Al2O3-Cr2O3材料与ISA炉熔渣的相互作用

采用动态抗渣方法进行了ISA炉熔渣对铝铬尖晶石耐火材料的侵蚀实验,并借助XRD、SEM、EDAX和化学分析等手段对熔渣与耐火材料的相互作用进行了研究,结果表明:艾萨熔炼炉熔渣渗入铝铬耐火材料中形成连续固溶体和高熔点的复合尖晶石;在SO2气氛下,在铝铬耐火材料表面形成尖晶石结构的自形晶磁铁矿保护层,均有利于铝铬耐火材料抗ISA炉熔渣的侵蚀.     

不烧Al2O3-C质耐火材料在水蒸气中的抗氧化性能

对高炉炉身下部用不烧Al2O3-C质耐火材料在水蒸气环境下的抗氧化性能进行了全面的氧化性能实验。通过对大量的实验结果进行归纳和分析，总结出其氧化规律，建立了不烧Al2O3-C耐火材料的氧化动力学模型。此外，还对氧化前后试样的抗折强度进行了测定和比较。     

铝碳滑板氧化动力学的研究

借助于微量热天平,通过在不同温度下进行等温氧化实验,研究了铝碳滑板砖的氧化行为和氧化动力学.研究结果表明,铝碳滑板砖的氧化规律为化学反应速度控制阶段--扩散速度控制阶段.随着温度的升高,氧化反应速率呈降低-增高-降低-增高的规律变化,总趋势在下降.     

钢包精炼炉用铝碳滑板的研制

以特级高铝钒土熟料作骨料，利用电熔刚玉细粉，鳞片石墨及添加剂优化基质相组成，采用水玻璃为主及助结合剂复合结合，加入适量的防氧化剂，研制出具有高的常温，高温强度，抗热冲击性能优良，抗侵蚀和冲刷能力强的不烧铝碳滑板，满足了钢包精炼的需要，试验表明，试样在８５℃，８ｈ干燥是有必要的，成型压力选在２００ＭＰａ左右为宜，助结合剂的加入量应小于５％。     

铝锆碳滑板使用前后显微结构与损毁机理

研究了在武钢使用的2种铝锆碳滑板的显微结构及其损毁机理.结果证实两种滑板在使用过程中,内部形成了SiC晶须,而滑板正是利用在其基质部分形成SiC晶须的机理来改善其性能.奥镁滑板在基质中大量使用塑性相金属硅,并且在高温使用过程中生成了大量晶须状SiC,从而进一步提高了其热震稳定性.     

MgO基和Al2O3基耐火材料对钢中夹杂物的影响

利用大样电解、图像分析、扫描电镜和能谱分析等检测手段研究了82B钢种选用Al2O3-MgO、MgO-Al2O3和MgO-CaO炉衬在1450 ℃保持80 min后生成的夹杂物种类和变化.结果表明,采用Al2O3-MgO作内衬时冶炼后钢中夹杂物的数量增加了近50%,夹杂物的尺寸大(100～900 μm)且硬度很高,夹杂物的主要成分为SiO2和Al2O3;以MgO-Al2O3作内衬时夹杂物数量略有降低(30%),尺寸(80～450 μm)和硬度相对较小,其主要成分为SiO2、MnO、CaO和MgO;而MgO-CaO材料对去除钢中夹杂物(降低70%)和降低其尺寸(30～350 μm)有明显效果,且夹杂物的硬度很小,其主要成分为CaO、Al2O3、SiO2和FeO.采用MgO-CaO材料时夹杂物的尺寸最小、数量最少,对钢水洁净度的贡献最大.     

用重选法去除锆刚玉中玻璃的试验研究

文章对用物理选矿去除锆刚玉中玻璃的方法进行了试验研究。含Na2O2．75％的锆刚玉经重选法去除玻璃后,Na2O含量可降至1．34％,其质量达到SJ-36锆刚玉砖的原料要求。     

铝锆碳质滑板中SiC晶须形成机理

以铝锆碳滑板基质部分为研究对象,以金属硅粉、石墨和碳黑为原料,混合后在埋碳气氛下,于1 200～1 600℃范围内进行高温处理.通过透射电镜和能谱仪分析,研究发现碳化硅晶须为哑铃状,并且随着热处理温度升高,哑铃状小球慢慢减少,在这个过程中,SiC晶须的生长机理为气-固反应模型.     

Thermal Shock Resistance of Al2 O3/ZrO2 (Y2O3) Composites

ZrO₂ containing 2% (mol fraction) Y₂O₃ and 3% (mol fraction) Y₂O₃ were added into Al₂O₃ matrix, compositing composites with 15% volume fraction of addictives mentioned above. The testing of property and analysis of SEM presented that, after vacuum sintering at 1550 °C, thermal shock resistance of two composites was superior to Al₂O₃ ceramic. The experiment showed that the properties of Al₂O₃ composites was higher than Al₂O₃ ceramic, and Al₂O₃/ZrO₂(3Y) was higher than Al₂O₃/ZrO₂(2Y) in thermal shock resistance. Improvement of thermal shock resistance of composites was attributed to many toughness machanisms of ZrO₂(Y₂O₃). By calculation, the fracture energy of Al₂O₃, Al₂O₃/ZrO₂ (2Y) and Al₂O₃/ZrO₂(3Y) was 38100.8 and 126.2 J·m⁻², respectively. Cracks initiation resistance (R') of Al₂O₃/ZrO₂(3Y) and Al₂O₃/ZrO₂(2Y) was higher than Al₂O₃ ceramic by 1.57 and 1.41 time, respectively, and cracks propagation resistance (R″″) was higher than Al₂O₃ ceramic by 1.46 and 1.38 time, respectively, which was corresponding to the results of residual strength.     

MgO基和Al2O3基耐火材料对钢中磷的影响

探讨了MgO-CaO、MgO-Al2O3和Al2O3-MgO耐火材料对82B钢中磷的影响。利用化学分析、图像分析、扫描电镜和能谱分析等检测手段测定了82B钢水在中频炉中经1450℃熔炼80min后耐火材料内衬成分变化及钢中磷的变化，还探讨了MgO-Ca0材料的脱磷机理。结果表明，MgO-CaO材料中的游离CaO能吸附钢中磷，达到脱磷效果，其中CaO含量30％的材料脱磷效果最佳达61％。     

铝碳耐火材料力学性能优化研究进展

铝碳耐火材料是冶金连铸、铁水包、中间包等部位常用的耐火材料,因其使用环境恶劣,对强度、抗热震性、抗渣侵蚀性等各项性能的要求都较高.优化铝碳耐火材料的力学性能能降低因机械应力引发的物理损毁和热应力引发的热震损毁,直接影响使用寿命.优化耐火材料的原料是易实现且高效的研究方向.从制备铝碳耐火材料的3种原料出发,分别从催化改性...     

镁质复合滑板材料与铝锆碳滑板材料性能比较

利用实验室感应炉炼钢装置,在同等条件下将镁质复合滑板材料和铝锆碳滑板材料镶嵌在感应炉中,模拟滑板在滑动水口装置中的使用情况,比较两种材质滑板材料的高温使用性能.结果发现:这种镁质复合滑板材料与现在广泛使用的铝锆碳质滑板材料相比具有显著的抗钢水侵蚀性.     

Structure of Laser Depositing of Al_2O_3 Coating

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Al_2O_3颗粒增强铝基复合材料的耐磨性研究

以粒度≤74μm的Al2O3为增强相,粒度≤30μm的铝粉为基体,采用粉末冶金法制备了Al2O3颗粒增强铝基复合材料。采用金相显微镜、SEM等分析手段对制备的复合材料进行组织观察,并对其进行耐磨性测试。结果表明,Al2O3含量为10%,烧结温度为660℃,混粉时间为90 min时,相对磨损率最小为0.1684%。随着Al2O3的含量的增加和烧结温度的升高,试样的耐磨性呈现出先升高后降低的趋势,混粉时间对试样的耐磨性影响不明显。     

Hydrogen Embrittlement Processes and AL／AL2O3 Hydrogen Resistance Coatings of NdFeB Magnets

After analyzing the phenomena and processes of hydrogen embrittlement of NdFeB permanent magnets, RF magnetron sputtering was used to fabricate A1 thin films and then oxidized to form the Al/Al2O3 composite films on the magnets as the hydrogen resistance coatings. SEM and EDS were used to examine the morphology and composition respectively. Hy-drogen resistance performance was tested by exposing the magnets in 10 MPa hydrogen gas at room temperature. The results show that the magnets with 8μm Al/Al2O3 coatings can withstand hydrogen of 10 MPa for 65 min without being embrittledinto powd er. The samples with and without hydrogen resistance coatings have almost the same magnetic properties.     

镁砂中Fe2O3、Al2O3、P2O5、TiO2的联合测定

镁砂产品检验中,采用碱熔融法共同预处理样品,在同一母液中,联合测定铁、铝、磷、钛的含量,缩短了检测时间。通过分别控制各元素的显色酸度,各元素线性良好,测得的Fe2O3、Al2O3、P2O5、TiO2的相对标准偏差分别小于1.11%、2.78%、4.84%、5.88%。实验结果表明,方法的准确度和精密度都较高。     

Wettability of silicon carbide ceramic by Al2O3/Dy2O3 and Al2O3/Yb2O3 systems

Wettability is an important phenomenon in the liquid phase sintering of silicon carbide (SiC) ceramics. This work involved a study of the wetting of SiC ceramics by two oxide systems, Al₂O₃ /Dy₂O₃ and Al₂O₃ /Yb₂O₃, which have so far not been studied for application in the sintering of SiC ceramics. Five mixtures of each system were prepared, with different compositions close to their respective eutectic ones. Samples of the mixtures were pressed into cylindrical specimens, which were placed on a SiC plate and subjected to temperatures above their melting points using a graphite resistance furnace. The behavior of the melted mixtures on the SiC plate was observed by means of an imaging system using a CCD camera and the sessile drop method was employed to determine the contact angle, the parameter that measures the degree of wettability. The results of variation in the contact angle as a function of temperature were plotted in graphic form which showed that the curves displayed a fast decline and good spreading. All the samples of the two systems presented final contact angles of 40° to 10° indicating their good wetting on SiC in the argon atmosphere. The melted/solidified area and interface between SiC and melted/solidified phase were evaluated by scanning electron microscopy (SEM) and their crystalline phases were identified by X-ray diffraction (DRX). The DRX analysis showed that Al₂O₃ and RE₂O₃ reacted and formed the Dy₃Al₅O₁₂ (DyAg) and Yb₃Al₅O₁₂ (YbAg) phases. The results indicated that the two systems had a promising potential as additives for the sintering of SiC ceramics.     

Microstructural observations of pressure cast Ni3Al/Al2O3 and Ni/Al2O3 composites

Pressure castings of Ni₃Al(IC218)/Al₂O₃ and Ni/Al₂O₃ composites, made with continuous DuPont FP α-Al₂O₃ and DuPont PRD166 α-Al₂O₃+20 wt pct partially stabilized ZrO₂ 20 μm diameter fibers, were examined by optical, scanning electron microscope (SEM), and transmission electron microscope (TEM) techniques. According to optical magnifications, excellent infiltration took place. However, in SEM and TEM magnifications, small gaps were found adjacent to regions where bonding had taken place between fibers. On the basis of available evidence, the gap formation was attributed to trapped gases and microshrinkage. Titanium was added to the metal to promote infiltration. Diffusion of Ti into the fibers of the Ni/Al₂O₃ composites occurred, but similar diffusion into the fibers of the IC218/Al₂O₃ composites did not take place. The qualitatively higher bond strength of the interfaces of the Ni/Al₂O₃ composites was ascribed to the diffusion of Ti into Al₂O₃. No interface reaction layer was found in any of the composites. Very little grain growth was found to take place in either the FP or PRD 166 fibers after casting and after a subsequent ten day anneal at 1150 °C.     

Effect of Al2O3 on Structure and Wearability of Composite Coating

Asasurface strengtheningtechnology ,thether malsprayhasevolvedfromearlynormal protectivecoatingtocurrentfunctionalcoating .Thedevelopmentofcompositepowderisanimportantbreakthroughinthisfield .Particularly ,thenewlydevelopedmetal basedceramiccoatings ,such…