Technology for obtaining high-strength, high-toughness and high-hardness platinum by means of component regulation and control and controlled cooling

Abstract

The invention relates to a technology for obtaining high-strength, high-toughness and high-hardness platinum by means of component regulation and control and controlled cooling, and belongs to the technical field of metal materials. The required high-strength, high-toughness and high-hardness platinum sheet, bar or wire is finally prepared through alloy smelting, component regulation and control, ordered oscillation, temperature-controlled precipitation and hot and cold machining. According to the method, component regulation and control and heat treatment control are carried out in the platinum smelting process, so that an ordered submicron-order alternately-distributed two-phase strengthening phase with superfine interlayer spacing is formed in a microstructure of the material, the purpose of synchronously improving the strength, toughness and hardness of platinum is achieved, and it can be guaranteed that the purity of platinum is 99.9% or above.

Description

Technical Field

[0001] The present invention relates to a technology for obtaining high-strength, high-toughness and high-hardness platinum through composition regulation and controlled cooling, and belongs to the technical field of metal materials. Background Art

[0002] Platinum has long held an important position in high-end jewelry and the medical field due to its excellent chemical stability, corrosion resistance, biocompatibility, and unique metallic luster. In jewelry manufacturing, platinum has become a high-end jewelry material that symbolizes eternity due to its pure silver-white luster and "never-fading" characteristics. However, its relatively soft texture (pure platinum has low hardness and is easily deformed) limits the implementation of complex process designs, and it is easily scratched or deformed by external forces during long-term wear, affecting its aesthetics and durability. In the medical field, platinum is widely used in implantable devices (such as pacemaker electrodes and vascular stents) and surgical tools (such as minimally invasive surgical instruments) because it is non-toxic and non-sensitizing to human tissue. However, the mechanical strength of traditional pure platinum is insufficient, resulting in implantable devices prone to fatigue failure under long-term physiological loads, while surgical tools face problems such as easy blunting of the cutting edge and short service life.

[0003] To enhance platinum's mechanical properties, traditional techniques often rely on alloying (e.g., adding elements like Ir and Ni to form alloys). However, high alloy content (typically >5%) significantly reduces platinum purity (<99%), resulting in a dull color and difficulty estimating its value in jewelry, as well as biocompatibility risks in the medical field (e.g., Ni may trigger allergic reactions). Furthermore, while conventional strengthening methods can increase strength, they do so at the expense of toughness, making it difficult to meet the stringent fatigue and fracture resistance requirements of medical devices.

[0004] Therefore, how to overcome the combined performance bottlenecks of platinum's strength, hardness, and toughness while maintaining a purity of ≥99.9% has become a core technical challenge urgently needed in the jewelry and medical fields. This invention, through innovative compositional manipulation and controlled cooling processes, constructs a submicron-scale reinforcement phase with ultra-fine interlayer spacing within the microstructure, providing a breakthrough solution for developing platinum materials that combine high purity, high strength, toughness, and high hardness. Summary of the Invention

[0005] The purpose of the present invention is to provide a technology for obtaining high-strength, high-toughness and high-hardness platinum by means of composition regulation and controlled cooling.

[0006] To achieve the above objectives, the present application provides a method for obtaining high-strength, high-toughness, and high-hardness platinum, the method comprising the following steps:

[0007] (1) Alloy smelting:

[0008] Platinum ingots are placed in an induction furnace for smelting at a temperature of 1800-2000°C for 0.5-1 hour to obtain molten metal liquid;

[0009] (2) Ingredient regulation:

[0010] Add yttrium hexaboride particles to the molten metal, wait until the melting reaction is complete, cool down and solidify, then continue to add platinum ingots, and heat up to obtain molten metal;

[0011] Add lanthanum hexaboride particles to the molten metal liquid, wait until the melting reaction is completed, cool down and solidify, then continue to add platinum ingots, and heat up to obtain molten metal liquid;

[0012] adding calcium hexaboride particles to the molten metal;

[0013] (3) Orderly oscillation:

[0014] The molten metal obtained in step (2) is uniformly poured into a graphite mold at a speed of 200-300 g / s, and the graphite mold is electrically heated to 1800° C. A water-cooled copper tube is wrapped around the outer ring and the bottom for preliminary cooling. The resonance device is started while the metal liquid is kept in a molten state, and the resonance frequency is set to 50-100 Hz and the resonance time is set to 30-120 s;

[0015] (4) Temperature control precipitation:

[0016] After the resonance ends, the heating of the graphite mold is stopped immediately, and supercooled water is passed through the outer ring cooling copper tube for cooling, and liquid nitrogen is passed through the bottom cooling copper tube for cooling;

[0017] (5) Hot and cold processing:

[0018] The cooled platinum ingot is processed into the required plates, bars or wires by hot forging, rolling, drawing, stamping and other means.

[0019] Optionally, in step (1), the weight of the platinum ingot placed in the induction furnace for smelting is 1 / 3 of the required total weight; and step (2) is:

[0020] Add yttrium hexaboride particles to the molten metal, wait until the melting reaction is complete, cool down and solidify, then add 1 / 3 of the required total weight of platinum ingots, and heat up to obtain molten metal;

[0021] Add lanthanum hexaboride particles to the molten metal, wait until the melting reaction is complete, cool down and solidify, then add 1 / 3 of the required total weight of platinum ingots, and heat up to obtain molten metal;

[0022] Calcium hexaboride particles are added to the molten metal.

[0023] Optionally, in step (2), the particle size of the yttrium hexaboride particles, lanthanum hexaboride particles, and calcium hexaboride particles is less than 1 micron.

[0024] Optionally, in step (2), the weight proportion of the added yttrium hexaboride particles is ≤0.1%, the weight proportion of the added lanthanum hexaboride particles is ≤0.1%, and the weight proportion of the added calcium hexaboride particles is ≤0.1%.

[0025] The present invention has achieved the following beneficial effects:

[0026] The present invention starts with the microstructure of the material and finally produces the required high-strength, high-toughness and high-hardness platinum sheets, rods or wires through alloy smelting, composition control, orderly oscillation, temperature-controlled precipitation, hot and cold processing. The present invention uses an alloy design with extremely low addition (<0.1%) and innovatively introduces oscillation treatment in the molten state to produce composition fluctuations to regulate the evolution of the microstructure. It uses graded cooling to accurately control the cooling rate and aging temperature, forming a gradient heterogeneous microstructure with a smooth transition of elements inside the material, and realizing the alternating distribution of submicron-level two-phase reinforcement phases with ultra-fine interlayer spacing in the platinum matrix to hinder dislocation movement and crack propagation, thereby simultaneously improving the strength, toughness and hardness of the material. This path breaks through the purity restrictions of traditional alloying and achieves a balance between high purity and high performance. It can reduce dependence on high-content alloys, reduce costs and improve processability. It has significant industrial application value and is suitable for a variety of scenarios requiring high-purity and high-strength platinum. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a microstructure picture of the prepared platinum material;

[0028] Figure 2 This is a microstructure picture of the prepared platinum material, showing alternating layered submicron phases. DETAILED DESCRIPTION

[0029] The specific embodiments of the present invention are described in detail below. All features disclosed in this specification, or steps in all methods or processes disclosed, except for mutually exclusive features and / or steps, can be combined in any manner.

[0030] Example 1 (Basic Process)

[0031] (1) Alloy smelting:

[0032] Take 3000g of platinum ingots (purity ≥99.95%) and smelt them in three steps:

[0033] First smelting: 1000g of platinum ingot was placed in a high-frequency induction furnace, heated to 1900°C under argon protection, and smelted for 0.8 hours to obtain molten platinum liquid.

[0034] Second smelting: add the second batch of 1000g platinum ingots, raise the temperature to 1900℃ and smelt for 0.8 hours.

[0035] Third smelting: Add the third batch of 1000g platinum ingots, raise the temperature to 1900℃ and smelt for 0.8 hours.

[0036] (2) Ingredient regulation:

[0037] First control: add 0.08% yttrium hexaboride (particle size ≤ 1 μm) to the platinum liquid after the first smelting, and after it is completely melted, cool it to 1600°C and solidify.

[0038] Second adjustment: add 0.07% lanthanum hexaboride (particle size ≤ 1 μm) to the platinum liquid after the second smelting, dissolve it, and then cool it to 1550° C. to solidify.

[0039] The third adjustment: add 0.05% calcium hexaboride (particle size ≤ 1 μm) to the platinum liquid after the third smelting, with a total addition amount of 0.20% (due to the presence of burn-off, the actual addition amount is subject to actual measurement).

[0040] (3) Orderly oscillation:

[0041] The molten metal was poured into a graphite mold preheated to 1800°C at a constant speed of 250g / s.

[0042] Start the resonance device, set the frequency to 80 Hz and the resonance time to 60 s.

[0043] (4) Temperature control precipitation:

[0044] When the resonance ends, the heating of the graphite mold is stopped immediately, and 5℃ supercooled water (flow rate 5L / min) is passed through the outer copper tube.

[0045] Liquid nitrogen was introduced into the bottom copper tube at a cooling rate of 150°C / s to room temperature.

[0046] (5) Hot and cold processing:

[0047] The ingot cooled to room temperature is annealed at 1200° C. for 20 min, and then hot forged into a slab or rod of a desired size. The obtained slab or rod is processed by cold rolling or drawing to obtain a plate or wire sample of a desired size.

[0048] Example 2 (high temperature smelting + rapid cooling)

[0049] (1) Alloy smelting:

[0050] Take 3000g of platinum ingots (purity ≥99.95%) and smelt them in three steps:

[0051] First smelting: 1000g of platinum ingot was placed in a high-frequency induction furnace, heated to 2000°C under argon protection, and smelted for 0.5 hours to obtain molten platinum liquid.

[0052] Second smelting: Add the second batch of 1000g platinum ingots, raise the temperature to 1900℃ and smelt for 0.5 hours.

[0053] Third smelting: Add the third batch of 1000g platinum ingots, raise the temperature to 1900℃ and smelt for 0.5 hours.

[0054] (2) Ingredient regulation:

[0055] First control: add 0.08% yttrium hexaboride (particle size ≤ 1 μm) to the platinum liquid after the first smelting, and after it is completely melted, cool it to 1600°C and solidify.

[0056] Second adjustment: add 0.07% lanthanum hexaboride (particle size ≤ 1 μm) to the platinum liquid after the second smelting, dissolve it, and then cool it to 1550° C. to solidify.

[0057] The third adjustment: add 0.05% calcium hexaboride (particle size ≤ 1 μm) to the platinum liquid after the third smelting, with a total addition amount of 0.20% (due to the presence of burn-off, the actual addition amount is subject to actual measurement).

[0058] (3) Orderly oscillation:

[0059] The molten metal was poured into a graphite mold preheated to 1800°C at a constant speed of 250g / s.

[0060] Start the resonance device, set the frequency to 80 Hz and the resonance time to 60 s.

[0061] (4) Temperature control precipitation:

[0062] When the resonance ends, the heating of the graphite mold is stopped immediately, and 5℃ supercooled water (flow rate 10L / min) is passed through the outer copper tube.

[0063] Liquid nitrogen was introduced into the bottom copper tube at a cooling rate of 250°C / s to room temperature.

[0064] (5) Hot and cold processing:

[0065] The ingot cooled to room temperature is annealed at 1200° C. for 20 min, and then hot forged into a slab or rod of a desired size. The obtained slab or rod is processed by cold rolling or drawing to obtain a plate or wire sample of a desired size.

[0066] Example 3 (Low-Frequency Long-Duration Oscillation)

[0067] (1) Alloy smelting:

[0068] Take 3000g of platinum ingots (purity ≥99.95%) and smelt them in three steps:

[0069] First smelting: 1000g of platinum ingot was placed in a high-frequency induction furnace, heated to 1900°C under argon protection, and smelted for 0.8 hours to obtain molten platinum liquid.

[0070] Second smelting: add the second batch of 1000g platinum ingots, raise the temperature to 1900℃ and smelt for 0.8 hours.

[0071] Third smelting: Add the third batch of 1000g platinum ingots, raise the temperature to 1900℃ and smelt for 0.8 hours.

[0072] (2) Ingredient regulation:

[0073] First control: add 0.08% yttrium hexaboride (particle size ≤ 1 μm) to the platinum liquid after the first smelting, and after it is completely melted, cool it to 1600°C and solidify.

[0074] Second adjustment: add 0.07% lanthanum hexaboride (particle size ≤ 1 μm) to the platinum liquid after the second smelting, dissolve it, and then cool it to 1550° C. to solidify.

[0075] The third adjustment: add 0.05% calcium hexaboride (particle size ≤ 1 μm) to the platinum liquid after the third smelting, with a total addition amount of 0.20% (due to the presence of burn-off, the actual addition amount is subject to actual measurement).

[0076] (3) Orderly oscillation:

[0077] The molten metal was poured into a graphite mold preheated to 1800°C at a constant speed of 250g / s.

[0078] Start the resonance device, set the frequency to 50 Hz and the resonance time to 120 s.

[0079] (4) Temperature control precipitation:

[0080] When the resonance ends, the heating of the graphite mold is stopped immediately, and 5℃ supercooled water (flow rate 5L / min) is passed through the outer copper tube.

[0081] Liquid nitrogen was introduced into the bottom copper tube at a cooling rate of 150°C / s to room temperature.

[0082] (5) Hot and cold processing:

[0083] The ingot cooled to room temperature is annealed at 1200° C. for 20 min, and then hot forged into a slab or rod of a desired size. The obtained slab or rod is processed by cold rolling or drawing to obtain a plate or wire sample of a desired size.

[0084] Example 4 (Composition Control + Frequency Change)

[0085] (1) Alloy smelting:

[0086] Take 3000g of platinum ingots (purity ≥99.95%) and smelt them in three steps:

[0087] First smelting: 1000g of platinum ingot was placed in a high-frequency induction furnace, heated to 1900°C under argon protection, and smelted for 0.8 hours to obtain molten platinum liquid.

[0088] Second smelting: add the second batch of 1000g platinum ingots, raise the temperature to 1900℃ and smelt for 0.8 hours.

[0089] Third smelting: Add the third batch of 1000g platinum ingots, raise the temperature to 1900℃ and smelt for 0.8 hours.

[0090] (2) Ingredient regulation:

[0091] First control: add 0.05% yttrium hexaboride (particle size ≤ 1 μm) to the platinum liquid after the first smelting, and after it is completely melted, cool it to 1600°C and solidify.

[0092] Second adjustment: add 0.05% lanthanum hexaboride (particle size ≤ 1 μm) to the platinum liquid after the second smelting, dissolve it, and then cool it to 1550° C. to solidify.

[0093] The third adjustment: add 0.03% calcium hexaboride (particle size ≤ 1 μm) to the platinum liquid after the third smelting, with a total addition amount of 0.20% (due to the presence of burn-off, the actual addition amount is subject to actual measurement).

[0094] (3) Orderly oscillation:

[0095] The molten metal was poured into a graphite mold preheated to 1800°C at a constant speed of 250g / s.

[0096] Start the resonance device, set the frequency to 100 Hz and the resonance time to 60 s.

[0097] (4) Temperature control precipitation:

[0098] When the resonance ends, the heating of the graphite mold is stopped immediately, and 5℃ supercooled water (flow rate 5L / min) is passed through the outer copper tube.

[0099] Liquid nitrogen was introduced into the bottom copper tube at a cooling rate of 150°C / s to room temperature.

[0100] (5) Hot and cold processing:

[0101] The ingot cooled to room temperature is annealed at 1200° C. for 20 min, and then hot forged into a slab or rod of a desired size. The obtained slab or rod is processed by cold rolling or drawing to obtain a plate or wire sample of a desired size.

[0102] Comparative Example 1 (Conventional Pt-10% Ir alloy)

[0103] (1) Alloy smelting:

[0104] 2700g of platinum ingot + 300g of iridium ingot (purity 99.95%), melting temperature 2100°C, time 1 hour.

[0105] (2) Ingredient regulation:

[0106] No hexaboride added.

[0107] (3) Orderly oscillation:

[0108] No oscillation processing.

[0109] (4) Temperature control precipitation:

[0110] Natural cooling (no controlled cooling).

[0111] (5) Hot and cold processing:

[0112] The naturally cooled ingot is annealed at 1200° C. for 20 min and then hot forged into a slab or rod of desired size. The obtained slab or rod is processed by cold rolling or drawing to obtain a plate or wire sample of desired size.

[0113] Comparative Example 2 (no oscillation and rapid cooling)

[0114] (1) Alloy smelting:

[0115] Same as Example 1.

[0116] (2) Ingredient regulation:

[0117] Same as Example 1 (Y-B6 0.08%, La-B6 0.07%, Ca-B6 0.05%).

[0118] (3) Orderly oscillation:

[0119] The resonance step is omitted and the casting is allowed to solidify naturally.

[0120] (4) Temperature control precipitation:

[0121] Only 5℃ water is passed through the bottom for cooling, and there is no active cooling on the outer ring.

[0122] (5) Hot and cold processing:

[0123] Same as Example 1.

[0124] Comparative Example 3 (Pure Platinum without Additives)

[0125] (1) Alloy smelting: 3000 g pure platinum ingot (purity 99.95%), smelting temperature 1900° C., time 0.8 h.

[0126] (2) Ingredient regulation:

[0127] No hexaboride added.

[0128] (3) Orderly oscillation:

[0129] Same as Example 1.

[0130] (4) Temperature control precipitation:

[0131] Same as Example 1.

[0132] (5) Hot and cold processing:

[0133] Same as Example 1.

[0134] The test results of the embodiments and comparative examples are as follows:

[0135]

[0136]

[0137] The above-described embodiments merely represent specific implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, and all such variations and improvements fall within the scope of protection of the present invention.

Claims

1. A method for obtaining high-strength, high-toughness and high-hardness platinum, characterized in that: The method comprises the following steps: (1) Alloy smelting: Platinum ingots are placed in an induction furnace for smelting at a temperature of 1800-2000°C for 0.5-1 hour to obtain molten metal liquid; (2) Ingredient regulation: Add yttrium hexaboride particles to the molten metal, wait until the melting reaction is complete, cool down and solidify, then continue to add platinum ingots, and heat up to obtain molten metal; Add lanthanum hexaboride particles to the molten metal liquid, wait until the melting reaction is completed, cool down and solidify, then continue to add platinum ingots, and heat up to obtain molten metal liquid; Calcium hexaboride particles are added to the molten metal. (3) Orderly oscillation: The molten metal obtained in step (2) is uniformly poured into a graphite mold at a speed of 200-300 g / s, and the graphite mold is electrically heated to 1800° C. A water-cooled copper tube is wrapped around the outer ring and the bottom for preliminary cooling. The resonance device is started while the metal liquid is kept in a molten state, and the resonance frequency is set to 50-100 Hz and the resonance time is set to 30-120 s; (4) Temperature control precipitation: After the resonance ends, the heating of the graphite mold is stopped immediately, and supercooled water is passed through the outer ring cooling copper tube for cooling, and liquid nitrogen is passed through the bottom cooling copper tube for cooling; (5) Hot and cold processing: The cooled platinum ingot is processed into the required plates, bars or wires by hot forging, rolling, drawing, stamping and other means.

2. The method according to claim 1, characterized in that In step (1), the weight of the platinum ingot placed in the induction furnace for smelting is 1 / 3 of the required total weight; 3. The method according to claim 2, characterized in that Step (2) is: Add yttrium hexaboride particles to the molten metal, wait until the melting reaction is complete, cool down and solidify, then add 1 / 3 of the required total weight of platinum ingots, and heat up to obtain molten metal; Add lanthanum hexaboride particles to the molten metal, wait until the melting reaction is complete, cool down and solidify, then add 1 / 3 of the required total weight of platinum ingots, and heat up to obtain molten metal; Calcium hexaboride particles are added to the molten metal.

4. The method according to claim 1, wherein In step (2), the particle size of the yttrium hexaboride particles is less than 1 micron.

5. The method according to claim 1, wherein In step (2), the particle size of the lanthanum hexaboride particles is less than 1 micron.

6. The method according to claim 1, characterized in that In step (2), the particle size of calcium hexaboride particles is less than 1 micron.

7. The method according to claim 1, characterized in that In step (2), the weight proportion of the added yttrium hexaboride particles is ≤0.1%.

8. The method according to claim 1, characterized in that In step (2), the weight proportion of the added lanthanum hexaboride particles is ≤0.1%.

9. The method according to claim 1, characterized in that In step (2), the weight proportion of the added calcium hexaboride particles is ≤0.1%.

10. High-strength, high-toughness and high-hardness platinum obtained by the method according to any one of claims 1 to 9.

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