Rhenium metal

Rhenium metal particles are silver grey, high melting point (~3180°C), high hardness, high density (~21.02g/cm³), good thermal and electrical conductivity, chemically stable, high oxidation resistance at high temperatures, and have important applications in aerospace, the electronics industry, chemical catalysis and many other fields.

Characteristic

Density: Density of 21.02g/cm³, in addition to platinum, osmium, iridium, the most dense metal, which makes the rhenium metal particles of large mass, in the application of a certain weight advantage, for example, in the field of aerospace can increase the stability and durability of components.

Melting point: With a melting point of 3186°C, rhenium has the second highest melting point of any metal after tungsten, making it a refractory metal. Its high melting point allows it to maintain a stable structure and properties at high temperatures, and it can be used in high temperature alloys, high temperature instruments, and other areas where high temperature resistance is required.

Boiling point: Boiling point is 5596℃, the higher boiling point ensures that rhenium metal particles are not easy to gasify under high temperature conditions, and can maintain good shape and performance in high temperature working environment.

Crystal structure: the crystal structure is six dense stacking, this crystal structure makes rhenium metal particles have high hardness and strength, as well as good resistance to deformation.

Colour: Rhenium metal has a silvery-white luster, but the colour of powdered rhenium pellets is between grey and black.

Thermal conductivity: The thermal conductivity is 48.0W/(m・K), which has good thermal conductivity and can transfer heat quickly, which is advantageous in application scenarios such as heat dissipation and heat transfer.

Resistivity: the resistivity at 20℃ is 193nΩ・m, which belongs to the metal with better conductivity, but the resistivity is relatively high, and may need to be further optimised or compounded with other metals with better conductivity in some applications with very high requirements for conductivity.

Coefficient of Expansion: The coefficient of thermal expansion is 6.2μm/(m・K), which is relatively small, and the dimensional change is small when the temperature changes, which is very important for the parts or devices that need to maintain high accuracy of the dimensions, for example, in the field of electronic components, precision instruments, and so on.

Hardness: Mohs hardness is 7.0, Vickers hardness is 1760MPa, with high hardness, making it has good wear resistance and scratch resistance, able to maintain the integrity and performance of the surface in the harsh working environment.

Strength: tensile strength of 1070MPa, yield strength of 290MPa, with high strength, able to withstand large external forces without deformation or rupture, in the structural components to withstand high stress has the value of application.

Ductility: good ductility, easy to machine, can be drawn into a fine wire or rolled into thin plates, but hot processing needs to be carried out in hydrogen or vacuum environment, because in the hot process, rhenium grain boundaries will generate low melting point rhenium oxide.

Modulus of elasticity: high modulus of elasticity, good elasticity recovery ability, can be quickly restored to its original shape and size after being subjected to external forces.

Chemical reactivity: rhenium is insoluble in hydrochloric acid, but can be dissolved in nitric acid to produce perrhenic acid: 3Re + 7HNO₃ → 3HReO₄ + 7NO + 2H₂O; can also be dissolved in ammonia-containing hydrogen peroxide solution to produce ammonium perrhenate: 2Re + 2NH₃ + 4H₂O₂ → 2NH₄ReO ₄ + 3H₂.

Stability: At room temperature, rhenium is stable in air, but it starts to oxidise when heated to 300°C, and the oxidation reaction is rapid when it exceeds 600°C.

Applications

Aerospace field:

Manufacture of aero-engine components: rhenium metal has a high melting point, high strength and good oxidation and corrosion resistance, it will be added to tungsten, molybdenum and other metals to form an alloy can be used to manufacture aero-engine single-crystal turbine blades, combustion chambers, and other key components. These components are subject to high temperatures, high pressures and high speeds when the engine is in operation, rhenium alloys are able to meet these harsh working conditions and improve the performance and durability of the engine.

For rocket nozzle: The rocket tail flame temperature is extremely high, need high temperature resistant materials to make the nozzle. Rhenium metal particles due to its high melting point, high hardness and strong oxidation resistance, etc., suitable for the manufacture of rocket nozzle, and its density is small, the same volume under the lighter mass, is conducive to reducing the weight of the rocket, improve the flight efficiency.

Protective and structural materials for spacecraft: coatings containing rhenium elements can significantly improve the heat resistance of carbon and graphite parts in low-oxygen environments and avoid carbon contamination, thus obtaining higher performance and a cleaner spacecraft environment. In addition, rhenium and its alloys are also used in the manufacture of structural components such as the shells of satellites and ballistic missiles, heat shields for spacecraft, and protective plates for atomic reactors.

Electronic industry field:

Electron-emitting cathode materials: rhenium metal has high electron-emitting properties, can be used to manufacture the cathode of the electronic tube components, with good performance in emitting electrons, long service life and other advantages.

Electrode materials for integrated circuits: In some high-performance integrated circuits, rhenium metal particles can be used as electrode materials, using its good conductivity and stability, to improve the performance and reliability of integrated circuits.

Making high-temperature thermocouple: tungsten rhenium thermocouple can work in a high-temperature environment, measuring high temperature above 3000 ℃, commonly used in high-temperature furnaces, iron and steel smelting and other high-temperature industrial processes in the temperature measurement.

Petrochemical field:
Catalyst: rhenium metal is a highly efficient catalyst, can be in the petrochemical industry in the organic matter in the ‘hydrocarbon group’ separation, increase the yield of gasoline, aromatics and hydrogen, etc.; can also be ‘hydrocarbon group’ dispersed and combined with other groups, in chemical synthesis They can also be used as catalysts for ‘hydrogenation’, decomposition of polymers and production of fuel oil from waste plastics.

Petroleum reforming catalyst: In petroleum refining process, petroleum reforming is an important process to improve the quality of petrol and to produce aromatics and other chemical raw materials. Rhenium can be used as an active component of petroleum reforming catalysts to improve the efficiency and selectivity of the reforming reaction.

Medical field:
Medical radioisotope production: in nuclear medicine, some radioisotopes need to be produced by accelerators or reactors. Rhenium metal pellets can be used as targets for the production of certain medical radioisotopes, such as rhenium-188. These radioisotopes can be used for radiotherapy of tumours, diagnosis of diseases, etc.

Manufacture of medical devices: Because rhenium metal has good biocompatibility and mechanical properties, it can be used in the manufacture of some special medical devices, such as the electrodes of cardiac pacemakers, coatings for artificial joints, and so on.

Other fields:
Manufacture of fountain pen nibs: rhenium metal particles can be added to the material of fountain pen nibs to improve the hardness and abrasion resistance of the nibs, making the nibs more smooth and durable for writing.

High-temperature heating elements: can be used to make high-temperature furnace heaters, ultra-high-temperature heaters and other heating elements, to maintain stable performance in a high-temperature environment.