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.
关键词:
RE
,
null
,
null
佟媛媛
,
华勤
上海金属
doi:10.3969/j.issn.1001-7208.2010.03.011
运用热分析技术研究了冷却曲线特征值与319铝合金中化学成分之间的关系,并进行回归分析.结果表明,在不考虑工艺因素的情况下,试样的硅含量与α-Al枝晶生长回升温度TαDENG之间的相关性最大,相关系数r为-0.65,以硅含量可预测α-Al枝晶生长回升温度.在浇注过程中,冷却速度与α-Al枝晶生长回升温度TαDENG密切相关,相关系数为r=-0.72.在相同的冷却条件下,铝合金的浇注温度和浇注量对冷却速度有明显的影响,因此,可以通过调整浇注温度和浇注量,控制铝合金的冷却速度,进而也可预测铝合金中α-Al枝晶生长回升温度TαDENG.
关键词:
319铝合金
,
热分析
,
特征值
,
浇注工艺
Journal of Applied Physics
Motivated by the recent experimental fabrication of half-metallic MnSb and CrSb thin films with metastable zinc-blende structure [Aldous et al. Phys. Rev. B 85, 060403(R) (2012); Deng et al. J. Appl. Phys. 99, 093902 (2006)], we investigate the structural, electronic, and magnetic properties of TiSb in both ground-state NiAs and metastable zinc-blende phases by using the first-principles calculations. It is shown that the ground-state NiAs phase is metallic and nonmagnetic, but the metastable zinc-blende phase exhibits half-metallic ferromagnetism with a magnetic moment of 1.00 mu(B) per formula unit. We also reveal that the half-metallicity in bulk ZB TiSb is lost at the Sb-terminated (001) surface due to the appearance of surface states within the gap of the minority-spin channel, but the Ti-terminated (001) surface retains the bulk half-metallicity, which makes ZB TiSb a promising candidate for the possible epitaxial growth of half-metallic thin films or multilayers on semiconductor substrates for spintronic applications. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4739744]
关键词:
room-temperature ferromagnetism;molecular-beam epitaxy;crsb;cras;spintronics;state;mnas
