A high-purity platinum-ruthenium alloy and its preparation method and application

Abstract

The present invention provides a high-purity platinum-ruthenium alloy and a preparation method and application thereof, wherein the preparation method comprises: mixing platinum and ruthenium to obtain a platinum-ruthenium raw material, subjecting the platinum-ruthenium raw material to suspension smelting to obtain an ingot; subjecting the ingot to heat treatment to obtain a blank, subjecting the blank to hot forging and cold rolling in sequence to obtain a platinum-ruthenium alloy. The preparation method of the platinum-ruthenium alloy provided by the present invention controls the impurity inclusion of the platinum-ruthenium alloy through suspension smelting, and at the same time, improves the hardness, color and processability of the alloy, without the need to add additional regulating or strengthening elements, avoiding the influence of some elements on human health, ensuring the high purity of the platinum-ruthenium alloy, and making the platinum-ruthenium alloy more conducive to jewelry application.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal material preparation, and relates to a platinum-ruthenium alloy, and in particular to a high-purity platinum-ruthenium alloy and a preparation method and application thereof. Background Art

[0002] Platinum-ruthenium alloy is an alloy composed of platinum (Pt) and ruthenium (Ru) elements. Platinum metal itself has excellent corrosion resistance, stability and noble luster, so it is favored by the jewelry industry. However, pure platinum has a relatively low hardness and is easy to scratch and deform, which may affect the appearance and durability of jewelry during daily wear. Ruthenium is a rare precious metal with high hardness, strength and good corrosion resistance. Platinum-ruthenium alloy can significantly improve the hardness and wear resistance of platinum metal, enhance its scratch resistance, while maintaining the luster and appearance of platinum, allowing jewelry to better maintain its shape and texture during long-term wear. Therefore, in recent years, platinum-ruthenium alloy has gradually become a very popular material in the luxury jewelry market.

[0003] CN107058788A discloses a multi-component platinum-ruthenium alloy and a preparation method thereof. The components of the multi-component platinum-ruthenium alloy are as follows in percentage by mass: 95% platinum, 0.5-1% ruthenium, 2.5-4.2% copper, 0.2-2.0% palladium, and 0.1-0.3% cobalt. Other additive elements are added to the platinum-ruthenium alloy to improve the color, hardness, density, ductility and other properties of the platinum-ruthenium alloy. The quality of the alloy product is improved through the preparation method of smelting and oil tank cooling.

[0004] CN115961159A discloses a method for preparing a platinum-ruthenium-gallium alloy for platinum jewelry. The preparation method uses platinum, ruthenium and gallium elements to perform vacuum melting and casting in a crucible to obtain an ingot, and then the ingot is subjected to homogenization heat treatment, hot forging and cold rolling to obtain a platinum-ruthenium-gallium alloy that can be used for platinum jewelry, thereby improving the hardness and color of the alloy.

[0005] In the above patents and other prior arts, in order to improve the color, processability and other properties of platinum-ruthenium alloys, copper, gallium, palladium, cobalt and other elements are added to the platinum-ruthenium alloys. On the one hand, the addition of elements to the platinum-ruthenium alloys reduces the purity of the platinum-ruthenium alloys. On the other hand, some of the added elements may be harmful to the human body and may also affect the color of the platinum-ruthenium alloys, which is not ideal. At the same time, the existing preparation methods of platinum-ruthenium alloys are prone to introduce impurity elements, which is not conducive to improving the properties of the alloys.

[0006] Therefore, in view of the problems existing in the existing process, the present invention provides a high-purity platinum-ruthenium alloy and a preparation method and application thereof. Summary of the invention

[0007] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a high-purity platinum-ruthenium alloy and a preparation method and application thereof, to prepare a high-purity platinum-ruthenium alloy, to improve the hardness, color and machinability of the platinum-ruthenium alloy, without the need to add additional regulating or strengthening elements, with high purity and low impurity content.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a method for preparing a high-purity platinum-ruthenium alloy, the preparation method comprising the following steps:

[0010] (1) mixing platinum and ruthenium to obtain a platinum-ruthenium raw material, and performing suspension smelting on the platinum-ruthenium raw material to obtain an ingot;

[0011] (2) The ingot is heat treated to obtain a billet, and the billet is hot forged and cold rolled in sequence to obtain a platinum-ruthenium alloy.

[0012] The preparation method provided by the present invention adopts suspension smelting, and reduces impurities in the smelting process through the suspension smelting without a crucible and a casting mold, thereby ensuring the high purity of the platinum-ruthenium alloy. At the same time, the color and processability of the platinum-ruthenium alloy are improved through the suspension smelting method, without the need to additionally add regulating or strengthening elements such as copper, gallium, palladium or cobalt, thereby avoiding the influence of some elements on human health, making the platinum-ruthenium alloy more conducive to jewelry application.

[0013] In the present invention, the platinum and ruthenium in step (1) are platinum and ruthenium respectively.

[0014] In the present invention, the high-purity platinum-ruthenium alloy refers to an alloy in which only platinum and ruthenium elements are added, and the impurity content is below 500 ppm.

[0015] Preferably, the purity of the platinum in step (1) is greater than 99.95%, for example, it can be 99.955%, 99.96%, 99.965%, 99.97%, 99.975%, 99.98%, 99.985%, 99.99% or 99.995%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0016] Preferably, the purity of ruthenium in step (1) is greater than 99.95%, for example, it can be 99.955%, 99.96%, 99.965%, 99.97%, 99.975%, 99.98%, 99.985%, 99.99% or 99.995%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0017] Preferably, the mass of ruthenium in step (1) is 0.1-15% of the mass of the platinum ruthenium raw material, for example, it can be 0.1%, 0.5%, 1%, 2%, 4%, 5%, 6%, 8%, 10%, 12%, 14% or 15%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0018] Preferably, the mass of platinum in step (1) is 0.1-20 kg, for example, 0.1 kg, 0.5 kg, 1 kg, 3 kg, 5 kg, 8 kg, 10 kg, 12 kg, 15 kg, 18 kg or 20 kg, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0019] Preferably, the suspension smelting process in step (1) includes: first heating the platinum ruthenium raw material to a first smelting temperature, then heating it to a second smelting temperature for refining, then cooling it to a third smelting temperature, and cooling it with the furnace after smelting.

[0020] In the present invention, suspension smelting adopts a three-stage smelting method, the raw material is first heated to a first smelting temperature to melt platinum and ruthenium to form a platinum-ruthenium alloy, and then refined at a second smelting temperature, at which low-melting-point metal impurities in the platinum-ruthenium alloy are smelted and volatilized, and oxide inclusions are decomposed, effectively controlling the impurity level in the platinum-ruthenium alloy. After the impurity removal process is completed, the platinum-ruthenium alloy is homogenized at a third smelting temperature, which is conducive to solidification while maintaining a suspended state, so that a platinum-ruthenium alloy with uniform composition and low impurity content is finally obtained.

[0021] Preferably, the first smelting temperature is 1900-2100°C, for example, 1900°C, 1950°C, 2000°C, 2050°C or 2100°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0022] Preferably, the smelting time at the first smelting temperature is 30-60 min, for example, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min or 60 min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0023] Preferably, the second smelting temperature is 2200-2500°C, for example, it can be 2200°C, 2250°C, 2300°C, 2350°C, 2400°C, 2450°C or 2500°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0024] Preferably, the refining time is 5-10 min, for example, 5 min, 6 min, 7 min, 8 min, 9 min or 10 min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0025] Preferably, the third melting temperature is 1600-1750°C, for example, it can be 1600°C, 1620°C, 1650°C, 1680°C, 1700°C, 1720°C or 1750°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0026] Preferably, the holding time of the third smelting temperature is 5-30 min, for example, 5 min, 10 min, 15 min, 20 min, 25 min or 30 min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0027] Preferably, the vacuum degree of the suspension smelting in step (1) is 10 -2 -10Pa, for example, it can be 10 -2 Pa, 3×10 - 2 Pa, 5×10 -2 Pa, 8×10 -2 Pa, 10 -1 Pa, 5×10 -1 Pa, 1Pa, 5Pa or 10Pa, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0028] Preferably, the temperature of the heat treatment in step (2) is 1000-1200°C, for example, it can be 1000°C, 1020°C, 1050°C, 1080°C, 1100°C, 1120°C, 1150°C, 1180°C or 1200°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0029] Preferably, the heat treatment time in step (2) is 10-30 min, for example, it can be 10 min, 12 min, 15 min, 18 min, 20 min, 22 min, 25 min, 28 min or 30 min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0030] Preferably, the single-pass deformation of the hot forging in step (2) is 15-35%, for example, it can be 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32% or 35%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0031] Preferably, during the hot forging process in step (2), annealing is performed between every two passes.

[0032] Preferably, the annealing temperature is 1000-1200°C, for example, it can be 1000°C, 1020°C, 1050°C, 1080°C, 1100°C, 1120°C, 1150°C, 1180°C or 1200°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0033] Preferably, the annealing time is 5-10 min, for example, 5 min, 6 min, 7 min, 8 min, 9 min or 10 min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0034] Preferably, the single-pass deformation of the cold rolling in step (2) is 5-15%, for example, it can be 5%, 8%, 10%, 12% or 15%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0035] Preferably, when preparing a platinum-ruthenium alloy sheet, the hot forging in step (2) is performed to an alloy thickness of 18-30 mm, for example, 18 mm, 20 mm, 22 mm, 25 mm, 28 mm or 30 mm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0036] Preferably, when preparing a platinum-ruthenium alloy sheet, the cold rolling in step (2) to an alloy thickness of 1.0-3.0 mm, for example, may be 1.0 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2.0 mm, 2.2 mm, 2.5 mm, 2.8 mm or 3.0 mm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0037] Preferably, when preparing a platinum-ruthenium alloy rod, in step (2), the billet is hot forged and cold rolled into a strip alloy, and then drawn to obtain the platinum-ruthenium alloy rod.

[0038] Preferably, the length of the wide side of the hot forged billet is 12-16 mm, for example, it can be 12 mm, 12.5 mm, 13 mm, 13.5 mm, 14 mm, 14.5 mm, 15 mm, 15.5 mm or 16 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0039] Preferably, the length of the wide side of the cold-rolled billet is 4.0-7.0 mm, for example, 4.0 mm, 4.5 mm, 5.0 mm, 5.5 mm, 6.0 mm, 6.5 mm or 7.0 mm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0040] Preferably, when preparing the platinum-ruthenium alloy wire, the preparation method further comprises: cold drawing and annealing the platinum-ruthenium alloy rod to obtain the platinum-ruthenium alloy wire.

[0041] Preferably, the single-pass surface reduction rate of the cold drawing is 5-20%, for example, 5%, 10%, 15% or 20%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0042] Preferably, the diameter of the alloy wire obtained by cold drawing is 0.5-3.0 mm, for example, it can be 0.5 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2.0 mm, 2.2 mm, 2.5 mm, 2.8 mm or 3.0 mm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0043] Preferably, the annealing treatment is carried out after the total processing rate of cold drawing is ≥80%, for example, it can be 80%, 85%, 90%, 95%, 100%, 120% or 150%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0044] Preferably, the annealing temperature is 1000-1200°C, for example, it can be 1000°C, 1020°C, 1050°C, 1080°C, 1100°C, 1120°C, 1150°C, 1180°C or 1200°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0045] Preferably, the annealing treatment time is 10-15 min, for example, it can be 10 min, 11 min, 12 min, 13 min, 14 min or 15 min, but it is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0046] As a preferred technical solution of the preparation method provided by the present invention, the preparation method comprises the following steps:

[0047] (a) preparing platinum with a purity greater than 99.95% and ruthenium with a purity greater than 99.95% to obtain a platinum-ruthenium raw material, wherein the mass of the ruthenium is 0.1-15% of the mass of the platinum-ruthenium raw material, placing the platinum-ruthenium raw material in a suspension smelting device, and evacuating the device to 10 -2-10Pa, adjust the power of the suspension smelting device, first increase the temperature to 1900-2100℃, keep it warm for 30-60min, then increase it to 2200-2500℃ for refining, the refining time is 5-10min, then reduce the temperature to 1600-1750℃, keep it warm for 5-30min, after the smelting is completed, maintain the vacuum state, turn off the heating, cool with the furnace, and obtain the ingot;

[0048] (b) heat treating the ingot at a temperature of 1000-1200° C. for a time of 10-30 min to obtain a billet;

[0049] (c) hot forging the blank, wherein the deformation amount of a single pass of the hot forging is 15-35%, and annealing is performed between each two passes during the hot forging process, wherein the annealing temperature is 1000-1200° C., and the annealing time is 5-10 min. After the hot forging is completed, cold rolling is performed, wherein the deformation amount of a single pass of the cold rolling is 5-15%;

[0050] When preparing a platinum-ruthenium alloy plate, the step (c) is hot forging to an alloy thickness of 18-30 mm, and then cold rolling to an alloy thickness of 1.0-3.0 mm to obtain the platinum-ruthenium alloy plate;

[0051] Alternatively, when preparing a platinum-ruthenium alloy rod, in step (c), the billet is hot-forged into a rod-shaped alloy, the wide side length of the rod-shaped alloy is 12-16 mm, then cold-rolled to a wide side length of 4.0-7.0 mm, and finally drawn to obtain the platinum-ruthenium alloy rod;

[0052] Alternatively, when preparing a platinum-ruthenium alloy wire, the preparation method further includes: cold drawing the platinum-ruthenium alloy rod, the single-pass surface reduction rate of the cold drawing is 5-20%, the cold drawing is performed until the alloy diameter is 0.5-3.0 mm, the total processing rate of the cold drawing is ≥80%, and then annealing is performed, the annealing temperature is 1000-1200°C, and the annealing time is 10-15min, to obtain the platinum-ruthenium alloy wire.

[0053] In a second aspect, the present invention provides a high-purity platinum-ruthenium alloy, wherein the high-purity platinum-ruthenium alloy is prepared by the preparation method described in the first aspect.

[0054] In a third aspect, the present invention provides an application of the high-purity platinum-ruthenium alloy described in the second aspect, wherein the high-purity platinum-ruthenium alloy is used for platinum jewelry.

[0055] Compared with the prior art, the present invention has the following beneficial effects:

[0056] The preparation method of the platinum-ruthenium alloy provided by the present invention controls the impurity inclusion of the platinum-ruthenium alloy through suspension smelting, and at the same time improves the hardness, color and processability of the alloy without the need to add additional regulating or strengthening elements, thereby avoiding the influence of some elements on human health, ensuring the high purity of the platinum-ruthenium alloy, and making the platinum-ruthenium alloy more conducive to jewelry application. DETAILED DESCRIPTION

[0057] The technical solution of the present invention is further illustrated below through specific implementation methods.

[0058] Example 1

[0059] This embodiment provides a method for preparing a high-purity platinum-ruthenium alloy, the preparation method comprising the following steps:

[0060] (1) Ingredients: Weigh 4.25 kg of platinum with a purity of 99.95% and 0.75 kg of ruthenium with a purity of 99.95%, wherein ruthenium accounts for 15% of the total mass of platinum and ruthenium;

[0061] (2) Suspension smelting: The prepared platinum and ruthenium are placed in a suspension smelting device, which is a split water-cooled copper crucible. The device is first evacuated to 10 -2 Pa, then adjust the power for heating, first the heating temperature reaches 2100℃ to form a platinum-ruthenium alloy, keep it warm for 60min, then adjust the power to raise the temperature to 2500℃ for refining, the refining time is 10min, then adjust the power to reduce the temperature to 1750℃, keep it warm for 30min, keep the vacuum state after the smelting is completed, turn off the heating, do not cast, cool to room temperature (25℃) with the furnace, and obtain an ingot;

[0062] (3) Heat treatment: The ingot is placed in an annealing furnace at a temperature of 1200°C for 30 min.

[0063] (4) Hot forging: The blank is then hot forged with an air hammer. The deformation of a single pass is 15%. The forging is completed in three passes. Annealing is performed between each pass. The annealing temperature is 1200°C and the annealing time is 10 minutes. After the hot forging is completed, the thickness of the blank obtained is 18 mm.

[0064] (5) Cold rolling: The blank is cold rolled using a two-roll rolling mill, with a deformation amount of 5% per pass, until the thickness of the finished product is 1.0 mm. After trimming, a platinum-ruthenium alloy sheet is obtained.

[0065] Example 2

[0066] This embodiment provides a method for preparing a high-purity platinum-ruthenium alloy, the preparation method comprising the following steps:

[0067] (1) Ingredients: Weigh 20 kg of platinum with a purity of 99.99% and 1.052 kg of ruthenium with a purity of 99.95%, wherein ruthenium accounts for 5% of the total mass of platinum and ruthenium;

[0068] (2) Suspension smelting: The prepared platinum and ruthenium are placed in a suspension smelting device, which is a split water-cooled copper crucible. The device is first evacuated to 10 -2 Pa, then adjust the power for heating, first the heating temperature reaches 1900℃ to form a platinum-ruthenium alloy, keep it warm for 30 minutes, then adjust the power to raise the temperature to 2200℃ for refining, the refining time is 5 minutes, then adjust the power to reduce the temperature to 1600℃, keep it warm for 5 minutes, keep the vacuum state after the smelting is completed, turn off the heating, do not cast, cool to room temperature (25℃) with the furnace, and obtain an ingot;

[0069] (3) Heat treatment: The ingot is placed in an annealing furnace at a temperature of 1000°C for 10 min.

[0070] (4) Hot forging: The blank is then hot forged with an air hammer, with a deformation of 35% per pass. After one pass, the thickness of the blank is 30 mm.

[0071] (5) Cold rolling: The blank is cold rolled using a two-roll rolling mill, with a deformation amount of 15% per pass, until the thickness of the finished product is 3.0 mm. After trimming, a platinum-ruthenium alloy sheet is obtained.

[0072] Example 3

[0073] This embodiment provides a method for preparing a high-purity platinum-ruthenium alloy, the preparation method comprising the following steps:

[0074] (1) Ingredients: Weigh 2 kg of platinum with a purity of 99.95% and 105.2 g of ruthenium with a purity of 99.99%, wherein ruthenium accounts for 5% of the total mass of platinum and ruthenium;

[0075] (2) Suspension smelting: The prepared platinum and ruthenium are placed in a suspension smelting device, which is a split water-cooled copper crucible. The device is first evacuated to 10 -2 Pa, then adjust the power for heating, first the heating temperature reaches 1900℃ to form a platinum-ruthenium alloy, keep it warm for 40 minutes, then adjust the power to raise the temperature to 2200℃ for refining, the refining time is 5 minutes, then adjust the power to reduce the temperature to 1600℃, keep it warm for 5 minutes, keep the vacuum state after the smelting is completed, turn off the heating, do not cast, cool to room temperature (25℃) with the furnace, and obtain an ingot;

[0076] (3) Heat treatment: The ingot is placed in an annealing furnace at a temperature of 1000°C for 15 min.

[0077] (4) Hot forging: The ingot is then forged into a bar with a side length of 12 mm using an air hammer. The deformation of a single pass is 35%. The forging is completed in two passes. Annealing is performed between each pass. The annealing temperature is 1000°C and the annealing time is 5 min. Finally, the ingot is forged into a bar with a side length of 12 mm.

[0078] (5) Cold rolling: The rods are rolled into square bars with a side length of 4.8 mm using a bar rolling mill;

[0079] (6) Drawing: The square bars were drawn into round bars with a diameter of 3.0 mm using a chain machine to obtain platinum-ruthenium alloy bars.

[0080] Example 4

[0081] This embodiment provides a method for preparing a high-purity platinum-ruthenium alloy, the preparation method comprising the following steps:

[0082] (1) Ingredients: Weigh 2 kg of platinum with a purity of 99.95% and 222.2 g of ruthenium with a purity of 99.95%, wherein ruthenium accounts for 10% of the total mass of platinum and ruthenium;

[0083] (2) Suspension smelting: The prepared platinum and ruthenium are placed in a suspension smelting device, which is a split water-cooled copper crucible. The device is first evacuated to 10 -2 Pa, then adjust the power for heating, first the heating temperature reaches 2000℃ to form a platinum-ruthenium alloy, keep it warm for 50 minutes, then adjust the power to raise the temperature to 2400℃ for refining, the refining time is 10 minutes, then adjust the power to reduce the temperature to 1700℃, keep it warm for 10 minutes, keep the vacuum state after the smelting is completed, turn off the heating, do not cast, cool to room temperature (25℃) with the furnace, and obtain an ingot;

[0084] (3) Heat treatment: The ingot is placed in an annealing furnace at a temperature of 1100°C for 20 min.

[0085] (4) Hot forging: The ingot is then forged into a bar with a side length of 14 mm using an air hammer. The deformation of a single pass is 25%. The forging is completed in two passes. Annealing is performed between each pass. The annealing temperature is 1100°C and the annealing time is 10 min. Finally, the ingot is forged into a bar with a side length of 14 mm.

[0086] (5) Cold rolling: The bars are rolled into square bars with a side length of 5.2 mm using a bar rolling mill;

[0087] (6) Drawing: The square bars were drawn into round bars with a diameter of 3.0 mm using a chain machine to obtain platinum-ruthenium alloy bars.

[0088] Example 5

[0089] This embodiment provides a method for preparing a high-purity platinum-ruthenium alloy, the preparation method comprising the following steps:

[0090] (1) Ingredients: Weigh 2 kg of platinum with a purity of 99.99% and 105.2 g of ruthenium with a purity of 99.99%, wherein ruthenium accounts for 5% of the total mass of platinum and ruthenium;

[0091] (2) Suspension smelting: The prepared platinum and ruthenium are placed in a suspension smelting device, which is a split water-cooled copper crucible. The device is first evacuated to 10 -2 Pa, then adjust the power for heating, first the heating temperature reaches 1900℃ to form a platinum-ruthenium alloy, keep it warm for 30 minutes, then adjust the power to raise the temperature to 2200℃ for refining, the refining time is 8 minutes, then adjust the power to reduce the temperature to 1600℃, keep it warm for 15 minutes, keep the vacuum state after the smelting is completed, turn off the heating, do not cast, cool to room temperature (25℃) with the furnace, and obtain an ingot;

[0092] (3) Heat treatment: The ingot is placed in an annealing furnace at a temperature of 1000°C for 10 min.

[0093] (4) Hot forging: The ingot is then forged into a bar with a side length of 12 mm using an air hammer. The deformation of a single pass is 25%. The forging is completed in two passes. Annealing is performed between each pass. The annealing temperature is 1000°C and the annealing time is 8 min. Finally, the ingot is forged into a bar with a side length of 12 mm.

[0094] (5) Cold rolling: The rods are rolled into square bars with a side length of 4.8 mm using a bar rolling mill;

[0095] (6) Drawing: The square bar is drawn through a tungsten steel die using a chain machine to form a round bar with a diameter of Φ3.0 mm;

[0096] (7) Cold drawing: The round rod is cold drawn through a tungsten steel die by a wire drawing machine to a thick wire with a diameter of 1.0 mm in multiple passes. The single cold drawing reduction rate is 20%. When the total cold drawing processing rate exceeds 80%, annealing treatment is performed at a temperature of 1000°C for 10 minutes to obtain a platinum-ruthenium alloy wire.

[0097] Example 6

[0098] This embodiment provides a method for preparing a high-purity platinum-ruthenium alloy, the preparation method comprising the following steps:

[0099] (1) Ingredients: weigh 2 kg of platinum, the purity of which is 99.95%, and 20.2 g of ruthenium, the purity of which is 99.95%, wherein ruthenium accounts for 1% of the total mass of platinum and ruthenium;

[0100] (2) Suspension smelting: The prepared platinum and ruthenium are placed in a suspension smelting device, which is a split water-cooled copper crucible. The device is first evacuated to 10 -2 Pa, then adjust the power for heating, first the heating temperature reaches 1900℃ to form a platinum-ruthenium alloy, keep it warm for 30 minutes, then adjust the power to raise the temperature to 2200℃ for refining, the refining time is 5 minutes, then adjust the power to reduce the temperature to 1600℃, keep it warm for 15 minutes, keep the vacuum state after the smelting is completed, turn off the heating, do not cast, cool to room temperature (25℃) with the furnace, and obtain an ingot;

[0101] (3) Heat treatment: The ingot is placed in an annealing furnace at a temperature of 1000°C for 10 min.

[0102] (4) Hot forging: The ingot is then forged into a bar with a side length of 12 mm using an air hammer. The deformation of a single pass is 35%. The forging is completed in two passes. Annealing is performed between each pass. The annealing temperature is 1000°C and the annealing time is 8 min. Finally, the ingot is forged into a bar with a side length of 12 mm.

[0103] (5) Cold rolling: The rods are rolled into square bars with a side length of 4.0 mm using a bar rolling mill;

[0104] (6) Drawing: The square bar is drawn through a tungsten steel die using a chain machine to form a round bar with a diameter of Φ6.0 mm;

[0105] (7) Cold drawing: The round rod is cold drawn through a tungsten steel die by a wire drawing machine to a thick wire with a diameter of 0.85 mm. The single reduction rate of cold drawing is 20%. When the total processing rate of cold drawing exceeds 80%, annealing treatment is performed at a temperature of 1000°C for 12 minutes to obtain a platinum-ruthenium alloy wire.

[0106] Example 7

[0107] This embodiment provides a method for preparing a high-purity platinum-ruthenium alloy. Compared with Example 1, the refining temperature in the suspension smelting of step (2) is controlled to be 2000° C., and the rest is the same as Example 1.

[0108] Example 8

[0109] This embodiment provides a method for preparing a high-purity platinum-ruthenium alloy. Compared with Example 1, the refining temperature in the suspension smelting of step (2) is controlled to be 2700° C., and the rest is the same as Example 1.

[0110] Example 9

[0111] This embodiment provides a method for preparing a high-purity platinum-ruthenium alloy. Compared with Example 1, the third melting temperature of the suspension melting in step (2) is controlled to be 1500° C., and the rest is the same as Example 1.

[0112] Example 10

[0113] This embodiment provides a method for preparing a high-purity platinum-ruthenium alloy. Compared with Example 1, the third melting temperature of the suspension melting in step (2) is controlled to be 1900° C., and the rest is the same as Example 1.

[0114] Embodiment 11

[0115] This embodiment provides a method for preparing a high-purity platinum-ruthenium alloy. Compared with Embodiment 1, the process of suspension smelting in step (2) is controlled as follows: the power of the suspension smelting device is adjusted to directly raise the temperature to 2500° C. for suspension smelting. The suspension smelting time is 40 minutes. The rest is the same as Embodiment 1.

[0116] Comparative Example 1

[0117] This comparative example provides a method for preparing a platinum-ruthenium alloy. Compared with Example 1, the suspension melting in step (2) is replaced by vacuum melting and casting. The specific process of the vacuum melting and casting is as follows: the prepared platinum and ruthenium are placed in a magnesium oxide crucible, and the vacuum is evacuated to 10 -2 Pa, adjusting the power to raise the temperature to 2500°C for vacuum melting, the melting time is 40 minutes, after the melting is completed, casting is carried out in a graphite mold to obtain an ingot, and the rest is the same as Example 1.

[0118] Comparative Example 2

[0119] This comparative example provides a method for preparing a platinum-ruthenium alloy. Compared with Example 1, the heat treatment in step (3) is not performed, and the rest is the same as Example 1.

[0120] The platinum-ruthenium alloys prepared in the examples and comparative examples were tested for impurity content, hardness, glossiness and processing performance. The test results are listed in Table 1.

[0121] The impurity content was determined by ICP quantitative analysis, the hardness was determined by Vickers hardness, the glossiness was determined by colorimetric card comparison, and the processing performance was described based on the turning tool rate.

[0122] Table 1

[0123]

[0124]

[0125] As can be seen from Table 1, the platinum-ruthenium alloy prepared by the preparation method of the present invention has high alloy purity, the impurity content is controlled below 500ppm, and has suitable hardness and machinability, without the need to add additional strengthening or auxiliary elements. The main factor affecting the hardness and whiteness of the platinum-ruthenium alloy is the ruthenium content. The higher the ruthenium content, the greater the hardness of the alloy material and the better the whiteness. Under the existing processing technology, the hardness range of the platinum-ruthenium alloy is relatively easy to process. When the ruthenium content is small, the material performance will be soft and the knife sticking phenomenon will occur.

[0126] Compared with Example 1, in Examples 7-10, after adjusting the temperature of suspension melting, incomplete impurity removal, uneven composition or defects in the alloy may occur, resulting in unstable alloy properties and a significant decrease in hardness; in Example 11, one-stage suspension melting is adopted, and there are more alloy defects, resulting in unstable alloy properties, and a significant decrease in hardness and processing performance.

[0127] Compared with Example 1, in Comparative Example 1, suspension melting is not used but conventional vacuum melting and casting are adopted, so the refractory inclusions in the material caused by the crucible or the mold cannot be eradicated, the material performance is extremely unstable, the material defects are relatively large, the material is brittle, and there is a certain probability of cracking during turning; in Comparative Example 2, no heat treatment is performed, which is easy to affect the alloy microstructure and reduce the performance.

[0128] In summary, the preparation method of the platinum-ruthenium alloy provided by the present invention controls the impurity inclusion of the platinum-ruthenium alloy through suspension smelting, and at the same time improves the hardness, color and processability of the alloy without the need to add additional regulating or strengthening elements, thereby avoiding the impact of some elements on human health, ensuring the high purity of the platinum-ruthenium alloy, and making the platinum-ruthenium alloy more conducive to jewelry applications.

[0129] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a high-purity platinum-ruthenium alloy, characterized in that: The preparation method comprises the following steps: (1) mixing platinum and ruthenium to obtain a platinum-ruthenium raw material, and performing suspension smelting on the platinum-ruthenium raw material to obtain an ingot; (2) The ingot is heat treated to obtain a billet, and the billet is hot forged and cold rolled in sequence to obtain a platinum-ruthenium alloy.

2. The preparation method according to claim 1, characterized in that: The purity of the platinum in step (1) is greater than 99.95%; Preferably, the purity of ruthenium in step (1) is greater than 99.95%; Preferably, the mass of ruthenium in step (1) is 0.1-15% of the total mass of the platinum ruthenium raw material.

3. The preparation method according to claim 1 or 2, characterized in that: The suspension smelting process in step (1) comprises: heating the platinum ruthenium raw material to a first smelting temperature, then heating it to a second smelting temperature for refining, then cooling it to a third smelting temperature, and cooling it with the furnace after smelting; Preferably, the first smelting temperature is 1900-2100°C; Preferably, the smelting time at the first smelting temperature is 30-60 min; Preferably, the second smelting temperature is 2200-2500°C; Preferably, the refining time is 5-10 min; Preferably, the third smelting temperature is 1600-1750°C; Preferably, the holding time of the third smelting temperature is 5-30min; Preferably, the vacuum degree of the suspension smelting in step (1) is 10 -2 -10Pa.

4. The preparation method according to any one of claims 1 to 3, characterized in that The temperature of the heat treatment in step (2) is 1000-1200°C; Preferably, the heat treatment time in step (2) is 10-30 min.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The single-pass deformation of the hot forging in step (2) is 15-35%; Preferably, during the hot forging process in step (2), annealing is performed between every two passes; Preferably, the annealing temperature is 1000-1200°C; Preferably, the annealing time is 5-10 min.

6. The preparation method according to any one of claims 1 to 5, characterized in that: The deformation amount of a single cold rolling pass in step (2) is 5-15%.

7. The preparation method according to any one of claims 1 to 6, characterized in that: When preparing a platinum-ruthenium alloy sheet, the hot forging in step (2) is performed until the alloy thickness is 18-30 mm, and the cold rolling is performed until the alloy thickness is 1.0-3.0 mm; Preferably, when preparing a platinum-ruthenium alloy rod, in step (2), the billet is hot-forged and cold-rolled into a strip alloy, and then drawn to obtain the platinum-ruthenium alloy rod; Preferably, the length of the wide side of the hot forged blank is 12-16 mm; Preferably, the length of the wide side of the cold-rolled blank is 4.0-7.0 mm; Preferably, when preparing a platinum-ruthenium alloy wire, the preparation method further comprises: cold drawing and annealing the platinum-ruthenium alloy rod to obtain a platinum-ruthenium alloy wire; Preferably, the single-pass reduction rate of the cold drawing is 5-20%; Preferably, the diameter of the alloy wire obtained by cold drawing is 0.5-3.0 mm; Preferably, the annealing treatment is performed after the total processing rate of cold drawing is ≥80%; Preferably, the annealing temperature is 1000-1200°C; Preferably, the annealing treatment time is 10-15 minutes.

8. The preparation method according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: (a) preparing platinum with a purity greater than 99.95% and ruthenium with a purity greater than 99.95% to obtain a platinum-ruthenium raw material, wherein the mass of the ruthenium is 0.1-15% of the mass of the platinum-ruthenium raw material, placing the platinum-ruthenium raw material in a suspension smelting device, and evacuating the device to 10 -2 -10Pa, adjust the power of the suspension smelting device, first increase the temperature to 1900-2100℃, keep it warm for 30-60min, then increase it to 2200-2500℃ for refining, the refining time is 5-10min, then reduce the temperature to 1600-1750℃, keep it warm for 5-30min, after the smelting is completed, maintain the vacuum state, turn off the heating, cool with the furnace, and obtain the ingot; (b) heat treating the ingot at a temperature of 1000-1200° C. for a time of 10-30 min to obtain a billet; (c) hot forging the blank, wherein the deformation amount of a single pass of the hot forging is 15-35%, and annealing is performed between each two passes during the hot forging process, wherein the annealing temperature is 1000-1200° C., and the annealing time is 5-10 min. After the hot forging is completed, cold rolling is performed, wherein the deformation amount of a single pass of the cold rolling is 5-15%; When preparing a platinum-ruthenium alloy plate, the step (c) is hot forging to an alloy thickness of 18-30 mm, and then cold rolling to an alloy thickness of 1.0-3.0 mm to obtain the platinum-ruthenium alloy plate; Alternatively, when preparing a platinum-ruthenium alloy rod, in step (c), the billet is hot-forged into a rod-shaped alloy, the wide side length of the rod-shaped alloy is 12-16 mm, then cold-rolled to a wide side length of 4.0-7.0 mm, and finally drawn to obtain the platinum-ruthenium alloy rod; Alternatively, when preparing a platinum-ruthenium alloy wire, the preparation method further includes: cold drawing the platinum-ruthenium alloy rod, the single-pass surface reduction rate of the cold drawing is 5-20%, the cold drawing is performed until the alloy diameter is 0.5-3.0 mm, the total processing rate of the cold drawing is ≥80%, and then annealing is performed, the annealing temperature is 1000-1200°C, and the annealing time is 10-15min, to obtain the platinum-ruthenium alloy wire.

9. A high-purity platinum-ruthenium alloy, characterized in that: The high-purity platinum-ruthenium alloy is prepared by the preparation method described in any one of claims 1-8.

10. An application of the high-purity platinum-ruthenium alloy as claimed in claim 9, characterized in that: The high-purity platinum-ruthenium alloy is used for platinum jewelry.

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