转炉全铁法开炉对镁碳砖性能影响的研究

1 前言武钢转炉炉衬现已全部采用了自产的MgO-C砖,实现了镁碳砖化。在这种情况下,为节约焦炭和时间,采用了全铁水法开炉。本文论述了全铁水开炉时,炉衬MgO-C砖性能的变化。 2 镁碳砖抗热震性试验按以往用过的方法进行了两次镁碳砖抗热震稳定性试验.本试验是将四块不同材     

铝碳材料热震稳定性影响因素的分析

通过试验探讨了粒度组成、锆莫来石和磷片石墨加入量对铝碳材料抗热震性能的影响。研究表明,就提高抗热震性能而言,较佳的粒度组成为骨料/细粉=40/60,锆莫来石加入量以20%～25%为宜,石墨加入量以15%～25%为佳。     

锆英石的加入对MgO-C砖性能的影响

介绍了用锆英石取代MgO-C砖中的部分碳，从而降低向钢水内的增碳量的试验。实验证明，添加适当比例的锆英石，可以既降低碳含量，减少向钢水增碳，又能在维持良好抗热震性的基础上，提高材料的抗蚀性，降低热应力。     

红土镍矿回转窑用低导镁铝锆砖的研制与实践

红土镍矿回转窑直接还原生产镍铁工艺,具有渣含量高、波动大、黏度低的特点,对耐火材料性能要求苛刻。试验利用微孔镁铝合成料、高纯烧结镁砂、电熔镁铝尖晶石、锆源细粉为主要原料制备低导镁铝锆砖,该锆砖具有气孔率高、体密低、高热震稳定性的特点,微孔镁铝合成料引入可明显降低材料的导热率和体积密度,降低简体温度和载荷,进而实现节能降耗的目的,在红土镍矿回转窑中取得了良好的使用效果。     

无碳钢包渣线耐火材料的研究

研究了几种不同添加物对镁基耐火材料抗渣性和热震稳定性的影响。发现向镁基材料中添加10％左右的ZrO2制成的镁锆砖，对碱性渣的侵蚀具有很高的抵抗能力、同时具有较高的热震稳定性和抗剥落性，是一种较好的无碳钢包渣线耐火材料。     

水泥窑用镁钙锆质耐火材料的发展

介绍了水泥回转窑用耐火材料的发展历程以及国内外镁钙锆质耐火材料的研究现状,指出MgO-CaO-ZrO2复相材料既具有镁质材料的优点,矿物相组成中又包含一定数量的钙硅酸盐相,从而具有良好的抗热震性、较高的荷重软化温度及优异的抗硅酸盐水泥熟料的侵蚀性能、适宜的力学强度等,具有较高的实用价值.     

镁铝砖等几种耐火材料性能的检测

对镁铝砖、高镁砖镁铬砖、电熔镁砖，铝铬渣砖等几种耐火材料的组织结构、抗热震稳定性、抗金属侵蚀性及抗渣性进行了检测，并对检测结果进行了简要的综合评定。     

添加剂对连铸用浸入式水口抗渣侵蚀性能影响的研究

研究了加入金属铝、锰、硅粉等及其复合添加剂对铝锆碳质浸入式水口的性能影响。加入适量的Mg粉、A1粉、Mn粉添加剂可有效改善A1203-Zr02-C材料的显气孔率及体积密度,从而提高了材料抵抗氧化的性能。研究发现,Mn粉添加剂对试样的改善效果最好。从各性能指标看,Mn粉的加入不仅可以提高铝锆碳质浸入式水口的强度,而且对材料的抗氧化性和抗热震性有显著改善。     

ZrO2和结合剂对烧成镁钙砖烧结性能的影响

研究了电熔氧化锆、单斜氧化锆和两种结合剂（无水无羟基树脂和液体石蜡）对烧成镁钙砖烧结性能的影响。结果表明：作结合剂用时无水无羟基树脂效果好于液体石蜡；作为添加剂时电熔氧化锆和单斜氧化锫均能显著促进镁钙砖的烧结，其中单斜氧化锆的效果好于电熔氧化锆。加入的ZrO2与CaO反应生成了CaZrO3，存在于主晶相的晶界中，为离子扩散提供了迁移的途径，从而促进了烧结。     

LaCrO3- ZrO2材料的性能和显微结构

讨论了LaCrO3- ZrO2材料的性能和显微结构.通过测定试样的体积密度、热震性、常温电阻率,并借助电镜观察、微区分析等手段,对LaCrO3- ZrO2烧结材料的显微结构性进行了探讨.结果表明,在LaCrO3材料中,添加氧化锆后,对烧结体的抗热震性,电阻率及其显微结构均有一定的影响.可使材料烧结体的结构致密,晶粒发育良好且大小均匀,常温电阻率增加,热震稳定性改善.     

Zirconia modified monolithic macroporous Pt/CeO2/Al2O3 catalyst used for water-gas shift reaction

Monolithic macroporous Pt/CeO2/Al2O3 and zirconia modified Pt/CeO2/Al2O3 catalysts were prepared by using concentrated emulsions synthesis route. The catalytic performances over the platinum-based catalysts were investigated by water-gas shift (WGS) reaction in a wide temperature range (180-300 oC). The samples were characterized with thermogravimetry (TG), X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM) and temperature programmed reducti...     

Effect of Nozzle Base Material on the Rate of Clogging during the Continuous Casting of Aluminum‐Killed Steels

One approach to solving the problem of nozzle clogging during the continuous casting of aluminum‐killed steels is through careful selection of nozzle materials. In this study, the rate of clogging was measured while casting steel through simulated nozzles produced from alumina, zirconia, magnesia, zirconia‐graphite, and alumina‐graphite ‐ three common base materials and two common carbon‐containing nozzle materials. Spent nozzles were characterized using optical and cathodoluminescence microscopy. Interactions between the nozzles and steel were not observed in the alumina, zirconia, and zirconia‐graphite nozzles. Slight interactions were observed in the magnesia nozzles as alumina inclusions within the steel interacted with the nozzle to produce alumina‐magnesia spinel. Greater amounts of interaction were observed with alumina‐graphite nozzles. No statistical differences in the mean rate of clogging were observed between all of the pure oxide nozzles and zirconia‐graphite nozzles. However, the alumina‐graphite nozzles clogged at a much higher rate than the other nozzles. The higher rate of clogging is thought to be due to refractory‐steel interactions.     

水热法制备纳米二氧化锆粉体

二氧化锆纳米粉体是制造高科技氧化锆系陶瓷的重要原材料。纳米粉体的制备方法有很多种，但由于水热法可以控制微粉的粒径、形态、结晶度和组成，所以水热法是目前生产纳米粉体方法中最具发展潜力的工艺方法之一。国内外对水热法的研究已有相当进展。并正向工业化迈进。对目前国际上出现的应用于制备纳米二氧化锆系粉体的各种水热方法进行了介绍，着重介绍了制备过程中应用的各种新技术。并展望了水热法的发展前景。     

组成对MgO-ZrO2-CaO系合成料结构与性能的影响

以脱硅锆、轻烧氧化镁、消石灰为原料，进行了MgO-ZrO2-CaO系原料的合成，研究了化学组成(包括ZrO2含量、CaO／ZrO2比)，烧成温度，杂质等对合成料性能和组织结构的影响。     

X射线荧光光谱法测定氧化锆质耐火材料中主次成分

以无水四硼酸锂和碳酸锂混合熔剂作熔剂,采用玻璃熔片法制样,建立了测定氧化锆质耐火材料中ZrO2、HfO2、Al2O3、SiO2、Fe2O3、TiO2、CaO、MgO、Y2O3等组分的X射线荧光光谱法(XRF)。根据氧化锆质耐火材料中主次成分含量范围,采用有证参考物质和具有成分含量梯度并经其他方法定值的自制标准样品绘制校准曲线。并对熔剂选择、熔融条件及基体效应校正进行了探讨。将X射线荧光光谱法用于3个稳定氧化锆试样的分析,并与ICP-AES法进行比对,测试结果吻合。     

直接热解法制备棒状二氧化锆粉体

以氧氯化锆为原料, 借助DTG、SEM、XRD等表征手段, 考察了热解温度、热解气氛等工艺参数对直接热解法制备棒状二氧化锆的影响规律。结果表明, 氧氯化锆在氧化或水蒸气气氛中均可分解为氧化锆, 在同一气氛下的反应路径取决于热解温度。温度、气氛和前驱体种类对氧氯化锆热解产物的形貌和粒度影响较为显著。以ZrOCl₂·3.84H₂O为热解前驱体, 在H₂O-N₂气氛中于450℃温度下进行热解, 可得到粒度较为均匀、长径比为4~6的棒状二氧化锆, 通过分解温度的调控, 可获得四方相、单斜晶型或两者混合物的二氧化锆粉体。      

Modifiing Effect of Zirconia Nanoparticles during Electric Arc Welding

The structure of the weld metal after welding using a flux-cored wire with the addition of 0.3% zirconia flaky nanoparticles is studied. The weld consists of an acicular ferrite. This finding can indicate that the dissociation of zirconia in an electric arc is not an obstacle to a modifying effect, which manifests itself in both the interaction of zirconium with oxygen and the surface activity of zirconium in an iron-based solidifying melt. Thus, zirconia is a modifier of both the first and second kinds for the solidifying weld metal. Excess oxygen is likely to form individual pores less than 1 μm in diameter in the weld metal; however, they only wealy affect the mechanical properties of the welded joint. These results will be used to develop electrode materials for welding pipe steels.     

Zirconia as a ceramic biomaterial

Zirconia ceramics have several advantages over other ceramic materials, due to the transformation toughening mechanisms operating in their microstructure that can give to components made out of them, very interesting mechanical properties. The research on the use of zirconia ceramics as biomaterials started about twenty years ago, and now zirconia (Y-YZP) is in clinical use in THR, but developments are in progress for application in other medical devices. Recent developments have concentrated on the chemistry of precursors, in forming and sintering processes, and on surface finish of components. Today's main applications of zirconia ceramics is in THR ball heads. This review takes into account the main results achieved up to now, and is focused on the role that microstructural characteristics play on the TZP ceramics behaviour in ball heads, namely mechanical properties and their stability, wear of the UHMWPE paired to TZP, and their influence on biocompatibility.     

Microstructure and thermal cycling behavior of nanostructured yttria partially stabilized zirconia (YSZ) thermal barrier coatings

Nanostructured yttria partially stabilized zirconia(YSZ) coatings were prepared by atmospheric plasma spraying(APS) using the conglomeration made by zirconia nanoparticle as the raw materials.The measurement methods,which consisted of scanning electron microscopy(SEM),transmission electron microscopy(TEM) and thermal cycling behavior,were used to character the morphology,composition and thermal oxidation behavior of the powder and the coatings.From the results,it was shown that the YSZ coating was the laminar structure,and the elements distribution in the bond and top coat were well-proportioned.The YSZ coatings were composed of fine grains with size ranging from 30 to 110 nm.The laminar layers with columnar grains were surrounded with unmelted parts of the nanostructured powder and some equiaxed grains.In the as-sprayed nanostructured zirconia coatings,there existed pores that were less than 1 μm.The cracks were observed on some of the crystal border.The cyclic oxidation experiment showed that the nanostructured coating had longer thermal cycling lifetime to exhibit the promising thermal cyclic oxidation resistance.The failure of the nanostructured TBC was similar to the failure of conventional APS TBC.     

添加ZrO2对YAG纤维物相和形貌的影响

以氯化铝、金属铝粉、氧化钇、氧氯化锆、醋酸为原料,采用溶胶-凝胶法制备了钇铝石榴石(YAG)纤维,并研究添加ZrO2对YAG纤维的物相和形貌的影响.结果表明,添加ZrO2的YAG纤维物相仍为钇铝石榴石相,纤维表面光滑且直径均匀;ZrO2可作为YAG纤维的增韧相.