Yuantao NING+
,
Fei WEN
,
Huaizhi ZHOU
,
Deguo DENG
,
Institute of Precious Metals Kunming
,
650221
,
China
材料科学技术（英文）
The influence of 0.1-0.6 at.-%RE additions (RE= La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er, Yb) on the mechanical properties of Pd was studied. All above RE additions increased not only the strength properties at ambient temperature but also the tensile strength, creep rupture time and activation en- ergy at high temperatures, simultaneously increased the elongation of Pd. In the range of dilute con- centration, the strength properties of Pd-RE alloy enhanced linearly with RE concentration. When the strength properties of Pd-RE alloys were normalized at 0.1 at.-%RE, it was found that light RE elements had stronger effect on the properties of Pd than heavy RE, whereas Eu, Yb, Ce had anoma- lous effect. In all Pd-RF alloys, Pd-Eu alloy had the highest strength properties, successively Pd-Yb and Pd-Ce alloy. The effect mechanisms of RE in alloy, such as purifying impurities, increasing recrystallization temperature, refining grain size. expanding crystal lattice, increasing dislocation den- sity and decreasing stacking fault energy, forming stable RE oxidation by internal oxidation, and so on, were observed. They were strengthening sensitive factors. The influence of the factors on strength properties and elongation of Pd was discussed.
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RE
,
null
,
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Fei WEN
,
Yuantao NING
,
Huaizhi ZHAO and Deguo DENG(Kunming Institute of Precious Metals
,
Kunming
,
650221
,
China)
材料科学技术（英文）
The influence of RE (RE = La, Ce. Pr. Nd, Sm, Eu, Gd. Tb. Dy, Er, Yb) additives with dilute concentrations on the electrical properties of Pd has been studied. All RE elements increase the specific resistivity (ρ) and decrease the resistance temperature coefficient (α) of Pd. and (ρ.α) Pd-RE ls equal to (ρ· α)Pd.The RE elements before Gd reduce the thermo-emf of Pd on Cu. other heavy RE enhance the thermo-emf.The experimental data of normalized Pd-0.1 at.-%RE alloys indicate that the effect of light RE additives on the specific resistivity of Pd is larger than that of heavy RE and Ce. Eu and Yb show anomalous strong effect. The valence and atomic size are main factors influencing the electrical properties.
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