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N. V. Ishkova L. S. Opaleichuk R. S. Krivosheeva V. K. Ovchinnikova 《Glass and Ceramics》1988,45(9):334-335
Translated from Stekli i Keramika, No. 9, p. 19, September, 1988. 相似文献
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文章探讨了纳米AlN对Na2O-B2O3-SiO2硼硅酸盐玻璃体系陶瓷结合剂金刚石磨具结构与性能的影响.在不同气氛条件下烧结的陶瓷结合剂金刚石磨具试样,利用万能压力试验机、洛氏硬度计、扫描电子显微镜等仪器,测试磨具试样的抗折强度、洛氏硬度、耐磨性,以及显微结构等.结果表明:纳米AlN含量为6wt%时,结合剂的开始熔融温度为670℃,比纯结合剂低10℃,且烧结温度范围增大;在氩气气氛下烧成,金刚石磨具试样的抗折强度、洛氏硬度、耐磨性等,比在大气气氛下烧成磨具的均有所提高,其中折强度为60.46MPa,洛氏硬度为88;由SEM图谱可以看出,加入纳米AlN后,结合剂与磨粒间结合良好,且组织均匀. 相似文献
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研究了聚烯烃/霞石复合材料的拉伸性能、弯曲性能和表面硬度,并采用扫描电镜直接观察其冲击断面的形态结构以及霞石在基体材料中的分布状态和被包裹状态。研究结果表明:采用硅烷偶联剂可以增进霞石与基体材料间的相互作用,有效地改善材料的力学性能,其处理效果优于只能作为分散剂使用的磷酸酯和聚乙二醇;霞石可以在HDPE、PP中使用,提高材料的综合性能 相似文献
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《Ceramics International》2020,46(13):21202-21210
Differences in structure and properties of Na2O–Al2O3–B2O3–SiO2 vitrified bonds and vitrified diamond composites prepared by sol-gel and melting methods were methodically discussed. Results showed that the vitrified bond prepared by sol-gel method contained more [AlO4] tetrahedron and owned higher bending strength, with the maximum value reaching 137 MPa, 31.73% higher than that prepared by melting method (104 MPa). As the sintered temperature rose, coefficient of thermal expansion of the vitrified bond prepared by sol-gel method increased first and then decreased, acquiring a maximum value of 5.75 × 10−6 °C −1 at 720 °C, which was still much lower than the minimum value of vitrified bond prepared by melting method (7.02 × 10−6 °C −1). The vitrified diamond composite prepared by sol-gel method possessed lower sintering shrinkage than that prepared by melting method, and could be applicable to the production of grinding tools with high dimensional accuracy. What's more, the maximum bending strength of vitrified diamond composites obtained by sol-gel method was 106 MPa, 24.7% higher than that of vitrified diamond composites prepared by melting method (85 MPa). 相似文献
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Small additions of ground nepheline syenite tailings were incorporated into various sewer-pipe bodies. The lost-cost tailings contained 2 to 3% Fe2 O3 and significantly improved the physical properties of the sewer-pipe bodies. 相似文献
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D. A. DUKE J. F. MacDowell B. R. KARSTETTER 《Journal of the American Ceramic Society》1967,50(2):67-74
Electron micrographic and X-ray diffraction techniques were used to study the nucleation and growth of titania-nucleated nepheline in glass. On heating, the glasses phase-separated as a prelude to the crystallization sequence. The first crystalline phase identified was the metastable phase, carnegieite. With time, the equilibrium phase, nepheline, crystallized and the titania crystallized to anatase. The resulting materials were nonporous and largely crystalline. These nepheline glass-ceramics were chemically strengthened by treatments in molten potassium salts. A K+ → Na+ exchange took place and effected transformation of nepheline to kalsilite. This transformation was a function not only of the exchange treatment, but of the composition of the initial nepheline crystals. Confining the kalsilite surface against a volume increase during the phase transformation created a surface compressive stress. Glass-ceramics containing nepheline crystals with an appropriate structure were chemically strengthened in this manner to yield bulk, abraded modulus of rupture values above 200,000 psi. 相似文献
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《Journal of the European Ceramic Society》2004,24(7):2095-2102
The microhardness and indentation fracture toughness of a vitrified industrial waste, in the form of ash, were characterized by the method of static indentation test. These properties were investigated as a function of composition and thermal treatment conditions. To further understand the influence of the constitutive oxides, additional measurements were made in a series of synthetic products, where a mixture of iron and lead oxides was used as a substitute for the ash. The underlying deformation mechanisms controlling the mechanical properties of such complex systems as determined by static indentation tests are discussed. It was found that plasticity, in the amorphous products, is mainly governed from the silica content, even in the cases where silica is not found in sufficient quantity in order to build an extended three-dimensional vitreous network. On the other hand, the morphology of the separated crystalline phases is the dominant factor affecting plasticity in the glass-ceramic products. 相似文献
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Breda Kegl 《Fuel》2008,87(7):1306-1317
This paper deals with numerical and experimental analysis of the influence of fuel temperature on the injection process. The tested injection system is the mechanically controlled diesel fuel injection M system of a bus diesel engine. The considered fuels are neat biodiesel from rapeseed oil and neat mineral diesel. All injection parameters, obtained with biodiesel, are compared to those of mineral diesel. At first, attention is focused on a single injection assembly (plunger-in-barrel assembly, high pressure tube, and injector). The flow through a single assembly to one cylinder is investigated numerically by using an one-dimensional mathematical model. The injection process is simulated at different operating regimes. On the basis of the numerical results, the influence of fuel temperatures on the injection characteristics, especially on fuelling at some stage of injection, mean injection rate, mean injection pressure, injection delay, and injection timing is investigated in view of harmful emissions reduction. Furthermore, the fuel flow through the whole injection system (all six injection assemblies) to all six cylinders is investigated experimentally with respect to fuel temperature. The pressure drop through the fuel filter and fuelling through each of six injection assemblies are analyzed. 相似文献
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M. H. Nielsen S. J. Jepsen H. Outtrup 《Journal of the American Oil Chemists' Society》1981,58(5):644-649
The increasing use of synthetic fibers which cannot tolerate temperatures above 50–60 C has changed the washing habits during
the past 5–10 years toward the use of lower washing temperatures. Furthermore, the energy crisis has focused interest on washing
at ambient temperatures for the purpose of saving energy. In order to compensate for the lower washing efficiency at decreased
temperatures, enzyme producers have devoted much R&D capacity to screen for new proteolytic enzymes which are more suitable
for washing at lower temperatures. The result of a screening program carried out for several years, a new detergent protease
with interesting characteristics, is discussed.
Presented at ISF-AOCS World Congress, New York City, April 1980. 相似文献
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霞石微晶玻璃热膨胀系数的研究 总被引:1,自引:0,他引:1
霞石微晶玻璃热膨胀系数的研究刘小波(湘潭矿业学院411201)StudyonThermalExpansionCoefficientofNephelineGlass-Ceramics¥LiuXiaobo(XiangtanMiningInstitute)... 相似文献