麦饭石基铝系远红外基元材料的制备及应用

将天然麦饭石与Al2O3、MgO、Ti O2、ZrO2进行混合烧结,通过XRD、IR、红外热效应、红外辐射检测等测试,结果表明,Al2O3-MgO-Ti O2-ZrO2系远红外材料在麦饭石的加入后烧结,有堇青石的生成,所显示的衍射峰分别对应于六方结构堇青石的(112)、(202)、(211)特征峰,(100)晶面衍射峰为堇青石的最强峰;所制基元材料红外热效应明显,A7、MA7 10min的温升分别能够达48.2、51.3℃;红外辐射率分别为0.83、0.86。将制备的远红外基元材料加入到涂料中,涂料红外发射率为0.85。     

Fe3+,Cr3+固溶尖晶石结构的红外辐射性能

用常规固相合成法成功地制备出Fe2O3和Cr2O3掺杂改性的尖晶石型红外辐射材料,并通过XRD、IR和IRE-2红外辐射仪测试了材料的微观结构,进而分析了材料的结构特征与红外辐射性能的关系,发现Fe2O3和Cr2O3的掺杂导致Fe3 和Cr3 分别以一定的配位形式进入体系中,并形成了(Mg,Fe)(Cr,Al)2O4混合型尖晶石结构,且随着体系中Fe2O3含量的提高,Cr2O3含量的降低,材料的红外辐射性能得到了很大改善,体系在全波段的辐射率为0.91,在＜8μm波段具有较低的红外辐射率,而在8～25μm波段的具有较高的辐射率,可达0.97.     

SiO2-Fe2O3-Cr2O3-MnO2高温红外辐射节能涂料的制备及应用

以SiO2、Fe2O3、Cr2O3、MnO2为原料按比例混合,经固相高温烧结制备成基体粉料,再与粘结剂混合球磨制备出高温红外辐射节能涂料。通过XRD、半球点测试仪、红外辐射测量仪、纳米粒度测试仪对材料的微观结构和理化性能进行了表征,采用热震法对涂层的抗热震性能进行了研究。研究结果表明,随着平均粒径的减小,合成的SiO2-Fe2O3-Cr2O3-MnO2体系全波段红外辐射率有明显增大的趋势。当平均粒径达到2μm左右时,涂料全波段红外辐射率最高达到0.93。涂料的最高使用温度达1400℃以上,涂层的抗热震性能良好。此外,在燃气梭式干燥窑上使用该高温红外辐射节能涂料后,降低能耗15%左右,抗老化性能优良,使用一年后辐射率仍在0.90以上。     

低温远红外辐射陶瓷材料研究

用过渡金属氧化物MnO2、Fe2O3为主要原料，ZrO2、TiO2作为辅助添加剂，经传统的固相烧结，可以得到低温远红外辐射陶瓷材料。但是，这种材料具有热膨胀系数大、不耐冲击的缺点。与质量分数75％的堇青石复合后，可以减少热膨胀系数到1．87×10-6／℃，提高整个红外波段的辐射率到87％以上，同时降低了成本。     

核-壳结构粒子SiO_2@Bi_2O_3的制备及红外发射率研究

为了研究制备复合隐身粒子的方法,采用溶胶-凝胶法制备了核-壳结构SiO2@Bi2O3粒子.通过XRD、TEM及发射率测试仪对制备的材料的结构、形貌和性能进行了表征.XRD表明在700℃可以得到Bi2O3纯相;红外发射率测试表明,Bi2O3具有较低的红外发射率,在SiO2表面包覆Bi2O3后,在3～5μm和8～14μm两个测试波段都能降低SiO2的红外发射率.通过核-壳结构的形式,在较高发射率的样品表面涂覆红外发射率较低的样品,可以提高红外隐身效果.     

(Ca,Fe)共掺铈酸镧陶瓷的制备及红外辐射性能研究

以La_2O_3、CeO_2、Ca O和Fe_2O_3为起始原料,采用高温固相烧结工艺制备得到(Ca,Fe)共掺铈酸镧(La_(1.9)Ca_(0.1)Ce_(1.9)Fe_(0.1)O_7)红外辐射陶瓷材料。采用X射线衍射仪、扫描电子显微镜、能谱仪、紫外–可见–近红外(UV-Vis-NIR)分光光度计分别对样品的物相组成、显微结构、化学成份、UV-Vis-NIR反射率及UV-Vis吸收进行了表征,同时采用IR-2双波段红外发射率测量仪测试了样品3~5μm波段的红外发射率。结果表明:掺杂元素(Ca,Fe)均固溶进入铈酸镧晶格,共掺后样品的晶体结构也为萤石结构;(Ca,Fe)共掺样品内部形成杂质能级,强化了自由载流子吸收与杂质能级吸收,使样品红外短波段(0.75~5μm)性能由高反射转变为高吸收(辐射),其中在0.75~2.5μm波段的平均红外吸收率为0.88,3~5μm波段的红外发射率为0.752,与未掺杂样品相比分别提高了1660%与60%。     

多波段兼容隐身功能填料的制备及其性能研究

采用共沉淀法制得了Cr2O3包覆片状铝粉的Al/Cr2O3复合粒子。借助XRD、IR、SEM以及激光粒度仪对Al/Cr2O3粉末的相组成、形貌和粒径分布进行了表征。此外,测试了Al/Cr2O3粉末的红外辐射率和1.06μm波长处的反射率性能。结果表明,实验制得的Al/Cr2O3复合粒子厚度基本均匀,平均粒径较原始铝粉有所增加;红外辐射率为0.66,属于中低红外辐射率;1.06μm波长处的反射率为0.41%,激光吸收性能强。同时,复合粒子本身的绿色还可以起到可见光隐身的效果。     

红外高发射率ZnO∶Al粉末的制备

基于红外高发射率材料的应用,用固相法制备了Zn1-xAlxO(x=0.01,0.02,0.05,0.07)粉末,并研究预煅烧和二次煅烧后样品的红外发射率.X射线衍射和扫描电镜分析结果表明,当Al掺杂浓度达到2％(原子比)时,出现了尖晶石相ZnAl2O4.预煅烧和二次煅烧后的样品结晶质量差,有尖晶石相ZnAl2O4形成.红外发射率分析表明,1200℃时,随着掺杂浓度的增大,样品在3～5μm,8～ 14μm,1～ 22 μm三个波段内的发射率都降低了.随着煅烧温度的升高,在8～14μm波段内,Zn0.99Al0.01O发射率先升高后降低,在0.984 ～ 0.987之间.Zn0.99Al0.01O经过预煅烧和二次煅烧后,在这三个波段内的发射率都升高了.二次煅烧温度为1200℃时,得到的8～ 14μm内的发射率最高,为0.989.二次煅烧温度为1300℃的样品在三个波段内的整体发射率大于0.95.     

热压烧结AlON透明陶瓷的烧结行为及性能

本文以醇盐水解法自制的γ-Al2O3粉体为原料,利用热压反应烧结技术,在N2气氛中一步制备得到γ-AlON透明陶瓷,并着重研究了Y2O3和MgO两种氧化物烧结助剂及其含量对产物的烧结性能及透光性的影响。结果显示加入Y2O3或MgO作为烧结助剂,不但有助于促进固相反应进行,还可通过形成固溶体大大改善烧结性能。较MgO而言,采用Y2O3作为烧结助剂的产物的硬度及相对密度均更好。添加1wt%Y2O3,在1950℃热压条件下即可得到γ-AlON透明陶瓷。XRD、SEM及密度测试结果表明产物的物相组成单一、内部结构致密,其相对密度可达99.22%。IR分析结果显示该样品在1.5~4.5μm的红外波段内具有可透过性,最大透过率为18.42%(2.5μm处)。     

核壳型ATO/空心玻璃微珠复合材料的制备及其热反射性能

采用水浆混合烧结法——空心玻璃微珠与SnO2、Sb2O3微纳粉水浆混合并在530℃烧结,制备核壳型结构ATO/空心玻璃微珠复合材料,作为彩色热反射材料。激光粒度分析仪测试水浆中氧化物的粒度分布;SEM、XRD分析表征复合材料的结构特点;傅立叶红外光谱仪测试该种材料制成的有机硅涂层近、中红外反射率。结果显示,水浆中粒度为0.6μm以下的氧化物,约占总量的93%;530℃烧结后,Sb2O3与SnO2合成ATO,包覆在空心玻璃微珠表面,形成厚度约600nm的壳层;在800～2100nm近红外波段,由复合材料制成的有机硅涂层反射率是50%～41%;在5～12μm红外波段,涂层的吸收率超过90%,预示该复合材料有较高的红外辐射率,可作为一种彩色凉颜料。     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.     

Study on Bond Ability of Arc-Spraying Coatings with Different Surface Pretreatment on Cast-Iron

Arc spraying coatings are widely used in various applications, but uncommon in cast iron substrate. Different surface pretreatment technology is tested on substrates of gray cast iron. Surface roughness and residual stress were measured by TR200 and X-ray diffraction analyzer. Influence of different surface pretreatment methods ( dry blasting and fusebond) on roughness and residual stress was analyzed. The arc-sprayed coatings of wire 3Cr13 (φ2mm) on gray cast iron substrate is studied. The microstructure and interface of bonding layer were observed by SEM. The bond strength was taken by tensile test. Results show that bond strength with grit blasting is higher than fuse-bond; it is feasible to make wire 3Cr13 coating with arc spraying on cast iron substrate roughened by grit blasting.     

Structural Characteristics of TiO2 Ceramic Coating by Micro-Plasma Oxidation

TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.     

Evaluation of fatigue life of steel using steel grain size

The insightful discussion of the relationship between the construction of metallographic and fatigue life and proposition of mathematical relationships describing this relationship was conducted in the paper. This paper presents a method for estimating the fatigue life, based on the construction of the microstructural material taking into account the grain size and the participation of ferrite and pearlite phase.