The role of sintering temperature in determining the microstructure, mechanical properties, and γ-ray shielding of Fe–18W–0.4C high tungsten alloy

High tungsten alloy shielding material, Fe–18W–0.4C (wt. %), was synthesized via powder metallurgy, including mechanical alloying, compaction, and liquid phase sintering. Process parameters, such as mechanical alloying conditions, compaction pressure, sintering temperature, and schedule, were optimized to achieve high sintered density. JMatPro software was used to determine the liquid phase formation temperature, guiding the selection of sintering temperatures. The microstructure, phase evolution, and mechanical properties of the alloy were characterized using scanning electron microscopy (SEM), tensile testing, and x-ray diffraction. The sintered alloy consisted of an α-Fe matrix phase and binding phases such as Fe2W, WC, and Fe7W6. The sintering temperature significantly influenced the density and microstructure. At 1400 °C, the alloy achieved a tensile strength of 337 MPa and ductility of 24.5%. SEM fracture analysis revealed a mixed fracture mode, including ductile and brittle features in α-Fe and W particles. At 1450 °C, the alloy demonstrated optimal properties. The microhardness, density, and compactness reached 472 HV, 8.8 g/cm3, and 99.84%, respectively. γ-ray shielding performance was evaluated using a BH1326 γ-ray shielding tester. The alloy exhibited superior shielding capability, with a half-attenuation thickness significantly lower than that of traditional lead materials.