Influence of microelement Hf on microstructure, mechanical properties and shielding effect of W-Ni-Fe alloy

W-Ni-Fe-Hf series alloy with different Hf contents were prepared through liquid phase sintering. Influences of Hf on mechanical properties, shielding effect and microstructure of W-Ni-Fe-Hf alloy are analyzed and discussed by using SEM, XRD device, metalloscope, BH1326 γ-ray shield tester and so on. The results of the study show that adding the microelement Hf could increase dispersity of powder effectively. Hf distributes in the binding phase of W-Ni-Fe-Hf series alloy (percentage) as an intermediate phase. This intermediate phase not only could refine crystals, but also has good affinity to the microelement Hf, thus enabling to improve mechanical properties and shielding effect of the alloy. However, the intermediate phase formed by excessive Hf is easy to cause segregation on the interface between W crystal boundaries and Ni-Fe binding phase, which would weaken interface binding strength and thereby deteriorate mechanical properties of the alloy.