原位合成磷酸铝助烧剂制备轻质氧化铝空心球陶瓷

采用氧化铝空心球和α Al2 O3微粉为原料 ,以磷酸溶液为结合剂制备了轻质氧化铝空心球陶瓷。研究结果表明 ,磷酸与α Al2 O3微粉原位反应生成的磷酸铝能促进轻质氧化铝空心球陶瓷的烧结 :以浓度 2 5wt%的磷酸为结合剂并经 90 0℃保温 4h烧结后的轻质氧化铝空心球陶瓷 (密度为 1.4g·cm- 3) ,耐压强度达 11.8MPa ,可直接用于窑炉砌筑 ,并可在使用过程中通过二次烧结进一步提高其强度 ;以浓度为 5 0wt%的磷酸结合并经 170 0℃保温4h烧结后的轻质氧化铝空心球陶瓷 (密度为 1.4g·cm- 3) ,耐压强度达到 2 2 .8MPa ,荷重软化温度超过170 0℃ (0 .1MPa)。     

熔剂法制备硼酸铝晶须的实验研究

以Al2O3和B2O3为原料，采用熔剂法制备了性能良好的硼酸铝晶须．通过正交实验，得到了本方法生产硼酸铝晶须的最佳工艺条件，探讨了熔剂法制备硼酸铝晶须的机理．运用XRD,SEM等分析检测技术对硼酸铝晶须进行了测试，结果表明：其主要性能指标达到或接近日本同类产品的水平．     

铬锆掺杂磷酸铝介孔材料低热固相合成及表征

通过固相反应直接合成了磷酸铝、磷酸铝铬、磷酸铝铬锆介孔材料。用X射线衍射、高分辨透射电镜、电子扫描电镜、N2脱附-吸附、红外光谱仪等技术对材料进行了物相织构表征;用电感耦合等离子发射光谱对掺杂元素的含量进行了分析;比较了磷酸铝、介孔材料磷酸铝铬及磷酸铝铬锆红外光谱的变化。结果表明,锆、铬均能进入磷酸铝晶格。介孔材料磷酸铝铬锆(ZrCrAlPO)和磷酸铝铬(CrAlPO)的微观结构形貌主要呈蠕虫状、无定形的球状结构,并具有高BET比表面积。锆和铬的掺入使磷酸铝中的P—O—Me(Me=Cr,Zr)键的伸缩振动、弯曲振动以及磷酸铝的晶格振动均依次向低波数移动,吸收峰的振动强度也依次降低。     

晶须改性二苯甲烷型双马来酰亚胺树脂体系的研究

以硼酸铝晶须、钛酸钾晶须为增强剂，以N，N′-二胺基二苯甲烷型双马来酰亚胺(BMI)／O，O′-二烯丙基双酚A(BA)体系作为基体，采用浇注成型工艺制备了晶须增强二苯甲烷型双马来酰亚胺树脂基复合材料。研究了晶须对树脂体系凝胶特性的影响，晶须对体系固化反应性的影响；晶须的种类、表面处理方法、含量对树脂体系力学性能和热性能的影响；树脂体系的固化工艺材料对性能的影响。结果表明，晶须对树脂体系固化工艺影响不大；硼酸铝晶须增强效果优于钛酸钾晶须；偶联剂以丙酮作溶剂处理的效果优于乙醇水溶液，酸化溶剂的效果更好；晶须可明显改善体系的力学性能和耐热性，在晶须添加量为15％左右时，所得体系的综合性能较好；改进的固化工艺有助于树脂体系性能的改善。在本研究中，弯曲强度最大提高了约18％，热变形温度最大提高了12％。     

硼酸铝晶须的生长机理

通过高温熔剂法生成硼酸铝晶须,结合Ｘ射线分析及扫描电镜,研究了合成过程中的热力学及硼酸铝晶须的生长机理,探讨了硼酸铝晶须的生长模型．     

凝胶注模-固相反应法制备硼酸铝多孔陶瓷

为了提高硼酸铝基陶瓷的强度和隔热性能，以Al₂O₃纳米粉和B₂O₃微粉为主要原料，采用叔丁醇基凝胶注模结合原位固相反应工艺制备硼酸铝多孔陶瓷，研究了Al、B物质的量比(分别为9∶2、9∶4和9∶6)、热处理温度(分别为1 000、1 200和1 400℃)对硼酸铝多孔陶瓷性能的影响。结果表明：1)由于B₂O₃在高温下易挥发，过量的B₂O₃有利于硼酸铝晶须的生成；但过量太多会使生成的硼酸铝晶须过于粗大，导致试样致密度过高。2)热处理温度过低，硼酸铝晶须发育较差，试样致密度较低；而热处理温度过高，晶须之间会发生烧结致密化。3)当Al、B物质的量比为9∶4,热处理温度为1 200℃时，硼酸铝晶须长径比较大，并相互交织形成三维网络结构；所得多孔陶瓷具有较小的体积密度(0.67 g·cm^-3)、较低的热导率(室温下0.141 W·m^-1·K^-1)和较高的常温...     

PTFE／GF透波复合材料成型工艺与性能研究

为制备高性能聚四氟乙烯(PTFE)基透波复合材料,对玻璃布(GF)增强PTFE的成型工艺进行了研究。通过差示扫描量热法确定了PTFE/GF复合材料的烧结温度,考察了烧结时间、冷却速率、压制压力及组分配比等因素对复合材料性能的影响。结果表明,当GF质量含量为40%、压制压力为45MPa时,PTFE/GF复合材料的拉伸强度最大,可达81.2MPa,介电性能也满足透波复合材料的要求。     

硼酸铝晶须和石墨粉复合增强型涂料的耐磨性能

为了提高涂料的耐磨性能,采用在环氧酚醛涂料里添加分散好的硼酸铝晶须和石墨粉的方法,制备出一种复合增强型涂料.采用环盘式摩擦磨损试验机测试涂料的耐磨性能.结果表明,晶须的钉扎作用和石墨的润滑作用提高了复合增强型涂料的耐磨性能,最佳配比为5%硼酸铝晶须和2%石墨粉(均为质量分数).此时,涂料的磨损量达到最小,为0.164 6 g,是环氧酚醛涂料磨损量的30%.     

凝胶法氢氧化铝制备三聚磷酸铝工艺参数研究

以拜耳法赤泥和85%工业磷酸为原料制备三聚磷酸铝。拜耳法赤泥通过高温烧结改性,用碳酸钠碱溶法溶出改性赤泥中的铝,制备高活性氢氧化铝凝胶,烘干得到氢氧化铝干胶。采用氢氧化铝干胶与工业磷酸,通过中和反应、缩合反应、水化反应,制备三聚磷酸铝。最佳工艺参数:磷酸与氢氧化铝体积质量比(mL/g)为30/10,缩合温度为290℃,缩合时间为4 h,中和温度为常温,加水量为10 mL。对样品进行了化学分析、红外光谱分析和盐雾试验测试,结果表明样品为合格的三聚磷酸铝产品,防腐性能达到工业指标。     

高功率高透波材料的研究

本文叙述了以 TRR 树脂为基体，分别用 B 型石英玻璃纤维和 UHMWPE 纤维为增强材料，与 T 蜂窝复合制得高功率高透波材料的研究情况，两种蒙皮和 T 蜂窝在 9.375GHz 下的?和 ?分别为 2.79、3×10-4；2.13、4×10-4 和 1.14、9.43×10-4；夹层结构的插入损耗分别为 0.019－0.02dB 和 0.030－0.041dB。     

一种高浓度氧化铝凝胶及溶胶的制备方法

主要介绍了一种高浓度氧化铝凝胶（氢氧化铝凝胶）的制备方法，即以碳酸钠和三氯化铝为原料，水为溶剂，乙酸为稳定用添加剂的制备路线，并且也介绍了使用特定的胶溶剂一价强酸－盐酸，硝酸将凝胶溶为氧化铝溶胶的方法。     

Electrochemical investigations into polypyrrole/aluminum flake pigmented coatings

In this study polypyrrole was synthesized in the presence of aluminum flake to produce polypyrrole/aluminum flake hybrids. The resulting flakes were incorporated into a standard epoxy coating at relatively high pigment volume concentrations with the end goal of producing a conducting film capable of providing corrosion inhibition to an aluminum alloy. To further investigate the coatings, electrochemical impedance spectroscopy (EIS) was used to characterize the effects of the pigment volume concentration (PVC) on the impedances of the coatings. Additionally, the nature of the polypyrrole, chemical composition, and surface morphology of the hybrid were characterized by a density test and scanning electron microscopy (SEM).     

Hydrolysis control of alumina and AlN mixture for aqueous colloidal processing of aluminum oxynitride

AlN powder, surface modified by phosphoric acid treatment was employed for the aqueous colloidal processing of Aluminum Oxynitride (AlON). The hydrolysis of AlN leads to the formation of Al(OH)₃ and NH₃. On mixing of alumina to the phosphoric acid treated AlN in aqueous medium this reaction reoccurred. The phosphoric acid shield around AlN particles is ruptured by alumina addition thus exposing AlN surface to hydrolysis reactions. Hence hydrolysis can be effectively controlled by providing a phosphoric acid treatment to the alumina, prior to its addition to AlN. AlON precursor mixture thus obtained can be successfully shaped by an aqueous slip casting process and sintered to phase pure AlON at 1925 °C for 2 h. Viscosity, pH, SEM, FTIR, and XRD measurements are employed to elucidate the effect of Al₂O₃ addition on surface modified AlN for colloidal processing of AlON.     

铝毒的危害及其防治

铝是当今社会不可或缺的重要金属元素,它的广泛应用导致了水体、土壤中以各种水生物、动植物体内残余铝含量不断升高,直接或间接地危害到人体身心健康,破坏了生态平衡,威胁着人类的生存和发展。密切关注铝的流失途径及其在生命代谢中的作用机制,克制而又有计划地保护、合理开发和利用各种铝资源,是最有效的铝毒防治策略。     

Utilization of aluminum sludge and aluminum slag (dross) for the manufacture of calcium aluminate cement

Four calcium aluminate cement mixes were manufactured from aluminum sludge as a source of calcium oxide and Al₂O₃ and aluminum slag (dross) as a source of aluminum oxide with some additions of pure alumina. The mixes were composed of 35–50% aluminum sludge, 37.50–48.75% aluminum slag (dross) and 12.50–16.25% aluminum oxide. The mixed were processed then sintered at different firing temperatures up to 1500 °C or 1550 °C. The mineralogical compositions of the fired mixes investigated using X-ray diffraction indicated that the fired mixes composed of variable contents of calcium aluminate (CA), calciumdialuminate (CA₂), calciumhexaaluminate (CA₆) in addition to some content of magnesium aluminate spinel (MA). Sintering parameters (bulk density, apparent porosity and linear change) and mechanical properties (cold crushing strength) of the fired briquettes were tested at different firing temperature. Refractoriness of the cement samples manufactured at the optimum firing temperature was detected. Cementing properties (water of consistency, setting time and compressive strength as a function of curing time up to 28 days of hydration) of pasted prepared from the manufactured cement mixes at the selected optimum firing temperatures (1400 °C or 1500 °C) were also tested. Cement mixes manufactured from 45 to 50% aluminum sludge, 37.50–41.25% aluminum slag (dross) with 12.50–13.75% alumina were selected as the optimum mixes for manufacturing calcium aluminate cement since they satisfy the requirements of the international standard specifications regarding cementing and refractory properties as a result of their content of CA (the main hydraulic phase in calcium aluminate cement) and CA₂(the less hydraulic but more refractory phase). Although the recognized high refractoriness of CA₆, its formation affect badly the cementing properties of the other non-optimum mixes.     

化工储槽喷铝防腐蚀技术的应用

介绍了喷铝防腐蚀技术的原理、施工工艺、质量检查,以及施工过程中的注意事项。此项技术的推广应用可大大延长设备的寿命,或者用喷铝设备代替高品质材料,可为企业创造可观的经济效益。     

喷漆常见故障分析

本文依据实践经验对喷漆的一些常见故障进行了分析,并提出了纠正措施。     

Side wall anodization of aluminum thin film on silicon substrate

Anodization of aluminum with restricted surface areas is reported in this study. Particularly, the side wall of aluminum thin film is anodized for the purpose of obtaining the confined number of pores with high aspect ratio. It has been observed that side wall anodization does not occur uniformly since the anodization speed is not uniform at the both interfaces and in the middle of the film. For this reason, the resultant pore front profile shows a parabolic shape, which resembles the parabolic velocity profile of fluid flow through two slabs. During the anodization process, the pores tend to break apart and the structure becomes more complex. Side wall anodization is investigated at various applied voltages and the resultant pore structures are shown.     

钛酸铝耐火材料的合成研究

通过对原料进行预处理，并添加一定的预合成物和添加剂，在１４００℃下所制得的钛酸铝基本上克服了合成材料的开裂现象，从而使ＡＴ材料的性能得以改善。     

Thermal decomposition of coal fly ash by concentrated sulfuric acid and alumina extraction process based on it

The industrial applications of acidic leaching processes for alumina extraction from coal fly ash (CFA) have been limited due to its excessive usages of acid and fluoride. This limitation can be lifted by calcining the CFA with the concentrated sulfuric acid at high temperature. When CFA was mixed with the concentrated sulfuric acid of same amount and calcined at 300 °C, most of its aluminum components were transformed into aluminum sulfate. Excessive sulfuric acid was recycled by collecting sulfur trioxide produced during heating process. Morphological and X-ray diffraction evidence indicated that mullite inside CFA was thermally decomposed. Alumina and mullite were transformed into aluminum sulfate. A practical process of alumina extraction from CFA was developed based on this observation. The adoption of calcination process significantly reduced the sulfuric acid usage, shortened the process cycle, and eliminated the use of fluoride. The alumina extraction efficiency was improved up to 85%.