利用铝型材厂污泥和叶腊石制备莫来石材料

以铝型材厂污泥和叶腊石为主原料制备莫来石材料,属于固体废料和矿物资源的综合利用项目.采用XRD法和SEM法表征各试样的晶相结构和显微结构;用Rietveld Quantification法确定各试样中各晶相的含量.结果表明不同配方的各试样均形成三种晶相,莫来石固溶体Al4.59Si1.41O9.7、Al2O3、SiO2,其中Al4.59Si1.41O9.7是主晶相,其含量为85.3%～97.8%;分析结果确定最佳的配方组成为:污泥为75wt%,叶腊石为25wt%,Al2O3/SiO2物质的量比为2.4.     

MgO矿化剂对自结合钛酸铝/莫来石复相材料结构和性能的影响

在铝厂污泥,龙岩高岭土和工业二氧化钛合成出的良好稳定性的钛酸铝/莫来石熟料基础上,添加MgO矿化剂进行改性,其能与钛酸铝/莫来石材料形成固溶体,能抑制Al2TiO5的分解,使得钛酸铝/莫来石复相材料在保持低热膨胀系数的同时,较大辐度地提高了材质的机械强度.采用XRD和SEM法表征各试样的晶相和显微结构;各试样中各晶相的含量由用Rietveld Quantification 法确定;测试各试样的性能.从结构与性能分析结果,确定1.5％为MgO的最佳添加量,形成的三个晶相Al2-xMgx+yTi1-yO5-0.5x-y、Al4.59Si1.41O9.70和α-Al2O3分别为68.2％、26.5％和5.3％,对应的抗折强度为45.67 MPa,体积密度为2.95 g/cm3,吸水率为1.81％,气孔率为4.99％,热震后抗折强度保持率为90.0％.     

ZrO2矿化剂对钛酸铝材料结构与性能的影响

在利用铝型材厂污泥合成的Al2TiO5中添加少量ZrO2矿化剂,ZrO2矿化剂与Al2TiO5形成置换固溶体,能抑制Al2TiO5的分解,增加Al2TiO5含量和提高Al2TiO5的热稳定性.采用XRD和SEM表征试样的晶相结构和显微结构;用Rietveld Quantification 法确定各试样中各晶相含量;测试各试样的性能.结构与性能分析结果确定较佳ZrO2矿化剂添加量为2%,对应的抗折强度为35.32 MPa,体密度为2.86 g/cm3,气孔率为23.0%,吸水率为8.1%,热震后抗折强度保持率为84.2%.     

SiO2矿化剂对钛酸铝材料结构与性能的影响

以铝型材厂污泥为主原料合成Al2TiO5材料,在合成的Al2TiO5中添加少量SiO2矿化剂,与Al2TiO5形成固溶体,抑制Al2TiO5的分解,达到提高Al2TiO5热稳定性的目的.采用XRD法和SEM法表征各试样的晶相结构和显微结构;用Rietveld Quantification 法确定各试样中各晶相的含量;测试各试样的性能.结构与性能分析结果表明较佳SiO2矿化剂添加量为2%,较佳烧结温度为1450 ℃,对应抗折强度为44.3 MPa,体积密度为3.28 g/cm3,气孔率为6.3%,吸水率为1.9%,热震后抗折强度保持率为84.2%.     

Al粉、Si粉对低碳Al2O3-C滑板显微结构和高温力学性能的影响

为了改善低碳Al2O3-C滑板的高温力学性能,在质量分数65%的电熔白刚玉颗粒、25%的白刚玉细粉、6%活性α-Al2O3粉、4%的石墨+炭黑、外加4%酚醛树脂的滑板配料中,分别以3%(w)的Al粉或Si粉或3%(w)Al粉+3%(w)Si粉等量替代白刚玉细粉,混匀后在150 MPa下压制成140 mm×25 mm×25 mm的试样,经200℃24 h干燥,1 400℃埋焦炭处理3 h后,检测其高温抗折强度和抗热震性,并分析物相组成及显微结构。结果表明:单加Al粉的试样高温抗折强度高于单加Si粉的,但前者热震后残余抗折强度比后者低;与单加Al粉或Si粉的试样相比,同时加Al粉和Si粉的试样具有更高的高温抗折强度和更优的抗热震性。力学性能的变化与试样中原位生成的非氧化物相密切相关:在单加Al粉或Si粉的试样中分别有棒状AlN晶须或纤维状SiC晶须生成;而同时加Al粉和Si粉的试样中除了有AlN晶须和SiC晶须生成外,还原位生成了六角板状的SiAlON相,并相互交织在一起。     

煅烧温度与保温时间对合成莫来石材料结构与性能的影响

本研究是利用铝型材厂污泥与叶腊石合成莫来石材料.主要探讨煅烧温度和保温时间对莫来石合成料中形成的晶相、微观形貌及其含量的影响;从中确定较佳的煅烧温度和保温时间.采用XRD法和SEM法表征各试样形成的晶相和显微结构;用Rietveld Quantification 法确定各试样中各晶相的含量.实验结果表明不同煅烧温度和保温时间各试样形成的主晶相都是莫来石固溶体(Al4.59Si1.41O9.7),确定较佳煅烧反应温度为1600 ℃,较佳煅烧保温时间为3 h,对应的莫来石固溶体含量为96.4wt%.     

一次合成法合成Fe-Cr-Mn系黑色氧化铝陶瓷及其性能研究

以α-Al2O3为主要原料,采用一次合成法制备了黑色氧化铝陶瓷。通过X射线衍射图谱对样品进行物相分析,通过样品的体积密度、吸水率、体积电阻率和弯曲强度,对实验配方进行优化。实验结果表明:黑色氧化铝陶瓷的最佳配方(质量分数)为:Al2O3 85%,Fe2O3 1.5%,Cr2O3 2.5%,Mn O2 3%,Ti O2 4%,Si O2 3%和Mg O 1%。在1450℃下样品着色效果好,力学性能优良。晶相为α-Al2O3和少量尖晶石,体积密度为3.64 g/cm3,吸水率为0.57%,体积电阻率为1.6×1013Ω·cm,抗折强度为237.24 MPa。     

Al2O3-SiC复相粉对Al2O3-SiC-C材料性能的影响

以电熔白刚玉(3～1、≤1、≤0.044 mm)、Al2O3-SiC复相粉(d50≤5μm)、α-Al2O3微粉(d50=1.2μm)、SiC粉(≤0.044 mm)、鳞片石墨(≤0.088 mm)、Si粉(d50=42.8μm)和B4C(d50≤10μm)为主要原料,热固酚醛树脂为结合剂,研究了分别用4%、8%、12%、16%质量分数的Al2O3-SiC复相粉等比例取代α-Al2O3微粉和SiC细粉对Al2O3-SiC-C试样在180℃固化后和1 000、1 500℃埋焦炭热处理后的显气孔率、体积密度、常温抗折强度、常温耐压强度、高温抗折强度(1 400℃)、抗热震性(1 100℃,水冷)以及抗氧化性(1 000、1 500℃)的影响。结果表明:随Al2O3-SiC复相粉加入量的增加,试样经180℃固化后常温性能下降,1 000℃热处理后常温性能变化不大,1 500℃热处理后除耐压强度显著提高外,其余各项常温性能变化不大;而高温抗折强度下降,抗热震性明显提高,试样经1 500℃氧化后的抗氧化性以加入4%质量分数复相粉的最佳。其原因可能是由于该复相粉的粒度更细,反应活性更高,其氧化层中更易生成莫来石,形成表面致密层从而有效地阻碍氧气向材料内部扩散。     

TiO2对用铝厂污泥和叶腊石制备莫来石材料的影响

本研究以铝型材厂污泥和叶腊石为主要原料制备莫来石材料,在研究确定最佳配方、最佳煅烧温度和最佳保温时间的基础上,探讨TiO2矿化剂对莫来石晶相结构、显微结构和性能的影响,从而确定出最佳TiO2矿化剂添加量. 采用XRD法和SEM法表征各试样的晶相结构和显微结构;用Rietveld Quantification 法确定各试样中各晶相的含量;测试各试样的性能.综合结构与性能分析结果,确定最佳TiO2添加量为1.0%,对应莫来石固溶体含量为98.5%,体积密度为2.48 g·cm-3,气孔率为13.1%,吸水率为5.30%,抗折强度为22.66 MPa,折强度保持率为83.9%.     

Cr2O3对废建筑玻璃研制的微晶玻璃结构及性能影响

本研究以正交实验确定的最佳制备微晶玻璃的工艺条件为基础,探讨cr2O3晶核剂不同添加量对利用废建筑玻璃研制的微晶玻璃的微观结构及性能的影响.利用XRD法和SEM 法确定不同试样的晶相与形貌;用半定量法确定各试样的晶相与玻璃相的含量,按微晶玻璃的测试标准测试各试样的体积密度、吸水率、抗折强度.实验结果:添加cr2O3;晶核剂析出的主晶相为Na2Ca3Si6O16和SiO2,Na2Ca3Si6O16晶体呈针状,SiO2晶体呈粒状;且试样中的晶相含量随着晶核剂添加量增加而增加.经分析:确定Cr2O3最佳添加量为8wt%,对应的晶相(Na2Ca3Si6O16SiO2、Na2CrO4)含量为47.21%,抗折强度为95.05Mpa.体积密度为2.336g/cm3,吸水率为O.12%.     

利用铝厂污泥合成莫来石/刚玉复相材料

采用铝型材厂污泥和粘土为原料合成莫来石刚玉复相材料，主要探讨不同Al2O3／SiO2比值对形成的晶相结构影响。采用XRD和SEM表征各样品的晶相，结果表明各样品都形成2种晶相：莫来石固溶体和刚玉相，其中No．2配方中莫来石和刚玉的比例为：71．6：28．4，莫来石在扫描电镜下呈柱状交织，为较佳配方。     

微波烧结SiC-Cu/Al复合材料的工艺及机理

用微波烧结工艺成功制备了铜包裹碳化硅颗粒增强铝基(SiC-Cu/Al)复合材料,利用扫描电镜和X射线衍射分析仪对烧结样品进行表征,并讨论了烧结过程及机理.研究表明:采用多晶莫来石纤维棉、硅碳棒和氧化铝坩锅组合设计的保温结构能很好地促进烧结.烧结温度为720℃时,SiC-Cu/Al复合材料的密度取得最大值为2.53g/cm3.SiC-Cu/Al复合材料的硬度随烧结温度的升高的变化成马鞍状.烧结温度对样品显微结构的影响较大,随着烧结温度的升高,相分布的均匀性降低,在较高的烧结温度下会出现SiC颗粒的偏聚.涡流损耗和界面极化损耗是促进微波烧结的主要动力.     

氧化铬对菱镁矿风化石制备堇青石材料的影响

本研究以辽南地区菱镁矿风化石、工业氧化铝、二氧化硅微粉为原料制备堇青石材料,研究分析氧化铬对制备堇青石材料中晶相、晶胞参数、晶相含量及显微结构的影响.用XRD和SEM表征各试样中的晶相和显微结构;用X' Pert Plus软件对晶相的晶胞参数和晶相含量进行分析.结果表明:以菱镁矿风化石为原料经过1350℃烧成可以制备出以堇青石为主晶相的堇青石材料.氧化铬与堇青石形成有限的固溶体,当氧化铬加入量为0.8％时,堇青石晶格常数及晶胞体积都最大;小于1.2％的氧化铬的加入会降低了系统中晶相的含量,当氧化铬加入量大于1.2％时,系统中晶相的含量随着氧化铬加入量的增加而逐渐增大.     

Influence of Cu2O on Interface Behavior of Copper/SiCp Composite Prepared by Spark Plasma Sintering

Copper/SiC_p composites were prepared by spark plasma sintering. X-ray photoelectron spectroscopy, X-ray diffraction, transmission electron microscopy, and energy dispersive spectroscopy techniques were used to characterize the sintered samples. Cu₂O was found to facilitate the physical wetting at the interface through the formation of an amorphous intergranular phase. The reaction between SiC and copper was detected in the samples containing little Cu₂O. It led to the degradation of SiC reinforcements and the decrease in hardness of copper/SiC_p composites.     

氧化钛对铝厂污泥合成的镁铝尖晶石晶相结构的影响

用铝型材厂污泥和碱式碳酸镁[(MgCO3)4·Mg(OH)2·5H2O]为主要原料合成镁铝尖晶石(MgAl2O4),探讨氧化钛(TiO2)矿化剂对合成的MgAl2O4晶相结构、晶胞参数及微观形貌的影响.用X射线衍射,扫描电镜及相关分析软件,如:Philips plus,Rietveld quantification等表征得到的MgAl2O4.结果表明:当TiO2添加的质量分数(下同)低于2%时,MgAl2O4的相对含量及晶格参数随TiO2的增加而增加,TiO2的最佳添加量确定为2%,此时,生成的MgAl2O4相对含量达到92%,TiO2可与MgAl2O4形成固溶体,固溶量约为2%.TiO2添加超过2%则会形成含钛化合物.     

低品位菱镁矿与工业铝灰制备镁铝尖晶石

以低品位菱镁矿与工业铝灰为原料制备镁铝尖晶石材料。分析讨论了不同煅烧温度对工业铝灰材料组成与微观结构的影响,并进一步研究了煅烧温度对制备镁铝尖晶石材料的组成、镁铝尖晶石相晶胞常数及材料微观结构的影响。用X射线衍射（XRD）和扫描电镜（SEM）对煅烧后试样的物相和显微结构进行研究。利用X′ pert plus软件对试样中主晶相的晶格常数进行计算,比较不同温度煅烧试样的相对结晶度。结果表明：随着工业铝灰煅烧温度的升高,材料中主晶相六方晶型的刚玉相晶胞常数呈现各向异性的变化趋势。低品位菱镁矿与工业铝灰经1 400 ℃高温煅烧可以制备出以镁铝尖晶石为主晶相的镁铝尖晶石材料,该温度煅烧的镁铝尖晶石材料晶粒相对均匀、结构相对致密,主晶相镁铝尖晶石相晶格常数最大。     

Reactivity of BaTiO3-Ca10(PO4)6(OH)2 phases in composite materials for biomedical applications

In this work the reactivity of barium titanate (BT) and hydroxyapatite (HA) composites from commercial and synthesized powders was studied. Raman spectroscopy, X-ray diffraction and scanning electron microscopy were used for characterization of sintered composites. Moreover, biotoxicity assays were performed to evaluate the effect of secondary phases in the sintered composites in relation to BT and HA phases. The formation of secondary phases and transformation of hydroxypatite into tricalcium phosphate depended on the reactivity of the starting materials. The piezoelectric voltage coefficient, calculed from permittivity and piezoelectric constant for composites containing 20 vol% HA, generated promising values for a good osteogenic response. The secondary phases formation during the sintering process favored the ions release to the incubation solution; consequently, the composite biocompatibility highly depended on samples composition. Composites made of synthesized HA and commercial BT produced valuable results for biomedical applications.     

Sintering and properties of borosilicate glass/Li-Na-K-feldspar composites for electronic applications

Glass/ceramic composites are considered as one of the most important materials for electronic applications. In the present work, an attempt for using Li-Na-K containing feldspar in addition to borosilicate glass to fabricate glass/ceramic composites having good properties was conducted. Firstly, the glass frit was prepared and grinded by high energy ball mill to get nano powder. Then, five designed batches of glass/feldspar composites containing 10, 20, 30, 40 and 50 wt% feldspar were mixed, pressed and sintered at 850 °C. Bulk density and apparent porosity of sintered specimens were determined by Archimedes method. Identification of the formed phases was examined by X-ray diffraction (XRD) analysis. Microstructure of sintered bodies was examined by scanning electron microscope. Microhardness of sintered samples was determined using Vickers indentation technique whereas the fracture toughness was determined by Indentation Fracture (IF) method. The dielectric constant of sintered composites was measured at 1 MHz. The thermal expansion coefficient (TEC) was also measured in the temperature range from room temperature to 1000 °C. The results revealed that Li-Na-K feldspar and borosilicate glass were successfully used to fabricate composites with good electrical properties and thermal expansion suitable for electronic applications. The inhibition of cristobalite amount and the formation of beta spodumene in addition to the quartz were responsible for the improvement of the electrical and thermal properties. The formed amount of beta spodumene was the ideal amount after which the higher amount can cause crack in the body due to the volume change occurred by the differences in thermal expansion of alpha and beta spodumene.     

助熔剂对氧化铝陶瓷结构及性能影响的研究

以铝型材厂废渣和可塑粘土为主要原料,添加滑石及碳酸钡复合助熔剂研制氧化铝陶瓷。主要探讨助熔剂不同添加量对产品微观结构及各项性能指标的影响。采用XRD和SEM等主要测试手段探讨其晶相结构和显微结构,以气孔率、吸水率、体积密度等性能指标为主要评价标准选择最佳的助熔剂添加量。结果表明:体系内除刚玉相外,还有少量莫来石、镁铝尖晶石和钡冰长石相。当滑石含量为3.5%,碳酸钡的含量为5.5%时,瓷球吸水率、气孔率和体积密度达到了极值,此时吸水率为0.21%,气孔率为0.67%,体积密度为3.18 g/cm3。     

Apatite Wollastonite–Titanium Biocomposites: Synthesis and In Vitro Evaluation

The present paper discusses the consolidation of apatite wollastonite (AW) glass ceramic/titanium composites with various percentages of Ti (5–40 wt%) in an argon atmosphere, and, evaluation of the sintered properties and bioactivity in simulated body fluid (SBF). The sintered density of the composites was found to increase with an increase in Ti content and was found to be in the range of 2.25 (5 wt% Ti)–2.70 g/cm³ (40 wt%) as compared with those of sintered AW (2.06 g/cm³) and Ti (4.5 g/cm³). Biaxial flexural strength of the composites was found to be in the range of 13–45 MPa. X-ray diffraction studies of the sintered AW/Ti composites showed Ti phases (TiPO₄+CaTiO₃+Ti₂O₃) and wollastonites (CaSiO₃+MgSiO₃+CaMgSiO₄) as dominating phases. In vitro bioactivity of the composites was studied by soaking the composites in SBF for 7, 14, and 21 days, and the sample surfaces as well as the remaining SBF were analyzed to study the interaction between the material and SBF. The results indicated that the growth of phosphates increased in about 7 days of soaking in SBF, after which a steady state was reached, confirming the samples to be bioactive.