纳米-亚微米结构SiC-Al_2O_3复合陶瓷快速制备

Study on the Fast Preparation of Nano-submicro Structure SiC-Al_2O_3 Composites

采用粒径为600nm和200nm的高纯氧化铝、40nm碳化硅为原料,应用放电等离子(SPS)烧结工艺,在200℃/min的升温速率条件下,研究了原料粒径、温度条件对于纳米SiC-Al2O3复合陶瓷制备过程中晶粒生长以及致密度变化的影响。研究结果表明:在烧结温度1450℃、压力100MPa、保温2min的条件下,2种不同原料的纳米复合陶瓷的晶粒尺寸均在亚微米范围,烧结体致密度达98%。在相同温度压力条件下,小粒径烧结体密度小于大粒径烧结体。

Experimental sintering studies on SiC-Al2O3 powder were taken with fast heating rate （200 ℃/min） by SPS sintering technique. Two kinds of a-Al2O3 powders （200 and 600 nm） were used as the raw materials. The effects of sintering temperature and powder size on the density and grain growth were studied. The microstructural changes of specimens were examined and the corresponding detailed data on the densification and grain size were presented. For both fine and coarsen powder, nearly 98% density composites with alumina controlled in submicro size could be obtained by sintering at 1 450℃ for 2 min under 100 MPa. The relative density of sintered Al2O3 from finer powders is a slightly lower compared with that from coarser powders under the same pressure and sintering temperature.