The internal oxidation behavior of Pd-40Ag-1RE (RE = Sm, Eu, Gd, Y) alloy wires has been studied in air at 800 °C 1200°C. The dependence of internal oxidation depth ξ on reaction time t can be expressed as ...The internal oxidation behavior of Pd-40Ag-1RE (RE = Sm, Eu, Gd, Y) alloy wires has been studied in air at 800 °C 1200°C. The dependence of internal oxidation depth ξ on reaction time t can be expressed as ξ = Ktn, the reaction index n = 0.50 approximately 0.75. The higher the oxidation temperature is, the larger the n value is. It means that the internal oxidation of wire sampls at high temperature deviates from parabola rule observed on plate sample. The activation energies of the studied alloys range over 120 approximately 160 kJ/mol. The internal oxidation process is controlled by the bulk diffusion of oxygen.展开更多
Splat foils with 30-35 μm thickness and spum ribbon with 50-55 μm thickness of Mo-4Th-0.4B and Mo-8Th-0.8B were made by arc melt hammer-anvil and melt spinning techniques. Both alloys have high hardness and a strong...Splat foils with 30-35 μm thickness and spum ribbon with 50-55 μm thickness of Mo-4Th-0.4B and Mo-8Th-0.8B were made by arc melt hammer-anvil and melt spinning techniques. Both alloys have high hardness and a strong age hardening response, especially Mo-8Th-0.8B. The precipitates associated with age hardening were ThB4(tetragon) and Mo2B (C16, BTC). The times for reaching a age hardening peak for both alloys are not the same and depended on the precipitation extent of Th and B solutes from the metastable solid solution. Grain refinement was observed. The work indicates that new high strength Mo alloys can be developed by rapid solidification.展开更多
文摘The internal oxidation behavior of Pd-40Ag-1RE (RE = Sm, Eu, Gd, Y) alloy wires has been studied in air at 800 °C 1200°C. The dependence of internal oxidation depth ξ on reaction time t can be expressed as ξ = Ktn, the reaction index n = 0.50 approximately 0.75. The higher the oxidation temperature is, the larger the n value is. It means that the internal oxidation of wire sampls at high temperature deviates from parabola rule observed on plate sample. The activation energies of the studied alloys range over 120 approximately 160 kJ/mol. The internal oxidation process is controlled by the bulk diffusion of oxygen.
文摘Splat foils with 30-35 μm thickness and spum ribbon with 50-55 μm thickness of Mo-4Th-0.4B and Mo-8Th-0.8B were made by arc melt hammer-anvil and melt spinning techniques. Both alloys have high hardness and a strong age hardening response, especially Mo-8Th-0.8B. The precipitates associated with age hardening were ThB4(tetragon) and Mo2B (C16, BTC). The times for reaching a age hardening peak for both alloys are not the same and depended on the precipitation extent of Th and B solutes from the metastable solid solution. Grain refinement was observed. The work indicates that new high strength Mo alloys can be developed by rapid solidification.
