A palladium-based multi-component alloy and a preparation method and application thereof

Abstract

This invention discloses a palladium-based multi-element alloy, its preparation method, and its applications, belonging to the field of alloy smelting technology. By mass percentage, it comprises the following components: 20-40 wt% copper, 8-18 wt% silver, 2-8 wt% gold, 2-8 wt% platinum, 0.5-3 wt% ruthenium, and 0.5-1.5 wt% zinc, with the balance being palladium and unavoidable impurities, the total content of which is ≤1 wt%. This invention, through precise control of the ratio of basic and modifying elements and the weight ratio between metals, combined with a customized preparation process, enables the alloy to form a stable B2 crystal structure, reducing precipitate formation and achieving a synergistic effect of high electrical conductivity and high hardness. Simultaneously, the process exhibits strong controllability, is suitable for industrial mass production, and has a wide range of applications.

Description

Technical Field

[0001] This invention belongs to the field of alloy technology, and particularly relates to a palladium-based multi-element alloy, its preparation method, and its application. Background Technology

[0002] Currently, palladium-based alloys have broad application prospects in fields such as electronic connectors, high-end contact materials, and components for corrosive environments. However, existing palladium-based alloys generally suffer from the following key technical bottlenecks: (1) Poor synergy between conductivity and hardness: When traditional palladium-based alloys increase hardness (e.g., through solid solution strengthening or precipitation strengthening), lattice distortion often intensifies, electron scattering is enhanced, and conductivity decreases significantly, making it difficult to meet the application requirements of high conductivity and high wear resistance; (2) High tendency to form precipitates: During heat treatment or long-term service, copper-rich, silver-rich, and other second-phase particles are easily precipitated in the alloy, which not only destroys the continuity of the matrix but also becomes the corrosion initiation point, accelerating material failure; (3) Low controllability of preparation process: Existing smelting and heat treatment processes have insufficient precision in controlling compositional segregation, grain size, and phase composition, making it difficult to stably obtain the target microstructure, resulting in large performance fluctuations between batches, which restricts industrial mass production.

[0003] The aforementioned problems collectively limit the large-scale application of palladium-based alloys in high-end fields such as high-reliability electronic devices, marine engineering, and precision instruments. Therefore, there is an urgent need to develop a novel palladium-based multi-element alloy system that can achieve stable formation of an ordered B2 structure by precisely controlling the weight ratio of the base elements and modifying elements, thereby fundamentally suppressing the precipitation of harmful phases, simultaneously improving electrical conductivity, hardness, and corrosion resistance, and constructing a repeatable and scalable standardized preparation process. Summary of the Invention

[0004] To address the problems of poor synergy between electrical conductivity and hardness, insufficient corrosion resistance, easy formation of precipitates, and low controllability of preparation processes in existing palladium-based alloys, this invention provides a palladium-based multi-element alloy, its preparation method, and its applications. By precisely controlling the ratio of basic elements to modifying elements and the weight ratio between metals, combined with a customized preparation process, the alloy forms a stable B2 crystal structure, reduces precipitate formation, and achieves synergistic performance of high electrical conductivity, high hardness, and high corrosion resistance. At the same time, the process is highly controllable, suitable for industrial mass production, and has a wide range of applications.

[0005] In a first aspect, the present invention provides a palladium-based multi-element alloy comprising, by weight percentage: 20-40 wt% copper, 8-18 wt% silver, 2-8 wt% gold, 2-8 wt% platinum, 0.5-3 wt% ruthenium, 0.5-1.5 wt% zinc, with the balance being palladium and unavoidable impurities, the total content of said impurities being ≤1 wt%.

[0006] The palladium-based multi-element alloy prepared by this invention contains a crystalline phase with a B2 crystal structure, and the volume percentage of silver, palladium, and binary silver-palladium compound precipitates is ≤5%. Palladium is the base element of the alloy and the core element for forming the B2 crystal structure, while ensuring the alloy's conductivity and corrosion resistance. If the palladium content is too low, it is difficult to form a stable B2 crystal structure, resulting in a decrease in the alloy's hardness and strength; if the content is too high, it increases the alloy cost and reduces the conductivity. Copper and palladium synergistically form the B2 crystal structure (CsCl type body-centered cubic structure). If the copper content is too low, the proportion of the B2 crystal structure will be insufficient; if it is too high, copper-based precipitates will easily form, affecting the alloy's conductivity and oxidation resistance. Silver acts as a conductivity enhancer, improving the alloy's conductivity, and also participates in the formation of the B2 crystal structure. If the silver content is too low, the conductivity enhancement effect will be insignificant; if it is too high, silver precipitates will easily form, leading to fluctuations in the alloy's contact resistance.

[0007] Gold and platinum, as corrosion-resistant modifiers, can significantly improve the corrosion resistance and oxidation resistance of alloys when introduced synergistically, making them suitable for harsh working conditions such as acidic electroplating environments and high-humidity semiconductor testing environments. At the same time, gold and platinum can refine the alloy grains and improve the mechanical strength of the alloy. If the content of the two is too low, the corrosion resistance modification effect will be insufficient; if the content is too high, it will reduce the electrical conductivity of the alloy and significantly increase the cost. Ruthenium is a precipitation hardening element, which forms precipitates in the alloy and is mainly distributed at the grain boundaries, thereby achieving grain boundary strengthening, improving the hardness and high-temperature stability of the alloy, and preventing grain growth and creep. If the ruthenium content is too low, the strengthening effect will be insufficient; if the content is too high, a large amount of ruthenium precipitates will be generated, affecting the conductivity of the alloy. Zinc is a grain refiner. Trace amounts of zinc can effectively refine the average grain size of the alloy, improving the plasticity and formability of the alloy. If the zinc content is too low, the refining effect will be insignificant; if the content is too high, zinc oxide will be generated, affecting the electrical contact performance of the alloy. Impurities are unavoidable trace elements in the alloy preparation process, such as iron, nickel, and carbon. Their total content is controlled within 1 wt% to avoid impurities affecting the crystal structure and performance uniformity of the alloy.

[0008] Preferably, the weight ratio of palladium to copper is 1.1 to 1.5, the weight ratio of palladium to silver is 3.3 to 5.5, and the molar ratio of palladium to ruthenium is ≥4:1. This range is key to forming a stable B2 crystal structure, ensuring that palladium, copper, and silver fully participate in the formation of the B2 crystal structure and reducing the formation of precipitates of silver, palladium, and binary silver-palladium compounds. At the same time, at least 90 vol% of the ruthenium precipitates formed in the alloy are distributed at the alloy grain boundaries, achieving efficient grain boundary strengthening and improving the hardness and tensile strength of the alloy.

[0009] Preferably, the crystalline phase with the B2 crystal structure has a silver content ≥9wt%, a palladium content 41~53wt%, and a copper content 22~38wt%. Within this composition range, the B2 crystal structure exhibits higher stability, resulting in better synergy between electrical conductivity and hardness in the alloy. The palladium-based multi-element alloy has an average grain size ≤1.5μm, an electrical conductivity ≥28%IACS, and a Vickers hardness ≥400HV. 0.05 With a tensile strength ≥1350MPa, its overall performance is significantly better than that of existing palladium-based alloys.

[0010] Further preferred, the weight percentages of each element are: 45-52 wt% palladium, 28-36 wt% copper, 10-15 wt% silver, 3-6 wt% gold, 3-6 wt% platinum, 1-2 wt% ruthenium, and 0.8-1.2 wt% zinc, with a total impurity content ≤0.5 wt%; the volume percentage of silver, palladium, and binary silver-palladium compounds as precipitates is ≤2%. Under this optimal ratio, the alloy's various properties achieve the best synergy, with electrical conductivity increasing to ≥30% IACS and hardness ≥420 HV. 0.05 It has a tensile strength ≥1400MPa and excellent corrosion resistance and oxidation resistance.

[0011] Secondly, the present invention provides a method for preparing a palladium-based multi-element alloy, comprising the following steps: S1. Pre-alloying preparation: Palladium and ruthenium are vacuum melted and pre-alloyed to obtain palladium-ruthenium pre-alloy, wherein the molar ratio of palladium to ruthenium is ≥4:1. Ruthenium has a high melting point and poor compatibility with palladium. Pre-alloying can fully integrate palladium and ruthenium, avoid compositional segregation during subsequent melting, and improve the compositional uniformity of the alloy.

[0012] S2. Vacuum Melting and Casting Ingots: The palladium-ruthenium pre-alloy, copper, silver, gold, platinum, and zinc are weighed according to the specified ratio and placed in a vacuum induction melting furnace at a vacuum degree ≤10. -3 The alloy is smelted under a protective gas atmosphere at a temperature 50-80°C higher than its melting point. The smelting is then poured into a copper mold and cooled to form an alloy ingot. The protective gas is argon with a partial pressure of 20-80 mbar. Vacuum smelting effectively removes gaseous impurities (such as oxygen, nitrogen, and hydrogen) from the raw materials, preventing defects such as porosity and looseness in the alloy. Argon protection prevents the loss of easily evaporable elements such as silver, ensuring the accuracy of the alloy composition. The smelting temperature, 50-80°C higher than the melting point, ensures complete melting of the raw materials while avoiding element burn-off and thermal shock to the mold caused by excessive heating.

[0013] Preferably, in step S2, all raw materials are pretreated before smelting. The pretreatment involves vacuum drying at 150~200℃ for 2~4 hours to remove surface moisture and adsorbed gases, further reducing gaseous impurities in the alloy. The melt temperature during casting is 50~60℃ higher than the alloy melting point. The copper mold is an uncooled permanent copper mold to ensure a moderate cooling rate of the ingot and prevent cracks from forming in the ingot.

[0014] S3. Multi-stage annealing and rolling: The alloy ingot undergoes multiple annealing-quenching-rolling cycles. Each annealing cycle involves holding the ingot at 800~920℃ for 20~60 min, followed by water quenching at a cooling rate ≥15℃ / s. The cross-sectional thinning rate of a single rolling cycle is 40~60%, and the cycle is repeated 3~5 times. Annealing eliminates internal stress in the ingot, rearranges the alloy's crystal structure, and promotes the formation of B2 crystal structure. Quenching quickly fixes the high-temperature phase structure of the alloy, preventing precipitate formation. Rolling refines the alloy grains, improving the alloy's density and mechanical strength. Multiple cycles allow for gradual optimization of the alloy's structure and properties, preventing alloy cracking caused by excessive deformation in a single rolling cycle.

[0015] S4. Precision rolling: The alloy billet processed in step S3 is precision rolled to a final thickness of 20~100μm to obtain alloy strip / wire. Precision rolling can further improve the density and dimensional accuracy of the alloy to meet the dimensional requirements of formed bodies such as probes, springs, and wires.

[0016] S5. Age Hardening Treatment: The finely rolled alloy strip / wire is held at 360~400℃ for 3~6 minutes to complete age hardening, yielding the palladium-based multi-element alloy product. Age hardening promotes the uniform precipitation and distribution of ruthenium precipitates at grain boundaries, achieving precipitation hardening and grain boundary strengthening. Simultaneously, it further stabilizes the B2 crystal structure, improving the alloy's hardness and electrical conductivity.

[0017] Preferably, in step S3, the annealing is carried out in a reducing atmosphere, which is a carbon monoxide atmosphere, to prevent the alloy from oxidizing during high-temperature annealing and to ensure the surface quality and compositional uniformity of the alloy. After the last annealing-quenching-rolling, the cross-sectional dimensions of the alloy billet are 1.5 to 2 times larger than the final product, leaving machining allowance for subsequent precision rolling.

[0018] Preferably, in step S5, the aging hardening treatment is carried out in an argon protective atmosphere, and after the heat preservation is completed, it is naturally cooled to room temperature to prevent oxidation of the alloy surface and ensure the performance stability of the alloy.

[0019] Thirdly, the present invention provides a molded body of the above-mentioned palladium-based multi-element alloy, wherein the molded body is one of a probe, an electroplated fixture spring, and a sliding contact wire; the probe is a cylindrical structure with a minimum cross-section of ≤500μm and a maximum cross-section of ≤10mm at the bottom, suitable for micro-electrical contact testing of semiconductor wafers; the electroplated fixture spring is a thin sheet structure with a thickness of 0.08~0.12mm to ensure the elasticity and conductive contact performance of the spring; the sliding contact wire is a wire with a circular cross-section and a diameter of 50~500μm, suitable for the sliding electrical contact requirements of electrical equipment.

[0020] Fourthly, this invention provides applications of the aforementioned palladium-based multi-element alloy, specifically in the manufacture of probes for semiconductor wafer integrated circuit testing, the manufacture of conductive springs for silicon wafer electroplating fixtures in electroplating processes, and the manufacture of sliding contacts or electrical contacts for electrical equipment. In these applications, the alloy achieves stable high-current transmission, low contact resistance, wear resistance, and corrosion resistance, significantly improving the service life and performance of electrical contact elements.

[0021] Compared with the prior art, the present invention has the following beneficial effects: (1) The palladium-based multi-element alloy of the present invention achieves high electrical conductivity (≥28% IACS) and high hardness (≥400HV) by precisely controlling the ratio and weight ratio of palladium, copper and silver basic elements, combined with the synergistic effect of gold, platinum, ruthenium and zinc modifying elements, so that the alloy forms a stable B2 crystal structure and the volume ratio of silver, palladium and binary silver-palladium compound precipitates is ≤5%. 0.05 The alloy exhibits synergistic properties of high tensile strength (≥1350MPa), while the gold-platinum synergy effectively enhances the alloy's corrosion resistance and oxidation resistance. Ruthenium enables efficient grain boundary strengthening, and zinc refines the grains. The overall performance of the alloy is significantly superior to existing palladium-based alloys.

[0022] (2) The preparation method of the present invention adopts the pre-alloying + vacuum melting method, which effectively solves the problems of poor compatibility between ruthenium and palladium and easy compositional segregation, and improves the compositional uniformity of the alloy; the multi-stage annealing-quenching-rolling cycle treatment promotes the formation of B2 crystal structure, reduces the formation of precipitates, and refines the grains; the customized age hardening treatment realizes the efficient combination of precipitation hardening and grain boundary strengthening, the process is highly controllable, the alloy yield is high, and it is suitable for industrial mass production.

[0023] (3) The palladium-based multi-element alloy of the present invention can be prepared into various shaped bodies such as probes, electroplating fixture springs, and sliding contact wires, and can be applied to multiple fields such as semiconductor testing, electroplating, and electrical contact. It is suitable for harsh operating conditions, has stable electrical contact performance, is wear-resistant, corrosion-resistant, has a long service life, and has high technical added value, and has broad market application prospects. Detailed Implementation

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] This invention discloses a palladium-based multi-element alloy, comprising the following components by mass percentage: 20-40 wt% copper, 8-18 wt% silver, 2-8 wt% gold, 2-8 wt% platinum, 0.5-3 wt% ruthenium, 0.5-1.5 wt% zinc, with the balance being palladium and unavoidable impurities, the total content of which is ≤1 wt%.

[0026] In some preferred embodiments, the weight ratio of palladium to copper is 1.1 to 1.5, the weight ratio of palladium to silver is 3.3 to 5.5, and the molar ratio of palladium to ruthenium is ≥4:1. This range is key to forming a stable B2 crystal structure, ensuring that palladium, copper, and silver fully participate in the formation of the B2 crystal structure and reducing the formation of precipitates of silver, palladium, and binary silver-palladium compounds. At the same time, at least 90 vol% of the ruthenium precipitates formed in the alloy are distributed at the alloy grain boundaries, which is beneficial to achieving efficient grain boundary strengthening and improving the hardness and tensile strength of the alloy.

[0027] In some preferred embodiments, the palladium-based multi-element alloy with a B2 crystal structure has a silver content ≥9wt%, a palladium content of 41~53wt%, and a copper content of 22~38wt%. Within this composition range, the B2 crystal structure exhibits higher stability, resulting in better synergy between electrical conductivity and hardness. The palladium-based multi-element alloy has an average grain size ≤1.5μm, an electrical conductivity ≥28%IACS, and a Vickers hardness ≥400HV. 0.05 With a tensile strength ≥1350MPa, its overall performance is significantly better than that of existing palladium-based alloys.

[0028] In some preferred embodiments, the weight percentages of each element are: 45~52wt% palladium, 28~36wt% copper, 10~15wt% silver, 3~6wt% gold, 3~6wt% platinum, 1~2wt% ruthenium, and 0.8~1.2wt% zinc, with a total impurity content ≤0.5wt%; the volume percentage of the binary silver-palladium compound precipitate is ≤2%. Under this optimal ratio, the alloy achieves the best synergy in various properties, with electrical conductivity ≥30% IACS, hardness ≥420HV0.05, tensile strength ≥1400MPa, and excellent corrosion resistance and oxidation resistance.

[0029] This invention also provides a method for preparing a palladium-based multi-element alloy, comprising the following steps: S1. Pre-alloying preparation: Palladium and ruthenium are vacuum melted and pre-alloyed to obtain palladium-ruthenium pre-alloy, wherein the molar ratio of palladium to ruthenium is ≥4:1. Ruthenium has a high melting point and poor compatibility with palladium. Pre-alloying can fully integrate palladium and ruthenium, avoid compositional segregation during subsequent melting, and improve the compositional uniformity of the alloy.

[0030] S2. Vacuum Melting and Casting Ingots: The palladium-ruthenium pre-alloy, copper, silver, gold, platinum, and zinc are weighed according to the specified ratio and placed in a vacuum induction melting furnace at a vacuum degree ≤10. -3 The alloy is smelted under a protective gas atmosphere at a temperature 50-80°C higher than its melting point. The smelting is then poured into a copper mold and cooled to form an alloy ingot. The protective gas is argon with a partial pressure of 20-80 mbar. Vacuum smelting effectively removes gaseous impurities (such as oxygen, nitrogen, and hydrogen) from the raw materials, preventing defects such as porosity and looseness in the alloy. Argon protection prevents the loss of easily evaporable elements such as silver, ensuring the accuracy of the alloy composition. The smelting temperature, 50-80°C higher than the melting point, ensures complete melting of the raw materials while avoiding element burn-off and thermal shock to the mold caused by excessive heating.

[0031] S3. Multi-stage annealing and rolling: The alloy ingot undergoes multiple annealing-quenching-rolling cycles. Each annealing cycle involves holding the ingot at 800~920℃ for 20~60 min, followed by water quenching at a cooling rate ≥15℃ / s. The cross-sectional thinning rate of a single rolling cycle is 40~60%, and the cycle is repeated 3~5 times. Annealing eliminates internal stress in the ingot, rearranges the alloy's crystal structure, and promotes the formation of B2 crystal structure. Quenching quickly fixes the high-temperature phase structure of the alloy, preventing precipitate formation. Rolling refines the alloy grains, improving the alloy's density and mechanical strength. Multiple cycles allow for gradual optimization of the alloy's structure and properties, preventing alloy cracking caused by excessive deformation in a single rolling cycle.

[0032] S4. Precision rolling: The alloy billet processed in step S3 is precision rolled to a final thickness of 20~100μm to obtain alloy strip / wire. Precision rolling can further improve the density and dimensional accuracy of the alloy to meet the dimensional requirements of formed bodies such as probes, springs, and wires.

[0033] S5. Age Hardening Treatment: The finely rolled alloy strip / wire is held at 360~400℃ for 3~6 minutes to complete age hardening, yielding the palladium-based multi-element alloy product. Age hardening promotes the uniform precipitation and distribution of ruthenium precipitates at grain boundaries, achieving precipitation hardening and grain boundary strengthening. Simultaneously, it further stabilizes the B2 crystal structure, improving the alloy's hardness and electrical conductivity.

[0034] In some preferred embodiments, in step S2, all raw materials are pretreated before smelting. The pretreatment involves vacuum drying at 150~200℃ for 2~4 hours to remove surface moisture and adsorbed gases from the raw materials, further reducing gaseous impurities in the alloy. The melt temperature during casting is 50~60℃ higher than the alloy melting point. The copper mold is an uncooled permanent copper mold to ensure a moderate cooling rate of the ingot and avoid cracking of the ingot.

[0035] In some preferred embodiments, in step S3, annealing is carried out in a reducing atmosphere, which is a carbon monoxide atmosphere, to prevent the alloy from oxidizing during high-temperature annealing and to ensure the surface quality and compositional uniformity of the alloy; after the last annealing-quenching, the cross-sectional dimensions of the alloy billet are 1.5 to 2 times larger than the final product, leaving machining allowance for subsequent precision rolling.

[0036] In some preferred embodiments, in step S5, the aging hardening treatment is carried out in an argon protective atmosphere, and after the heat preservation is completed, it is naturally cooled to room temperature to prevent oxidation of the alloy surface and ensure the performance stability of the alloy.

[0037] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to specific embodiments.

[0038] It should be noted that any aspects not described in detail in the embodiments of the present invention are conventional techniques in the field and will not be elaborated upon.

[0039] The electrical conductivity test is based on standard GB / T 351-2019; the microhardness test is based on standard GB / T4340.1-2024; the tensile strength test is based on standard GB / T 228.1-2021; and the second phase precipitate volume ratio test is based on standard GB / T 15749-2020.

[0040] Example 1 A palladium-based multi-element alloy, wherein the weight percentages of each element are: 42wt% palladium, 31wt% copper, 12wt% silver, 8wt% gold, 3wt% platinum, 3wt% ruthenium, 0.8wt% zinc, and the total impurity content is 0.2wt%.

[0041] The preparation process of palladium-based multi-element alloys is as follows: S1, Pre-alloying preparation: Palladium and ruthenium are mixed and then subjected to a vacuum of 10... -3 Palladium-ruthenium pre-alloy was obtained by vacuum melting and pre-alloying under Pa and argon atmosphere (partial pressure of 50 mbar) at a melting temperature of 1700℃. S2. Vacuum Melting and Casting Ingots: Weigh the palladium-ruthenium pre-alloy, copper, silver, gold, platinum, and zinc (copper, silver, gold, platinum, and zinc are added in elemental form) according to the above proportions. Vacuum dry all raw materials at 180°C for 3 hours to remove surface moisture and adsorbed gases. After pretreatment, place the materials in a vacuum induction melting furnace at a vacuum degree of 10... -3 The alloy was smelted under an argon atmosphere (partial pressure of 50 mbar) at a temperature of 1660℃ (the melting point of the palladium-ruthenium pre-alloy is 1585℃), and then cast into a copper mold to cool and solidify, thus obtaining an alloy ingot. S3. Multi-stage annealing and rolling: The alloy ingot is subjected to multiple annealing-quenching-rolling cycles. Each annealing is held at 900℃ for 50 minutes, followed by water quenching at a cooling rate of 20℃ / s. The cross-sectional thinning rate of a single rolling (cold rolling, the same below) is 50%, and the cycle is repeated 4 times. S4. Finish rolling: The alloy billet processed in step S3 is finished rolled (cold rolled, the same below) to a final thickness of 50μm to obtain an alloy strip; S5. Age hardening treatment: The finely rolled alloy strip is held at 400℃ for 5 minutes to complete the age hardening and obtain the palladium-based multi-element alloy finished product.

[0042] Testing revealed that the volume percentage of the binary silver-palladium compound precipitate in the palladium-based multi-element alloy prepared in this embodiment was only 1.3%, and the alloy's electrical conductivity could be increased to 35% IACS, with a hardness of 450 HV. 0.05 Tensile strength 1450MPa.

[0043] Example 2 A palladium-based multi-element alloy, wherein the weight percentages of each element are: 42.3 wt% palladium, 39 wt% copper, 10 wt% silver, 2 wt% gold, 3 wt% platinum, 3 wt% ruthenium, 0.5 wt% zinc, and the total impurity content is 0.2 wt%.

[0044] The preparation process is the same as in Example 1.

[0045] Testing revealed that the volume percentage of the binary silver-palladium compound precipitate in the palladium-based multi-element alloy prepared in this embodiment was only 1.1%, and the alloy's electrical conductivity could be increased to 40% IACS, with a hardness of 405 HV. 0.05 Tensile strength 1494 MPa.

[0046] Example 3 A palladium-based multi-element alloy, wherein the weight percentages of each element are: 40wt% palladium, 27wt% copper, 12wt% silver, 8wt% gold, 8wt% platinum, 3wt% ruthenium, 1.5wt% zinc, and the total impurity content is 0.5wt%.

[0047] The preparation process is the same as in Example 1.

[0048] Testing revealed that the volume percentage of the binary silver-palladium compound precipitate in the palladium-based multi-element alloy prepared in this embodiment was only 1.5%, and the alloy's electrical conductivity could be increased to 36% IACS, with a hardness of 410 HV. 0.05 Tensile strength 1412 MPa.

[0049] Example 4 A palladium-based multi-element alloy, wherein the weight percentages of each element are the same as in Example 1.

[0050] The preparation process is as follows: S1-S2, same as in Example 1; S3. Multi-stage annealing and rolling: The alloy ingot is subjected to multiple annealing-quenching-rolling cycles. Each annealing is held at 850℃ for 60 minutes, followed by water quenching at a cooling rate of 25℃ / s. The cross-sectional thinning rate of each rolling is 45%, and the cycle is repeated 5 times. S4, -S5, same as in Example 1.

[0051] Testing revealed that the volume percentage of the binary silver-palladium compound precipitate in the palladium-based multi-element alloy prepared in this embodiment was only 1.15%, and the alloy's electrical conductivity could be increased to 36% IACS, with a hardness of 415 HV. 0.05 Tensile strength 1508MPa.

[0052] Comparative Example 1 A palladium-based multi-element alloy, wherein the weight percentages of each element are: 36wt% palladium, 31wt% copper, 16wt% silver, 4wt% gold, 3wt% platinum, 9wt% ruthenium, 0.8wt% zinc, and the total impurity content is 0.2wt%.

[0053] The preparation method is the same as in Example 1.

[0054] Testing revealed that the molar ratio of palladium to ruthenium in this comparative example was 3.8:1. The volume percentage of the binary silver-palladium compound precipitate in the palladium-based multi-element alloy prepared in this comparative example was only 2.7%. The alloy exhibited an electrical conductivity of 15% IACS and a hardness of 465 HV. 0.05 Tensile strength 1308MPa.

[0055] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A palladium-based multi-element alloy, characterized in that, It comprises, by weight percentage, the following components: 20-40 wt% copper, 8-18 wt% silver, 2-8 wt% gold, 2-8 wt% platinum, 0.5-3 wt% ruthenium, 0.5-1.5 wt% zinc, with the balance being palladium and unavoidable impurities, the total content of which is ≤1 wt%.

2. The palladium-based multi-element alloy according to claim 1, characterized in that, The mass ratio of palladium to copper is 1.1 to 1.5, and the mass ratio of palladium to silver is 3.3 to 5.5; the molar ratio of palladium to ruthenium is ≥4:

1.

3. A method for preparing a palladium-based multi-element alloy as described in claim 1 or 2, characterized in that, Includes the following steps: S1. Palladium and ruthenium are vacuum melted and pre-alloyed to obtain a palladium-ruthenium pre-alloy; S2. Weigh the palladium-ruthenium pre-alloy with copper, silver, gold, platinum, and zinc according to the specified ratio, and heat under a vacuum of ≤10. -3 Vacuum melting is carried out under a protective gas atmosphere; Cooling and shaping yields an alloy ingot; S3. The alloy ingot is subjected to an annealing-quenching-rolling cycle treatment, and the cycle treatment is repeated 3 to 5 times. S4. The alloy billet treated in step S3 is precision rolled to a final thickness of 20~100μm to obtain an alloy strip; S5. Hold the finely rolled alloy strip at 360~400℃ for 3~6 minutes to complete the age hardening and obtain the palladium-based multi-element alloy product.

4. The preparation method according to claim 3, characterized in that, In step S2, the vacuum melting process is carried out at a melting temperature that is 50-80°C higher than the alloy melting point.

5. The preparation method according to claim 3, characterized in that, Before smelting in step S2, all raw materials are pretreated by vacuum drying at 150-200°C for 2-4 hours.

6. The preparation method according to claim 4, characterized in that, The protective gas is argon with a partial pressure of 20~80 mbar.

7. The preparation method according to claim 3, characterized in that, The single annealing is carried out at 800~920℃ for 20~60min, followed by water quenching with a cooling rate ≥15℃ / s. The cross-sectional thinning rate of the single rolling is 40~60%.

8. The preparation method according to claim 3, characterized in that, The aging hardening treatment in S5 is carried out in an argon protective atmosphere, and after the heat preservation is completed, it is naturally cooled to room temperature.

9. The application of the palladium-based multi-element alloy as described in claim 1 or 2 in the preparation of probes for testing semiconductor wafer integrated circuits, conductive springs for silicon wafer electroplating fixtures in electroplating processes, and sliding contacts or electrical contacts for electrical equipment.