【摘要】 以自蔓延高温合成β-氮化硅粉为原料,添加稀土化合物Y2O3和MgO复合烧结助剂,采用放电等离子烧结后高温热处理的方法制备氮化硅陶瓷。研究β-氮化硅粉体制备致密氮化硅陶瓷的条件。讨论粉体种类(β-氮化硅或α-氮化硅)及SPS保温时间对氮化硅陶瓷热导率的影响。研究表明,采用β-氮化硅粉体制备的氮化硅陶瓷的热导率比采用相同工艺α-氮化硅粉体制备的氮化硅陶瓷高15%以上。采用SPS工艺在1873K烧结5min,然后再在2173K保温3h可以获得致密的氮化硅陶瓷,其热导率高达105W·(m·K)-1。更多还原

【Abstract】 Spark plasma sintering (SPS) followed by heat treatment were adopted to fabricate Si3N4 ceramics using SHS β-Si3N4 raw powder and Y2O3 -MgO additives. The sintering densification was improved by changing sintering conditions. The effect of powder type (β-Si3N4 powder or α-Si3N4 powder) and SPS holding time on thermal conductivity of the ceramics was focused. The result shows that thermal conductivity of samples fabricated with β-Si3N4 powder is above 15% higher than that of samples fabricated with α-Si3N4 powder under the same sintering conditions. Dense Si3N4 ceramics with a highest thermal conductivity of 105 W·(m·K)-1 can be prepared by spark plasma sintering at 1873K for 5 min and the followed heat treatment at 2173K for 3h.更多还原