Synergistic Enhancement of Strength and Toughness in High-Density WNiFe Alloys via CeO2 Micro-Doping and Cyclic Heat Treatment

The aim of this investigation is to enhance the comprehensive performance of a WNiFe high-density alloy by employing a novel composite process combining CeO 2 doping and cyclic heat-treatment. Different microstructural features that have been focused on are grain refinement, dispersed CeO 2 particles, and phase boundary cohesion. A 93WNiFe alloy prepared through the powder metallurgy route using high-energy ball milling and mechanical alloying was imparted a two-step sintering and cyclic heat-treatment to obtain a microstructure comprising finely dispersed CeO 2 particles within the matrix that reinforces the tungsten grains. While the CeO 2 doping influences the densification and grain refinement of WNiFe alloys, the cyclic heat-treatment is also expected to play a significant role in microstructural homogenization and stress relief. The effect of the composite process on the microstructure and mechanical properties of the alloy was studied. It is observed that appropriate CeO 2 doping effectively promotes sintering densification, refines tungsten grains, and enhances interfacial bonding. The application of cyclic heat-treatment further optimizes the microstructure and eliminates internal stresses, thereby synergistically improving the overall properties. In this work, the effectiveness of this composite process in simultaneously improving the strength, ductility, and toughness of W-Ni-Fe alloys has been confirmed, and the related strengthening mechanisms have been analyzed, providing a new approach for the development of a new generation of high-performance tungsten-based alloys.