Stability of Selected Submicron Refractory Dispersoids in Tungsten
Tungsten-dispersed second-phase alloys (6.5 vol. %) were obtained from milled powder mixes by several consolidation techniques. Hot-compaction was established as a superior mode of consolidation with respect to retention of particle size and densificaron. Chemical and particle stability of the dispersoids in tungsten were investigated by thermogravimetric analysis and electron microscopy. Included in this investigation were thoria and the oxides, nitrides, and carbides of hafnium and zirconium. None of these refractory dispersions showed complete stability at all temperatures, although dispersions of <1.0-μ mean particle size were retained after 1-hr annealing at 2600°C in some compositions.
KeywordsTungsten Oxide Milled Powder Interparticle Spacing Tungsten Powder Complete Stability
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