Microstructures and properties of molybdenum wires doped with La

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The structures and properties of the La-doped molybdenum(La-Mo) powder , compact , rodsand wires anncaled at different temperatures were investigated. The experimental results showthat the to exists in the powders in the forms of lanthanum nitrate , lanthana and complex oxidesof molylxlenum and lanthanum , whereas the bo exsists in the compacts, reds and annealed wiresin the form of lanthana. Upon annealing at 1600 ℃ , the elongated La_2O_3 in wires breaks up intorows of La_2O_3 particles. The recrystallization temperature of molybdenum wires has been in-creased , and its ductility and the creepresistunt properties have also been improved by addition oflower-content of La_2O_3. Morever , grain structure with large aspect ratio has been formed in theMo wires doped with lower content of La_2O_3. When the La_2O_3 reaches higher content , the La-Mowires show excellent thermionic electron properties and less recrystallised low-temperature embrit-tlement.