利用铝矾土制备钛酸铝陶瓷

钛酸铝陶瓷是集低膨胀系数和高熔点为一体的新型陶瓷材料,传统钛酸铝的合成采用工业纯的氧化铝和二氧化钛为原料,生产成本较高。本文采用廉价的高铝矾土取代Al2O3制备钛酸铝陶瓷,实验分别取了三种铝钛比,通过性能测试,确定Al2O3:TiO2=1:0.90可制得综合性能较佳的Al2TiO5陶瓷,此时α=2.05×10-6℃-1,抗折强度σ=35Mpa,热震稳定性达到32次。     

Effect of magnesium and nickel coatings on the wetting behavior of alumina toughened zirconia by molten Al-Mg ahoy

The wettability of alumina toughened zirconia (ZTA) by Al-Mg alloy was investigated using the sessile drop technique.The effects of nickel coating,magnesium content,nitrogen atmosphere,and processing temperature on the contact angle between the molten alloy and the substrate were determined.Likewise,the effect of these factors on the wetting properties was studied.The results showed that the nickel coating on the ceramic substrate caused a significant reduction in solid/liquid surface energy and the contact angle decreased obviously.The presence of magnesium in the molten aluminum alloy in nitrogen atmosphere reduced the contact angle effectively.The presence of magnesium in the alloy must be at a minimum amount of 2wt％-3wt％.Moreover,it was suggested that some chemical reactions in the Al-Mg-N system led to the production of Mg3N2 and A1N compositions.These compositions improved the wetting properties of the systems by reducing the surface energy of the molten.It was shown that increasing the temperature is also an effective factor for the enhancement of wetting properties.     

Effect of magnesium and nickel coatings on the wetting behavior of alumina toughened zirconia by molten Al-Mg alloy

The wettability of alumina toughened zirconia (ZTA) by Al-Mg alloy was investigated using the sessile drop technique. The effects of nickel coating, magnesium content, nitrogen atmosphere, and processing temperature on the contact angle between the molten alloy and the substrate were determined. Likewise, the effect of these factors on the wetting properties was studied. The results showed that the nickel coating on the ceramic substrate caused a significant reduction in solid/liquid surface energy and the contact angle decreased obvi-ously. The presence of magnesium in the molten aluminum alloy in nitrogen atmosphere reduced the contact angle effectively. The presence of magnesium in the alloy must be at a minimum amount of 2wt%-3wt%. Moreover, it was suggested that some chemical reactions in the Al-Mg-N system led to the production of Mg3N2 and AlN compositions. These compositions improved the wetting properties of the systems by reducing the surface energy of the molten. It was shown that increasing the temperature is also an effective factor for the enhancement of wetting properties.     

氧化铝生产过程液位测量的方法研究

在铝冶炼生产过程中,槽罐液位测量是否准确,直接关系到生产是否正常进行。本文结合氧化铝液位测量情况,重点介绍斜插安装取压法的隔离原理、防堵原理,及取压管长度的测量方法,取压管材料尺寸选取及安装。将研究结果应用到氧化铝液位的测量上,经验证,斜插安装取压法在工业测量中对提高仪表运行周期、准确度及降低成本方面有效。     

ZrO2—Al2O3系浆料性能的研究

本文研究了加入高分子电解质——聚丙烯酸(PAA),对于pH值在中性范围内ZrO_2-H_2O、Al_2O_3-H_2O系统的流变和动电特性的影响。根据胶体化学基础知识,利用计算机对实验数据进行分析、处理并设计实验。讨论了PAA在氧化物表面的吸附机理及其饱和吸附量,找到了一种确定ZrO_2-Al_2O_3双组分浆料稳定悬浮条件的新方法。     

氧化铝纳米粉体悬浮液强化导热研究

利用非稳态热丝法测定了2种纳米氧化铝粉分别分散于水和乙二醇（EG）中制备在悬浮液的导热系数，分析研究了悬浮液pH值，分散剂、纳米氧化铝粉体积含量，基体液体导热系数以及纳米氧化铝粉体团聚状态对悬浮液导热系数的影响，结果表明：悬浮液的导热系数随粉体加入量的增加而增加，相同体积含量的同一粉体悬浮液，基体液体为乙二醇的导热系数相对增加量明显比基体液体为水的大；团聚较多的粉体悬浮液的导热系数大于团聚较少粉体的悬浮液，pH值对悬浮液的导热系数无明显影响，分散剂的加入，增大了粉体和基体液体间的界面热阻，降低了悬浮液的有效导热系数。     

KNO3/Al2O3催化环戊二烯甲基化反应

研究了固体碱KNO3/Al2O3(KNA)催化合成甲基环戊二烯的反应性能,考察了KNO3负载量、反应温度、反应时间以及酸碱性位中毒等因素对环戊二烯甲基化反应的影响。结果表明,KNO3负载量为质量分数26%时样品的催化活性最高,450℃时能催化转化33%的环戊二烯,甲基环戊二烯的选择性达到86%。催化剂通过原位氧气焙烧除去积炭即可恢复活性。     

IR studies of Re2O7 metathesis catalysts supported on alumina and phosphated alumina

FTIR data from Re₂O₇/-Al₂O₃ metathesis catalysts indicate that a low Re contents ReO₄ ions have predominantly reacted with basic surface OH groups, while at higher Re₂O₇ loadings they have also reacted with neutral and more acidic OH groups.On phosphated -Al₂O₃ the phosphate has reacted with the more acidic OH groups on the -Al₂O₃; in catalysts based on this support, the ReO₄ ^– ions have also reacted with the phosphorus-bonded OH groups already at low Re₂O₇ loadings, resulting in more active catalysts.     

C3H6选择性催化还原NO催化剂Ag／γ—A12O3的研究

采用低负载量的(0～3％)Ag／γ-A12O3体系作为C3H6选择性催化还原(C3H3-SCR)NO的催化剂，考察了银负载量、反应温度、空速对NO转化率的影响．同时对于原料气中氧的作用进行了研究．结果表明：银负载量为1．5％时，催化剂表现出最高的反应活性；在考察的条件范围内，原料气中含氧对NO的还原有促进作用，适宜的氧浓度为0．27％；反应温度的过高会导致还原气中C3H6大幅度转化为CO2。