增材用铝粉表面的包覆改性研究

为减少铝粉在光固化树脂中的沉降,使其适用于光固化增材制造,使用不同表面活性剂对铝粉进行预处理,增强铝粉表面对有机物的亲和性;利用乳液聚合法使单体聚合在铝粉表面形成一层有机物薄膜,研究几种单体对铝粉包覆性能的影响,利用可见光分光光度计、傅里叶红外光谱仪表征其包覆性能。结果表明:使用十二烷基硫酸钠(K12)预处理的铝粉在光固化树脂中分散性最好,透光率为11%,分散1 h后透光率变化不大;使用苯乙烯（St）+丙烯酸丁酯(BA)、丙烯酸(AA)+丙烯酸丁酯(BA)二元聚合包覆的铝粉在树脂中静置1 h,未发现明显沉降;红外光谱图显示,两组配方中的铝粉表面存在单体聚合产物。     

Interfacial Processes and Tribocharging: Effect of Plasma Surface Modification and Physisorption

The tribocharging characteristics of polymer powders have a significant impact on several industrial processes such as electrostatic powder coating and polymer powder processing. The nature of chemical species on the surface of powder influences the triboelectric charging characteristics. An atmospheric-pressure helium plasma was used to modify tribocharging properties of polystyrene microspheres and acrylic powders. Plasma surface modification reduced the magnitude of tribocharging for the test polymer powders. When tribocharged against stainless steel, the net charge-to-mass ratio (Q/M) for both polystyrene microspheres and acrylic powders was less than that for the control samples. Plasma surface modification also reduced the tribocharging of mannitol, a pharmaceutical powder, against stainless steel. Further, Mars simulant dust (JSC Mars 1) was used as a test sample to study the effect of carbon dioxide physisorption on tribocharging. The Q/M of the sample with physisorbed CO₂ was less than that of the control in all size ranges.     

航空用铝合金表面处理的研究现状与展望

全面介绍了国内外铝合金在建筑、汽车、航空航天等行业的应用及研究进展.主要阐述了航空航天领域结构胶接在国内外的发展状况、胶接用铝合金表面处理方法的目的、表面处理的机理及分类、影响表面处理质量的工艺参数、现代表面分析技术等.并对近年来国内外应用最广、技术最成熟的磷酸阳极化表面处理技术的应用及优缺点进行了分析,并展望了该领域研究的发展趋势.     

Surface Preparation of Aluminum Nitride for Metallization

Currently, the surface preparation of aluminum nitride (AlN) substrates prior to metallization includes an aqueous cleaning step. Surface reactions that occur in this step cause performance and reliability issues with AlN substrates to be used in microelectronic packaging. There is a lack of published data on the reactivity of AlN substrates with common solvents. This study investigated the effects of different solvents on the surface corrosion of AlN substrates. The variables studied were pH, aqueous vs. organic solutions, prior surface condition, and time (up to 3.6 Ms or 42 days). The solvents tested were hydrochloric acid (HCl) with pH values ranging from 2 to 5, sulfuric acid (H₂SO₄) with pH values ranging from 2 to 5, sodium hydroxide (NaOH) with pH values ranging from 8 to 12, 1 M citric acid, oleic acid, Micro-90, methanol, ethanol, isopropanol, acetone, and deionized water. Three types of surface reaction behavior were observed in this study. The substrates either showed no reaction (HCl pH = 2, methanol, ethanol, isopropanol, acetone, citric acid, and oleic acid), slight corrosion without spalling (Micro-90, HCl pH = 3, H₂SO₄pH = 3), or they were severely corroded and spalled (HCl pH = 5, H₂SO₄pH = 5, all NaOH solutions, and deionized water).     

铝材表面的自组装成膜新工艺

铝材表面易氧化从而影响后续涂层质量.以有机膦化合物、氨三乙酸和聚环氧琥珀酸为主要原料,采用一步法对铝表面自组装成膜,通过正交试验确定了最佳成膜工艺,将此工艺制得的自组装膜的形貌、性能与传统铬酸盐转化膜比较,并探讨了自组装成膜机理.结果表明:最佳成膜工艺为5.0 mL/L有机膦化合物,5.0 g/L氨三乙酸,2.5 mL...     

Surface Preparation of Aluminum Nitride for Metallization: Effect of Temperature on Surface Reactivity

The current aqueous cleaning step in the surface preparation of aluminum nitride (AlN) prior to metallization causes performance and reliability issues for the substrates used for microelectronic packaging due to surface reactions. These issues limit the use of AlN and its replacing of BeO, an environmentally hazardous material currently used. The aim of this investigation was to determine the effects of different solutions on the surface of AlN substrates under varying conditions at times up to 2419.2 ks (28 days). Concentration of the solutions, temperature, and immersion time were varied for the AlN samples in the solutions. Both elevated temperatures (50°C and 90°C) and low temperatures (5°C) were investigated.

Four general types of behavior were observed: minor changes in average surface roughness and microstructure, linear change in average surface roughness and pitted grains, nonlinear change in average surface roughness and product formation on AlN surface, and miscellaneous change in average surface roughness with surface product formation.

The surface roughening kinetics were very complex due to changes in both the reaction product morphology and reaction mechanism with temperature, solvent, and pH for a specific solvent. Minor changes in average surface roughness and microstructure were observed for HCl pH = 5, H₂ SO₄ pH = 5, NaOH pH = 8, NaOH pH = 10, NaOH pH = 12, deionized water and Alfred tap water at 5°C, HCl pH = 3 and oleic acid at 50°C and citric acid and oleic acid at 90°C. Linear changes in average surface roughness and pitted grains were observed for HCl pH = 2 and H₂SO₄ pH = 3 at 50°C and HCl pH = 2, H₂SO₄ pH = 3, and deionized water at 90°C. Non-linear change in average surface roughness and product formation on AlN surface was observed for HCl pH = 5, NaOH pH = 8 and Alfred tap water at 50°C and HCl pH = 5 and H₂SO₄ pH = 2 at 90°C. Miscellaneous changes in average surface roughness with surface product formation were observed for H₂SO₄ pH = 2, H₂SO₄ pH = 5, NaOH pH = 10, NaOH pH = 12, citric acid, Micro-90 and deionized water at 50°C and HCl pH = 3, H₂SO₄ pH = 5, NaOH pH = 8, NaOH pH = 10, NaOH pH = 12, Micro-90 and Alfred tap water at 90°C.     

薄层钝化纳米铝粒子研究

采用蒸发冷凝方法制备纳米铝粉,由于其表面具有很高的活性,对所制备的纳米铝粒子进行了表面钝化.采用小角X射线散射测定纳米铝粉粒度,SEM、TEM、HRTEM、XRD、ED等方法分析钝化纳米铝的形貌、化学组成和结构.结果表明,所制备的钝化纳米铝的平均粒度为80nm,ED分析有Al和Al2O3的衍射斑点但,Al2O3的含量较少,与XRD的分析结果一致,HRTEM可见在Al颗粒的表面形成了厚度小于5nm的均匀氧化膜.     

铝粉的表面改性

铝粉的表面改性是功能铝粉生产中非常重要的工艺。本文中综合铝粉改性的手段及改性后铝粉的功能,介绍了铝粉表面改性常用的几种方法,包括机械化学改性、氧化改性、表面化学改性、胶囊改性、包覆改性和沉淀改性等。     

铝基超疏水表面的耐海水腐蚀性能研究

研究了喷砂和阳极氧化技术相结合,在铝合金表面构建合适的微米/纳米二级结构,并通过氟硅烷的修饰降低表面自由能,以制备铝基超疏水表面材料,并对表面的耐海水腐蚀性能进行了研究,研究表明,当采用100g/L硫酸、10g/L草酸、10g/L丙三醇作为电解液进行阳极氧化,孔洞孔径达200nm时,接触角达157°。模拟人工海水中的腐蚀实验,结果表明,超疏水表面材料的腐蚀速率比未经处理的空白试样缓慢一个数量级。     

铝制品表面水垢的化学清洗

铝制品容器、管件被广泛应用于工业及家用电器中.经长期使用后,铝制品表面会形成很厚的水垢,阻碍热的传导,使热效率大大降低,增加耗能,同时大量水垢的存在使铝制品在加热过程中局部过热,造成铝制品过早损坏.     

我国90年代铝型材表面处理技术的回顾

综述了我国９０年代铝型材表面处理技术的发展，工艺革新，设备更新和品质提高。与国外同行业先进水平作了对比，展望未来十年中我国铝型材表面处理的发展前景，并提出具体措施。     

铝合金表面铈基转化膜研究进展

铝合金具有成本低、强度质量比高、可加工性能良好等优点,被广泛应用于航空、交通、建筑等领域.但铝合金表面易发生小孔腐蚀和晶间腐蚀,需要进行防腐处理才能满足应用要求.稀土元素铈因具有特有的电子层结构和物理化学特性,是制备铝合金稀土转化膜最具优越性的元素,以此为防腐基材开发的稀土转化膜技术被认为是最有可能替代铬酸盐钝化的技术.目前所报道的铈基转化膜工艺有化学浸泡法、溶胶-凝胶法、电化学法、磁控溅射法等.其中,化学浸泡法制备过程简单,但铈离子的转化和沉积速率较难控制一致,膜层微米级裂纹较多;溶胶-凝胶法制备的膜层与基体结合强度高,耐蚀性好,但需要大量铈盐,且产生较多废酸、碱液,成本高,环境污染大;电化学法在低温下实现性能可控的铈基转化膜,成本低,但成膜有大量晶间裂纹,结构疏松,成膜质量差;磁控溅射法制备的涂层均匀,成分可控,但靶材的利用率低,难以实现强磁性材料的低温高速溅射.总体来看,目前所报道的铈基转化膜工艺存在溶液体系稳定性差,所制备的转化膜层不稳定、容易开裂,以及制备成本较高的问题,难以满足工业化应用的要求.铈基转化膜成膜机理被普遍认为是阴极成膜理论,即铝合金表面形成了氧化还原微电池.溶液中的溶解氧以及加入的H2 O2可作为羟基的供体,通过改变溶液局部pH值、物质、电子和电荷浓度来影响稀土元素的氧化反应和在基体表面的沉积.铈基转化膜的耐蚀机理是阴极抑制机理,即在铝合金表面形成的铈基转化膜阻止了氧的传输和电子的转移和传递,从而阻止了阴极微区上的还原反应,防止了铝合金表面的腐蚀溶解.但该机制只强调了阴极抑制,而忽略了也可能发生的阳极抑制.同时,由于涉及到电化学动力学抑制,因此铈基转化膜有"自愈能力".本文综述了国内外铝合金铈基转化膜制备工艺的研究进展,指出了各工艺的优点和缺点,阐述了铈基转化膜主流成膜和耐蚀理论的研究,并对制备工艺的改进方向及未来理论的研究方向进行了展望.     

建筑铝型材表面处理电源简介

介绍了建筑铝型材表面处理用的各种电源，着重介绍了建筑铝型材各种氧化电源，着色电源的性能和应用情况，结合生产经验和设备制作技术，提高我国铝型材表面处理电源设备的制造水平。     

表面处理对阳极氧化铝模板光发射性质的影响

阳极氧化铝模板是一种得到广泛研究和应用的重要模板物质。针对阳极氧化铝模板的光致发光起源问题进行了探讨,主要研究了表面因素是否对阳极氧化铝的发光有影响,以及如何影响的问题。利用二次阳极氧化法制备了阳极氧化铝模板,之后利用氩离子轰击氧化铝模板的表面,在室温下测定了氩离子处理后的氧化铝模板的发光特性,研究了氩离子轰击前后氧化铝模板的光致发光性质变化和氩离子轰击对氧化铝模板光发射性能的影响。结果表明,表面因素对阳极氧化铝模板的发光有重要影响。     

用于热敏CTP版材的版基砂目的研究

本文根据热敏CTP版的特点，研究铝版基的砂目粗糙度对版材成像性能的影响。研究了砂目粗糙度与版材的感光度、显影宽容度和亲水保水性的关系。确定了版基的砂目粗糙度最佳范围在0．4-0．5μm，可以实现1-99％的精细网点还原。     

基底特性对铝膜表面形貌的影响

用扫描电子显微镜对沉积在硅油表面的金属铝膜上、下表面的形貌进行了研究 ,证实了液体基底特性对金属铝膜表面形貌的重要影响。     

环保型铝合金阳极氧化表面处理研究进展

铝及其合金具有密度小、成形加工性能好、可回收利用和节能环保等优点,是飞机、汽车等现代交通工具制造的关键材料.但铝合金易发生局部腐蚀而失效,故工业应用中需对其进行阳极氧化以提高抗腐蚀能力.综述了近年来新型铝合金阳极氧化领域的研究现状,并重点关注了绿色环保型铝合金阳极氧化表面处理技术的研究进展,以期为新型航空铝合金及汽车铝合金表面处理技术的发展提供参考.     

铝合金表面各向异性A型条纹的疏水性

条纹表面不仅可用于物体表面的散热、疏水,还可用于各类航行体表面的减阻.在亲水性金属表面直接构造出疏水条纹表面的研究较少.采用电脑精雕工艺,在亲水性LY12铝合金表面加工了间距等于槽深、几何尺寸分别为0.15mm和0.2mm的单向平行A型条纹.条纹与其表面不规则粗糙结构共同构成了类荷叶表面的双重微结构.采用座滴法在光学显微镜下测试了条纹表面的疏水性.实验得出,淡水在间距为0.15mm的A型条纹表面的正/侧面表观接触角为111±2°/85±2°,相应地0.2mm△型条纹为133±2°/77±2°;盐水在间距为0.2mm的A型条纹表面的正/侧面表现接触角为139±2°/92士2°.解释了条纹表面液滴呈半椭球状,液滴的接触存在各向异性的现象.