Platinum alloy electrode material and preparation method thereof

Abstract

The invention discloses a platinum alloy electrode material and a preparation method thereof, and belongs to the technical field of rare and noble metal high-temperature alloys. Metal of high-melting-point Pt (1772 DEG C), Ni (1450 DEG C), V (1902 DEG C) and Ru (2334 DEG C) serves as alloy elements, the vacuum induction melting and suction casting rapid solidification technology is adopted for preparing PtNiVRu quaternary alloy block-shaped and cylindrical cast ingots, and the cast ingots have the advantages of being uniform in structure, free of segregation, shrinkage cavities and looseness and the like; products in the shapes of sheets and wires are finally obtained through proper heat treatment and cold machining processes. The finally obtained platinum alloy electrode material is high in density, high in hardness, low in resistivity and good in fusion welding resistance and arc ablation resistance.

Description

Technical Field

[0001] The invention relates to a platinum alloy electrode material and a preparation method thereof, belonging to the technical field of rare and precious metal high-temperature alloys. Background Art

[0002] Platinum alloy electrode materials mainly include Pt-Ir alloys. At high temperatures, Pt and Ir form a continuous solid solution. As the temperature decreases, a miscible gap of (Pt, Ir) → (Pt) + (Ir) appears in the entire composition range, so that although the Pt-Ir alloy has excellent performance at high temperatures, it exhibits component segregation at low temperatures. In order to further improve the performance of Pt-Ir contact materials, improve their hardness, arc corrosion resistance, welding resistance, and performance in high temperature stress environments, the method of adding alloy elements is usually adopted; for example: Pt-Ir-Os, Pt-Ir-Rh, Pt-Ir-Cr, Pt-Ir-Ni and other materials, which improve their high temperature working performance, but increase resistivity and are expensive. Adding appropriate amount of La, Sm, Y rare earth elements to Pt-Ir alloy, rare earth elements cause grain refinement and produce dispersed precipitation phase, so that the strength of the alloy is improved; adding Zr, Mo, Ni, W and other elements to Pt-Ir alloy, while refining the alloy structure, improves the melting point, density, hardness of the alloy, improves the high temperature stability of the electrical contact material, and reduces the cost. For Pt-Ir electrical contact materials used under high temperature conditions (above 1500℃), in addition to paying attention to the chemical, physical, mechanical and processing properties of the materials, we should also pay attention to the physical and electrical properties of the materials under high temperature environment and DC current conditions, microstructure, high temperature mechanical properties, arc erosion, metal atom migration performance, surface welding and oxidation corrosion of the contact points and other characteristics.

[0003] How to connect and disconnect load current at low cost and high efficiency, and improve the reliability, stability, accuracy and service life of various switches, electrical appliances, instruments and meters, especially for electrode materials used in high temperature conditions above 1500℃ such as aircraft engine ignition contacts and gas turbine spark plug electrodes, has always been a difficult problem that needs to be solved in the use of electrode materials.

[0004] At present, the main problems of Pt-Ir electrode materials in China are: the traditional vacuum melting and water-cooled copper mold casting technology and process have alloy material structure segregation, shrinkage, cold shut and loose defects accounting for 50%, low yield rate, resulting in unstable physical and mechanical properties of materials in different parts of the upper, middle and lower parts of the same ingot; resulting in poor resistance to welding and arc ablation of materials, and the life of the electrode is only 50,000 times. The price of Pt-Ir electrode materials is expensive, etc. The above problems have become the main bottleneck restricting the development of platinum alloy electrode materials. Summary of the invention

[0005] To overcome the problems in the background art, the object of the present invention is to provide a platinum alloy electrode material and a preparation method thereof.

[0006] To achieve the above object, the present invention is realized through the following technical solutions:

[0007] A platinum alloy electrode material, comprising elements in the following weight percentages: 1.0% - 5.0% Ni, 1.0% - 5.0% V, 1.0% - 5.0% Ru, and the balance being Pt.

[0008] The present invention micro - alloyizes Ni, V, and Ru to form a PtNiVRu quaternary alloy, which improves the electrical properties of the alloy without affecting its thermal conductivity. Therefore, the platinum alloy electrode material of the present invention has good electrical properties at the same time.

[0009] A preparation method of a platinum alloy electrode material comprises the following steps:

[0010] (1) According to the component content of the platinum alloy electrode material, the alloy raw materials are subjected to induction melting, and then a platinum alloy ingot blank is obtained by vacuum suction casting;

[0011] (2) The platinum alloy ingot blank is subjected to rolling and drawing treatments; intermediate annealing is carried out during the rolling and drawing processes, and finally a platinum alloy electrode material is obtained.

[0012] The present invention adopts vacuum induction melting + suction casting rapid solidification technology, and the cooling rate reaches 1×10 3 K / s or more. The formed PtNiVRu - based quaternary alloy has the characteristics of uniform structure, no segregation, no shrinkage cavity, no porosity, etc., and has high density, high hardness, low resistivity, good anti - fusion welding property and arc erosion resistance.

[0013] More preferably, the temperature of the induction melting is 1400 - 2000 °C, and the time is 10 - 30 min.

[0014] More preferably, in the vacuum suction casting, the liquid flow diameter is Ф5mm - Ф8mm, the suction casting vacuum degree < 4×10 -3 Pa, and the cooling rate of the vacuum suction casting is 1×10 3 K / s or more.

[0015] More preferably, the intermediate annealing is at 1100 - 1300 °C, and the time is 30 - 60 min.

[0016] Advantages of the present invention: The present invention uses metals with high melting points, such as Pt (1772 °C), Ni (1450 °C), V (1902 °C), and Ru (2334 °C), as alloying elements, and prepares bulk and cylindrical ingots of PtNiVRu quaternary alloys by vacuum induction melting + suction casting rapid solidification technology. The ingots have the characteristics of uniform structure, no segregation, no shrinkage cavity, and no porosity; through appropriate heat treatment and cold working processes, products in the shape of sheets and wires are finally obtained. The finally obtained platinum alloy electrode material has a high density, high hardness, low resistivity, good anti-welding property, and good arc erosion resistance. Specific embodiments

[0017] The following further elaborates on the present invention with reference to specific embodiments, but the protection scope of the present invention is not limited thereto.

[0018] Example 1

[0019] A preparation method of a platinum alloy electrode material, the preparation steps are as follows:

[0020] (1) Platinum alloy melting and suction casting are carried out in a vacuum (vacuum degree < 4×10 -3 Pa) induction melting + vacuum suction casting integrated equipment (specific alloy composition: Ni 1.0%, V 1.0%, Ru 1.0%, the balance is Pt; melting temperature is 1400 °C, time is 10 min, liquid flow diameter is Ф5 mm, suction casting vacuum degree < 4×10 -3 Pa, the cooling rate of vacuum suction casting is 1×10 3 K / s, and the thickness of the obtained bulk ingot blank is 8 mm, and the diameter of the cylindrical ingot blank is Ф8 mm.

[0021] (2) The intermediate annealing temperature is 1100 °C and the time is 30 min. Cold working such as rolling and drawing of the platinum alloy ingot blank is carried out. Finally, the thickness of the PtNiVRu quaternary alloy sheet product is ≠0.5 mm, the diameter of the wire product is Ф0.5 mm, and the density is 20.8 g / cm 3 , hardness (Hv0.2) 180.0, resistivity 21.0 μΩ·cm.

[0022] Example 2

[0023] A preparation method of a platinum alloy electrode material, the preparation steps are as follows:

[0024] (1) Platinum alloy melting and suction casting are carried out in a vacuum (vacuum degree < 3×10 -3 Pa) induction melting + vacuum suction casting integrated equipment (specific alloy composition: Ni 2.0%, V 2.0%, Ru 2.0%, the balance is Pt; melting temperature is 1450 °C, time is 15 min, liquid flow diameter is Ф6 mm, suction casting vacuum degree < 3×10 -3Pa, the cooling rate of vacuum suction casting is 1×10 3 K / s, and the thickness of the block ingot blank is 9 mm, and the diameter of the cylindrical ingot blank is Ф9 mm.

[0025] (2) The intermediate annealing temperature is 1200 °C and the time is 40 min. Cold working such as rolling and drawing of the platinum alloy ingot blank is carried out. Finally, the thickness of the PtNiVRu quaternary alloy sheet product is ≠0.5 mm, the diameter of the wire product is Ф0.5 mm, and the density is 22.3 g / cm 3 , the hardness (Hv0.2) is 220.0, and the resistivity is 26.0 μΩ·cm.

[0026] Example 3

[0027] A preparation method of a platinum alloy electrode material, the preparation steps are as follows:

[0028] (1) Platinum alloy melting and suction casting are carried out in a vacuum (vacuum degree < 2×10 -3 Pa) induction melting + vacuum suction casting integrated equipment (specific alloy composition: Ni 3.0%, V 3.0%, Ru 3.0%, the balance is Pt; the melting temperature is 1500 °C, the time is 20 min, the liquid flow diameter is Ф7 mm, and the suction casting vacuum degree < 2×10 -3 Pa, the cooling rate of vacuum suction casting is 1×10 3 K / s, and the thickness of the block ingot blank is 10 mm, and the diameter of the cylindrical ingot blank is Ф10 mm.

[0029] (2) The intermediate annealing temperature is 1250 °C and the time is 45 min. Cold working such as rolling and drawing of the platinum alloy ingot blank is carried out. Finally, the thickness of the PtNiVRu quaternary alloy sheet product is ≠0.5 mm, the diameter of the wire product is Ф0.5 mm, and the density is 25.1 g / cm 3 , the hardness (Hv0.2) is 280.0, and the resistivity is 29.0 μΩ·cm.

[0030] Example 4

[0031] A preparation method of a platinum alloy electrode material, the preparation steps are as follows:

[0032] (1) Platinum alloy melting and suction casting are carried out in a vacuum (vacuum degree < 1×10 -3 Pa) induction melting + vacuum suction casting integrated equipment (specific alloy composition: Ni 4.0%, V 4.0%, Ru 4.0%, the balance is Pt; the melting temperature is 1550 °C, the time is 40 min, the liquid flow diameter is Ф8 mm, and the suction casting vacuum degree < 1×10 -3 Pa, the cooling rate of vacuum suction casting is 1×10 3 K / s, and the thickness of the block ingot blank is 12 mm, and the diameter of the cylindrical ingot blank is Ф15 mm.

[0033] (2) The intermediate annealing temperature is 1300 °C and the time is 50 min. Cold working such as rolling and drawing of the platinum alloy ingot is carried out. Finally, the thickness of the PtNiVRu quaternary alloy sheet product is ≠0.5 mm, the diameter of the wire product is Ф0.5 mm, and the density is 26.6 g / cm 3 , the hardness (Hv0.2) is 330.0, and the resistivity is 34.0 μΩ·cm.

[0034] Example 5

[0035] A preparation method of a platinum alloy electrode material, and the preparation steps are as follows:

[0036] (1) Platinum alloy melting and suction casting are carried out in a vacuum (vacuum degree < 2×10 -3 Pa) induction melting + vacuum suction casting integrated equipment (specific alloy composition: Ni 5.0%, V 5.0%, Ru 5.0%, the balance is Pt; the melting temperature is 1600 °C, the time is 10 min, the liquid flow diameter is Ф8 mm, the suction casting vacuum degree < 2×10 -3 Pa, the cooling rate of vacuum suction casting is 1×10 3 K / s, and a block ingot with a thickness of 10 mm and a cylindrical ingot with a diameter of Ф10 mm are obtained.

[0037] (2) The intermediate annealing temperature is 1250 °C and the time is 60 min. Cold working such as rolling and drawing of the platinum alloy ingot is carried out. Finally, the thickness of the PtNiVRu quaternary alloy sheet product is ≠0.5 mm, the diameter of the wire product is Ф0.5 mm, and the density is 28.5 g / cm 3 , the hardness (Hv0.2) is 348.0, and the resistivity is 37.0 μΩ·cm.

[0038] The present invention also explores the influence of the composition of the platinum alloy electrode material on the performance of the silver-tungsten electrical contact material thin film, and finds that when a certain element (such as Ni, V, Ru) is missing in the platinum alloy electrode material, the hardness HV of the platinum alloy electrode material 0.2 significantly decreases, and the change in resistivity is not obvious.

[0039] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not restrictive. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A platinum alloy electrode material, characterized in that: The elements are included in the following weight percentages: 1.0%-5.0% Ni, 1.0%-5.0% V, 1.0%-5.0% Ru, and the balance is Pt.

2. The method for preparing the platinum alloy electrode material according to claim 1, characterized in that: The steps include: (1) induction melting the alloy raw material according to the composition content of the platinum alloy electrode material, and then obtaining a platinum alloy ingot by vacuum suction casting; (2) The platinum alloy ingot is rolled and drawn; intermediate annealing is performed during the rolling and drawing process to finally obtain a platinum alloy electrode material.

3. The method for preparing the platinum alloy electrode material according to claim 1, characterized in that: The induction melting temperature is 1400-2000°C and the time is 10-30 minutes.

4. The method for preparing the platinum alloy electrode material according to claim 1, characterized in that: The diameter of the liquid flow in the vacuum casting is Φ5mm-Φ8mm, and the vacuum degree of the suction casting is less than 4×10 -3 Pa, the cooling rate of vacuum casting is 1×10 3 K / s or more.

5. The method for preparing the platinum alloy electrode material according to claim 1, characterized in that: The intermediate annealing temperature is 1100-1300° C. and the time is 30-60 minutes.