刚玉中铁氧化物含量对β-SiAlON结合刚玉砖性能的影响

Influence of ferric oxide content in corundum on properties of β-SiAlON bonded corundum products

以板状刚玉(w(Fe2O3)=0.10%)、低铁棕刚玉(w(Fe2O3)=0.33%)、高铁棕刚玉(w(Fe2O3)=0.60%)、硅粉、铝粉和αAl2O3微粉等为原料,首先分别采用3种铁氧化物含量不同的刚玉细粉与合成纯βSiAlON(z=2.75)用的粉料(即硅粉、铝粉和αAl2O3微粉)混合制样,在氮化炉内于1450℃保温16h氮化烧成后,测定试样的质量变化率,然后在上述试验的基础上分别添加3种不同的刚玉骨料进行相同的试验,并测定试样的体积密度、耐压强度和抗折强度。结果发现:无骨料试样氮化后的质量变化率随刚玉原料中铁氧化物含量的增加而增大,3个试样的质量变化率分别为15.7%、15.9%和16.3%,说明3种试样中硅粉的氮化率随刚玉中铁氧化物含量的增加而増大;在使用刚玉骨料的试验中,采用高铁棕刚玉的试样的体积密度和强度均最高。

Tabular corundum with 0 10% Fe2O3,low ferric oxide brown corundum with 0. 33% Fe2O3 and high ferric oxide brown corundum with 0.60% Fe2O3, silicon powder, aluminum powder and α-Al2O3 micro-powder were used as the starting materials in the experiment. Firstly,the specimens were prepared by mixing the corundum powders with different Fe2O3 contents with the fine powders including silicon powder,aluminum powder and α-Al2O3 micro-powder which were used for synthesizing pure β-SiAlON （z=2.75 ）, respectively, pressing and firing in nitrification furnace at 1450 ℃ for 16 h, then measuring the mass increasing rate of the specimens to calculate their nitridation rate. Based on the above experiment, adding different corundum aggregates to do similar experiment, then determining BD, CCS and MOR of the specimens. The results showed the mass increasing rate of nitrified specimens without corundum aggregates increased with the increase of Fe2O3 content in corundum materials,which were 15.7%, 15.9% and 16.3% respectively,showing that the nitridation rate of the specimens also increased with the increase of Fe2O3 content in corundum materials. In the experiment using corundum aggregate,the specimens prepared with high ferric oxide brown corundum aggregate has the highest bulk density and strength.