Microstructure and hydrogen permeability of Nb40Hf30Ni30 ternary alloy

The microstructure and hydrogen permeability of the Nb40Hf30Ni30 ternary alloys were investigated in particular. The as-cast Nb40Hf30Ni30 alloy consists of the bcc- (Nb,Hf) solid solution, the Bf-HfNi compound and the fine eutectic phase of {(Nb,Hf) + HfNi}. The annealed Nb40Hf30Ni30 alloy consists of the bcc-(Nb, Hf) solid solution and the fine eutectic phase of {(Nb,Hf) + HfNi}. The as-cast Nb40Hf30Ni30 alloy shows a high Φ value of 4.3 × 10−8 [mol H2 m−1 s−1 Pa−0.5] at 673 K, and for the annealed Nb40Hf30Ni30 alloy, the Φ value is 3.8 × 10−8 [mol H2 m−1 s−1 Pa−0.5] at 673 K. Annealing can’t enhance the hydrogen permeability of the Nb40Hf30Ni30 ternary alloy.