K.K. Zhang
,
D.R. Chen
,
J. Xue
,
D. W. Sun and H.C. Li( 1) Department of Materials Engineer
,
Xi'an Jiaotong University
,
Xi'an 710049
,
China 2) Luoyang Institute of Technology
,
Luoyang 471039
,
China 3) CITIC Heavy)
金属学报(英文版)
Base on a vast amount of testing and calculations for the welding thermal cycling curves of different testing points in fusion welding (TIG welding, gas welding) HAZ of zinc-based alloy with low melting points, this paper defines the welding thermal cycle parameters of microstructure stimulation of HAZ by zinc-based alloy fusion welding process. On the principle of which the microstrnct,are and harkness of the testing points in simulation specimens are basically correspondence with that of actual welding HAZ, the microstructure simulation of testing points Tm=370O℃. 305℃) of ZA12 alloy by fusion welding is carried out by the means of omhic-heating welding thermal simulation tester. The study results of the abrasion-resistance of simulation specimens HAZ by fusion welding process indicates that the abmsion-resistance is closely related to the form of eutectoid microstructure in or in the structure.
关键词:
zinc-based alloy
,
null
,
null
,
null
,
null
International Journal of Hydrogen Energy
A systematic investigation on the hydrogen storage properties of Li-Mg-N-H materials with various compositions was performed. Li-Mg-N-H hydrogen storage materials were prepared by mechanically milling LiNH2/MgH2 mixtures with initial molar ratios ranging from 1.5:1 to 3: 1, followed by de/rehydriding at 200 degrees C. It was found that the hydrogen storage capacity of the system was highly dependent on the initial phase ratio of the LiNH2/MgH2 mixture. An optimum hydrogen capacity of about 5 wt% was achieved in the 2.15:1 LiNH2/MgH2 mixture. Different carbon materials, such as the single-walled carbon nanotubes (SWNTs), multi-walled carbon nanotubes, graphite and activated carbon, were used as additive to improve the hydrogen storage performance. It was found that the dehydriding kinetics of the Li-Mg-N-H material could be markedly improved by adding a small amount of SWNTs, especially in the as-prepared state. (c) 2006 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.
关键词:
hydrogen storage;dehydriding kinetics;carbon nanotubes;arc-discharge method;system;microstructure;desorption;absorption;behaviors;property;imides
齐民华
,
沈琪
,
陈小平
,
翁林红
应用化学
doi:10.3969/j.issn.1000-0518.2003.07.004
无水YCl3与1-环戊烷基茚基锂以1/2的摩尔比在THF中反应合成了二(1-环戊烷基茚基)氯化钇(C5H9C9H6)2Y(μ-Cl)2Li(THF)2,产物用元素分析、红外光谱及XRD进行表征. 结果表明,其晶体属于正交晶系,Pna2(1)空间群,a =1.648 2(7) nm,b =1.877 2(8) nm,c =1.131 7(5) nm,V =3.501(3) nm3,Z=4,Dc=1.285 Mg/m3,最终的偏离因子R=0.068 3,Rw=0.114 3.
关键词:
环戊烷基茚基
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稀土配合物
,
合成
,
晶体结构
Acta Physica Sinica
A first-principles plane-wave pseudopotential method based on the density functional theory is used to investigate the dehydrogenation properties and the influence mechanism of Li(4)BN(3)H(10) hydrogen storage materials. The binding energy, the density of states and the Mulliken overlap population are calculated. The results show that the binding energy of crystal has no direct correlation with the dehydrogenation ability of (LiM)(4)BN(3)H(10)(M = Ni, Ti, Al, Mg). The width of band gap and the energy level of impurity are key factors to affect the dehydrogenation properties of (LiM)(4)BN(3)H(10) hydrogen storage materials: the wider the energy gap is, the more strongly the electron is bound to the bond, the more difficulty the bond breaks, and the higher wile the dehydrogenation temperature be. Alloying introduces the impurity energy level in band gap, which leads the Fermi level to enter into the conduction band and the bond to be weakened, thereby resulting in the improvement of the dehydrogenation properties of Li(4)BN(3)H(10). It is found from the charge population analysis that the bond strengths of N-H and B-H are weakened by alloying, which improves the dehydrogenation properties of Li(4)BN(3)H(10).
关键词:
hydrogen storage materials;first-principles calculation;element;substitution;dehydrogenation;linh2
张通和
,
吴瑜光
,
易仲珍
,
张旭
,
梁宏
,
马芙蓉
,
王晓妍
材料热处理学报
doi:10.3969/j.issn.1009-6264.2001.03.015
用多次扫描电位法研究了C和W单独及双注入H13钢对抗腐蚀特性的影响、抗腐蚀相生成的条件及其对抗腐蚀特性的作用,对改性机理进行了讨论.实验结果表明,碳、钨单独和双注入H13钢钨和碳可在注入层超饱和分布,特征为类高斯分布.双注入可在注入层中形成弥散的碳化钨WC和W2C、中间相Fe2W、铁钨碳化物FeW3C、Fe6 W6C和铁的碳化物Fe5C3,Fe3C,Fe2C等.其形状为丝状纳米相,丝状相沿样品法线生长.这种结构使注入层强化,增强了表面抗腐蚀特性;钨和碳双注入同时具有钨和碳单注入的优势,能更有效地提高H13钢的抗腐蚀性,随着W和C注入剂量的增加,抗腐蚀特性逐步增强;样品W5C5的Jp经55个周期腐蚀后,约为H13钢Jp的1/30.
关键词:
C和W注入
,
钢
,
抗腐蚀特性
,
电化学测量
Zhuhui QIAO
金属学报(英文版)
A novel hard material with various (W0.5Al0.5)C grain shapes was successfully prepared through mechanical alloying and in-situ high-pressure sintering process. X-ray diffraction apparatus and scanning electron microscopy were used to characterize the phase and the microstructures of the samples. The novel hard materials with ``fibrous", ``rounded" and ``plate-like" grains, which do not contain sharp edges, have the improved mechanical properties. The bulk boundless (W0.5Al0.5)C hard material with various (W0.5Al0.5)C grain shapes possesses good mechanical properties and light weight. The formation mechanism for the non-equilibrium (W0.5Al0.5)C grains during in-situ high-pressure sintering is also discussed.
关键词:
Novel hard material
李志宏
,
柳卫平
,
白希祥
,
郭冰
,
连钢
,
颜胜权
,
王宝祥
,
陆昀
,
曾晟
,
苏俊
原子核物理评论
doi:10.3969/j.issn.1007-4627.2005.01.006
利用8Li次级束测量了质心系能量7.8 MeV 2H(8Li, 9Li)1H反应的角分布, 导出了8Li(d, p)9Li反应的天体物理S因子及9Li→8Li+n虚衰变的渐近归一化系数.
关键词:
8Li(d,p)9Li反应
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角分布
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天体物理S因子
,
渐近归一化系数
刘奕新
,
杨书全
,
张丹丹
,
黎光旭
,
韦文楼
,
郭进
无机材料学报
doi:10.3724/SP.J.1077.2009.00813
利用机械合金化方法制备了Li-N-H络合氢化物,并研究B、C作为催化剂对其储氢性能的影响.结果表明:LiNH2、Li2NH为Li-N-H络合氢化物的主要储氢相,随B的加入,储氢相的非晶化程度提高.虽然B、C的添加均使储氢量下降,但n(B):n(C)=1:2的混合添加提高了有效储氢量,同时也提高吸放氢动力学性能;B的添加可有效降低可逆吸放氢温度,适当增加球磨时间,有利于提高可逆吸放氢量.
关键词:
Li-N-H络合氢化物
,
储氧性能
,
机械合金化
