A corrosion-resistant tantalum-tungsten-platinum alloy and its preparation method are disclosed. The alloy comprises, by mass percentage, 2%–5% tungsten, 0.08%–0.12% platinum, with the balance being tantalum. The preparation method includes: weighing and mixing tantalum powder, tungsten powder, and platinum powder according to their mass percentages to obtain a mixed powder; subjecting the mixed powder to vacuum hot pressing sintering and vacuum electron beam melting sequentially to obtain the tantalum-tungsten-platinum alloy. By adding a certain proportion of tungsten and platinum powder to the tantalum powder, the performance of the tantalum alloy is improved. The preparation method, combining powder mixing, vacuum hot pressing sintering, and vacuum electron beam melting, yields a tantalum-tungsten-platinum alloy material with uniform composition, stable chemical properties, and strong corrosion resistance.
Tantalum metal possesses significant advantages such as a high melting point, low coefficient of thermal expansion, good ductility, and extremely high corrosion resistance, and is widely used in various industries. However, with the rapid development of technology, single-metal tantalum can no longer meet the needs of industrial development. Against this backdrop, various tantalum alloys have emerged. Adding alloying elements to pure tantalum can improve its performance.
Currently, the most commonly used strengthening alloying element is tungsten. Tantalum-tungsten alloy is a rare metal alloy material with high density, high melting point, and high strength. It possesses high high-temperature strength, good ductility, weldability, and excellent corrosion resistance, making it suitable for high-temperature, high-pressure, and corrosion-resistant working environments. A tantalum-tungsten alloy powder and its preparation method are disclosed. The method includes the following steps: repeatedly melting and forging a tantalum-tungsten alloy ingot; subjecting the forged product to hydrogenation heat treatment in a hydrogen atmosphere; mechanically crushing the hydrogenation heat-treated product to obtain coarse powder; sieving powder with a particle size range of aμm to bμm from the coarse powder, where a = 10–20 and b = 50–60; subjecting the sieved powder to dehydrogenation heat treatment under vacuum; adding magnesium powder to the product from the previous step for oxygen reduction heat treatment; and subjecting the product from the previous step to plasma spheroidization treatment to achieve a powder sphericity of over 99%. The obtained tantalum-tungsten alloy exhibits uniform composition, concentrated particle size distribution, high sphericity, and low oxygen content. However, its performance begins to decline when the tungsten content exceeds a certain value.
To address this, researchers have begun doping a multi-component tungsten element into the tantalum metal matrix to leverage the advantages of each component, thereby further improving the performance of tantalum metal and obtaining a composite material with excellent overall properties. A novel tantalum-tungsten alloy material and its preparation method are described, with the following composition by weight percentage: tungsten 0.5–10%, tungsten diboride 0.5–8%, and the remainder being tantalum. The preparation method includes: weighing raw tantalum powder, tungsten powder, and tungsten diboride powder according to the weight ratio, placing them in a ceramic ball mill jar, and vacuum ball milling for 1–6 hours. The mixed powder is then filled into a graphite mold. Before filling, the inner wall of the mold is coated with HBN powder to prevent the mixed powder from reacting with the graphite and to facilitate subsequent demolding. The mold is then placed in a vacuum hot-pressing sintering furnace for hot-pressing sintering. After sintering, the mold is cooled with the furnace to obtain a novel tantalum-tungsten material. However, the prepared tantalum-tungsten material has a high oxygen content and insufficient corrosion resistance.
A corrosion-resistant tantalum-tungsten-platinum alloy and its preparation method are disclosed. By adding a certain proportion of tungsten and platinum powder to tantalum powder, the performance of the tantalum alloy is improved. The preparation method combines powder mixing, vacuum hot pressing sintering, and vacuum electron beam melting to obtain a tantalum-tungsten-platinum alloy material with uniform composition, stable chemical properties, and strong corrosion resistance.
The preparation method includes the following steps: (1) Weigh tantalum powder with a particle size of 4μm, tungsten powder with a particle size of 5μm and platinum powder with a particle size of 2μm according to the mass percentage and mix them to obtain a mixed powder; the purity of the tantalum powder, tungsten powder and platinum powder is 99.99%; (2) Vacuum hot pressing sintering is performed on the mixed powder obtained in step (1), the vacuum degree of vacuum hot pressing sintering is 1×10-3Pa, the temperature is raised to 1800℃ at a heating rate of 4℃/min, and the holding time is 180min to obtain an alloy billet; (3) Vacuum electron beam melting is performed on the alloy billet obtained in step (2), the vacuum degree of vacuum electron beam melting is 1×10-2Pa, the temperature is 3500℃, and the holding time is 3h to obtain the tantalum-tungsten-platinum alloy. A corrosion-resistant tantalum-tungsten-platinum alloy and its preparation method are provided. The tantalum-tungsten-platinum alloy is composed of the following components by mass percentage: 5% tungsten, 0.08% platinum, and the balance being tantalum.
When the tungsten content in the tantalum-tungsten-platinum alloy exceeds a certain value, the alloy's performance decreases. If the tungsten content is too low, the alloy's corrosion resistance cannot be improved. Adding an appropriate amount of platinum powder to the tantalum-tungsten alloy is beneficial to improving its chemical properties and corrosion resistance.
