In the vast field of materials science, high-density tungsten alloys stand out due to their unique properties, becoming a focal point across numerous industries. Tungsten alloy is a material with tungsten as the base (W content 85-99%) and small amounts of elements such as Ni, Cu, Co, Mo, and Cr added. Its density ranges from 16.5 to 18.75 g/cm3, more than double that of steel, making its remarkable high-density characteristic a key factor in its wide-ranging applications.
From a microstructural perspective, the tungsten phase in the alloy provides a foundation of high melting point, high hardness, and high density, while the added alloying elements enhance strength, improve processability, and impart other special properties. For instance, the addition of nickel can increase the alloy’s strength and toughness; copper improves its electrical conductivity and corrosion resistance; cobalt enhances its high-temperature strength and wear resistance, among others. The synergistic effect of these elements ensures that tungsten alloys not only possess high density but also exhibit a range of excellent properties, including high strength, good thermal conductivity, a low thermal expansion coefficient, and good weldability and processability.
Strong Radiation Absorption Capability
The high density of high-specific-gravity tungsten alloys is closely related to their radiation absorption capacity. The absorption of radiation by a material primarily relies on the photoelectric effect, Compton scattering, and pair production. The high atomic number of tungsten in the alloy enhances its ability to bind electrons, making the photoelectric effect more likely when radiation photons interact with the alloy’s atoms, generating photoelectrons that effectively absorb radiation energy. Additionally, the high density means a greater number of atoms per unit volume, increasing the probability of radiation-atom interactions and further boosting absorption efficiency.
In the medical field, X-rays and gamma rays are widely used in diagnostics and treatment but pose potential hazards to human health. Tungsten alloys, with their excellent radiation absorption capabilities, are used to manufacture various shielding materials, such as X-ray tube shields and collimators for radiotherapy equipment. For example, shields made from high-specific-gravity tungsten alloys can effectively block X-ray leakage, protecting medical staff and patients from unnecessary radiation exposure and ensuring the safety of medical procedures. Tungsten alloy collimators, a key component of linear accelerators, control and direct high-energy radiation beams to target tumor sites, effectively killing cancer cells while minimizing damage to surrounding healthy tissues. In the nuclear industry, where nuclear reactors generate significant radiation, tungsten alloys are used to produce shielding layers and nuclear waste storage containers. Their strong ability to absorb neutrons and gamma rays prevents radiation leakage, safeguarding the environment and personnel around nuclear facilities. Compared to traditional lead shielding materials, high-specific-gravity tungsten alloys offer a smaller volume and lighter weight for the same shielding effect, along with better corrosion resistance and mechanical properties, making them more suitable for the complex nuclear industry environment.
Excellent Counterweight Function
In the aerospace sector, the center of gravity and inertia distribution of aircraft are critical to their flight performance and stability. The high density of tungsten alloys allows for a smaller volume compared to other common metals under the same weight requirements, making them ideal for use as counterweight components in aircraft and satellites. This enables precise adjustment of the center of gravity within limited space, ensuring stability and maneuverability during flight. For instance, installing tungsten alloy counterweights on aircraft wings and engines can balance weight distribution, reduce vibration and noise during flight, and enhance safety and comfort.
In the mechanical field, many precision machines demand high balance and stability in their components. High-specific-gravity tungsten alloys are often used to manufacture counterweights for machine tool spindles, motor rotors, and similar parts. For example, during high-speed rotation, a misaligned spindle center of gravity can cause severe vibration, affecting machining accuracy and machine lifespan. Using tungsten alloy counterweights to adjust the spindle’s center of gravity ensures stability during high-speed rotation, improving machining precision and efficiency. Additionally, in automotive engine crankshaft counterweights, tungsten alloys play a vital role in reducing vibration and noise during operation, enhancing engine performance and reliability.
Robust Mechanical Performance Assurance
The high-density characteristic of high-specific-gravity tungsten alloys significantly enhances their strength and hardness. In the alloy, high density indicates stronger atomic bonding, resulting in higher strength and hardness. The addition of other elements (such as Ni, Co, etc.) forms solid solutions or intermetallic compounds with tungsten, further reinforcing the alloy’s microstructure and improving its mechanical properties.
In mold manufacturing, high-specific-gravity tungsten alloys are commonly used to produce injection molds and die-casting molds. These molds must withstand high temperatures, pressures, and high-speed friction during operation, and the alloy’s high strength, hardness, and wear resistance meet these requirements, extending mold lifespan and improving production efficiency. For instance, in injection molds, cores and cavities made from high-specific-gravity tungsten alloys can endure the high-speed impact and high-pressure injection of molten plastic, ensuring dimensional accuracy and surface quality to produce high-quality plastic products.
