【摘要】 以菱镁矿和煅烧二级铝矾土为主要原料、焦炭为还原剂,在氮气气氛下,通过碳热还原氮化法(CRN)合成复相Spinel-Sialon粉体,并制备出Spinel-Sialon复相耐高温材料。应用XRD和SEM等技术,研究了原料配比和粉体的预合成温度对复相耐高温材料抗折强度的影响。结果表明,所制备的Spinel-Sialon复相耐高温材料的物相为MgAl2O4和Si3Al3O3N5,其平均抗折强度可达239MPa;粉料在1500℃下预合成比在1600℃下预合成更有利于试样烧结致密和提高材料的抗折强度,并且随菱镁矿添加量的增加,试样的显气孔率降低、体积密度增加、平均抗折强度增加。更多还原

【Abstract】 Spinel-Sialon composites were fabricated using magnesite and bauxite as the main raw materials and coke as reductant by carbothermal reduction and nitridation (CRN) in nitrogen atmosphere. The effect of match ratio of raw materials and pre-synthesized temperature on the flexural strength of composites were studied by XRD,SEM and EDS. The results showed that the phases of the fabricated Spinel-Sialon composites were MgAl2O4 and Si3Al3O3N5. The flexural strength of the composite reached a maximum of 239 MPa. The powder pre-synthesized at 1500 ℃ was more favorable for the densification and increasing of the flexural strength of samples than the powder pre-synthesized at 1600 ℃. The apparent porosity of samples decreased and the bulk density and the flexural strength increased with the rising of magnesite amount.更多还原