳东创贵金属材料有限公司|White K gold target material and preparation method and application thereof|
    法律状态:
    2017-06-15| NV| New agent|Representative=s name: ING. ALESSANDRO GALASSI C/O PGA S.P.A., MILANO, CH |
    优先权:
    申请号 | 申请日 | 专利标题
    ITRM20120608|2012-12-03|
    PCT/IB2013/002683|WO2014087216A1|2012-12-03|2013-12-02|Discoloration-resistant gold alloy|
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