| 摘要 |
Small tooling and hardware for the metallurgy and melt-processing of nonferrous metals, produced with the aid of ceramic-ceramic composite materials consisting of a fibrous reinforcement made of ceramic fibres and a geopolymeric ceramic matrix containing: a) a poly(sialate) Mn(-Si-O-Al-O-)n and/or poly(sialate-siloxo) Mn(-Si-O-Al-O-Si-O-)n geopolymer, M denoting at least one alkali metal cation and n the degree of polymerisation, b) siliceous and/or aluminous and/or silicoaluminous ultrafine components less than 5 microns, preferably less than 2 microns, in size, the said geopolymeric ceramic matrix being obtained by polycondensation, at a temperature of between 20 DEG C and 120 DEG C, of an alkali metal aluminosilicate reaction mixture, the composition of the main ingredients of the said geopolymeric compound, expressed in terms of the molar ratios of the oxides, being within or equal to the following values: M2O/SiO2 0.10 to 0.95 SiO2/Al2O3 2.50 to 6.00 M2O/Al2O3 0.25 to 5.70 M2O denoting either Na2O and/or K2O or the mixture of at least one alkali metal oxide with CaO.
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