摘要:
A manganese-zinc ferrite having a high initial permeability in a wide band, especially an especially high initial permeability in a low-frequency region of about 10 kHz and a method for producing the same. The method including a main temperature maintaining step of maintaining the temperature at 1200 DEG to 1450 DEG C during baking is characterized in that before the main temperature maintaining step the method includes an in-baking temperature decreasing step in which the lowest temperature is in the range from 1000 DEG to 1400 DEG C which is 50 DEG C or more lower than the temperature maintained in the main temperature maintaining step. The thus produced manganese-zinc ferrite contains as main components 50 to 56 mol% of iron oxide in terms of Fe2O3, 22 to 39 mol% of manganese oxide in terms of MnO, and 8 to 25 mol% of zinc oxide in terms of ZnO and has an average grain size of 50 to 150 mu m.
摘要:
The present invention pertains to the production of materials used in high-temperature oxidising media, wherein said materials can be used in the production of high-temperature electric heaters as well as in the production of parts, sensors and instruments operating at temperatures of 1900 DEG C and above. These materials, which essentially contain tungsten and molybdenum silicides MeSi2-Me5Si3 as well as silicon carbide, are characterised in that they exhibit high levels of heat-resistance, of resistance to thermal shocks, of high-temperature strength and of wear resistance. Doping with rhenium, tantalum, titanium, zirconium, niobium and hafnium silicides increases the mechanical properties of these materials. These materials, which have a desired porosity, can be used for increasing the specific electric resistance and for reducing thermal conductivity relative to high-density materials, while having a reduced density.
摘要:
The initial permeability of a manganese-zinc ferrite in the high-frequency zone of 10-500 Khz is improved by mixing a manganese-zinc ferrite comprising 50-56 mole % of Fe2O3, 22-39 mole % of Mno and 8-25 mole % of Zno with at most 800 ppm (in terms of Bi2O3) of bismuth oxide component and at most 1,200 ppm (in terms of MoO3) of molybdenum oxide component and firing the mixture. The mean crystal grain diameter is adjusted to 5-50 mu m or less.
摘要翻译:通过混合包含50-56摩尔%的Fe 2 O 3,22-39摩尔%的MnO和8-25摩尔的锰 - 锌铁氧体,提高10-500Khz的高频区域中的锰锌铁氧体的初始磁导率 氧化铋组分中最多800ppm(以Bi 2 O 3计)和氧化钼组分最多为1200ppm(以MoO 3计)的ZnO的%的ZnO,并焙烧该混合物。 平均晶粒直径调整为5-50μm或更小。
摘要:
A body of sintered silicon nitride contains new non-glassy phases which produce significant X-ray diffraction peaks at 2-theta diffraction angles corresponding to d-spacings of about 2.86 Angstroms and 3.59 Angstroms and process for making same, which process includes (a) comminuting a slurry of a silicon-containing powder, water, about 0.1 to 5 volume percent of Fe2O3, about 0.1 to 5 volume percent Al2O3, and about 0.5 to 10 volume percent CeO2, wherein all volume percents are based on the volume of the resultant silicon nitride, the composition of the slurry being such that about a 4 to 12 volume percent liquid phase is achieved during sintering; (b) reducing the water content of the reacted slurry to form a dry mass; (c) nitriding the dry mass by exposure to a nitriding gas at an elevated temperature to form silicon nitride; and (d) sintering the silicon nitride at about 1450-2100 °C.