Although carbon is typically present in trace amounts in tungsten-nickel-iron alloy, its influence on alloy performance is significant. Carbon exhibits a "double-edged sword" effect: small amounts enhance strength and hardness through solid-solution strengthening and carbide dispersion strengthening, while excessive carbon reduces toughness and fatigue resistance due to brittle phase precipitation and interface weakening.

The impurity elements in tungsten-nickel-iron alloy (W-Ni-Fe) originate from complex sources, primarily involving raw materials, production processes, and environmental media.

Oxygen is a critical factor in regulating the performance of tungsten-nickel-iron alloy. Through mechanisms such as oxide inclusion formation, solid-solution strengthening, and grain boundary segregation, it impacts the alloy’s mechanical properties, thermal stability, and processability. Therefore, in practical applications, oxygen content must be controlled within reasonable limits through raw material purification, process optimization, and deoxidation techniques to fully leverage the alloy’s advantages in high density, high strength, and excellent corrosion resistance.

In addition to the primary elements tungsten, nickel, and iron, tungsten-nickel-iron alloy contains trace impurity elements such as hydrogen, oxygen, carbon, sulfur, and phosphorus. These impurities can compromise grain boundary integrity, form brittle phases, and reduce the alloy’s conductivity, high-temperature strength, and radiation resistance. Control is achieved through raw material purification and process optimization, such as vacuum sintering. The following outlines the impact of key impurity elements on alloy performance.