摘要:
The invention relates to cast parts which contain at least 87 wt. % silicon nitride and up to 13 wt. % of an additive combination comprised of Al2O3 and Y2O3. The initial composition of the mass formulation starts with Y2O3/Al2O3 ratios of less than 1.1, preferably with Y2O3 Al2O3 ratios of 0.2 to 1.09. 1% to 20% of the Y2O3 portion can thus be substituted by an additional element of the group IVb of the periodic table or by the oxide thereof. The cast parts can comprise up to 1.0 wt. % HfO2 and/or ZrO2. Said cast parts preferably have a thickness >98% of the theoretic thickness. At room temperature, the bending strength of the inventive cast parts amounts to ≧1100 MPa and amounts to ≧850 MPa at 1000° C. The inventive cast parts correspond to the formula Si6-zAlzOzN8-z. The degree of substitution z thus amounts to 0.20 to 0.60, preferably from 0.22 to 0.54, especially from 0.3 to 0.35.
摘要翻译:本发明涉及含有至少87重量% %的氮化硅和高达13wt。 由Al 2 O 3 3 Y 3和Y 2 O 3 3组成的添加剂组合的%。 质量配方的初始组成开始于Y 2 O 3 / N 2 O 3 O 3比率小于 1.1,优选为0.2〜1.09的Y 2 O 3 3 O 3 O 3比率。 1%至20%的Y 2 O 3 O 3部分可以被周期表IVb族的另外的元素或其氧化物所取代。 铸件可以包含至多1.0重量% %HfO 2 2和/或ZrO 2 2。 所述铸造件优选具有理论厚度的> 98%的厚度。 在室温下,本发明铸造件的弯曲强度达到> = 1100MPa,并且在1000℃下达到> = 850MPa。本发明的铸造件对应于式Si 6-z Al z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z z 因此,取代度z为0.20〜0.60,优选为0.22〜0.54,特别优选为0.3〜0.35。
摘要:
The present invention relates to a novel process for the production of spherical binary and multinary mixed oxide powders in a hot-wall reactor. Through the use of aqueous or organic salt solutions or suspensions having a limited salt or solid concentration in combination with additives in the form of surfactants and/or of inorganic salts which have an exothermic decomposition reaction, a compact spherical particle morphology can be obtained, where the average particle size is in the range from 5 nm to
摘要:
The invention relates to a method for producing a one-part, multinary metal oxide power which is suitable for producing high-temperature superconductors. To this end, a mixture of the corresponding metal salts and/or metal oxides and/or metals in the requisite stoichiometric ratio is introduced into a pulsed reactor with a pulsed gas flow resulting from flameless combustion and is partially or completely converted into the multinary metal oxide.