纳米ITO粉末爆炸压实及后续烧结工艺研究

为了探索生产ITO陶瓷靶材的新工艺方法,降低生产靶材的成本,提高靶材的性能,设计了纳米ITO陶瓷粉末经爆炸压实并附加烧结的工艺路线,提出了快速烧结,快速冷却的烧结工艺,对所得样品进行密度检测,并利用SEM对样品微观组织、形貌进行了分析.研究表明:使用高爆速炸药RDX和选择高温快速烧结方案能够获得密度高达98.71%理论密度,微观组织比较良好的陶瓷块体;纳米ITO粉末经爆炸压实后能够在高温突变条件下进行烧结处理;在快速冷却过程中,没有发现宏观裂纹的产生.     

ITO纳米粉末爆炸压实烧结致密化陶瓷靶材研究

对ITO商业复合粉末应用爆炸冲击方法压实烧结,并对样品进行了XRD和ESM检测.通过粉末和压实后样品的XRD图及SEM照片的比较,发现在爆炸冲击压实纳米ITO陶瓷粉末时,能够使晶粒度减小,有助于后续烧结密实过程中控制ITO靶材的晶粒度的过分长大;SEM图片显示,在1200℃烧结的靶材微观结构比较均匀.本文探索了纳米ITO粉末冲击压实烧结的微观机理,并与以往人们对粉末的冲击沉能结论进行了比较,得出结论:压实烧结的主要机理是破碎填充效应,使得一部分粉末颗粒表面原子间的距离达到了点阵量级,从而产生键合力;一部分表面原子间的距离达到了一定小的程度,Vander Waals力使其结合.     

冷爆炸压实中纳米陶瓷粉末摩擦传热研究

对纳米陶瓷颗粒在爆炸冲击波作用下的受力特点进行了分析,利用准静态弹性力学方法研究了颗粒间的冲击摩擦力大小,并利用热传导的尺寸效应和冲击摩擦的强瞬态性(忽略传热的边界散射影响),研究了摩擦引起的颗粒内部温度变化和温度场分布.ITO纳米陶瓷粉末参数的计算分析表明,冷爆炸压实中纳米陶瓷粉末颗粒间很难形成摩擦焊接.要提高纳米陶瓷粉末爆炸压实后的结合强度,必须加强陶瓷颗粒在压实过程中的烧结行为,建议在纳米陶瓷粉末的爆炸压实中采取预热爆炸压实的工艺路线.     

高密度氧化铟锡(ITO)靶材制备工艺的研究进展

ITO靶材是导电玻璃、LED、太阳能电池等行业的核心材料之一.综合评述了高密度ITO靶材的研究现状.介绍了ITO粉末的制备方法如机械混合法、喷雾热分解法、喷雾燃烧法、化学共沉淀法、金属醇盐水解法、水热合成法等以及ITO靶材的制备工艺.比较和分析了ITO粉体和靶材各制备工艺的优缺点.最后提出了制备高品质ITO靶材的研究方向.     

铟锡氧化物陶瓷靶的制备

研究了铟锡氧化物(ITO)粉末退火后的组织和结构,比较了不同状态的粉末和制备工艺对ITO靶材的影响.结果表明,纳米ITO粉末在800℃以下具有体心立方In2O3结构,1100℃退火后由In2O3和SnO2两相组成;ITO粉末经过喷雾造粒后,形成了实心球形颗粒并具有合理的颗粒级配,通过气氛烧结可以制备出高密度优良的ITO...     

退火处理对铟锡氧化物粉末的影响

对两种不同比表面积(BET)的铟锡氧化物(ITO)纳米粉末进行退火处理,研究和比较了温度对两种粉末微观组织和结构的影响,并对这两种粉末烧结的靶材进行了比较。结果表明,在800～1500℃进行不同温度的退火处理后,在1200℃以上,两种比表面积的ITO粉末粒径增长显著,颗粒之间出现了相互合并和结合长大现象,而高BET粉末的粒径增加幅度比低BET粉末的更大;在1525℃烧结后,用高BET粉末烧成的靶材的晶粒和气孔尺寸更大,气孔数量也更多。     

粉末的爆炸压实工艺

为指导粉末爆炸压实工艺,综述了影响粉末爆炸压实的各种工艺参数,阐述了爆炸装置、装粉套筒、原始粉末、炸药以及其他因素的选择原则,分析了这些工艺因素对粉末爆炸成型质量的影响,提出了粉末爆炸压实中工艺参数优化的复杂性,并展望了爆炸压实工艺在粉末成型中的应用前景.     

爆炸压实中爆轰压力与粉末致密度的关系

在粉末材料爆炸压实试验中,爆轰压力是一个重要的工艺参数.本文结合质量不变条件、粉末材料泊松比与相对密度之间的关系、粉末材料的屈服准则以及粉末材料塑性变形时应力应变关系,研究爆炸压实工艺中爆轰压力与粉末致密度之间的关系,以便为实际的爆炸压实试验选择爆轰压力时提供理论依据.结果表明,随着爆轰压力增加,粉末爆炸压实坯的致密度也增加;当采用与其屈服强度相等的爆轰压力时,只能获得80.4%理论密度的棒坯;只有采用16倍屈服应力的爆轰压力时,爆炸压实才有可能获得99%理论密度的棒坯;无论爆轰压力多么大,爆炸压实法也不能得到完全致密的棒坯.     

ITO靶材的研究现状与发展趋势

概述了ITO靶材的应用范围和日益增大的市场需求;对ITO靶材的加工技术和工艺进行了探讨,对ITO薄膜的特性进行了描述;并讨论了ITO靶材所面临的技术问题及发展趋势     

直热式ITO靶材热压设备的设计北大核心CSCD

随着平面显示技术的发展,氧化铟锡(ITO)靶材的需求大增,然而国内生产的靶材多为低密度的中低端产品,ITO靶材的制备目前多采用的是热压烧结的形式,实现ITO靶材的制备突破研制合适的装备及工艺成为焦点问题。本文结合直热式制备ITO靶材工艺给出了ITO靶材热压炉中核心加热区的设计方法,并利用ANSYS软件对设计完成的石墨模具进行了仿真分析。     

Effects of sintering processes on the element chemical states of In,Sn and O in ITO targets

The element chemical states of In, Sn and O could affect the resistivity of ITO targets so as to affect the electrical property of ITO films. In the work, nine kinds of ITO targets were prepared in order to investigate the effects of sintering processes on the element chemical states of In, Sn and O in ITO targets by XPS. The results show that the heating rate of 60 °C/h, the sintering temperature of 1580 °C, the holding time of 5 h and the cooling rate of 240 °C/h are favorable for the preparation of ITO targets with the optimum conductivity. The change rule of the element chemical states of In, Sn and O in ITO targets sintered with different sintering process parameters has been proved by the theoretical analysis of thermal decomposition kinetics of In₂O₃ and SnO₂.     

溶胶-凝胶法制备ITO薄膜研究进展

概述了近年来国内外溶胶-凝胶法(Sol-Gel)制备ITO薄膜的研究状况,对Sol-Gel法制备ITO薄膜工艺做了简要介绍,重点讨论了Sol-Gel法制备ITO薄膜的溶胶体系,分析比较了有机醇盐、无机盐以及掺入ITO粉末方法体系的优缺点,最后讨论了甩膜法、提拉法及平铺法在Sol-Gel法制备ITO薄膜中镀膜的应用.指出Sol-Gel法是一种高效可行的制备ITO薄膜的方法,有着广阔的应用前景.     

Effect of zinc content on the refractive index of Co-sputtered Zn-doped ITO films

In this study, we investigated the possibility of using Zn-doped ITO film as an alternative material for conventional SiO2 waveguides used in optical communication. The Zn-doped ITO films were deposited on quartz substrates using a combinatorial sputtering system, which yielded composition spread Zn-In-Sn-O (ZITO) films by co-sputtering two targets of ITO and ZnO. The Zn-doped ITO films deposited at room temperature exhibited an amorphous phase in the Zn content [Zn/(Zn+In+Sn)] range of 39-54 at%. The Zn-doped ITO films deposited at low oxygen partial pressure showed resistivity below 10(-3) ohms cm and optical transmittance of approximately 85% at 550 nm. The refractive index calculated by the Swanepoel method was found to be dependent on the Zn content in the Zn-doped ITO films. The calculated bending loss from the refractive index indicated that Zn-doped ITO could be utilized as a new waveguide material for various optical devices, such as optical splitters, wavelength division multiplexers (WDMs), optical modulators, and optical switches.     

气化粉与湿法粉制备ITO靶材过程及性能对比研究

分别以ITO气化粉和湿法粉为原料,在相同工艺条件下,经过球磨、造粒、成型等工序制备了ITO靶材,研究了ITO气化粉和湿法粉制靶中间品及最终靶材的主要性能。结果表明:模压和CIP后,湿法粉坯体密度均低于气化粉的,但由于ITO湿法粉原料粒径细而均匀,烧结活性更高,故在较低的烧结条件下可制备出更高密度的靶材。     

Development of transparent heat mirrors based on metal oxide thin film structures

The aim of this work is the preparation of RF sputtered indium-tin oxide (ITO) thin films for application as transparent heat mirrors. The heat mirrors are important elements for the photothermal solar energy conversion. In combination with moderate spectral selectivity of the solar absorbers they could increase the efficiency of the solar collector. The optical properties of ITO and double-layer ITO with titanium dioxide (TiO₂) structures in the visible and infrared ranges were investigated. The films were deposited on glass substrates by RF sputtering technique. Tin-doped indium, as well as titanium targets was used. The influence of the In-Sn target composition and the deposition parameters on the film properties were studied. The films' surface morphology and structure were investigated by SEM, TEM and XRD, the composition was studied applying electron probe microanalyzer (EPMA). The thicknesses of the films were determined by the laser ellipsometry method. The measurements in the infrared range were performed on Fourier transform infrared spectrophotometer (FTIR). The single layer ITO structures showed reflectance in the infrared range not exceeding 50% at longer wavelengths. The double layer structures with TiO₂ under layer showed increased reflectance in the infrared range with high visible transmittance reaching 85%.     

In-line deposition of organic light-emitting devices for large area applications

Light-emitting diodes based on organic semiconductors show promising features for display and lighting applications. A vertical in-line deposition technique for organic light-emitting diode (OLED) manufacturing was developed.OLED devices with electrically doped transport layers show low operating voltage, high efficiency and long lifetime. The preparation of p-i-n type devices was performed with the in-line fabrication tool resulting in highly efficient OLED with low operating voltage. The lowest operating voltage was achieved for green diodes with 2.9 V for 100 cd/m². This demonstrates that the p-i-n device concept can be applied under manufacturing conditions. In-line manufactured highly efficient red, green and blue OLED are presented.One important aspect for fabrication cost is the used ground contact, which is commonly made by indium tin oxide (ITO). For low cost fabrication an alternative for ITO has to be used. In this work, ITO was replaced by aluminium doped zinc oxide (ZAO). The results are comparable to OLEDs using ITO as transparent conductive oxide.     

Grain size control in ITO targets and its effect on electrical and optical properties of deposited ITO films

Tin-doped indium oxide (ITO) ceramic targets with three types of grain size (<10, 10–20 and >20 μm) were prepared by controlling sintering process. It is found that all targets show polycrystalline structure and a rapid heating and short holding time contributes to refining grain size. The ITO films were deposited using these ITO targets with three types of grain sizes under dc and rf mode. The effects of grain size on the structural, electrical and optical properties of the as-deposited films were systematically investigated. The results indicate that all ITO films are the (222) preferred orientation, and the surface grain morphologies are round (dc mode) and triangular (rf mode). The sheet resistance, transmittance and uniformity of the ITO films are significantly impacted by the grain size. The small grain size (<10 μm) contributes to improving the uniformity of electrical and optical properties. The optimal uniformity of sheet resistance under dc and rf mode is about 13 and 10 %, respectively.     

A method for the direct measurement of the fibre bed compaction curve of composite prepregs

A method to measure the fibre bed compaction curve directly from composite prepreg is presented. The method was used to measure the compaction curve of unidirectional and quasi-isotropic AS4/3501-6 carbon–epoxy prepregs. Similar compaction curves were obtained in all cases. The compaction curve obtained was used by a finite element process model, COMPRO, to simulate the uniaxial compaction of 8 and 16 ply laminates at different temperatures. The force–displacement response predicted by the model closely matched the experimental results. The method which can be used on both tape and fabric prepregs, has the major advantages of being a direct measure of the prepreg behaviour, and requires no special preparation of the sample.     

Structural, electrical and optical properties of indium tin oxide thin films prepared by RF sputtering using different density ceramic targets

There is an active demand for the commercial indium tin oxide (ITO) target with density above 99% of the theoretical density (TD). Some works found the increase of the target density could lead to a slight decrease of the resistivity of the direct current (DC) sputtered ITO films, however, the possible effect of target density on the radio frequency (RF) sputtered ITO films is not clear. In this paper, ITO targets with different densities are successfully prepared. The structural, electrical and optical properties of the thin films deposited from these targets are studied at the substrate temperature of 750 °C. It is found that the target density has no effect on the above properties and the deposition rate of the RF sputtered ITO thin films, different from the DC sputtered films. So for the RF sputtered process, the target needs not high density so that the used target can be just compacted from the powders without sintering. All the as-prepared ITO films with different densities have a resistivity of 1.56 × 10⁻⁴ Ω cm and a transmittance of ∼87%, which are lower than the ITO films prepared at temperatures lower than 400 °C.