【摘要】 采取相同的塑化剂配方和成型压力,研究了碳化硅颗粒级配(粗粉800～1600μm,中粉100μm,细粉1.2～14μm)对硅碳棒热端挤出密度以及电性能和抗氧化性的影响。结果表明:1)在硅碳棒热端塑性挤出工艺中,当粗、中粉之和与细粉(含塑化剂)的体积比为7:5时,坯体的挤出成型密度最高;2)在硅碳棒热端的挤出成型中,粗、细粉的粒径都对坯体密度有较大的影响,当粗粉为1.4mm占40%(体积分数,下同)和600μm占25%,中粉为100μm占10%,细粉为5μm占25%时,制得坯体的密度高达2.56g.cm-3;3)硅碳棒热端的电阻率与碳化硅颗粒烧结颈的多少和粗细有很大关系,合适的级配能使硅碳棒中的碳化硅颗粒基本烧成一体,减少其颗粒之间的界面,从而提高制品的导电性能和抗氧化性能。更多还原

【Abstract】 The influence of grain size composition(coarse grain 800~1 600 μm,medium grain 100 μm,fine grain 1.2~14 μm)on extruding density and other properties of silicon carbide heating elements was studied.The results show that:1)In heating elements plastics extruding process of silicon carbide,when the sum volume ratio of coarse and medium grain to fine grain(contain plasticizing agent)is 7:5,the extruding shaping density of the silicon carbide heating element is the highest;2)During the extruding shaping process of silicon carbide heating elements,particle sizes of both coarse and fine grain have great influence on the density of the silicon carbide heating elements.And when 1.4 mm coarse grain accounts for 40%(volume percent,the same below),600 μm coarse grain accounts for 25%,100 μm medium grain accounts for 10%,5 μm fine grain accounts for 25%,the density is the highest,2.56 g·cm-3;3)The quantity and size of connection part of silicon carbide have great influence on the resistivity of the silicon carbide heating elements;proper grain size composition can make the silicon carbide particles sintering well,and can reduce the interface area around the particles,thus improve the electrical conductivity and oxidation resistance.更多还原