摘要
选取碳化硅晶须[SiC(w)]及氧化铝纤维[Al_2O_2(f)],研究晶须(纤维)-氧化锆复合增韧莫来石的工艺,晶须(纤维)加入对材料力学行为的影响。采用表面活性剂改善了纤维及晶须在基质中的分散性。热压烧结的莫来石/25vol% ZrO_2/15vol%Al_2O_3(f)与增韧莫来石(ZTM)相比,室温强度、韧性分别提高近20%、30%。热压烧结的莫来石/25vol% ZrO_2/15vol% SiC(w),室温强度为510—530MPa,韧性为6～7MPam^(1/2)800℃对强度为400-420MPa。室温韧性及高温强度较 ZTM 有明显提高。用 SEM 分析断口,确定晶须拔出机制对强韧化起主要作用。
The processing techniques for zirconia-toughened mullite composites further rei-nforced by SiC whiskers or Al_2O_3 fibres and the influence of the addition of reinfo-rcer on their mechanical properties were investigated.With the help of smallamount of surfactant,Al_2O_3 fibres or SiC whiskers were homogenously dispersedin ceramic matrix.The flexural strength and toughness for the-hotpressed composi-tes,containing 15 vol% SiC whiskers and 25% vol% ZrO_2,can be increased by20% and 30% respectively in comparison with zirconia-toughened mullite ceramicswithout whiskers or fibres.The above-mentioned specimen gave the strength at roomtemperature 510-530 MPa,400-420 MPa at 800℃,and fracture toughness 6-7MPa m^(1/2),which were significantly improved,in comparison with ZTM ceramics.The observation of fracture surface by SEM showed that the pull out mechanism ofwhiskers should play an important role in toughening.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
1990年第1期55-60,共6页
Journal of Inorganic Materials
