Tungsten alloy rods are high-performance materials with tungsten as the matrix, formed by adding different metal elements. Their composition affects mechanical properties, physical properties and chemical stability, thereby defining the boundaries of their application fields. According to different material compositions, there is a classification of tungsten alloy rods into tungsten-copper alloy rods, tungsten-silver alloy rods, tungsten-molybdenum alloy rods, tungsten-nickel-copper alloy rods, tungsten-nickel-iron alloy rods and tungsten-containing high-entropy alloy rods.
I. Tungsten-Copper Alloy Rods
Tungsten-copper alloy rods have tungsten and copper as the main components, and their core performance stems from the complementary properties of tungsten and copper—tungsten's high melting point, high hardness and excellent ablation resistance, combined with copper's high electrical conductivity and high thermal conductivity, while possessing a low thermal expansion coefficient. In application scenarios, tungsten-copper alloy is used in high-voltage switchgear as contacts and conductive rods for vacuum interrupters, maintaining structural stability under arc high temperatures and quickly dissipating heat; in electrical processing fields, as EDM electrodes; in electronic packaging fields, as heat dissipation substrates for high-power semiconductor devices.
II. Tungsten-Silver Alloy Rods
Tungsten-silver alloy rods belong to the category of pseudo-alloys, with tungsten and silver not mutually soluble. Their most outstanding performance is excellent arc erosion resistance and anti-sticking properties; under frequent on-off electrical conditions, the surface is not prone to forming a molten layer, maintaining stable contact resistance; while combining tungsten's high hardness and silver's excellent conductivity. Tungsten-silver alloy rods are mainly used in key conductive components of high-voltage electrical equipment.
III. Tungsten-Molybdenum Alloy Rods
The core advantage of tungsten-molybdenum alloy rods lies in the optimization of high-temperature mechanical properties—compared to pure tungsten rods, the addition of molybdenum lowers the alloy's ductile-brittle transition temperature while retaining tungsten's high melting point and high strength, maintaining excellent tensile strength in high-temperature environments. In the metallurgical industry, as heating elements and crucible support rods for sapphire crystal growth furnaces; in electron beam welding equipment, as cathode rods for electron guns; in the nuclear industry, for manufacturing control rod sleeves in nuclear reactors.
IV. Tungsten-Nickel-Copper Alloy Rods
Tungsten-nickel-copper alloy rods are prepared by powder metallurgy, with nickel-copper alloy phase as the binder phase wrapping tungsten particles to form a dense structure. Their most significant characteristic is the combination of "high density + non-magnetic", while possessing good machinability. Tungsten-nickel-copper alloy is suitable for high-end fields sensitive to magnetic fields. In the medical field, as counterweights and positioning parts for MRI equipment; in the electronic field, as balance blocks for radar antennas and shielding parts for microwave devices; in the aerospace field, as gyro rotors for inertial navigation systems.
V. Tungsten-Nickel-Iron Alloy Rods
Tungsten-nickel-iron alloy rods are the most widely used tungsten-based alloy rods. Their core advantage lies in the balance of comprehensive properties—high density, strong tensile strength, while possessing good ductility and impact toughness. In the military field, as core materials for armor-piercing projectiles; in civilian fields, for manufacturing counterweights for racing cars, balance wheels for clocks, etc.; in the medical field, for shielding parts in radiotherapy.
VI. Tungsten-Containing High-Entropy Alloy Rods
Tungsten-containing high-entropy alloy rods are a research hotspot in the materials field in recent years, usually composed of five or more main elements such as tungsten, molybdenum, titanium in equal or near-equal molar ratios, prepared by vacuum arc melting. Their most outstanding feature is breaking through the performance boundaries of traditional alloys—through the synergistic effect of multiple elements, achieving simultaneous improvement in high-temperature strength, corrosion resistance and wear resistance. Currently, tungsten-containing high-entropy alloys are moving from laboratory to industrial applications.
