Elevated temperature properties of Mg- 12Li-Al-MgO composites

1 Introduction Mg-Li alloys have potential for use in aerospace applications because they are exceptionally light and their specific stiffness is high[1?3]. However, there are some practical difficulties, such as poor creep behavior and microstructural in…     

Microstructure and high-temperature shape-memory effect in Ni54Mn25Ga21 alloy

1 Introduction Shape memory alloys (SMAs) have developed rapidly in the past few decades as new functional materials, with commercial applications in pipe couplings, medical implants, electrical connectors and various actuators etc[1?3]. But the highest …     

Diffusion bonding of γ-TiAl alloy to Ti-6Al-4V alloy under hot pressure

1 Introduction Alloys based on the ?-TiAl intermetallic compounds have been of much interest in recent years as light-mass structural materials for elevated temperature aerospace applications[1- 5]. Successful joining and cost effective fabrication method…     

Effects of H_2O_2 pretreatment on surface characteristics and bioactivity of NaOH-treated NiTi shape memory alloy

1Introduction It has been reported that chemical treatment in alkali solutions is an effective method to prepare bioactive titanium metals for medical applications[1?5].The structural changes of titanium surfaces during alkaline treatment lead to the form…     

Supermolecular template route to fabrication of well crystallized hollow antimony microspheres

1 Introduction The preparation of hollow spheres in the nanometer to micrometer scale is of particular interest due to their specific structure and wide applications in artificial cells[1], light-mass structured materials[2,3], catalysts[4], controlled re…     

EIS ANALYSIS ON THE ANODIC PROCESS OF ZINC IN AN ALKALINE SOLUTION

1.IntroductionDue to its low equilibrium potential, good reversibility, high volumetric energy density, low cost and low toxicity, zinc has a wide variety of applications as a negative electrode material in Zn-Mn, Zn-Ag, Zn-Ni and Zn-air batteries[1-19]. Increasing efforts have recently been devoted to the development of secondary zinc batteries[20], which makes it a promising candidate in electric vehicle applications, as well as in military and commercial aircraft. However, these seconda…     

Numerical simulation of copper based filler metal droplets spreading under arc brazing

1 INTRODUCTION Arc brazing technology is a newly developed joining technology .For its advantages ,it has been used more and more frequently in automobile industry and other wiring equipments . And this technology is considered to have a big foreground in practical joining applications . But up to now, the studies of this technology are restrained in practical production applications[1 3]and experi- mental analyses[4 ,5]; and few researchers have studied the spreading of liquid droplets ,…     

Temperature distribution in adiabatic shear band for ductile metal based on JOHNSON-COOK and gradient plasticity models

1 Introduction Adiabatic shear localization is one of the most important deformation and failure mechanisms in some titanium alloys subjected to moderate and high shear strain rates. Adiabatic shear band(ASB) can be observed in various applications, such as metal forming, perforation, impact on structures, ballistic impact, machining, torsion, explosive fragmentation, grinding, interfacial friction, powder compaction and granular flow[1?15]. The formation of ASBs is often followed by ductile…     

Effect of external stress on phase diagrams and dielectric properties of epitaxial ferroelectric thin films grown on orthorhombic substrates

1 Introduction Ferroelectric thin films have been widely investigated in recent years. Not only the ferroelectric, dielectric, and piezoelectric properties were found to be promising for microelectric and micromechanical applications[1], but also the phy…     

Continuous cooling transformation curve of a novel Al-Cu-Li alloy

1 Introduction Al-Li alloy is perspective for wide applications in aircraft industry. It has an attractive combination of medium strength with good plasticity, fracture toughness, corrosion resistance and weldability[1- 3]. Continuous cooling transformati…     

脉冲激光沉积及硒化法制备Cu(In,Ga)Se2薄膜研究

采用脉冲激光沉积和硒化后热处理的方法在石英衬底上制备Cu(In,Ga)Se2（简写为CIGS）薄膜,研究脉冲激光沉积（PLD）技术在制备CIGS薄膜太阳能电池材料上的应用,分析了不同预制层沉积顺序及厚度对CIGS薄膜组织结构、表面形貌、成分以及光学性能的影响。实验结果表明：(1)利用PLD技术及后硒化处理的工艺,制得的CIGS太阳能电池吸收层具有纯相和高结晶度等特性;(2)CuGa/In金属预制层的叠层顺序和叠层数、硒化退火温度对薄膜的结晶质量、晶粒尺寸、成分都具有重要的影响,其中叠层顺序影响最为明显;(3)样品均表现出对可见光区具有透射率低和吸收系数高的光学特性。本工作为制备性能优良的CIGS太阳能电池吸收层,提供了一个新颖的工艺手段。     

Optical and electrical properties of TiO2/Au/TiO2 multilayer coatings in large area deposition at room temperature

TiO2/Au/TiO2 multilayer thin films were deposited at polymer substrate at room temperature using dc (direct current) magnetron sputtering method.By varying the thickness of each layer,the optical and electrical properties of the TiO2/Au/TiO2 multilayer films can be tailored to suit different applications.The thickness and optical properties of the Au layer and the quality of the Au-dielectric interfaces are critical for the electrical and optical performance of the Au-dielectric multilayer thin films.At the thickness of 8 nm,the Au layer forms a continuous structure having the lowest resistivity and it must be thin for high transmittance.The multilayer stack can be optimized to have a sheet resistance of 6 Ω/sq.at a transmittance over 80% at 680 nm in wavelength.The peak transmittance shifts towards the long wavelength region when the thickness of the two TiO2 (upper and lower) layers increases.When the film thickness of the two TiO2 film is 45 nm,a high transmittance value is obtained for the entire visible light wavelength region.     

溶胶-凝胶法制备的钛酸钡薄膜光学性质的影响因素概述

铁电体具有反常光生伏打效应,是一类极具发展潜力的新型太阳能电池材料和光电敏感材料。钛酸钡是最为典型的一种铁电材料,为将它用作太阳能电池和光电敏感材料,国内外对它的光学性质进行了广泛研究。综述了溶胶凝胶制备条件、膜厚、掺杂与钛酸钡铁电薄膜光学性质的关系,并提出了研究中亟待解决的问题。     

CuS-based thin films for architectural glazing applications produced by co-evaporation: Morphology, optical and electrical properties

Copper sulphide thin films in the 90–300 nm thickness range have been deposited on soda–lime glass substrates by thermal co-evaporation of Cu and S. Depending on the film thickness, the optical transmittance in the visible region is of about 50% for the thinnest film and 19% for the thickest film, with the corresponding near-infrared transmittance dropping from 11% to near-zero at 2500 nm as the film thickness increases from 90 to 300 nm. A resistivity of ρ ~ 10^− 4 Ω cm has been obtained for the films. The optoelectronic properties of the films remained practically unchanged after one year stored under laboratory ambient. The optical properties obtained for selected CuS-based films make them suitable for their use as effective solar control glazings in warm climates.     

Synthesis and characterization of Cu2ZnSnS4 thin films grown by PLD: Solar cells

As-deposited and annealed Cu₂ZnSnS₄ (CZTS) thin films have been synthesized onto Mo coated glass substrates at different deposition times using pulsed laser deposition (PLD) technique. The effect of deposition time (film thickness) and annealing onto the structural, morphological, compositional and optical properties of CZTS thin films have been investigated. The polycrystalline CZTS thin films with tetragonal crystal structure have been observed from structural analysis. FESEM and AFM images show the smooth, uniform, homogeneous and densely packed grains and increase in the grain size after annealing. The internal quantitative analysis has been carried out by XPS study which confirms the stoichiometry of the films. The optical band gap of CZTS films grown by PLD is about 1.54 eV, which suggests that CZTS films can be useful as an absorber layer in thin film solar cells. Device performance for deposited CZTS films has been studied.     

N2流量对室温磁控溅射制备Ti-N薄膜太阳能光谱吸收特性的影响

利用非平衡磁控溅射技术,在室温条件下制备了一系列不同N2流量的Ti-N薄膜,研究了N2流量对薄膜微观形貌和光学性能的影响。根据分析结果设计并制备了四层结构的Ti-N太阳能选择性吸收薄膜,通过软件对薄膜进行了优化设计并进行了实验验证。结果表明,随着N2流量的增加,薄膜的微观形貌发生变化,逐渐出现气泡状沉积物及气泡破裂状形貌,直至变为无定型态。通过紫外-可见-近红外光谱分析可知,选用合适的工艺可有效提高太阳能吸收薄膜光学性能,利用软件对薄膜进行优化设计可使薄膜光学性能获得进一步改进,经过优化的薄膜吸收率达0.9048,可用作太阳能光谱选择性吸收薄膜。     

MICROSTRUCTURES AND OPTICAL PROPERTIES OF Te_（81）Ge_（15）Sb_4 THIN FILMS USED FOR PHASE CHANGE RECORDING MATERIALS

ＭＩＣＲＯＳＴＲＵＣＴＵＲＥＳＡＮＤＯＰＴＩＣＡＬＰＲＯＰＥＲＴＩＥＳＯＦＴｅ_（８１）Ｇｅ_（１５）Ｓｂ_４ＴＨＩＮＦＩＬＭＳＵＳＥＤＦＯＲＰＨＡＳＥＣＨＡＮＧＥＲＥＣＯＲＤＩＮＧＭＡＴＥＲＩＡＬＳ￥Ｓｏｎｇ，Ｌｉａｎｐｅｎｇ；Ｈｕａｎｇ，Ｓｈｕｗａ?..     

浸渍式提拉法制备TiO2薄膜的微观结构和润湿性

目的研究工艺参数与TiO_2薄膜的微观结构、光学性质及润湿性的关系。方法以钛酸四丁酯为原料,乙醇为溶剂,采用溶胶-凝胶浸渍式提拉法,改变工艺参数(提拉次数、提拉速度),在玻璃衬底上制备了TiO_2薄膜,并通过光学表面形貌仪、紫外可见分光光度计及接触角测试仪分析了不同参数下制备的TiO_2薄膜的微观结构、光学性质和润湿性。结果提拉次数和提拉速度都会影响薄膜的微观结构,提拉2次,提拉速度在3~7 cm/min之间制备的TiO_2薄膜表面平整、致密。在提拉方向上,存在厚度梯度,厚度梯度为1 nm/μm。透射光谱显示TiO_2薄膜在可见光区透明,吸收边与提拉工艺有关,提拉速度为7 cm/min,提拉2次制备的TiO_2薄膜,禁带宽度为3.57 e V,此时,接触角为14.8°。结论提拉速度、提拉次数影响TiO_2薄膜的微观结构、光学性质和润湿性。通过提拉工艺参数的调整,可以制备均匀致密、具有亲水性的半导体TiO_2薄膜。     

The effect of thickness on the properties of Ti-doped ZnO films by simultaneous r.f. and d.c. magnetron sputtering

For Ti-doped ZnO (ZnO:Ti) films, the crystallinity and degree of orientation of the ZnO:Ti films were closely related to the film thickness. The crystal size increased with the increase of film thickness. With decreasing film thickness, there were more defects existing in the ZnO:Ti films and surface roughness decreased. The resistivity increased with the decrease of film thickness. The main scattering mechanism in the thin ZnO:Ti films was defect scattering. The transmission in UV region decreased strongly with the increase of film thickness. Such behavior was due to the films with different thickness showing different structural and electrical properties. As the results, film thickness affected the properties of ZnO:Ti films significantly.     

高迁移率的钛掺杂氧化铟薄膜在晶硅/非晶硅异质结电池上的应用研究

采用钛掺杂氧化铟旋转靶制备透明导电薄膜应用在晶硅/非晶硅异质结电池上。在不同氧含量下,研究钛掺杂氧化铟薄膜(T100薄膜)的光电性能,同时对比分析ITO薄膜。在电镜下T100薄膜呈现出柱状结构,并且展示出优异的光学性能。T100薄膜最大载流子迁移率可以达到75.6 cm~2·(V·s)^-1。相比于ITO薄膜,T100薄膜具有优异的电学传导和透光率,因此在异质结电池量产线上电池转换效率可以实现0.26%的提升。