| Abstract Scope |
Refractory metals such as tungsten (W) and molybdenum (Mo) are useful in many technologies, including fusion energy, aerospace, microelectronics and other applications under extreme environments. Processing such a refractory metal at high-temperature conditions (sintering, thermomechanical processing and heat treatments), unavoidably results in heterogeneous behaviors in sintering, grain growth, plastically response and recrystallization, makes it difficult to produce microstructural refinement and uniformity. Meanwhile, the contaminated impurity often leads to terrible uncertainty of microstructural evolution when considering material design. Therefore, this work starts by presenting polycrystalline W with different purity, aiming to understand the microstructural and mechanical evolution during sintering, hot-rolling and recrystallization, and the possible effect of contaminated impurities on them. Further, it provides a simple pressureless sintering method to fabricate dense bulk W and other refractory metals with uniform microstructure and ~200 nm grain size. |