硅渣和玻璃粉直接烧结制备多孔材料的气孔结构与力学性能

以硅渣和玻璃粉为原料,采用粉体直接烧结法制备多孔材料,研究了烧结温度(700~900℃)、烧结时间(15~120min)和升温速率(10~100℃·min^-1)对多孔材料表观密度、气孔率、物相组成、抗压强度的影响。结果表明:气孔结构均匀性随烧结温度的升高而降低;表观密度随烧结温度的升高先减小后增大,随保温时间的延长而增大,随升温速率的增大而减小,气孔率的变化趋势与表观密度的相反;多孔材料的主要物相为玻璃相和硅、SiC、SiO2、Ca2Al2SiO7等结晶相,且结晶度随烧结温度的升高而降低;抗压强度随烧结温度的升高呈先增大后减小的趋势;当烧结温度为750℃,升温速率为30℃·min^-1,烧结时间为30 min时,多孔材料的主晶相为硅和Ca2Al2SiO7,抗压强度最大(1.60MPa),表观密度为0.43g·cm^-3,气孔率为80%。

Pore Structure and Mechanical Property of Porous Materials Prepared by Direct Sintering of Silicon Slag and Glass Powder

Porous materials were prepared by the powder direct sintering method with silicon slag and glass powder as raw materials.The effect of sintering temperature(700-900 ℃),sintering time(15-120 min)and heating rate(10-100℃·min^-1)on the apparent density,porosity,phase composition and compressive strength of the porous materials was investigated.The results show that the uniformity of pore structure deteriorated with the increase of sintering temperature.The apparent density decreased first and then increased with the increase of sintering temperature,increased with the extension of sintering time and decreased with the increase of heating rate.The variation of porosity was opposite to that of apparent density.The main phases of porous materials included glass phase and crystalline phases of Si,SiC,SiO2 and Ca2Al2SiO7,and the crystallinity decreased with the increase of sintering temperature.The compressive strength increased and then decreased with increasing sintering temperature.When the powder mixture was sintered at 750 ℃ for 30 min with heating rate of 30 ℃·min^-1,the obtained porous material had main crystalline phases of Si and Ca2Al2SiO7,the maximum compressive strength of 1.60 MPa,the apparent density of 0.43 g·cm^-3 and the porosity of 80%.