Strength Properties of Yttrium-Oxide-Dispersed Tungsten Alloy

Itoh, Yoshiyasu; Ishiwata, Yutaka

doi:10.1299/jsmea1993.39.3_429

Cited by 17 publications

(19 citation statements)

References 4 publications

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“…4) are indicative of the formation of a liquid phase. Such features have been noted by many researchers [2,11]. Therefore, for T s (sintering temperature) > T tr (transition temperature), only solid phase sintering of tungsten powders occurs and the second phases (Y 2 O 3 ) can act as obstacles in the sintering.…”

Section: Sintering Behavior and Microstructurementioning

confidence: 89%

“…The mechanical strength of its alloys also decreases markedly with increasing temperature. The lack of strength has been overcome by dispersion-hardening the materials with thorium oxide (ThO 2 ) and lanthanum oxide (La 2 O 3 ) [2][3][4][5]. Although ThO 2 -dispersed tungsten exhibits high mechanical strength at elevated temperature, its radioactive potential is an obstacle to practical applications [4].…”

Section: Introductionmentioning

confidence: 99%

“…According to Itoh, et al [2], the addition of Y 2 O 3 particles enhances the densification of tungsten powders and serves to reduce the sintering temperature. However, the amount of Y 2 O 3 particles dispersed in the tungsten matrix is in the range 1.5 to 6.0 wt.% and the mechanical properties of its alloy are deteriorated with an increase of second phases.…”

Section: Introductionmentioning

confidence: 99%

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The effect of yttrium oxide on the sintering behavior and hardness of tungsten

et al. 2006

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In this study, the relative density and hardness of Y2O3 dispersed tungsten alloy were investigated as functions of the Y2O3 content and sintering temperature. The sintering temperature and the amount of the second phase were varied from 1800 to 2500 o C and 0 to 2.0 weight pct, respectively. The relative density of the alloys is higher than that of pure tungsten in the range from 2000 to 2500 o C, whereas the density is lower at 1800 o C. As the Y2O3 content increases, the sintered density increases at a given temperature. The transition temperature (Ttr), where the relative density of the alloys exceeds that of pure tungsten, is reduced with increased Y2O3 particle content. In order to examine the effect of the second phase on the mechanical property, the hardness of pure tungsten and the alloys are measured. The hardness is mainly dependent upon the relative density of the alloys, rather than the amount of the second phase and tungsten grain size. The relationship between hardness and density is discussed according to the plasticity theory of porous materials.

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Section: Sintering Behavior and Microstructurementioning

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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The effect of yttrium oxide on the sintering behavior and hardness of tungsten

et al. 2006

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“…It was reported, however, that Y 2 O 3 particles significantly improved the oxidation resistance of W al loys [15,19] and W Y 2 O 3 alloys were able to enhance the high tem perature strength retention of W. The same phenomenon is observed in the case of W Ti alloys, and the W 4Ti 0.5Y 2 O 3 alloy overcame the mechanical performance of the W 4Ti counterpart at 800 °C even though they presented inferior strength and tough ness at ambient temperature. The W 2Ti 0.5Y 2 O 3 , whose proper ties did not improve very much with temperature, presented excellent strength retention at high temperature, and its behavior at 800 °C and above was better than that of the W 4Ti alloy.…”

Section: Mechanical Properties and Failure Micromechanismsmentioning

confidence: 95%

“…For instance, it has been shown that La 2 O 3 dispersion or Al K Si doping can signifi cantly improve the mechanical strength and the RCT of W, but it appears that the DBTT cannot be lowered this way [6,12 14]. Y 2 O 3 additions strengthen W and increase its creep resistance [15,16] and it has recently been reported that Y 2 O 3 doped W pro duced by powder metallurgy (PM) and consolidated by hot iso static pressing (HIP) achieves certain ductility at 400 °C [17]. In addition, this Y 2 O 3 doped W presented enhanced mechanical properties and a remarkable oxidation resistance at high tempera tures, in comparison to W produced by the same procedure [17].…”

Section: Introductionmentioning

confidence: 99%

Mechanical properties of Y2O3-doped W–Ti alloys

Aguirre

Martı́n

Pastor

et al. 2010

Journal of Nuclear Materials

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W and W alloys are currently considered promising candidates for plasma facing components in future fusion reactors but most of the information on their mechanical properties at elevated temperature was obtained in the 1960s and 1970s. In this investigation, the strength and toughness of novel Y 2 O 3 doped W Ti alloys manufactured by powder metallurgy were measured from 25 °C up to 1000 °C in lab oratory air and the corresponding deformation and failure micromechanisms were ascertained from anal yses of the fracture surfaces. Although the materials were fairly brittle at ambient temperature, the strength and toughness increased with temperature and Ti content up to 600 °C. Beyond this tempera ture, oxidation impaired the mechanical properties but the presence of Y 2 O 3 enhanced the strength and toughness retention up to 800 °C.

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