图书来源:二元合金相图及中间相晶体结构 二元合金相图及中间相晶体结构
作 者:唐仁政 田荣璋
出版时间:2009-05
定 价:320元
图书ISBN:978-7-81105-831-4
出版单位:中南大学出版社
Pengfei Zhang,Litong Zhang and Xiaowei Yin National Key Laboratory of Thermostructure Composite Materials,Northwestern Polytechnical University,Xi an 710072,China
摘 要:To improve the corrosion resistance of porous Si3N4 used in the high temperature environments,which contain water vapor and volatile species,porous Si3N4-Lu2Si2O7 composite ceramics were fabricated by a process of oxidation bonding and pressureless sintering in flowing N 2 atmosphere at the temperatures lower than 1550 ° C.The pores in ceramics were formed by removing the pore-forming agent(phenolic resin).SiO2 derived by the oxidation of Si3N4 at 1250 ° C in air reacted with Lu2O3 at various sintering temperatures,leading to the formation of Lu2Si2O7 with excellent oxidation and corrosion resistance.The phase composition,microstructure,and mechanical properties of the porous ceramics depended on the sintering temperatures.Si3N4-Lu2Si2O7 composite ceramics with the porosity of 52% and the pore size of 0.2 μm were obtained by oxidation bonding at 1250 ° C for 1 h and pressureless sintering at 1550 ° C for 2 h using 4 wt pct Lu2O3 additive.
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