氧化铝陶瓷直接凝固注模成型(DCC)工艺参数的研究

直接凝固注模成型(DCC)是利用陶瓷浆料粘度变化制备陶瓷坯体的先进成型方法,脱模时间长是限制其应用的主要问题.通过调整DCC工艺参数,减小充模前浆料的粘度以利于成形,而在充模后使浆料的粘度迅速增加,缩短脱模时间.将高固含量(体积分数为70%)低粘度的陶瓷浆料浇注到模具中,通过改变浆料的pH值或浆料离子浓度来改变其胶体化学行为,调节浆料流动性能;通过温度控制加速浆料凝固,使充模后10 min的浆料粘度与充模前浆料粘度比值达到13,3倍于传统浆料成型方法,充模后1 h即可得到有足够脱模强度的陶瓷坯体,效率显著提高.     

煤系高岭土光固化浆料的流变性能EI北大核心CSCD

基于光敏树脂体系制备煤系高岭土光固化浆料,采用流变仪对浆料的流变性能进行表征,研究分散剂和增塑剂加入量对浆料流变性能的影响。结果表明:油酸作为分散剂具有降低浆料黏度的效果,当油酸加入量为高岭土粉体的1%(质量分数)时浆料的黏度最小,在该条件下40%(体积分数)高岭土浆料的黏度为49.56 Pa·s。加入增塑剂PEG-300能够进一步降低浆料的黏度,浆料黏度随着增塑剂加入量的增加而减小,当增塑剂加入量为光敏树脂的20%(质量分数)时40%(体积分数)高岭土浆料的黏度下降为19.77 Pa·s,已经能较好地满足浆料涂布的要求。采用流变性能优化的浆料进行光固化成形,经过排胶、烧结后得到复杂形状的高岭土陶瓷件。     

氯化法钛白粉浆料的黏度影响研究

针对氯化钠除疤工艺生产的氯化法钛白粉浆料存在黏度增大的现象,采用洗涤压滤的除盐工艺降低浆料中的氯化钠含量,通过调节浆料pH、六偏磷酸钠用量、浆料黏度,确定氯化钠用量为2‰(wt,质量分数)、pH=6、六偏磷酸钠用量为3‰(wt,质量分数)、钛白粉浆料浓度为450g/L,可以获得黏度为58mPa·s的钛白粉浆料,达到钛白粉浆料后处理表面包膜的黏度指标要求。     

蔗糖脂肪酸酯对碳化硅浆料分散性的影响

以蔗糖脂肪酸酯(SE)为分散剂制备得到稳定性好、分散性高的SiC水基浆料,研究SiC浆料pH值、分散剂含量、浆料固相体积分数等因素对SiC浆料分散性的影响,并对SE的作用机理进行分析。结果表明:使用SE作为分散剂,能够均匀有效地分散SiC浆料,且能制备得到分散性优异的高质量浓度SiC浆料;当浆料pH值为10、分散剂质量分数为25%、SiC体积分数为20%～30%时,SiC粉末颗粒能够均匀地分散在水基体系中,此时SiC浆料的流动性和分散性最好,并最终制备SiC浆料的固相体积分数高达65%。     

基于液相化学还原法的电子浆料导电相可控制备装置及控制方法的研究进展

电子浆料是用于制造电子元件的基础材料,随着电子信息产业的迅速发展,电子浆料的性能需要进一步的提高,电子浆料的性能主要由电子浆料导电相的形貌和粒径决定。文章结合近年来电子浆料及控制领域的研究状况,介绍了电子浆料导电相最常用的制备方法及制备过程中影响电子浆料导电相形貌和粒径的因素,阐述了电子浆料导电相制备装置国内外发展现状,着重阐述了基于液相化学还原法的电子浆料导电相可控制备装置及其控制方式。     

凝胶注模成型延迟固化研究

凝胶注模成型工艺中, 为了延长操作时间, 通常希望陶瓷浆料能延迟固化, 即延长浆料的聚合诱导期. 传统的方法是通过调节催化剂、引发剂的用量以及控制浆料的温度来实现这一目的. 本文研究了其它各种延长诱导期的方法, 包括改变浆料pH值、增加浆料中离子强度、加入阻聚剂等. 研究发现, 浆料中离子强度较高会使固化延迟; 浆料pH?值偏酸或偏碱, 诱导期会急剧增加; 加入适当的阻聚剂在不同温度下都可以使浆料延迟固化.     

离心成型制备HA陶瓷工艺中浆料的特性研究

主要研究了pH值对HA粉体Zeta电位的影响,分析了分散剂含量和浆料固相含量对HA浆料粘度的影响,研究了HA浆料的流变性和稳定性,并测量了不同工艺条件下所制备的HA生坯的密度。研究结果表明,在pH=9时,HA粉体表面的Zeta电位值达到最大,HA浆料具有良好的分散性。在分散剂含量为5%(质量分数),浆料固相含量为60%(质量分数)时,HA浆料的粘度达到最低值476.1mPa·s,HA浆料具有较好的充型能力。HA浆料具有剪切变稀特性,室温静置12h时浆料具有较好的稳定性。与干压成型相比,60%HA(质量分数)浆料离心成型所得到的生坯密度更高,更有利于HA生物陶瓷的烧结。     

制备工艺因素对碳化硅水基浆料粘度的影响研究

研究了浆料搅拌时间、分散剂含量、粉体含量和p H值等对碳化硅水基浆料粘度的影响。结果表明,水基浆料的粘度随搅拌时间的增加而减小,超过24 h后趋于平稳;水基浆料粘度随分散剂含量的增加而减小,但超过一定含量时反而增大;随着Si C水基浆料中粉体含量的逐渐增加,浆料的粘度总体呈逐渐增大的趋势,粉体含量超过30%时,浆料的搅拌分散时间会延长1.5倍;p H值高于5.5后,水基浆料的粘度随p H值的增加急剧提高,超过8.15时略有下降。通过优化工艺参数,可制备出粘度低于1.0 Pa·s、粉体含量为30%的Si C水基浆料。     

电子浆料用有机载体的研究现状及发展趋势

介绍了电子浆料的分类、组成及电子浆料用有机载体的研究现状,综述了电子浆料用有机载体对浆料流平性、挥发特性、电学性能、力学性能等方面影响的研究进展。最后提出了电子浆料用有机载体存在的问题,并展望了其今后的研究方向。     

盐离子对纳米氧化锆浆料流变性能的影响

通过测定浆料的Ｚｅｔａ电位和粘度曲线,研究了含高浓度盐溶液电解质对纳米氧化锆浆料电动性能和流变性能的影响。研究结果表明,盐离子的加入可显著改变浆料的悬浮特性,增加盐离子的浓度,氧化锆浆料的Ｚｅｔａ电位降低,粘度增大,对同一种电解质而言,浆料的等电点并不随离子浓度的改变而改变,说明氧化锆浆料对这些盐离子无特性吸附,从浆料 的粘度贡线可以看出,盐离子的加入均对浆料产生絮凝作用,使颗粒间产生一种相互相吸     

Structural morphology and magnetism of electroless-plated NiP films on a surface-modified Si substrate

NiP thin films were deposited on an H₃PO₄-etched Si substrate by means of electroless-plating. By varying the plating time, we were able to deposit NiP films with various thicknesses. Thickness effects upon the structural morphology and magnetic properties of the NiP films were investigated, and they can be comprehended with a model of the deposition mechanism. The results demonstrate that the etched Si surface contained groove-like microstructure which shaped the columnar structure inside the NiP films and favored the film deposition; this was hard to achieve with a smooth-surfaced Si substrate. The well-developed columnar structure resulted in a perpendicular anisotropy due to its vertical nature, which can become superior to the film's longitudinal anisotropy if the applied field is sufficient.     

碱性浆料下计算机硬盘NiP基板CMP机理的分析研究

通过对镍磷基板的化学性质分析，讨论了其动力学过程，指出化学反应过程是最慢的过程，是CMP的控制过程，分析了浆料在硬盘基板CMP中的重要性，指出浆料的化学成份是化学作用的关键，研制了新型碱性浆料，研究了碱性浆料下镍磷基板CMP机理，通过络合胺化剂的强络合作用实现了碱性浆料下的高凹凸选择性，获得了较高的去除速率；选用小粒径、低硬度的二氧化硅水溶胶磨料实现了较低的表面粗糙度。     

Effects of substrate temperature and texturing on the magnetic properties and crystallographic structures of CoCrTa/Cr thin film

Bi-layer CoCrTa/Cr films were deposited on textured aluminium or textured NiP-plated aluminium substrate by d.c. magnetron sputtering. The crystal anisotropy and thereby magnetic properties depending on substrate material, substrate temperature and texturing, were investigated. The magnetic crystal anisotropy induced by the mechanical texture on aluminium or NiP/Al substrates along the texture lines for the film deposited at high temperature, were clearly observed, while the film deposited at low temperature shows less prominent anisotropic behaviour. X-ray diffraction analysis indicates a change in the preferred orientation of the chromium and CoCrTa films sputtered on different substrates at different temperatures. It was found that a high substrate temperature was beneficial to the formation of Cr(002) and therefore epitaxial growth of Co(11¯20) on Cr(002) for either aluminium or NiP/Al substrates.     

Novel counter electrodes based on NiP-plated glass and Ti plate substrate for dye-sensitized solar cells

Novel counter electrodes based on NiP-plated glass and Ti plate substrate were prepared by thermal decomposition of H₂PtCl₆. Their properties and application in dye-sensitized solar cells were investigated. Platinized Ti plate electrode (Pt/TP electrode) and platinized NiP-plated glass electrode (Pt/NiP electrode) exhibited the same electrochemical activity for triiodide reduction as platinized fluorine-dope tin oxide (FTO) conducting glass electrode (Pt/FTO electrode). However, Pt/NiP electrode and Pt/TP electrode have the advantage over the Pt/FTO electrode in increasing the light reflectance and reducing the sheet resistance, which resulted to improve the light harvest efficiency and the fill factor of the dye-sensitized solar cells effectively. Examination of the anodic dissolution indicated the good stability of the Pt/NiP electrode and Pt/TP electrode in the electrolyte containing iodide/triiodide.     

Microstructure and corrosion characteristics of CrN/NiP sputtering thin films

The CrN top layer and NiP interlayer were sequentially deposited to form a CrN/NiP composite coating through sputtering technique. The CrN/NiP coating systems deposited at 350 °C, 450 °C, and 550 °C, showed amorphous/nanocrystalline, nanocrystallize with precipitations, and fully crystallized microstructure respectively for the NiP interlayers. With the introduction of NiP interlayer, the coating assemblies exhibited superior corrosion characteristics than single CrN coatings. The amorphous NiP interlayer deposited at 350 °C revealed a lower corrosion current as compared to those with crystallized NiP layers owing to their structural defects in the alloy layer. With the combination of CrN and NiP layers the corrosion attach was retarded and a better corrosion resistance was found for the CrN/NiP composite coating.     

KOH活化处理碳纳米管对其负载非晶态NiP催化性能的影响

经KOH活化处理和未经活化处理的碳纳米管分别用于负载非晶态NiP合金.以苯加氢为探针反应,研究了KOH活化处理温度和时间对碳纳米管的性质及其负载非晶态NiP催化剂活性的影响.研究结果表明:碳纳米管经KOH处理可以提高其负载非晶态NiP催化剂的催化活性,催化剂活性随活化温度升高和活化时间延长而增加.由于KOH处理改变了碳纳米管的微观结构,增加了其比表面积,所以非晶态NiP在碳纳米管上更易沉积分散,其负载的非晶态NiP合金催化剂的催化活性较高.     

Ni-P基多元合金镀层的耐腐蚀磨损性能

探索了石油工业中的抽油杆在化学沉积Ni P合金镀层后的高温耐腐耐磨性能。采用不同的工艺方法和试验条件 ,研究了Ni P合金镀层以及加入Co元素或SiC硬质颗粒后合金镀层的高温耐腐耐磨性能     

时效对无铅焊料Ni-P/Cu焊点的影响

研究了150℃等温时效为62Sn36Bp2Ag/Ni-P/Cu及共晶SnAg/Ni-P/Cu表面贴装焊点微结构及塑切强度的影响,结果表明,在钎料与Ni-P间的界面存在Ni3Sn4金属间化合物层,其厚度随时效时间增加,Ni-P层的厚度减小,时效后,SnPbAg,SnAg焊点的剪切强度下降,对于SnAg焊点,时效250h后其剪切强度剧烈下降,断裂发生在Ni-P/Cu界面上,在长时间时效后焊点一侧的Ni-P层中P的含量较主可能是Ni-P/Cu结合强度变差的主要原因,SnPbAg焊点保持着较高的剪切强度。     

Porous LiFePO4/NiP Composite nanospheres as the cathode materials in rechargeable lithium-ion batteries

We report the synthesis of porous LiFePO₄/NiP composite nanospheres and their application in rechargeable lithium-ion batteries. A simple one-step spraying technique was developed to prepare LiFePO₄/NiP composite nanospheres with an electrical conductivity 10³–10⁴ times that of bulk particles of LiFePO₄. Electrochemical measurements show that LiFePO₄ nanospheres with a uniform loading of 0.86 wt%–1.50 wt% NiP exhibit high discharge capacity, good cycling reversibility, and low apparent activation energies. The superior electrode performance of the as-prepared composite nanospheres results from the greatly enhanced electrical conductivity and porous structure of the materials. Electronic Supplementary Material  Supplementary material is available for this article at and is accessible for authorized users. This article is published with open access at Springerlink.com