| 초록 |
In spite of the excellent high-temperature properties of tungsten, the high ductile-brittle transition temperature has been regarded as a barrier to the application at room temperature. Currently, yttria dispersion strengthened tungsten alloy has been actively studied as a strategy to overcome these drawbacks. The strengthening in W-Y2O3 composite is generally attributed to the grain refinement and pinning effect, but a few researchers reported conflicting debates on the interaction between Y2O3 and W matrix (e.g., compound or sintering behavior) that affects its mechanical properties. Although it is required a detailed study about this, the synthetic researches, including precipitation and mechanical milling, are incompatible with the suppression of the growth and segregation of Y2O3 particles due to solubility difference and large surface energy. As an attempt to further elucidate the effects of Y2O3 on the strengthening, in this presentation, W-Y2O3 composite with controlled Y2O3 fractions was successfully synthesized by ultrasonic spray pyrolysis in which the individual droplet acts as a micro-reactor. As result, the differences in microstructure and chemical states of the composite versus the ratio of Y2O3 were systematically investigated. |
