基于镶嵌原子势的纯Al快速凝固过程分子动力学模型

采用镶嵌原子势（ＥＡＭ）和分子动力学方法模拟了纯Ａｌ的液态，过冷的液态和和非晶态的微观结构，采用键取向和对分析方法考察了和结构转变的特征。     

A1－Cu合金液态过热处理的研究

对二元Ａｌ－１０ｗｔ％Ｃｕ亚共晶和Ａｌ－３３．２ｗｔ％Ｃｕ共晶合金液态进行７００～１２００℃范围过热处理，然后在粘土砂型和金属型中凝固。试验研究了液态过热对固态显微组织、显微硬度、宏观晶粒大小及凝固过程特征温度的影响，分析了Ａｌ－Ｃｕ合金的液态结构。     

Al—Cu合金液态过热处理的研究

对二元Ａｌ－１０ｗｔ％Ｃｕ亚共晶和Ａｌ－３３．２ｗｔ％Ｃｕ共晶合金液态进行７００￣１２００℃范围过热处理，然后在粘土砂型和金属型中凝固。试验研究了液态过热对固微组织、显微硬质、宏观晶粒大小及凝固过程特性温度的影响，分析了Ａｌ－Ｃｕ合金的液态结构。     

锌合金的液态模锻强化

利用ＳＥＭ，ＴＥＭ，ＸＲＤ及能谱分析研究了铸态和液态模锻ＺＡ１２，ＺＡ２７合金的显微组织，结构表明液态模锻不仅使晶粒细化，还具有固 化和弥散强韧化效应，富铝α相中Ｃｕ增多，断口形貌转变为韧性断口。     

核反应堆结构系统数值模拟方法与程序评述

本文在讨论了液态金属块增殖反应堆ＨＣＤＡ（假想堆芯破坏事故）过程中主要的物理现象和力学性质之后，重点评述了国际上进行这类核反应堆结构系统安全分析时进行ＨＣＤＡ模拟分析的理论基础及相应的程序系统。     

液态铝的润湿性测量

介绍了液态铝的润湿性测量原理,并采用改进的座滴法装置测定了纯铝和Ａｌ－０．５％Ｌａ合金在Ａｌ２Ｏ３表面的润湿性。结果表明,少量稀土元素的加入可以改善铝对Ａｌ２Ｏ３的润湿性,使其润湿角从９０．５°减小到８０．０°。     

锌合金液态模锻凝固特征探析

研究了ＺｎＡｌ４Ｃｕ３合金在常规铸造和液态模锻时的凝固过程，探讨了压力对液态金属凝固过程温度场的影响。给出了在压制过程中不同比压和冲头温度下模具与制件不同位置的温度变化情况，根据实验结果计算得出液态模锻下冷却速度较之自由凝固提高近１０倍，并由此分析了液态模锻的凝固特征。     

Au—Si—Be液态金属离子源发展综述

对Ａｕ－Ｓｉ－Ｂｅ液态金属离子源的发展进行了较详细的介绍，包括源的结构，发射特性，以及不同的合金配比，源工作温度，环境气体，系统真空度对源发射稳定性的影响。     

液态和非晶态Cu-Zr合金的研究进展

从性质、结构以及相图等方面论述了近年来液态和非晶态Cr Zr合金的研究现状。指出目前研究的主要内容集中在固态尤其是非晶态的结构和晶化以及相分离过程等方面 ,而对与凝固过程密切相关的液态Cu Zr合金的结构和性质方面的研究则涉及非常少。因而从液态Cu Zr合金的结构和性质入手 ,寻求液态、非晶态与晶态之间的相互关系 ,是一个值得研究的新课题     

3D打印聚氨酯微流道封装镓基液态金属柔性导线及其性能

利用3D打印制备了聚氨酯(TPU)微流道,并采用注射器将GaInSn液态金属注入后封装,得到液态金属柔性导线.采用扫描电子显微镜(SEM)和能谱分析仪(EDS)对液态金属的形貌及结构进行表征.利用万用表和电化学工作站分别测试了复杂流道中的液态金属及外力作用下不同尺寸柔性导线的导电性能,并通过对比商用柔性电路板(FPC),测试了柔性导线在反复弯曲及对折下的抗疲劳性.结果表明,该液态金属由67.2％Ga、20.1％In和12.7％Sn(均为质量分数)组成,将其与TPU柔性材料结合,可制备多层复杂的结构电路;在压力(0～190 N)和弯曲变形(0～360°)的外力作用下,外力对液态金属柔性导线的导通性能基本无影响,其中,微流道横截尺寸为0.5 mm×0.5 mm时,外力对其影响最小;对比商用FPC,液态金属柔性导线在循环弯曲24 h、对折压实200次的条件下仍未发生断裂,其电阻仅增加0.02Ω,展现了液态金属在复杂柔性电路制造领域的巨大应用潜力.     

An improved molecular dynamics potential for the Al-O system

Molecular dynamics (MD) simulations of aluminum oxide material and the aluminum oxidation process require a sufficiently sophisticated and well-calibrated potential, one that takes into account locally varying Al/O ratios and adaptive charge transfer between Al and O atoms. In this work we show that the Charge Transfer Ionic Potential (CTIP) by Zhou et al. [X.W. Zhou, H.N.G. Wadley, J.-S. Filhol, M.N. Neurock, Phys. Rev. B 69 (2004) 035402] in combination with a new, “Reference Free” version of the Modified Embedded Atom Method (RFMEAM) potential performs well for this purpose. This new potential has been parameterized by systematically fitting it to a large database of different Al_xO_y crystal energies, over a range of lattice constants and elastic deformations, using a recent method which separates the electrostatic and non-electrostatic fitting steps. The resulting potential yields more realistic atomic charges, crystal energies and lattice constants than earlier potentials. In particular, we show that the angular forces in the MEAM part are essential for α-Al₂O₃ to be the lowest-energy aluminum oxide. We compare the performance of our potential with the potential of Zhou et al., which lacks angular forces and was parameterized using a less involved fitting procedure, and show the results of a few molecular dynamics simulations. The two-step fitting method is generally applicable and can be adopted for constructing potentials for other metal-oxide systems.     

Density of Ni-Al Alloys in Liquid and Solid-Liquid Coexistence State Measured by a Modified Pycnometric Method

The density of Ni-AI alloys in both liquid state and solid-liquid coexistence state was measured with a modified pycnometric method. It was found that the density of Ni-AI alloys decreases with increasing temperature and Al concentration in the alloys. The molar volume of liquid Ni-AI binary alloys increases with the increase of temperature and Al concentration. The partial molar volume of Al in Ni-AI binary alloy was calculated approximately. The molar volume of liquid Ni-AI alloy determined in the present work shows a negative deviation from the ideal linear molar volume.     

Surface acoustic wave reflection from diamond-like carbon thin film reflecting arrays on LiNbO3 substrates

Surface acoustic wave (SAW) reflection from diamond-like carbon (DLC) strip reflecting arrays on Y-Z LiNbO₃ is investigated. The reflection from DLC strips with triangular cross section has been observed. Reflection increases in alternating DLC and Al strips in 90° reflecting arrays in comparison with pure Al structures. The values of reflection coefficient per period in the slanted reflecting arrays are estimated to be about 1.0% for pure DLC strips (height to wavelength ratio equal to 0.02), 2% for uniform Al coating on DLC reflecting arrays, and 3.5% for alternating DLC and Al strips. This value is higher than that for pure Al strips by about 0.7%. Reflection properties are briefly discussed, and preparation technique is presented     

Atomistic simulation of zeolite surfaces

The aim of this paper is to describe the current state of atomistic simulation of zeolite surfaces by describing what has been achieved and to show how the surface structures are modelled. This is illustrated by using atomistic simulation techniques to model the {100} surface of zeolite LTA. The pure siliceous and aluminated CaNa-A and Na-A with Si/Al=1 structures were considered. The surface showed three stable terminations but the relative stability varied with composition. The resulting surface structures and geometries show extensive framework distortions, especially in the aluminated forms where the cations formed strong interaction with the zeolite framework thereby increasing their adsorption energies and stabilising their cation position.     

Ni针尖/Au基体纳米压痕的分子动力学模拟

采用原子镶嵌势函数（EAM）模拟Ni针尖（约1．5mm）／Au基体纳米压痕过程．研究结果表明，当Ni针尖与Au基体间距离达到一定值时（约0．23 mm），机械的不稳定性使得针尖与基体间发生跳跃接触，产生纳米压痕和黏附现象（Au原子包裹在Ni针尖周围）．当压头离开基体表面，Ni针尖被拔起，随后在针尖与基体间形成连续的由Au组成的细颈．同时计算得到整个系统在针尖接近基体、跳跃接触、压痕、黏附、形成缩颈和一系列分离过程中的势能变化．     

铝合金表面制备二氧化钛薄膜及其光催化活性研究

分别以阳极氧化处理的6061铝合金和纯铝为载体,用液相沉积的方法在载体上制备了二氧化钛薄膜.结果表明,在6061铝合金上的TiO2纳米薄膜呈现带有孔洞的竹节状结构,而纯铝基片上的TiO2纳米薄膜具有良好的一维贯通结构.这主要是在AAO模板制备过程中,由于铝合金中的合金元素Mg被氧化,其产生的氧化物体积比Al2O3的体积小所致.在铝合金表面的TiO2薄膜光催化性能优于纯铝表面的TiO2薄膜.铝合金表面制备的TiO2薄膜因其特殊的带孔洞的竹节状结构,使其比表面积比纯铝上的TiO2薄膜大,因此其光降解甲基蓝效果更好.TiO2对甲基蓝的光催化降解符合一级反应动力学公式,在0.1 mol/L的氟钛酸铵溶液中沉积得到的TiO2薄膜光催化性能最好,表观反应速率为k=0.00444/min.     

Mathematical Models and Computer Simulation of Nitrogen Concentration Profiles in Pulse Plasma Nitrided Layers

Two materials, pure Fe and pure Al, were nitrided in a pulse plasma nitriding facility. The nitrogen profiles in surface layers and the surface phase structures of specimens nitrided at 500℃ for 8 h for Fe and for 6 h for Al were measured using the glow     

Influence of the aluminium doping on the antiferromagnetic structure of YBa2Cu3O6+x

The magnetic structure of YBCO with low oxygen content is severely influenced by Aluminium doping. The Al-NMR spectra confirm the position of the non-magnetic Al impurities in the Cu(1) layer with a shift from the regular Cu(1) site in <110> direction. The Cu(1) ions in the Al-O-Cu(1) clusters may be responsible for the transition between the antiferromagnetic AFI and AFII phases in the doped crystals. From the Cu-NMR in pure and Al doped single crystals different spin directions in the AFI and AFII phases have been determined, <100> for the pure YBCO and <110>for the Al doped in the AFII state.     

Enthalpies of Formation of Noble Metal Binary Alloys Bearing Rh or Ir

The modified embedded atom method proposed by authors has been applied to calculating the enthalpies of formation of random alloys and the ordered intermetallic compounds for noble metal binary systems bearing Rh or Ir. The present results are in good agreement with those of Miedema theory, available experiments and the first-principles quantum mechanics calculations. The present results indicate that Cu-Rh, Cu-Ir, Ag-Rh, Ag-Ir, Au-Rh, Au-Ir, Pd-Rh and Pd-Ir systems are repulsive, however, Ni-Rh, Ni-Ir, Pt-Ir, Pt-Rh and Rh-Ir systems form solid solutions and Ni-Rh, Ni-Ir and Pt-Rh show ordering tendency.