Zhentao YU
,
Lian ZHOU
,
Haichen GU
,
Ju DENG
材料科学技术（英文）
The SEM observation in situ of monotonic and cyclic deformed structure in Ti-ZA1-2.5Zr alloy was performed. The regularity of slippage, crack nucleation, propagation and the typical dislocation configuration were also investigated. The twin and twist play an important role in maintaining homogeneous deformation in the final plastic deformation stage.
关键词:
Dong LI
,
Zhentao YU
,
Weisheng TANG
,
Ju DENG
材料科学技术（英文）
NIN has developed a new type of Ti alloy. It is suitable for structure pieces applied in high-temperature and high-pressure water/steam conditions. Its nominal composition is Ti-4Al-2V. In this paper, its microstructure, mechanical properties and corrosion resistance were studied in detail.
关键词:
Weilu WU
,
Zhentao YU
,
Ju DENG
材料科学技术（英文）
The relationships among the deformation, texture and properties of TA16 alloy tube were investigated, an optimum processing parameter was obtained. High Q (the ratio of reduction of diameter to reduction of wall thickness) values increase tensile, flaring properties and reduce flattening, high Q values increase tensile strength, flattening, flaring, and decrease tensile elongation. The main circular textures of rolling tubes are basal (0001) and pyramidal {10(1) over bar 5}, {10(1) over bar 4}, {10(1) over bar 3)}etc., and the main axial textures are prism {10(1) over bar 0} and pyramidal {11(2) over bar 0}, {21(3) over bar 1}, {20(2) over bar 1} etc, under different Q and epsilon values. There are greater changes in the grain size under different epsilon values, compared with that under different Q values.
关键词:
Lin YANG
,
Zhentao YU
,
Ju DENG
材料科学技术（英文）
The corrosion behavior of Ti-2A1-2.5Zr alloy with 5 alloy contents and 5 surface states were studied in water steam at 400℃, 10.3 MPa for 72 h. The weight-increments of all samples are under 4 mg/dm2, better than Zr and Zr-alloy. α-Ti is oxidized into anatase-type TiO2 preferentially. The corrosion resistance is improved by adding Al element or pre-oxidizing treatment, the latter is more effective relatively.
关键词:
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
赵欣
,
李继定
,
陈剑
,
陈翠仙
膜科学与技术
doi:10.3969/j.issn.1007-8924.2003.06.003
在膜分离过程中,渗透物分子在聚合物膜内的扩散过程,是影响聚合物膜分离性能的关键因素.详细考察了目前被广泛使用的Vrentas-Duda扩散模型,对其进行改进,提出了新的计算ζ的公式.根据新提出的公式,对聚苯乙烯/甲苯(PS/toluene)、聚苯乙烯/乙苯(PS/ethylbenzene)、聚乙酸乙烯酯/甲苯(PVAc/toluene)3种体系中弱极性渗透物分子的扩散系数进行了预测,其较之原Vrentas-Duda扩散模型、Ju改进的Vrentas-Duda扩散模型有更好的预测结果.
关键词:
自由体积
,
扩散模型
,
聚合物膜
,
扩散系数
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
陈康
,
许希武
,
马凯
材料科学与工程学报
基于Ju和Chen提出的颗粒增强复合材料的一般细观力学方法,采用Qu给出的一阶近似修正的Eshelby张量,本文建立了考虑夹杂之间相互影响的含任意分布弱界面颗粒增强多相复合材料等效模量预测的一般细观力学方法,通过体积均匀化方法得到了一组细观力学本构方程.分别推导了忽略夹杂之间相互影响的弱界面多相复合材料宏观模量表达式以及考虑夹杂之间相互影响的弱界面两相复合材料的宏观模量表达式.此外,还给出了几种特殊复合材料体系在考虑界面弱化下的宏观等效性能参数的解析表达式,在界面粘结完好的假设下,给出的表达式均可以退化成经典的细观力学预测结果.在考虑夹杂之间相互影响的情况下,本文预测结果与实验数据吻合很好,验证了模型的有效性.
关键词:
夹杂之间相互影响
,
轻微弱化界面
,
细观力学
,
等效性能参数
,
颗粒增强复合材料
