Nickel-free platinum alloy composition

Abstract

0.0 to 5.0 mass% gold, 0.0 to 2.5 mass% cobalt, 0.0 to 3.0 mass% copper, 0.0 to 5.0 mass% iron, 0.0 to 2.75 mass% gallium, 0.0 to 3.0 mass% indium, 0.0 to 5.0 mass% iridium, 0.0 to 5.0 mass% manganese, 0.0 to 5.0 mass% palladium, 0.0 to 5.0 mass% rhenium, 0.0 to 5.0 mass% rhodium, 0 A platinum alloy composition containing 0.0 to 5.0 mass% ruthenium, 0.0 to 3.0 mass% tin, 0.0 to 5.0 mass% silver, and the total of platinum and iridium is 95.0 mass% or more, and containing unavoidable impurities, wherein the mass% of cobalt, copper, iron, gallium, indium, nickel, palladium, tin, rhodium, iridium, gold, ruthenium, rhenium, silver, and manganese contained in the alloy are respectively W Co , W Cu , W Fe , W Ga , W In , W Ni , W Pd , W Sn , W Rh , W Ir , W Au , W Ru , W Re , W Ag and W Mn Then, 60+W Pd *2.5 + W Rh *3.4 + W Ir *6.455 + W Au *11.93 + W Ru *13.241 + W Cu *14.328 + W Re *16.6 + W Ni *16.9 + W Mn *18.48 + W Co *18.69 + W Fe *21.879 + W In *29 + W Sn *28.207 + W Ga *42.379 + W Ag *9.0 ≧ 130 is satisfied. The mass percentages of cobalt, copper, iron, gallium, indium, nickel, palladium, tin, manganese, ruthenium, iridium, rhodium, gold, platinum, silver, and rhenium contained in the alloy are respectively W Co , W Cu , W Fe , W Ga , W In , W Ni , W Pd , W Sn , W Mn , W Ru , W Ir , W Rh , W Au , W Pt , W Ag and W Re Then, 16.6 < -0.10406*W Ag -0.1028*W Co - 0.1201*W Cu - 0.2113*W Fe - 0.3368*W Ga - 0.1125*W In - 0.1639*W Ni - 0.015*W Pd - 0.1959*W Sn + 17.276261 - 0.20*W Mn + 0.0678*W Ru + 0.035*W Ir + 0.045*W Rh - 0.059*W Au + 0.066*W Re ≦ 17.1, The mass percentages of cobalt, copper, iron, gallium, indium, nickel, palladium, tin, manganese, ruthenium, iridium, rhodium, gold, silver, and rhenium contained in the alloy are respectively W Co , W Cu , W Fe , W Ga , W In , W Ni , W Pd , W Sn , W Mn , W Ru , W Ir , W Rh , W Au , WAg and W Re Then, 4.22W Ag 2 + 0.041W Au W Co + 0.122W Au W In + 1.96W Au W Ni + 1.87W Au W Sn + 0.903W Au 2 + 1.74W Co W Ga + 13.4W Co W In + 1.24W Co W Mn + 5.04W Co W Sn + 1.02W Co 2 + 8.97W Cu W Fe + 1.74W Cu W Ga + 4.38W Cu W In + 1.16W Cu W Mn + 0.491W Cu W Ni + 3.69W Cu W Sn + 0.22W Cu 2 + 1.68W Fe W Ga + 3.31W Fe W In - 1.26W Fe W Mn + 5.07W Fe W Sn + 0.199W Fe 2 + 5.35W Ga W In + 0.086W Ga W Mn + 3.27W Ga W Re + 33.3W Ga W Rh + 4.56W Ga W Ru+ 2.21W Ga W Sn + 29.0W Ga + 8.49W Ga 2 + 9.09W In W Mn - 0.28W In W Ni + 15.4W In W Rh + 0.992W In W Ru + 11.7W In + 6.68W In 2 + 0.863W Ir 2 + 5.73W Mn W Ni - 0.02W Mn W Ru + 5.68W Mn W Sn + 18.4W Mn - 0.89W Mn 2 + 0.49W Ni W Ru + 0.186W Ni 2 + 4.48W Re W Sn + 1.15W Re 2 - 5.11W Rh W Sn + 2.04W Rh 2 + 0.885W Ru W Sn + 1.28W Ru 2 + 1.58W Sn + 9.49W Sn 2 + 11.6 ≦ 100 A platinum alloy composition comprising:

Description

[Technical Field]

[0001] The present invention relates to platinum alloy compositions, particularly platinum alloy compositions for use in jewelry, and to jewelry alloy compositions having improved castability and suitable for jewelry. [Background technology]

[0002] Pure platinum does not have sufficient hardness for jewelry applications. This not only reduces wear resistance, but can also lead to other problems, such as jewelry that is prone to deformation and does not securely hold gemstones in place. To increase the hardness of platinum jewelry, additional (alloying) elements are added to pure platinum to form an alloy. However, these alloying elements can adversely affect the castability of platinum alloys.

[0003] WO2022074363A1 describes alloys that fulfill a similar purpose. Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a platinum alloy having an improved balance between castability and solderability and a hardness suitable for jewelry. [Means for solving the problem]

[0005] According to the present invention, the composition of the present invention is 0.0 to 5.0 mass% of gold, 0.0 to 2.5 mass% of cobalt, 0.0 to 3.0 mass% of copper, 0.0 to 5.0 mass% of iron, 0.0 to 2.75 mass% of gallium, 0.0 to 3.0 mass% of indium, 0.0 to 5.0 mass% of iridium, 0.0 to 5.0 mass% of manganese, 0.0 to 5.0 mass% of palladium, 0.0 to 5.0 mass% of rhenium, 0.0 to 5.0 mass% of rhodium ... A platinum alloy composition containing 0.0 to 5.0 mass% of ruthenium, 0.0 to 3.0 mass% of tin, 0.0 to 5.0 mass% of silver, and a total of 95.0 mass% or more of platinum and iridium, and containing unavoidable impurities, wherein the mass% of cobalt, copper, iron, gallium, indium, nickel, palladium, tin, rhodium, iridium, gold, ruthenium, rhenium, silver, and manganese contained in the alloy are respectively W. Co , W Cu , W Fe , W Ga , W In , W Ni , W Pd , W Sn , W Rh , W Ir , W Au , W Ru , W Re , W Ag and W Mn Then, 60+W Pd *2.5 + W Rh *3.4 + W Ir *6.455 + W Au *11.93 + W Ru *13.241 + W Cu *14.328 + W Re *16.6 + W Ni *16.9 + W Mn *18.48 + W Co *18.69 + W Fe *21.879 + W In *29 + W Sn *28.207 + W Ga *42.379 + W Ag *9.0 ≧ 130 is satisfied. The mass percentages of cobalt, copper, iron, gallium, indium, nickel, palladium, tin, manganese, ruthenium, iridium, rhodium, gold, platinum, silver, and rhenium contained in the alloy are respectively W Co , W Cu , W Fe , W Ga , W In , W Ni , W Pd , W Sn , W Mn , W Ru , W Ir , W Rh , W Au , W Pt , W Ag and W Re Then, 16.6 < -0.10406*W Ag -0.1028*W Co - 0.1201*W Cu - 0.2113*W Fe - 0.3368*W Ga - 0.1125*W In - 0.1639*W Ni - 0.015*W Pd - 0.1959*W Sn + 17.276261 - 0.20*W Mn + 0.0678*W Ru + 0.035*W Ir + 0.045*W Rh - 0.059*W Au + 0.066*W Re ≦ 17.1, The mass percentages of cobalt, copper, iron, gallium, indium, nickel, palladium, tin, manganese, ruthenium, iridium, rhodium, gold, silver, and rhenium contained in the alloy are respectively W Co , W Cu , W Fe , W Ga , W In , W Ni , W Pd , W Sn , W Mn , W Ru , W Ir , W Rh , W Au , WAg and W Re Then, 4.22W Ag 2 + 0.041W Au W Co + 0.122W Au W In + 1.96W Au W Ni + 1.87W Au W Sn + 0.903W Au 2 + 1.74W Co W Ga + 13.4W Co W In + 1.24W Co W Mn + 5.04W Co W Sn + 1.02W Co 2 + 8.97W Cu W Fe + 1.74W Cu W Ga + 4.38W Cu W In + 1.16W Cu W Mn + 0.491W Cu W Ni + 3.69W Cu W Sn + 0.22W Cu 2 + 1.68W Fe W Ga + 3.31W Fe W In - 1.26W Fe W Mn + 5.07W Fe W Sn + 0.199W Fe 2 + 5.35W Ga W In + 0.086W Ga W Mn + 3.27W Ga W Re + 33.3W Ga W Rh + 4.56W Ga W Ru+ 2.21W Ga W Sn + 29.0W Ga + 8.49W Ga 2 + 9.09W In W Mn - 0.28W In W Ni + 15.4W In W Rh + 0.992W In W Ru + 11.7W In + 6.68W In 2 + 0.863W Ir 2 + 5.73W Mn W Ni - 0.02W Mn W Ru + 5.68W Mn W Sn + 18.4W Mn - 0.89W Mn 2 + 0.49W Ni W Ru + 0.186W Ni 2 + 4.48W Re W Sn + 1.15W Re 2 - 5.11W Rh W Sn + 2.04W Rh 2 + 0.885W Ru W Sn + 1.28W Ru 2 + 1.58W Sn + 9.49W Sn 2 + 11.6 ≦ 100 A platinum alloy composition is provided, characterized in that:

[0006] Such alloys offer an excellent balance of hardness, castability and solderability.

[0007] In one embodiment, the platinum alloy composition comprises, by weight, 95.0% or greater platinum. Such alloys are recognized worldwide as hallmarking standards for jewelry applications.

[0008] In one embodiment, the weight percent of cobalt, copper, iron, gallium, indium, nickel, palladium, tin, rhodium, iridium, gold, ruthenium, rhenium, silver, and manganese in the alloy is W. Co , W Cu , W Fe , W Ga , W In , W Ni , W Pd , W Sn , W Rh , W Ir , W Au , W Ru , W Re , W Ag and W Mn Then, the platinum alloy composition satisfies the following formula: 60+W Pd *2.5 + W Rh *3.4 + W Ir *6.455 + W Au *11.93 + W Ru *13.241 + W Cu *14.328 + W Re *16.6 + W Ni *16.9 + W Mn *18.48 + W Co *18.69 + W Fe *21.879 + W In *29 + W Sn *28.207 + W Ga *42.379 + W Ag *9.0 ≧ 140 Preferably, the following formula is satisfied: 60+W Pd *2.5 + W Rh *3.4 + W Ir *6.455 + W Au *11.93 + WRu *13.241 + W Cu *14.328 + W Re *16.6 + W Ni *16.9 + W Mn *18.48 + W Co *18.69 + W Fe *21.879 + W In *29 + W Sn *28.207 + W Ga *42.379 + W Ag *9.0 ≧ 150 More preferably, the following formula is satisfied: 60+W Pd *2.5 + W Rh *3.4 + W Ir *6.455 + W Au *11.93 + W Ru *13.241 + W Cu *14.328 + W Re *16.6 + W Ni *16.9 + W Mn *18.48 + W Co *18.69 + W Fe *21.879 + W In *29 + W Sn *28.207 + W Ga *42.379 + W Ag *9.0 ≧ 160 Even more preferably, the following formula is satisfied: 60+W Pd *2.5 + W Rh *3.4 + W Ir *6.455 + W Au *11.93 + W Ru *13.241 + W Cu *14.328 + W Re *16.6 + W Ni *16.9 + W Mn *18.48 + W Co *18.69 + W Fe *21.879 + W In *29 + W Sn *28.207 + W Ga*42.379 + W Ag *9.0 ≧ 170 Such alloys have high hardness, making them useful in certain jewelry applications.

[0009] In one embodiment, the mass percentages of gallium, indium, and tin in the alloy are W. Ga , W In and W Sn Then, the platinum alloy composition satisfies the following formula: W Sn + W In + W Ga ≧ 0.25, preferably W Sn + W In + W Ga ≧ 0.40, more preferably W Sn + W In + W Ga ≧0.50, most preferably W Sn + W In + W Ga ≧ 0.75 Such alloys have a higher hardness.

[0010] In one embodiment, the platinum alloy composition comprises 2.0 wt.% or less of iridium, providing a reduced cost alloy.

[0011] In one embodiment, the platinum alloy composition comprises 2.0 wt.% or less of rhodium, providing a reduced cost.

[0012] In one embodiment, the platinum alloy composition comprises ruthenium in an amount of 3.0% by weight or less, preferably 2.5% by weight or less, preferably 2.0% by weight or less, such alloys having reduced cost and low melting points.

[0013] In one embodiment, the platinum alloy composition comprises 2.0 wt.% or less of rhenium, providing a reduced cost alloy.

[0014] In one embodiment, the platinum alloy composition comprises no more than 2.0 wt. % indium, preferably no more than 1.7 wt. % indium, which provides improved castability and solderability.

[0015] In one embodiment, the platinum alloy composition has 2.0% by weight or less of tin, preferably 1.5% by weight or less, and more preferably 1.0% by weight or less of tin, which provides improved castability and solderability.

[0016] In one embodiment, the mass percentages of gallium, tin, silver, and gold in the alloy are each W. Ga , W Sn , W Ag and W Au Then, the platinum alloy composition satisfies the following formula: 0.45W Ag + 0.35W Au + 0.6W Sn + 0.6W In + W Ga ≦ 4.0 Preferably, 0.45W Ag + 0.35W Au + 0.6W Sn + 0.6W In + W Ga <= 3.0 Such alloys have a low freezing range.

[0017] In one embodiment, the platinum alloy composition comprises 3.0% or less, preferably 2.0% or less, more preferably 0.5% or less, and most preferably substantially no gold, by weight, which provides improved castability and solderability.

[0018] In one embodiment, the platinum alloy composition comprises no more than 2.0 wt. % copper, preferably no more than 1.0 wt. % copper. Such alloys have a narrow freezing range.

[0019] In one embodiment, the platinum alloy composition comprises no more than 2.0% gallium by weight, preferably no more than 1.5% gallium by weight, such alloys having a narrow freezing range.

[0020] In one embodiment, the platinum alloy composition has, by weight, a total weight percent of iridium, rhenium, rhodium, and ruthenium of 0.25% or more, preferably 0.5% or more, more preferably 0.75% or more, even more preferably 1.0% or more, even more preferably 1.2% or more, even more preferably 1.4% or more, and most preferably 1.5% or more. Such alloys have an increased melting point without a significant increase in the solidification range.

[0021] In one embodiment, the weight percent of cobalt, copper, iron, gallium, indium, nickel, palladium, tin, manganese, ruthenium, iridium, rhodium, gold, silver, and rhenium in the alloy is W. Co , W Cu , W Fe , W Ga , W In , W Ni , W Pd , W Sn , W Mn , W Ru , W Ir , W Rh , W Au , W Ag and W Re Then, 4.22W Ag 2 + 0.041W Au W Co + 0.122W Au W In + 1.96W Au W Ni + 1.87W Au W Sn + 0.903W Au 2 + 1.74W Co WGa + 13.4W Co IN In + 1.24W Co IN Mn + 5.04W Co IN Sn + 1.02W Co 2 + 8.97W Cu IN Fe + 1.74W Cu IN Ga + 4.38W Cu IN In + 1.16W Cu IN Mn + 0.491W Cu IN Ni + 3.69W Cu IN Sn + 0.22W Cu 2 + 1.68W Fe IN Ga + 3.31W Fe IN In - 1.26W Fe IN Mn + 5.07W Fe IN Sn + 0.199W Fe 2 + 5.35W Ga IN In + 0.086W Ga IN Mn + 3.27W Ga IN Re + 33.3W Ga IN Rh + 4.56W Ga IN Ru + 2.21W Ga IN Sn + 29.0W Ga + 8.49W Ga 2 + 9.09W In IN Mn - 0.28W In IN Ni + 15.4W In IN Rh + 0.992W In IN Ru + 11.7W In + 6.68W In 2+ 0.863W Ir 2 + 5.73W Mn W Ni - 0.02W Mn W Ru + 5.68W Mn W Sn + 18.4W Mn - 0.89W Mn 2 + 0.49W Ni W Ru + 0.186W Ni 2 + 4.48W Re W Sn + 1.15W Re 2 - 5.11W Rh W Sn + 2.04W Rh 2 + 0.885W Ru W Sn + 1.28W Ru 2 + 1.58W Sn + 9.49W Sn 2 + 11.6 ≦ 90 Preferably, 4.22W Ag 2 + 0.041W Au W Co + 0.122W Au W In + 1.96W Au W Ni + 1.87W Au W Sn + 0.903W Au 2 + 1.74W Co W Ga + 13.4W Co W In + 1.24W Co W Mn + 5.04W Co W Sn + 1.02W Co 2 + 8.97W Cu W Fe + 1.74W Cu W Ga+ 4.38W Cu IN In + 1.16W Cu IN Mn + 0.491W Cu IN Ni + 3.69W Cu IN Sn + 0.22W Cu 2 + 1.68W Fe IN Ga + 3.31W Fe IN In - 1.26W Fe IN Mn + 5.07W Fe IN Sn + 0.199W Fe 2 + 5.35W Ga IN In + 0.086W Ga IN Mn + 3.27W Ga IN Re + 33.3W Ga IN Rh + 4.56W Ga IN Ru + 2.21W Ga IN Sn + 29.0W Ga + 8.49W Ga 2 + 9.09W In IN Mn - 0.28W In IN Ni + 15.4W In IN Rh + 0.992W In IN Ru + 11.7W In + 6.68W In 2 + 0.863W Ir 2 + 5.73W Mn IN Ni - 0.02W Mn IN Ru + 5.68W Mn IN Sn + 18.4W Mn - 0.89W Mn 2 + 0.49W Ni INRu + 0.186W Ni 2 + 4.48W Re W Sn + 1.15W Re 2 - 5.11W Rh W Sn + 2.04W Rh 2 + 0.885W Ru W Sn + 1.28W Ru 2 + 1.58W Sn + 9.49W Sn 2 + 11.6 ≦ 85 More preferably, 4.22W Ag 2 + 0.041W Au W Co + 0.122W Au W In + 1.96W Au W Ni + 1.87W Au W Sn + 0.903W Au 2 + 1.74W Co W Ga + 13.4W Co W In + 1.24W Co W Mn + 5.04W Co W Sn + 1.02W Co 2 + 8.97W Cu W Fe + 1.74W Cu W Ga + 4.38W Cu W In + 1.16W Cu W Mn + 0.491W Cu W Ni + 3.69W Cu W Sn + 0.22W Cu 2 + 1.68W Fe W Ga + 3.31WFe IN In - 1.26W Fe IN Mn + 5.07W Fe IN Sn + 0.199W Fe 2 + 5.35W Ga IN In + 0.086W Ga IN Mn + 3.27W Ga IN Re + 33.3W Ga IN Rh + 4.56W Ga IN Ru + 2.21W Ga IN Sn + 29.0W Ga + 8.49W Ga 2 + 9.09W In IN Mn - 0.28W In IN Ni + 15.4W In IN Rh + 0.992W In IN Ru + 11.7W In + 6.68W In 2 + 0.863W Ir 2 + 5.73W Mn IN Ni - 0.02W Mn IN Ru + 5.68W Mn IN Sn + 18.4W Mn - 0.89W Mn 2 + 0.49W Ni IN Ru + 0.186W Ni 2 + 4.48W Re IN Sn + 1.15W Re 2 - 5.11W Rh IN Sn + 2.04W Rh 2 + 0.885W Ru IN Sn+ 1.28W Ru 2 + 1.58W Sn + 9.49W Sn 2 + 11.6 ≦ 80 Even more preferably, 4.22W Ag 2 + 0.041W Au W Co + 0.122W Au W In + 1.96W Au W Ni + 1.87W Au W Sn + 0.903W Au 2 + 1.74W Co W Ga + 13.4W Co W In + 1.24W Co W Mn + 5.04W Co W Sn + 1.02W Co 2 + 8.97W Cu W Fe + 1.74W Cu W Ga + 4.38W Cu W In + 1.16W Cu W Mn + 0.491W Cu W Ni + 3.69W Cu W Sn + 0.22W Cu 2 + 1.68W Fe W Ga + 3.31W Fe W In - 1.26W Fe W Mn + 5.07W Fe W Sn + 0.199W Fe 2 + 5.35W Ga W In + 0.086W Ga W Mn + 3.27W GaW Re + 33.3W Ga W Rh + 4.56W Ga W Ru + 2.21W Ga W Sn + 29.0W Ga + 8.49W Ga 2 + 9.09W In W Mn - 0.28W In W Ni + 15.4W In W Rh + 0.992W In W Ru + 11.7W In + 6.68W In 2 + 0.863W Ir 2 + 5.73W Mn W Ni - 0.02W Mn W Ru + 5.68W Mn W Sn + 18.4W Mn - 0.89W Mn 2 + 0.49W Ni W Ru + 0.186W Ni 2 + 4.48W Re W Sn + 1.15W Re 2 - 5.11W Rh W Sn + 2.04W Rh 2 + 0.885W Ru W Sn + 1.28W Ru 2 + 1.58W Sn + 9.49W Sn 2 + 11.6 ≦ 75 Most preferably, 4.22W Ag 2 + 0.041W Au W Co + 0.122W AuIN In + 1.96W Au IN Ni + 1.87W Au IN Sn + 0.903W Au 2 + 1.74W Co IN Ga + 13.4W Co IN In + 1.24W Co IN Mn + 5.04W Co IN Sn + 1.02W Co 2 + 8.97W Cu IN Fe + 1.74W Cu IN Ga + 4.38W Cu IN In + 1.16W Cu IN Mn + 0.491W Cu IN Ni + 3.69W Cu IN Sn + 0.22W Cu 2 + 1.68W Fe IN Ga + 3.31W Fe IN In - 1.26W Fe IN Mn + 5.07W Fe IN Sn + 0.199W Fe 2 + 5.35W Ga IN In + 0.086W Ga IN Mn + 3.27W Ga IN Re + 33.3W Ga IN Rh + 4.56W Ga IN Ru + 2.21W Ga IN Sn + 29.0W Ga + 8.49W Ga 2 + 9.09W In IN Mn - 0.28WIn W Ni + 15.4W In W Rh + 0.992W In W Ru + 11.7W In + 6.68W In 2 + 0.863W Ir 2 + 5.73W Mn W Ni - 0.02W Mn W Ru + 5.68W Mn W Sn + 18.4W Mn - 0.89W Mn 2 + 0.49W Ni W Ru + 0.186W Ni 2 + 4.48W Re W Sn + 1.15W Re 2 - 5.11W Rh W Sn + 2.04W Rh 2 + 0.885W Ru W Sn + 1.28W Ru 2 + 1.58W Sn + 9.49W Sn 2 + 11.6 ≦ 70 Such alloys have a narrow solidification range, which improves castability and solderability.

[0022] In one embodiment, the weight percent of cobalt, copper, iron, nickel, and palladium in the alloy is W. Co , W Cu , W Fe , W Ni and W Pd Then, the platinum alloy composition satisfies the following formula: W Co + W Pd + W Fe + W Ni + W Cu ≧ 1.0 Preferably, W Co + W Pd + W Fe + W Ni + W Cu ≧ 2.0 Such alloys have lower melting points without a significant increase in the freezing range.

[0023] In one embodiment, the platinum alloy comprises at least one element from the list of cobalt, palladium, iron, and copper, preferably at least 1.0% by weight of cobalt, palladium, iron, and copper, more preferably at least 1.1% by weight of cobalt, palladium, iron, and copper, providing an excellent balance of castability, solderability, and hardness.

[0024] In one embodiment, the platinum alloy composition comprises at least one element from the list of ruthenium, rhenium, iridium, and rhodium, preferably at least 0.25%, preferably at least 0.5%, more preferably at least 0.75%, more preferably at least 1.0%, more preferably at least 1.2%, and most preferably at least 1.4%, by weight of ruthenium, rhenium, iridium, and rhodium. Such alloys provide an excellent balance of castability, solderability, and hardness.

[0025] In one embodiment, the platinum alloy composition includes at least one element from the list of tin, indium, and gallium, preferably the sum of tin, indium, and gallium is 1.2% or more, more preferably 1.6% or more, by weight, and provides an excellent balance of castability, solderability, and hardness.

[0026] In one embodiment, the weight percent of cobalt, copper, iron, gallium, indium, nickel, palladium, tin, manganese, ruthenium, iridium, rhodium, gold, platinum, silver, and rhenium in the alloy is W. Co , W Cu , W Fe , W Ga , W In , WNi , W Pd , W Sn , W Mn , W Ru , W Ir , W Rh , W Au , W Pt , W Ag and W Re Then, the platinum alloy composition satisfies the following formula: 16.65 ≦ -0.10406*W Ag -0.1028*W Co - 0.1201*W Cu - 0.2113*W Fe - 0.3368*W Ga - 0.1125*W In - 0.1639*W Ni - 0.015*W Pd - 0.1959*W Sn + 17.276261 - 0.20*W Mn + 0.0678*W Ru + 0.035*W Ir + 0.045*W Rh - 0.059*W Au + 0.066*W Re Preferably, 16.70 ≦ -0.10406*W Ag -0.1028*W Co - 0.1201*W Cu - 0.2113*W Fe - 0.3368*W Ga - 0.1125*W In - 0.1639*W Ni - 0.015*W Pd - 0.1959*W Sn + 17.276261 - 0.20*W Mn + 0.0678*W Ru + 0.035*W Ir + 0.045*W Rh - 0.059*W Au + 0.066*W Re Such alloys have improved solderability while maintaining castability.

[0027] In one embodiment, the weight percent of cobalt, copper, iron, gallium, indium, nickel, palladium, tin, manganese, ruthenium, iridium, rhodium, gold, platinum, silver, and rhenium in the alloy is W. Co , W Cu , W Fe , W Ga , W In , W Ni , W Pd , W Sn , W Mn , W Ru , W Ir , W Rh , W Au , W Pt , W Ag and W Re Then, the platinum alloy composition satisfies the following formula: -0.10406*W Ag -0.1028*W Co - 0.1201*W Cu - 0.2113*W Fe - 0.3368*W Ga - 0.1125*W In - 0.1639*W Ni - 0.015*W Pd - 0.1959*W Sn + 17.276261 - 0.20*W Mn + 0.0678*W Ru + 0.035*W Ir + 0.045*W Rh - 0.059*W Au + 0.066*W Re ≦17.00 Such alloys have improved castability.

[0028] In one embodiment, the platinum alloy composition comprises platinum, indium, ruthenium, tin, and iron. Such alloys provide an excellent balance of castability, solderability, and hardness.

[0029] In one embodiment, the platinum alloy composition comprises platinum, ruthenium, iron, and gallium. Such alloys provide an excellent balance of castability, solderability, and hardness.

[0030] In one embodiment, the platinum alloy composition contains 0.5 to 2.0 wt % indium, which provides a low melting point and high hardness without significantly increasing the solidification range.

[0031] In one embodiment, the platinum alloy composition comprises 1.0 to 2.5 wt % ruthenium, which provides increased hardness without excessively increasing cost.

[0032] In one embodiment, the platinum alloy composition comprises 0.2 to 1.0 wt. % tin, which provides a low melting point and high hardness without significantly increasing the solidification range.

[0033] In one embodiment, the platinum alloy composition contains 0.5 to 1.75 mass % of iron. Such an alloy has a low melting point, high hardness, and a low risk of ferromagnetism, while being low cost.

[0034] In one embodiment, the platinum alloy composition comprises 0.5 to 1.75 wt.% gallium, which provides a low melting point and high hardness without significantly increasing the solidification range.

[0035] In one embodiment, the platinum alloy composition has iron at most 4.0%, preferably at most 2.5%, more preferably at most 2.25%, more preferably at most 2.0%, more preferably at most 1.75%, more preferably at most 1.75%, by weight, such alloys have a low risk of ferromagnetism.

[0036] In one embodiment, the platinum alloy composition comprises 2.0 wt. % or less of cobalt, preferably 1.0 wt. % or less of cobalt, and more preferably is substantially free of cobalt, resulting in a reduced risk of ferromagnetism and reduced allergy concerns.

[0037] In one embodiment, the platinum alloy composition comprises 3.0% by weight or less of palladium, preferably 2.5% by weight or less, more preferably 2.0% by weight or less, more preferably 1.5% by weight or less, more preferably 0.1% by weight or less of palladium, and most preferably the platinum alloy composition is substantially free of palladium, resulting in lower cost alloys.

[0038] In one embodiment, the platinum alloy composition comprises no more than 3.0 wt. % manganese, preferably no more than 2.5 wt. % manganese, more preferably no more than 0.1 wt. % manganese, and most preferably the platinum alloy composition is substantially free of manganese, resulting in a reduced risk of volatilization.

[0039] In one embodiment, the platinum alloy composition contains at least 0.5 wt. % indium, preferably at least 0.75 wt. % indium, and more preferably at least 1.0 wt. % indium, which provides improved hardness.

[0040] In one embodiment, the platinum alloy composition comprises 0.5 wt.% or more, preferably 0.8 wt.% or more, more preferably 1.0 wt.% or more, more preferably 1.2 wt.% or more of ruthenium, such alloys provide higher hardness at lower cost.

[0041] In one embodiment, the platinum alloy composition comprises 0.2% or more tin by weight, which provides an increased hardness.

[0042] In one embodiment, the platinum alloy composition comprises at least 0.25 wt. % iron, preferably at least 0.5 wt. % iron, more preferably at least 0.75 wt. % iron, and more preferably at least 1.0 wt. Such alloys provide increased hardness without significantly increasing the solidification range.

[0043] In one embodiment, the platinum alloy composition contains at least 0.5 wt. % gallium, preferably at least 0.75 wt. % gallium, and more preferably at least 1.0 wt. % gallium, resulting in a low melting point and high hardness.

[0044] In one embodiment, the platinum alloy composition contains 1.5 wt. % or less of the total of cobalt, palladium, iron, and copper, and the hardness of such an alloy is improved.

[0045] In one embodiment, the platinum alloy composition has a total of ruthenium, rhenium, iridium, and rhodium of 2.7% by weight or less, more preferably 2.6% by weight or less, resulting in a narrow freezing range.

[0046] In one embodiment, the platinum alloy composition contains 2.7% by weight or less of tin, indium, and gallium, and more preferably 2.5% by weight or less of the total of tin, indium, and gallium. Such alloys have improved castability and solderability.

[0047] In one embodiment, the platinum alloy composition comprises, in weight percent, 1.2±0.2% iron, 1.5±0.2% indium, 1.5±0.2% ruthenium, 0.6% tin, and the balance (optionally at least 95%) being platinum and unavoidable impurities. Such alloys exhibit excellent castability, solderability, and hardness.

[0048] In one embodiment, the platinum alloy composition comprises, by weight, 1.2±0.2% iron, 1.2±0.2% gallium, 2.4±0.2% ruthenium, and the balance (optionally at least 95%) platinum and unavoidable impurities. Such alloys exhibit excellent castability, solderability, and hardness.

[0049] In one embodiment, the platinum alloy composition comprises, in weight percent, 1.2±0.2% iron, 1.5±0.2% indium, 1.5±0.2% ruthenium, 0.6% tin, and the balance (optionally at least 95%) being platinum and unavoidable impurities. Such alloys exhibit excellent castability, solderability, and hardness.

[0050] The term "comprising" is used herein to indicate that a composition is 100% and excludes the presence of additional components to make the percentage 100%.

[0051] The present invention will now be more fully described, by way of example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0052] [Figure 1] FIG. 1 shows the porosity measured on cast samples of several examples of the present invention and comparative examples. [Figure 2] FIG. 2 shows the defects in the comparative castings in contrast to the absence of defects in the inventive examples. [Figure 3] FIG. 3 shows the solderability of the comparative example and the example of the present invention. [Figure 4] Figure 4 shows silica inclusions present on the fracture surface of Comparative Example 14. The presence of silica indicates poor castability of the alloy. [Figure 5] Figure 5 compares the trees of the example of the present invention and the tree of the comparative example, which were cast under the same conditions with the same shape. Unlike the comparative example, the example of the present invention shows excellent form filling ability. [Figure 6] Figure 6 shows an SEM EDX line scan perpendicular to several secondary dendritic arms in the as-cast state of a casting made in the comparative example, which shows severe segregation of Sn and In in the interdendritic spaces, which is usually associated with significant shrinkage porosity. DETAILED DESCRIPTION OF THE INVENTION

[0053] The hardness of platinum alloys is derived from two chemically determined mechanisms. I. Solid Solution Hardening - achieved by solute atoms distorting the platinum metal lattice due to differences in atomic radii. II. Precipitation Hardening - can occur when elements outside the solubility limits of platinum secondary phases are added. These phases increase the alloy's resistance to deformation.

[0054] While it is desirable to add elements to platinum to increase hardness, the addition of alloying elements can adversely affect the castability of the material as follows. i. Increased Melting Point - Adding certain elements to pure Pt increases the overall melting point of the alloy. A higher melting point increases the risk of molten metal attacking and reacting with the crucible and mold materials during the casting process. This increases the risk of casting defects and reduces the surface quality of the casting. Because crucibles are typically made of silica, which has a melting point close to that of pure platinum, molten platinum alloys cannot be heated above 1850°C before casting. Otherwise, the molten silica may contaminate the melt. For platinum alloys with high melting points, this restriction can reduce the fluidity of the alloy during casting, as the metal may solidify before the mold is completely filled. ii. Casting Microporosity - During the later stages of solidification during casting, liquid metal becomes trapped between the dendritic arms. The trapped liquid shrinks, resulting in the formation of porosity. The porosity is often visible and makes the cast jewelry item unacceptable in appearance. The degree of shrinkage and resulting porosity increases with the solidification range of the alloy, as thermal contraction becomes significant before the alloy is completely solidified. Alloying additives that cause significant volume changes in the liquid alloy metal are known to tend to increase microporosity. iii. Hot Tearing - Alloys with very wide freezing ranges are adversely affected by a combination of increased thermal stresses due to temperature reduction and limited mechanical strength due to liquid films between the growing grains. The combination of increased stresses and reduced mechanical strength can lead to metal cracking at high temperatures, forcing the part to be scrapped.

[0055] The alloys described in WO2022074363A1 were found to have low melting points, resulting in high hardness and good castability, while solderability was only a secondary consideration and the performance of many alloys depended heavily on the addition of nickel, a known allergy-causing element that was therefore increasingly undesirable in the jewellery industry.

[0056] In the present invention, acceptable castability is achieved by optimizing several material properties reflected in the figures of merit. These include a medium melting point index (which reduces the risk of silica inclusions appearing and improves castability) and a low freezing range index (which reduces porosity during casting and improves solderability). In other words, the values ​​of the melting point index and freezing range index are related to the risk of typical casting defects such as shrinkage porosity, inclusion formation, poor surface finish, and poor form filling.

[0057] By increasing the hardness index to at least 130, improved hardness improves wear resistance and jewelry setting capabilities, and excellent mechanical properties are achieved. The alloys of the present invention allow for tailorable hardness, achieving hardnesses of 150 HV or greater. This offers the possibility to trade off ease of formability for improved wear resistance, depending on the application.

[0058] Excellent solderability is achieved by avoiding the formation of low-melting-point regions in the as-cast state. These regions can be avoided by increasing the melting point of the alloy to a level higher than that suggested in WO2022074363A1 and by maintaining a narrow freezing range (both predicted using a figure of merit). This requirement is traded off with one of the requirements for good castability, a low alloy melting point. Therefore, an intermediate melting point is desirable, balancing the castability requirement (reduced silica inclusions) with solderability (avoidance of low-melting-point regions). While the freezing range can be minimized to improve both castability and solderability, this can be used to compensate for the fact that the melting point cannot be made as low as suggested in WO2022074363A1 to meet the solderability requirement.

[0059] A model-based approach is described that can be used to identify new platinum alloys that address at least some of the problems mentioned above. The approach utilizes a computational materials modeling framework combined with machine learning to estimate design-relevant properties across a wide compositional range. In principle, this alloy design tool can solve the so-called inverse problem, i.e., identify the optimal alloy composition that best satisfies a specified set of design constraints.

[0060] The first step in the design process is to define the table of elements and the associated upper and lower compositional limits. The present invention considers the compositional limits for each element, referred to as the "alloy design space." These compositional limits are detailed in Table 1. Table 1 shows the compositional ranges claimed by the present invention, as determined using the ABD method. These limits were selected by the inventors based on the explanations provided below. While some insights are derived from metallurgical experience, other insights, such as the impact on melting point, the impact on castability of platinum alloys, and the impact on the presence of inclusions, were established by the inventors based on thermodynamic calculations, described below, over a broader compositional range than those provided in Table 1. [Table 1]

[0061] It is relatively easy to increase the hardness of pure platinum by adding alloying elements. However, doing so simultaneously does not guarantee good castability and solderability. Among other things, it is necessary to limit the increase in the alloy's solidification range caused by the addition of alloying elements, avoid excessive precipitation of intermetallic phases during the final stages of solidification, and avoid slag formation caused by reactive elements. All of these mechanisms can lead to casting defects. Some elements are suitable for satisfying at least some of these conflicting requirements, but must be limited for other reasons. With this in mind, the elements and their ranges in Table 1 were selected for the following reasons:

[0062] The minimum amount of platinum in the alloy was set at 95.0% by weight, which is the common hallmarking standard for platinum alloys in jewelry applications. In some cultures, the iridium content of a platinum alloy is considered to be equivalent to platinum (i.e., the platinum content of the alloy is equal to the sum of platinum and iridium).

[0063] Cobalt, copper, iron, manganese, and palladium: All of these elements lower the melting point of pure platinum and increase its hardness through a combination of solid solution and precipitation strengthening. Furthermore, because these elements are relatively unreactive, these alloys containing platinum can be repeatedly remelted without significant changes in alloy composition due to reactions with the atmosphere, crucible walls, or mold walls. The amounts of cobalt, manganese, and iron are limited in Table 1 because their addition beyond the ranges specified in Table 1 is unlikely to provide additional benefits. This is because the melting point may not be significantly lowered, excessive intermetallic phases may form during cooling of the casting, and the freezing range may increase. Furthermore, high cobalt content can make the alloy ferromagnetic, causing manufacturing problems. Similarly, iron can cause undesirable ferromagnetism and, at high temperatures, can form intermetallic phases that adversely affect ductility. Manganese, on the other hand, can evaporate from the melt, causing processing problems. Each of these elements, independently of the others, may be limited to 5.0% by weight or less. Copper is limited to 3.0% by weight or less because it has been found to have a relatively large effect on extending the solidification range compared to other elements in the group, while imparting relatively little hardness. These effects are undesirable. Therefore, copper is preferably limited to 2.5% by weight or less, more preferably 2.0% by weight or less, even more preferably 1.5% by weight or less, most preferably 1.0% by weight or less, and even more preferably 0.5% by weight or less. Of these elements, iron is particularly useful because it extends the solidification range less than copper and does not have the drawbacks of the other elements (palladium is expensive, manganese tends to volatilize during processing, and cobalt imparts ferromagnetism in very small amounts, despite allergy concerns). Therefore, iron is preferably present in an amount of 0.25% by weight or more, preferably 0.5% by weight or more, and even more preferably 0.75% by weight or more. The best-performing alloys may contain 1.0% by weight or more of iron. On the other hand, iron is preferably limited to 4.0 mass % or less, further 3.0 mass % or less, further 2.5 mass % or less, further 2.25 mass % or less, further 2.0 mass % or less, and further 1.75 mass % or less.This allows the alloy to contain more of other elements that may have a stronger beneficial effect than iron, or may have a different beneficial effect. Cobalt is limited to 2.5% by weight or less because it can make the alloy ferromagnetic, causing manufacturing problems, and there are allergy concerns. For this reason, cobalt is desirably limited to 2.0%, 1.5%, or even 1.0% by weight or less. In one embodiment, cobalt is limited to 0.5%, 0.1%, or even substantially absent by weight. Palladium is limited to 5.0% by weight or less due to its high cost. Preferably, palladium is limited to 4.0%, 3.0%, 1.5%, 1.0%, or even 0.1%, by weight or less, to keep the cost of the alloy low. In one embodiment, palladium is present in an amount of 2.5% by weight or less (or 2.0% by weight or less) to take advantage of its melting point lowering and hardness increasing effects without unduly increasing the cost of the alloy. In one embodiment, palladium is absent to reduce costs. Manganese is limited to 5.0% by weight or less because it is prone to volatilization during processing. To avoid volatilization, manganese is preferably limited to 4.0% by weight or less, more preferably 3.0% by weight or less, or 2.5% by weight or less, or 2.0% by weight or less, even 1.5% by weight or less, or even 0.1% by weight or less. In one embodiment, palladium is absent. In one embodiment, at least one element selected from the group consisting of cobalt, palladium, iron, and copper is present to achieve a balance of hardness, solidification range, and melting point. In all of the following examples, the sum of cobalt, palladium, iron, and copper is preferably at least 1.0% by weight. In one embodiment, the sum of cobalt, palladium, iron, and copper is at least 1.5% by weight.

[0064] Gold and silver: Neither element is reactive; therefore, these alloys with platinum can be repeatedly remelted without significant changes in alloy composition due to reactions with the atmosphere, crucible walls, or mold walls. At low concentrations, both slightly lower the melting point and increase the hardness of platinum alloys. At high concentrations, however, both extend the solidification range of Pt alloys, adversely affecting solderability and castability. Therefore, gold and silver are limited to 5.0% by weight or less, more preferably 4.5% by weight or less, or 4.0% by weight or less. In one embodiment, gold and silver are limited to 3.0% by weight and 1.5% by weight, respectively, more preferably 2.5% by weight and 1.5% by weight, respectively, and even more preferably 2.0% by weight and 1.0% by weight, respectively. To avoid extending the solidification range, gold and / or silver may be limited to 0.5% by weight or less. Gold and silver are difficult to separate from platinum, and their presence in the alloy may hinder recyclability. Therefore, most preferably, gold and silver are not included in the alloy.

[0065] Rhodium, iridium, ruthenium, and rhenium: These elements are non-reactive; i.e., these alloys with platinum can be repeatedly remelted without significant changes in alloy composition due to reactions with the atmosphere, crucible walls, or mold walls. They also slightly increase hardness through solid-solution strengthening. However, excessive addition of iridium and / or rhodium and / or rhenium significantly increases the cost of the alloy and adversely affects the alloy's castability by increasing the melting point. Therefore, the amounts of rhodium, iridium, and rhenium are limited to 5.0% by weight or less, preferably 4.0% by weight or less, more preferably 3.5% by weight or less, even more preferably 3.0% by weight or less, and most preferably 2.5% by weight or less or 2.0% by weight or less. Rhodium, iridium, rhenium, and ruthenium are difficult to separate from platinum, and their presence in the alloy may hinder recyclability. Therefore, in one embodiment, one or more of rhodium, iridium, rhenium, and ruthenium are absent from the alloy. Of these elements, Ru is particularly useful because it is the least expensive and at the same time does not significantly increase the melting point and freezing range. Thus, in one embodiment, Ru is present in an amount of 0.5 wt.% or more, more preferably 0.8 wt.%, most preferably 1.0 wt.% or more, or even 1.2 wt.% or more.

[0066] Tin, indium, and gallium: All of these elements significantly lower the melting point of pure platinum and significantly increase its hardness through solid solution strengthening and / or precipitation strengthening. However, excessive addition of these elements can significantly increase the proportion of intermetallic phases or significantly increase the solidification range during cooling of the casting, potentially adversely affecting solderability and castability. Therefore, the amount of indium is limited to 3.0% by weight or less (preferably 2.5% by weight or less, or 2.0% by weight or less, most preferably 1.7% by weight or less), and the amount of tin is limited to 3.0% by weight or less (preferably 2.5% by weight or less, or 2.0% by weight or less, even more preferably 1.5% by weight or less, most preferably 1.0% by weight or less). The amount of gallium is limited to 2.75% by weight or less (preferably 2.25% by weight or less, or 2.0% by weight or less, or 1.75% by weight or less, or 1.5% by weight or less). Without these elements, it would be difficult to achieve high hardness in an alloy containing 95% platinum by weight. That is, the total amount of tin, indium, and gallium contained in the alloy is preferably 0.4% by mass or more, or 0.4% by mass or more, or even 0.6% by mass or more. For the same reason, as in Examples 1 and 2, the alloy preferably contains 0.2% by mass or more of tin and / or 0.5% by mass or more of gallium. Examples 1 and 2 demonstrate the benefits of at least 0.5% by mass of indium, which is preferred. 0.75% by mass or more of indium and / or gallium is even more preferred, and 1.0% by mass or more of indium and / or gallium is even more preferred.

[0067] In addition to the ranges listed in Table 1, the alloys of the present invention may contain small amounts of other elements as unavoidable impurities. These elements include titanium, aluminum, chromium, zinc, yttrium, hafnium, zirconium, vanadium, niobium, tantalum, molybdenum, tungsten, nickel, scandium, lanthanides, and germanium. The total amount of unavoidable impurities is 1.0% or less, by weight, of the alloy, and preferably 0.5% or less, by weight, of the alloy. Each type of impurity element is present at a level of 0.5% or less, by weight, preferably 0.25% or less, or even 0.1% or less. Many of these elements are highly reactive and may reduce castability and / or promote the formation of intermetallic precipitates. The formation of large amounts of intermetallic precipitates can lead to embrittlement and cracking at grain boundaries, which reduces ductility. In one embodiment, aluminum and / or chromium and / or titanium may be substantially absent.

[0068] The second step is based on thermodynamic calculations to calculate the phase diagrams and thermodynamic properties of specific alloy compositions, often referred to as the CALculation of PHAse Diagrams method.

[0069] The third step involves identifying alloy compositions that have the desired properties calculated in the second step. Candidate alloys within the investigated compositional range were selected for their good castability, good solderability, and good mechanical properties. These properties are reflected in various figures of merit, as described below.

[0070] The merit index indicating castability is as follows:

[0071] Melting Point Index: Reflects the melting point of an alloy. Melting point can be derived directly from thermodynamic calculations. Lowering the melting point suppresses metal-mold reactions, thereby reducing gas porosity and improving surface finish. Therefore, generally, lower melting point index values ​​are better. Lowering the melting point allows for a higher superheat compared to higher melting points. Higher superheat increases fluidity and improves the alloy's forming and filling properties. On the other hand, to ensure good solderability, the melting point of the alloy must be significantly higher than that of the solder material, imposing a lower melting point limit on the use of common solder materials. These tend to contain approximately 90% Pt by weight, with the remainder typically composed of elements such as Ga, In, and Ag that help lower the melting point below 1500°C, sometimes down to 950°C. Because the thermodynamic calculations for melting point are too complex to use here, a simpler figure of merit was derived to reflect the change in melting point as a function of alloy composition. Melting Point Index = -0.10406*W Ag -0.1028*W Co - 0.1201*W Cu - 0.2113*W Fe - 0.3368*W Ga - 0.1125*W In - 0.1639*W Ni - 0.015*W Pd - 0.1959*W Sn + 17.276261 - 0.20*W Mn + 0.0678*W Ru + 0.035*W Ir + 0.045*W Rh - 0.059*W Au + 0.066*W Re

[0072] The combination of a melting point index greater than 16.6 and a lower limit of the freezing range index ensures good castability and good solderability. Preferably, the melting point index is 16.65 or greater, more preferably 16.70 or greater. A melting point index of 17.1 or less ensures sufficient castability. Preferably, the melting point index is 17.00 or less.

[0073] Freezing Range Index: The temperature range over which an alloy will solidify if complete thermodynamic equilibrium is maintained throughout solidification. That is, assuming thermodynamic equilibrium, the freezing range is the temperature range between the temperature at which a liquid first appears and the temperature at which a solid last melts, assuming thermodynamic equilibrium. This range can be derived directly from thermodynamic calculations. In general, a wider range leads to excessive elemental segregation in the as-cast microstructure, resulting in reduced mechanical properties of the casting, an increased risk of hot tearing, increased porosity, and poor solderability. Because the thermodynamic calculations used to derive the freezing range are too complex to use here, a simpler figure of merit was instead derived to reflect changes in the freezing range. Coagulation range index = 4.22W Ag 2 + 0.041W Au W Co + 0.122W Au W In + 1.96W Au W Ni + 1.87W Au W Sn + 0.903W Au 2 + 1.74W Co W Ga + 13.4W Co W In + 1.24W Co W Mn + 5.04W Co W Sn + 1.02W Co 2 + 8.97W Cu W Fe + 1.74W Cu W Ga + 4.38W Cu W In + 1.16W Cu W Mn + 0.491W Cu W Ni + 3.69W Cu W Sn + 0.22W Cu 2 + 1.68W Fe W Ga + 3.31W Fe WIn - 1.26W Fe IN Mn + 5.07W Fe IN Sn + 0.199W Fe 2 + 5.35W Ga IN In + 0.086W Ga IN Mn + 3.27W Ga IN Re + 33.3W Ga IN Rh + 4.56W Ga IN Ru + 2.21W Ga IN Sn + 29.0W Ga + 8.49W Ga 2 + 9.09W In IN Mn - 0.28W In IN Ni + 15.4W In IN Rh + 0.992W In IN Ru + 11.7W In + 6.68W In 2 + 0.863W Ir 2 + 5.73W Mn IN Ni - 0.02W Mn IN Ru + 5.68W Mn IN Sn + 18.4W Mn - 0.89W Mn 2 + 0.49W Ni IN Ru + 0.186W Ni 2 + 4.48W Re IN Sn + 1.15W Re 2 - 5.11W Rh IN Sn + 2.04W Rh 2 + 0.885W Ru IN Sn + 1.28WRu 2 + 1.58W Sn + 9.49W Sn 2 + 11.6

[0074] As will be described below with reference to FIG. 1, it has been experimentally determined that a solidification range index of 100 or less results in good casting characteristics. A solidification range index of 90 or less is preferred because it results in even lower porosity. A solidification range index of 85.0 or less is preferred, and Examples 1-4, 6, 8, 9, 12, 13, 15, and 17-31 all achieve this and are therefore among the most preferred examples with respect to this characteristic. A solidification range of 80.0 or less is even more preferred. The alloys with the best low porosity and solderability have a solidification range index of 75 or less, or 70 or less, which are preferred.

[0075] The inventors have also discovered that ensuring the following formula is met helps produce alloys with a lower freezing range: Ag + 0.35W Au + 0.6W Sn + 0.6W In + W Ga ≦ 4.0 preferably 0.45W Ag + 0.35W Au + 0.6W Sn + 0.6W In + W Ga <= 3.0

[0076] Hardness Index: Indicates the hardness of an as-cast alloy based on its elemental composition. The index is based on a statistical analysis of experimental hardness data for a wide range of platinum alloys available in the literature. Hardness values ​​above approximately 220 HV may be undesirable in certain applications due to potential adverse effects on jewelry settings, but higher values ​​are generally better. Hardness index = 60 + W Pd *2.5 + W Rh *3.4 + W Ir *6.455 + W Au *11.93 + W Ru*13.241 + W Cu *14.328 + W Re *16.6 + W Ni *16.9 + W Mn *18.48 + W Co *18.69 + W Fe *21.879 + W In *29 + W Sn *28.207 + W Ga *42.379 + W Ag *9.0

[0077] The alloys of the present invention have a hardness index of 130 or greater. The lower limit of hardness ensures sufficient wear resistance. Even higher hardness is preferred, with the alloys preferably having a hardness index of 140 or greater, and more preferably 150 or greater. Examples 1-4, 6, 10, 12, 14, 15, and 17-31 all have a hardness index of 150 or greater, making them among the most preferred examples for this characteristic. The hardest alloys possible, while still meeting other criteria, have a hardness index of 160 or greater, or even 170 or greater.

[0078] Thus, in Examples 1 to 4, 6, 12, 15, and 17 to 31, the chemical composition is gold 0.0 to 5.0, cobalt 0.0 to 2.5, copper 0.0 to 3.0, iron 0.0 to 5.0, gallium 0.0 to 2.75, indium 0.0 to 3.0, iridium 0.0 to 5.0, manganese 0.0 to 5.0, palladium 0.0 to 5.0, rhenium 0.0 to 5.0, rhodium 0.0 to 5.0, ruthenium 0.0 to 5.0, tin 0.0 to 3.0, silver 0.0 to 5.0, the total of platinum and iridium is 95.0 or more, and unavoidable impurities. While maintaining the melting point index in the desired range (16.6 to 17.1), a good balance is achieved between hardness (hardness index 150 or more) and solidification range (solidification range 85.0 or less).

[0079] Thus, the alloys of the present invention are characterized by a combination of a narrow solidification range and an intermediate melting point, which provides good castability, solderability, and sufficient hardness. The alloying elements can be identified in three different groups: those that improve castability by lowering the melting point and not excessively widening the solidification range (Co, Fe, Pd, Cu), those that improve solderability by raising the melting point and not excessively widening the solidification range (Ru, Re, Ir, Rh), and those that increase hardness but widen the solidification range, thereby reducing castability and solderability (Sn, In, Ga).

[0080] Ideally, the alloys of the present invention should contain at least one element from each of the above groups. In particular, W Co + W Pd + W Fe + W Cu ≧ 1.0, preferably W Co + W Pd + W Fe + W Cu Achieving a W > 1.1 allows for a sufficient reduction in melting point without excessively widening the freezing range. Co + W Pd + W Fe + W Cu By satisfying W, the coagulation range is prevented from becoming too high. Ru + W Re + W Ir + W Rh ≧0.25, the melting point is increased without significant sacrifice in terms of widening the freezing range. Ru + W Re + W Ir + W Rh Further increasing W (e.g., ≧0.5 or ≧0.75 or ≧1.0, or even ≧1.2, preferably ≧1.4, and most preferably ≧1.5) increases the melting point without significantly widening the freezing range. In one embodiment, 2.7 ≧ W Ru + W Re + W Ir + W Rh , preferably 2.6 ≧ W Ru + WRe + W Ir + W Rh By so doing, excessive widening of the freezing range is avoided. To achieve the intermediate melting point index required by the present invention, it is preferred that one element from each of these two groups be present, i.e., at least one element from the group of Co, Fe, Pd, and Cu, and at least one element from the group of Ru, Re, Ir, and Rh. The most preferred elements of these two groups are Fe and Ru, since they both widen the freezing range the least among the elements of their respective groups. Furthermore, Ru does not significantly increase the melting point compared to the other elements of its group. Preferably, the alloy contains W. Sn + W In + W Ga By achieving a W > 0.25, the desired hardness is achieved, but at the expense of castability and solderability. Preferably, to achieve the desired hardness level, W Sn + W In + W Ga ≧ 0.5 or W Sn + W In + W Ga ≧0.75. Sn + W In + W Ga ≧ 1.2 or W Sn + W In + W Ga ≧1.6. In one embodiment, 2.7≧W to avoid poor castability and / or solderability. Sn + W In + W Ga , preferably 2.5 ≧ W Sn + W In + W Ga Preferably, the alloy contains at least one element from each of the three groups.

[0081] Examples and Comparative Examples Table 2 lists comparative examples and examples of the present invention. Comparative examples 1 to 5 are custom alloys prototyped in-house, while the rest are alloys commonly used in jewelry. [Table 2] JPEG2026507317000004.jpg101170

[0082] Figure 1 shows the porosity measured for cast samples of several examples and comparative examples. Due to the limited solidification range, the example alloys exhibit significantly lower porosity. All alloys were cast into the same tree under the same conditions (superheat, pour time and atmosphere, and mold geometry, material, and temperature). Optical metallography and image processing were used to measure porosity at multiple fixed locations on the cast tree. Some examples have multiple entries because the porosity of multiple samples was analyzed.

[0083] Figure 2 shows that, unlike the alloys of the present invention, several comparative examples suffered from the adverse effects of silica inclusions, primarily due to the alloys' high melting points. When the temperature of the metal exceeds the melting point of silica in the crucible / mold, silica erodes from the walls and is incorporated into the casting. The resulting inclusions accumulate at the grain boundaries, weakening them and causing extreme embrittlement. This results in casting defects and leads to the casting being scrapped. In comparative examples 4 and 14, embrittlement was readily apparent from large intergranular cracks. In contrast, no cracking was observed in example 3.

[0084] FIG. 3 shows the joint quality of several platinum alloy rings fabricated using a high-melting point (approximately 1700°C) solder (Stuller welding solder). Such solders are commonly referred to in jewelry as "refractory" solders because they melt more slowly, as opposed to "easy-melt" solders with lower melting points. Refractory solders are preferred in manufacturing because they allow for later solder repair. Refractory solders are typically repaired with simple soldering. If a part were fabricated using easy-melt solder instead, the solder could melt and destroy the part during a later repair attempt. Examples 1 and 3 of the present invention combine a relatively high melting point index with a narrow freezing range index, resulting in clean joints with minimal solder penetration into nearby ring surfaces. Such joints are easily machined to the original shape of the part. Comparative Examples 13, 15, and 17, on the other hand, have significantly lower melting point indices, resulting in ring distortion that is much more difficult to repair.

[0085] Figure 4 shows silica inclusions present on the fracture surface of Comparative Example 14. See the legend to Figure 2 for a detailed explanation.

[0086] Figure 5 shows the castings of Example 1 and Comparative Example 14, both of which have the same shape. Both molds were prepared in the same way, and in both cases the melt was preheated to the same temperature. The molds were provided with three mesh cavities so that the filling ability of the alloys could be evaluated. Example 1 shows a much larger mesh structure due to its lower melting point. The lower melting point allows the alloy to remain fluid longer, allowing for better filling of complex shapes. In contrast, Comparative Example 14 exhibited poor forming and filling characteristics.

[0087] Figure 6 shows an SEM EDX line scan perpendicular to several secondary dendritic arms in the as-cast state of a casting made in Comparative Example 16. This shows severe segregation of Sn and In in the interdendritic spaces, which is usually associated with significant shrinkage porosity. Note that the Sn and In signals have been combined into one because the EDX spectra of these two elements overlap and are difficult to accurately deconvolute.

[0088] Thus, Examples 1, 2, and 3 demonstrate an excellent combination of desirable properties. These examples demonstrate that alloys containing 0.5% to 2.0% by weight of indium (Examples 1 and 2) are preferred. Alternatively (Example 3) or additionally (Examples 1 and 2), alloys containing 1.0 to 2.5% by weight of ruthenium are preferred. Examples 1 and 2 demonstrate that the inclusion of 0.2 to 1.0% by weight of tin is also beneficial. Examples 1, 2, and 3 all have iron amounts of 0.5 to 1.75% by weight, which are even more advantageous. Example 3 demonstrates that the addition of 0.5 to 1.75% by weight of gallium, for example, as a replacement for or in addition to indium and / or tin, is beneficial.

[0089] In one embodiment, the alloy comprises, in mass percent, 1.2±0.2% iron, 1.5±0.2% indium, 1.5±0.2% ruthenium, 0.6% tin, and the remainder (optionally at least 95%) being platinum and unavoidable impurities.

[0090] In one embodiment, the alloy comprises, in weight percent, 1.2±0.2% iron, 1.2±0.2% gallium, 2.4±0.2% ruthenium, and the balance (optionally at least 95%) being platinum and unavoidable impurities.

[0091] In one embodiment, the alloy comprises, in mass percent, 1.2±0.2% iron, 1.5±0.2% indium, 1.5±0.2% ruthenium, 0.6% tin, and the remainder (optionally at least 95%) being platinum and unavoidable impurities.

[0092] The preferred ranges of alloys are shown in Table 3 below, with the preferred examples covering all of Examples 1-4, 6, 12, 15 and 17-31, and the more preferred range covering all of Examples 1-3. [Table 3]

Claims

1. 0.0 to 5.0 mass% gold, 0.0 to 2.5 mass% cobalt, 0.0 to 3.0 mass% copper, 0.0 to 5.0 mass% iron, 0.0 to 2.75 mass% gallium, 0.0 to 3.0 mass% indium, 0.0 to 5.0 mass% iridium, 0.0 to 5.0 mass% manganese, 0.0 to 5.0 mass% palladium, 0.0 to 5.0 mass% rhenium, 0.0 to 5.0 mass% rhodium, 0.0 to 5.0 mass% arsenic ... A platinum alloy composition containing 0 to 5.0 mass% ruthenium, 0.0 to 3.0 mass% tin, 0.0 to 5.0 mass% silver, and a total of 95.0 mass% or more of platinum and iridium, and containing unavoidable impurities, wherein the mass% of cobalt, copper, iron, gallium, indium, nickel, palladium, tin, rhodium, iridium, gold, ruthenium, rhenium, silver, and manganese contained in the alloy are respectively W Co , W Cu , W Fe , W Ga , W In , W Ni , W Pd , W Sn , W Rh , W Ir , W Au , W Ru , W Re , W Ag and W Mn Then, 60+W Pd *2.5 + W Rh *3.4 + W Ir *6.455 + W Au *11.93 + W Ru *13.241 + W Cu *14.328 + W Re *16.6 + W Ni *16.9 + W Mn *18.48 + W Co *18.69 + W Fe *21.879 + W In *29 + W Sn *28.207 + W Ga *42.379 + W Ag *9.0 ≧ 130 is satisfied. The mass percentages of cobalt, copper, iron, gallium, indium, nickel, palladium, tin, manganese, ruthenium, iridium, rhodium, gold, platinum, silver, and rhenium contained in the alloy are respectively W Co , W Cu , W Fe , W Ga , W In , W Ni , W Pd , W Sn , W Mn , W Ru , W Ir , W Rh , W Au , W Pt , W Ag and W Re Then, 16.6 < -0.10406*W Ag -0.1028*W Co - 0.1201*W Cu - 0.2113*W Fe - 0.3368*W Ga - 0.1125*W In - 0.1639*W Ni - 0.015*W Pd - 0.1959*W Sn + 17.276261 - 0.20*W Mn + 0.0678*W Ru + 0.035*W Ir + 0.045*W Rh - 0.059*W Au + 0.066*W Re ≦ 17.1, The mass percentages of cobalt, copper, iron, gallium, indium, nickel, palladium, tin, manganese, ruthenium, iridium, rhodium, gold, silver, and rhenium contained in the alloy are respectively W Co , W Cu , W Fe , W Ga , W In , W Ni , W Pd , W Sn , W Mn , W Ru , W Ir , W Rh , W Au , W Ag and W Re Then, 4.22W Ag 2 + 0.041W Au IN Co + 0.122W Au IN In + 1.96W Au IN Ni + 1.87W Au IN Sn + 0.903W Au 2 + 1.74W Co IN Ga + 13.4W Co IN In + 1.24W Co IN Mn + 5.04W Co IN Sn + 1.02W Co 2 + 8.97W Cu IN Fe + 1.74W Cu IN Ga + 4.38W Cu IN In + 1.16W Cu IN Mn + 0.491W Cu IN Ni + 3.69W Cu IN Sn + 0.22W Cu 2 + 1.68W Fe IN Ga + 3.31W Fe IN In - 1.26W Fe IN Mn + 5.07W Fe IN Sn + 0.199W Fe 2 + 5.35W Ga IN In + 0.086W Ga IN Mn + 3.27W Ga IN Re + 33.3W Ga IN Rh + 4.56W Ga IN Ru + 2.21W Ga IN Sn + 29.0W Ga + 8.49W Ga 2 + 9.09W In W Mn - 0.28W In W Ni + 15.4W In W Rh + 0.992W In W Ru + 11.7W In + 6.68W In 2 + 0.863W Ir 2 + 5.73W Mn W Ni - 0.02W Mn W Ru + 5.68W Mn W Sn + 18.4W Mn - 0.89W Mn 2 + 0.49W Ni W Ru + 0.186W Ni 2 + 4.48W Re W Sn + 1.15W Re 2 - 5.11W Rh W Sn + 2.04W Rh 2 + 0.885W Ru W Sn + 1.28W Ru 2 + 1.58W Sn + 9.49W Sn 2 + 11.6 ≦ 100 A platinum alloy composition comprising:

2. 2. The platinum alloy composition of claim 1, comprising, by mass%, 95.0% or more platinum.

3. The mass percentages of cobalt, copper, iron, gallium, indium, nickel, palladium, tin, rhodium, iridium, gold, ruthenium, rhenium, silver, and manganese contained in the alloy are respectively W Co , W Cu , W Fe , W Ga , W In , W Ni , W Pd , W Sn , W Rh , W Ir , W Au , W Ru , W Re , W Ag and W Mn The platinum alloy composition according to claim 1 or 2, which satisfies the following formula: 60 + W Pd *2.5 + W Rh *3.4 + W Ir *6.455 + W Au *11.93 + W Ru *13.241 + W Cu *14.328 + W Re *16.6 + W Ni *16.9 + W Mn *18.48 + W Co *18.69 + W Fe *21.879 + W In *29 + W Sn *28.207 + W Ga *42.379 + W Ag *9.0 ≧ 140 Preferably, the following formula is satisfied: 60 + W Pd *2.5 + W Rh *3.4 + W Ir *6.455 + W Au *11.93 + W Ru *13.241 + W Cu *14.328 + W Re *16.6 + W Ni *16.9 + W Mn *18.48 + W Co *18.69 + W Fe *21.879 + W In *29 + W Sn *28.207 + W Ga *42.379 + W Ag *9.0 ≧ 150 More preferably, the following formula is satisfied: 60 + W Pd *2.5 + W Rh *3.4 + W Ir *6.455 + W Au *11.93 + W Ru *13.241 + W Cu *14.328 + W Re *16.6 + W Ni *16.9 + W Mn *18.48 + W Co *18.69 + W Fe *21.879 + W In *29 + W Sn *28.207 + W Ga *42.379 + W Ag *9.0 ≧ 160 Even more preferably, the following formula is satisfied: 60 + W Pd *2.5 + W Rh *3.4 + W Ir *6.455 + W Au *11.93 + W Ru *13.241 + W Cu *14.328 + W Re *16.6 + W Ni *16.9 + W Mn *18.48 + W Co *18.69 + W Fe *21.879 + W In *29 + W Sn *28.207 + W Ga *42.379 + W Ag *9.0 ≧ 170

4. The mass percentages of gallium, indium, and tin contained in the alloy are W Ga , W In and W Sn The platinum alloy composition according to any one of claims 1 to 3, which satisfies the following formula: W Sn + W In + W Ga ≧ 0.25, preferably W Sn + W In + W Ga ≧ 0.40, more preferably W Sn + W In + W Ga ≧0.50, most preferably W Sn + W In + W Ga ≧ 0.75

5. 5. The platinum alloy composition according to claim 1, comprising 2.0% by mass or less of iridium.

6. 6. The platinum alloy composition according to claim 1, comprising 2.0% by weight or less of rhodium.

7. 7. A platinum alloy composition according to any one of claims 1 to 6, comprising up to 3.0% by weight of ruthenium, preferably up to 2.5% by weight, preferably up to 2.0% by weight.

8. 8. The platinum alloy composition of claim 1, comprising up to 2.0 wt.% rhenium.

9. 9. A platinum alloy composition according to any one of claims 1 to 8, comprising up to 2.0% by weight, preferably up to 1.7% by weight, of indium.

10. 10. The platinum alloy composition of claim 1, comprising up to 2.0 wt. % tin, preferably up to 1.5 wt. %, more preferably up to 1.0 wt. % tin.

11. The mass percentages of gallium, tin, silver, and gold contained in the alloy are W Ga , W Sn , W Ag and W Au The platinum alloy composition according to any one of claims 1 to 10, which satisfies the following formula: 0.45W Ag + 0.35W Au + 0.6W Sn + 0.6W In + In Ga ≦ 4.0 Preferably, 0.45W Ag + 0.35W Au + 0.6W Sn + 0.6W In + In Ga ≦ 3.0

12. 12. A platinum alloy composition according to any one of claims 1 to 11 comprising up to 3.0%, preferably up to 2.0%, more preferably up to 0.5%, by weight of gold, and most preferably being substantially gold-free.

13. 13. A platinum alloy composition according to any one of claims 1 to 12, comprising up to 2.0% by weight of copper, preferably up to 1.0% by weight of copper.

14. 14. A platinum alloy composition according to any one of claims 1 to 13, comprising up to 2.0% by weight, preferably up to 1.5% by weight, of gallium.

15. 15. The platinum alloy composition according to any one of claims 1 to 14, wherein the total mass% of iridium, rhenium, rhodium and ruthenium is, in mass%, 0.25% or more, preferably 0.5% or more, more preferably 0.75% or more, even more preferably 1.0% or more, even more preferably 1.2% or more, even more preferably 1.4% or more, and most preferably 1.5% or more.

16. The mass percentages of cobalt, copper, iron, gallium, indium, nickel, palladium, tin, manganese, ruthenium, iridium, rhodium, gold, silver, and rhenium contained in the alloy are respectively W Co , W Cu , W Fe , W Ga , W In , W Ni , W Pd , W Sn , W Mn , W Ru , W Ir , W Rh , W Au , W Ag and W Re 16. The platinum alloy composition according to claim 1, which satisfies the following formula: 4.22W Ag 2 + 0.041W Au IN Co + 0.122W Au IN In + 1.96W Au IN Ni + 1.87W Au IN Sn + 0.903W Au 2 + 1.74W Co IN Ga + 13.4W Co IN In + 1.24W Co IN Mn + 5.04W Co IN Sn + 1.02W Co 2 + 8.97W Cu IN Fe + 1.74W Cu IN Ga + 4.38W Cu IN In + 1.16W Cu IN Mn + 0.491W Cu IN Ni + 3.69W Cu IN Sn + 0.22W Cu 2 + 1.68W Fe IN Ga + 3.31W Fe IN In - 1.26W Fe IN Mn + 5.07W Fe IN Sn + 0.199W Fe 2 + 5.35W Ga IN In + 0.086W Ga IN Mn + 3.27W Ga IN Re + 33.3W Ga IN Rh + 4.56W Ga IN Ru + 2.21W Ga IN Sn + 29.0W Ga + 8.49W Ga 2 + 9.09W In IN Mn - 0.28W In IN Ni + 15.4W In IN Rh + 0.992W In IN Ru + 11.7W In + 6.68W In 2 + 0.863W Ir 2 + 5.73W Mn IN Ni - 0.02W Mn IN Ru + 5.68W Mn IN Sn + 18.4W Mn - 0.89W Mn 2 + 0.49W Ni IN Ru + 0.186W Ni 2 + 4.48W Re IN Sn + 1.15W Re 2 - 5.11W Rh IN Sn + 2.04W Rh 2 + 0.885W Ru IN Sn + 1.28W Ru 2 + 1.58W Sn + 9.49W Sn 2 + 11.6 ≦ 90 Preferably, 4.22W Ag 2 + 0.041W Au IN Co + 0.122W Au IN In + 1.96W Au IN Ni + 1.87W Au IN Sn + 0.903W Au 2 + 1.74W Co IN Ga + 13.4W Co IN In + 1.24W Co IN Mn + 5.04W Co IN Sn + 1.02W Co 2 + 8.97W Cu IN Fe + 1.74W Cu IN Ga + 4.38W Cu IN In + 1.16W Cu IN Mn + 0.491W Cu IN Ni + 3.69W Cu IN Sn + 0.22W Cu 2 + 1.68W Fe IN Ga + 3.31W Fe IN In - 1.26W Fe IN Mn + 5.07W Fe IN Sn + 0.199W Fe 2 + 5.35W Ga IN In + 0.086W Ga IN Mn + 3.27W Ga IN Re + 33.3W Ga IN Rh + 4.56W Ga IN Ru + 2.21W Ga IN Sn + 29.0W Ga + 8.49W Ga 2 + 9.09W In IN Mn - 0.28W In IN Ni + 15.4W In IN Rh + 0.992W In IN Ru + 11.7W In + 6.68W In 2 + 0.863W Ir 2 + 5.73W Mn IN Ni - 0.02W Mn IN Ru + 5.68W Mn IN Sn + 18.4W Mn - 0.89W Mn 2 + 0.49W Ni IN Ru + 0.186W Ni 2 + 4.48W Re IN Sn + 1.15W Re 2 - 5.11W Rh IN Sn + 2.04W Rh 2 + 0.885W Ru IN Sn + 1.28W Ru 2 + 1.58W Sn + 9.49W Sn 2 + 11.6 ≦ 85 More preferably, 4.22W Ag 2 + 0.041W Au IN Co + 0.122W Au IN In + 1.96W Au IN Ni + 1.87W Au IN Sn + 0.903W Au 2 + 1.74W Co IN Ga + 13.4W Co IN In + 1.24W Co IN Mn + 5.04W Co IN Sn + 1.02W Co 2 + 8.97W Cu IN Fe + 1.74W Cu IN Ga + 4.38W Cu IN In + 1.16W Cu IN Mn + 0.491W Cu IN Ni + 3.69W Cu IN Sn + 0.22W Cu 2 + 1.68W Fe IN Ga + 3.31W Fe IN In - 1.26W Fe IN Mn + 5.07W Fe IN Sn + 0.199W Fe 2 + 5.35W Ga IN In + 0.086W Ga IN Mn + 3.27W Ga IN Re + 33.3W Ga IN Rh + 4.56W Ga IN Ru + 2.21W Ga IN Sn + 29.0W Ga + 8.49W Ga 2 + 9.09W In IN Mn - 0.28W In IN Ni + 15.4W In IN Rh + 0.992W In IN Ru + 11.7W In + 6.68W In 2 + 0.863W Ir 2 + 5.73W Mn IN Ni - 0.02W Mn IN Ru + 5.68W Mn IN Sn + 18.4W Mn - 0.89W Mn 2 + 0.49W Ni IN Ru + 0.186W Ni 2 + 4.48W Re IN Sn + 1.15W Re 2 - 5.11W Rh IN Sn + 2.04W Rh 2 + 0.885W Ru IN Sn + 1.28W Ru 2 + 1.58W Sn + 9.49W Sn 2 + 11.6 ≦ 80 Even more preferably, 4.22W Ag 2 + 0.041W Au IN Co + 0.122W Au IN In + 1.96W Au IN Ni + 1.87W Au IN Sn + 0.903W Au 2 + 1.74W Co IN Ga + 13.4W Co IN In + 1.24W Co IN Mn + 5.04W Co IN Sn + 1.02W Co 2 + 8.97W Cu IN Fe + 1.74W Cu IN Ga + 4.38W Cu IN In + 1.16W Cu IN Mn + 0.491W Cu IN Ni + 3.69W Cu IN Sn + 0.22W Cu 2 + 1.68W Fe IN Ga + 3.31W Fe IN In - 1.26W Fe IN Mn + 5.07W Fe IN Sn + 0.199W Fe 2 + 5.35W Ga IN In + 0.086W Ga IN Mn + 3.27W Ga IN Re + 33.3W Ga IN Rh + 4.56W Ga IN Ru + 2.21W Ga IN Sn + 29.0W Ga + 8.49W Ga 2 + 9.09W In IN Mn - 0.28W In IN Ni + 15.4W In IN Rh + 0.992W In IN Ru + 11.7W In + 6.68W In 2 + 0.863W Ir 2 + 5.73W Mn IN Ni - 0.02W Mn IN Ru + 5.68W Mn IN Sn + 18.4W Mn - 0.89W Mn 2 + 0.49W Ni IN Ru + 0.186W Ni 2 + 4.48W Re IN Sn + 1.15W Re 2 - 5.11W Rh IN Sn + 2.04W Rh 2 + 0.885W Ru IN Sn + 1.28W Ru 2 + 1.58W Sn + 9.49W Sn 2 + 11.6 ≦ 75 Most preferably, 4.22W Ag 2 + 0.041W Au IN Co + 0.122W Au IN In + 1.96W Au IN Ni + 1.87W Au IN Sn + 0.903W Au 2 + 1.74W Co IN Ga + 13.4W Co IN In + 1.24W Co IN Mn + 5.04W Co IN Sn + 1.02W Co 2 + 8.97W Cu IN Fe + 1.74W Cu IN Ga + 4.38W Cu IN In + 1.16W Cu IN Mn + 0.491W Cu IN Ni + 3.69W Cu IN Sn + 0.22W Cu 2 + 1.68W Fe IN Ga + 3.31W Fe IN In - 1.26W Fe IN Mn + 5.07W Fe IN Sn + 0.199W Fe 2 + 5.35W Ga IN In + 0.086W Ga IN Mn + 3.27W Ga IN Re + 33.3W Ga IN Rh + 4.56W Ga IN Ru + 2.21W Ga IN Sn + 29.0W Ga + 8.49W Ga 2 + 9.09W In IN Mn - 0.28W In IN Ni + 15.4W In IN Rh + 0.992W In IN Ru + 11.7W In + 6.68W In 2 + 0.863W Ir 2 + 5.73W Mn IN Ni - 0.02W Mn IN Ru + 5.68W Mn IN Sn + 18.4W Mn - 0.89W Mn 2 + 0.49W Ni IN Ru + 0.186W Ni 2 + 4.48W Re IN Sn + 1.15W Re 2 - 5.11W Rh IN Sn + 2.04W Rh 2 + 0.885W Ru IN Sn + 1.28W Ru 2 + 1.58W Sn + 9.49W Sn 2 + 11.6 ≦ 70

17. The mass percentages of cobalt, copper, iron, nickel, and palladium contained in the alloy are W Co , W Cu , W Fe , W Ni and W Pd 17. The platinum alloy composition according to claim 1, wherein the following formula is satisfied: IN Co + In Pd + In Fe + In Ni + In Cu ≧ 1.0 Preferably, IN Co + In Pd + In Fe + In Ni + In Cu ≧ 2.0

18. 18. The platinum alloy composition of any one of claims 1 to 17, comprising at least one element from the list of cobalt, palladium, iron and copper, preferably the sum of cobalt, palladium, iron and copper being 1.0% by weight or more, more preferably 1.1% by weight or more.

19. 19. The platinum alloy composition of any one of claims 1 to 18, comprising at least one element from the list of ruthenium, rhenium, iridium and rhodium, preferably the sum of ruthenium, rhenium, iridium and rhodium is at least 0.25%, preferably at least 0.5%, more preferably at least 0.75%, more preferably at least 1.0%, more preferably at least 1.2%, and most preferably at least 1.4%, by weight.

20. 20. The platinum alloy composition of any one of claims 1 to 19, comprising at least one element from the list of tin, indium and gallium, preferably the sum of tin, indium and gallium being 1.2% by weight or more, more preferably 1.6% by weight or more.

21. 21. The platinum alloy composition of any one of claims 1 to 20, comprising platinum, indium, ruthenium, tin, and iron.

22. 22. The platinum alloy composition of any one of claims 1 to 21, comprising platinum, ruthenium, iron, and gallium.

23. 23. The platinum alloy composition of any one of claims 1 to 22, comprising 0.5 to 2.0 wt.% indium.

24. 24. The platinum alloy composition of any one of claims 1 to 23, comprising 1.0 to 2.5 wt.% ruthenium.

25. 25. The platinum alloy composition of claim 1, comprising 0.2 to 1.0 wt. % tin.

26. 26. The platinum alloy composition of any one of claims 1 to 25, comprising 0.5 to 1.75 wt.% iron.

27. 27. The platinum alloy composition of any one of claims 1 to 26, comprising 0.5 to 1.75 wt.% gallium.

28. 28. The platinum alloy composition of any one of the preceding claims, comprising up to 4.0%, by weight, of iron, preferably up to 2.5%, more preferably up to 2.25%, more preferably up to 2.0%, more preferably up to 1.75%, more preferably up to 1.75%.

29. 29. A platinum alloy composition according to any one of claims 1 to 28 comprising up to 2.0 wt. % cobalt, preferably up to 1.0 wt. %, and more preferably substantially free of cobalt.

30. 30. The platinum alloy composition of any one of claims 1 to 29, comprising palladium in an amount of not more than 3.0%, preferably not more than 2.5%, more preferably not more than 2.0%, more preferably not more than 1.5%, more preferably not more than 0.1%, by weight, and most preferably substantially free of palladium.

31. 31. A platinum alloy composition according to any one of claims 1 to 30 comprising up to 3.0%, preferably up to 2.5%, more preferably up to 0.1%, by weight of manganese, and most preferably substantially free of manganese.

32. The mass percentages of cobalt, copper, iron, gallium, indium, nickel, palladium, tin, manganese, ruthenium, iridium, rhodium, gold, platinum, silver, and rhenium contained in the alloy are respectively W Co , W Cu , W Fe , W Ga , W In , W Ni , W Pd , W Sn , W Mn , W Ru , W Ir , W Rh , W Au , W Pt , W Ag and W Re 32. The platinum alloy composition according to any one of claims 1 to 31, which satisfies the following formula: 16.65 ≦ -0.10406*W Ag -0.1028*W Co - 0.1201*W Cu - 0.2113*W Fe - 0.3368*W Ga - 0.1125*W In - 0.1639*W Ni - 0.015*W Pd - 0.1959*W Sn + 17.276261 - 0.20*W Mn + 0.0678*W Ru + 0.035*W Ir + 0.045*W Rh - 0.059*W Au + 0.066*W Re Preferably, 16.70 ≦ -0.10406*W Ag -0.1028*W Co - 0.1201*W Cu - 0.2113*W Fe - 0.3368*W Ga - 0.1125*W In - 0.1639*W Ni - 0.015*W Pd - 0.1959*W Sn + 17.276261 - 0.20*W Mn + 0.0678*W Ru + 0.035*W Ir + 0.045*W Rh - 0.059*W Au + 0.066*W Re

33. The mass percentages of cobalt, copper, iron, gallium, indium, nickel, palladium, tin, manganese, ruthenium, iridium, rhodium, gold, platinum, silver, and rhenium contained in the alloy are respectively W Co , W Cu , W Fe , W Ga , W In , W Ni , W Pd , W Sn , W Mn , W Ru , W Ir , W Rh , W Au , W Pt , W Ag and W Re 33. The platinum alloy composition according to any one of claims 1 to 32, which satisfies the following formula: -0.10406*W Ag -0.1028*W Co - 0.1201*W Cu - 0.2113*W Fe - 0.3368*W Ga - 0.1125*W In - 0.1639*W Ni - 0.015*W Pd - 0.1959*W Sn + 17.276261 - 0.20*W Mn + 0.0678*W Ru + 0.035*W Ir + 0.045*W Rh - 0.059*W Au + 0.066*W Re ≦17.00

34. 34. The platinum alloy composition of any one of claims 1 to 33, comprising at least 0.5 wt. % indium, preferably at least 0.75 wt. %, more preferably at least 1.0 wt. % indium.

35. 35. The platinum alloy composition of any one of the preceding claims, comprising at least 0.5%, preferably at least 0.8%, more preferably at least 1.0%, more preferably at least 1.2%, by weight of ruthenium.

36. 36. The platinum alloy composition of claim 1, comprising at least 0.2 wt.% tin.

37. 37. The platinum alloy composition of any one of the preceding claims, comprising at least 0.25%, preferably at least 0.5%, more preferably at least 0.75%, more preferably at least 1.0%, by weight, of iron.

38. 38. A platinum alloy composition according to any one of the preceding claims comprising at least 0.5%, preferably at least 0.75%, more preferably at least 1.0%, by weight of gallium.

39. 39. The platinum alloy composition of any one of claims 1 to 38, wherein the sum of cobalt, palladium, iron, and copper is 1.5 wt.% or less.

40. 40. The platinum alloy composition of any one of claims 1 to 39, wherein the sum of ruthenium, rhenium, iridium and rhodium is not more than 2.7 wt.%, more preferably not more than 2.6 wt.%.

41. 41. The platinum alloy composition of any one of claims 1 to 40, wherein the sum of tin, indium and gallium is not more than 2.7 wt.%, more preferably not more than 2.5 wt.%.

42. 1. A platinum alloy composition comprising, in weight percent, 1.2±0.2% iron, 1.5±0.2% indium, 1.5±0.2% ruthenium, 0.6% tin, and the balance (optionally at least 95%) being platinum and unavoidable impurities.

43. A platinum alloy comprising, in mass percent, 1.2±0.2% iron, 1.2±0.2% gallium, 2.4±0.2% ruthenium, and the remainder (optionally at least 95%) being platinum and unavoidable impurities.

44. A platinum alloy comprising, in mass percent, 1.2±0.2% iron, 1.5±0.2% indium, 1.5±0.2% ruthenium, 0.6% tin, and the remainder (optionally at least 95%) being platinum and unavoidable impurities.

45. 45. A cast article comprising the platinum alloy composition of any one of claims 1-44.

46. 45. An article of jewelry comprising the platinum alloy composition of any one of claims 1-44.

47. 48. The jewelry of claim 47, further comprising a gemstone embedded in the platinum alloy composition.

Images