在自增韧陶瓷的致密化过程中,添加-βSi3N4晶种有利于长柱状晶的形成与生长,可以改善陶瓷的强度和韧性;以MgO为添加剂,通过对原始Si3N4粉进行热处理,制备出转相充分、具有柱状形貌β-Si3N4晶种。重点研究了MgO对氮化硅相变和晶种形貌的影响。实验结果表明在MgO添加量在1.5wt%和2wt%时,在1750℃下热处理2小时能得到β相含量95%以上和具有大长径比的-βSi3N4晶种。
Abstract
In the sintering processing of the self-reinforced,the addition of β-Si3N4 as seeds material is effective for development and growth of long-pole crystal which can enhance the intensity and toughness of ceramics.In this paper,β-Si3N4 with completeness of phase transformation and pole-liked morphology have been developed by means of heating the initial Si3N4 powder with certain additive of MgO.The influence of MgO on phase transformation and seeds morphology was investigated.The result showed that taking MgO with 1.5wt% and 2wt% additive contents,under 1750℃ for two hours,the β-Si3N4 seeds with up to 95% β phase content could be gotten.
关键词
Si3N4 /
晶种 /
MgO
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Key words
Si3N4 /
seeds /
MgO
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参考文献
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脚注
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基金
国家科技部政府间合作项目(2005DFBA003)
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