红柱石粗颗粒预烧温度对莫来石-刚玉材料抗热震性的影响
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摘要
为了研究经过预烧的红柱石粗颗粒对莫来石-刚玉耐火材料抗热震性的影响,将20%(w)的未经预烧或分别经1 300、1 400、1 500、1 600℃保温3 h预烧的南非红柱石粗颗粒(5～3 mm)分别与莫来石颗粒(3～1和≤1 mm)以及板状刚玉粉、活性氧化铝粉和SiO_2微粉配料,制样,于1 450℃保温3 h烧后制成莫来石-刚玉试样,检测其烧后线变化率、弹性模量、抗热震性,并进行显微结构分析。结果表明:随着红柱石粗颗粒预烧温度的提高,试样的常温抗折强度逐渐提高,但抗热震性能变差。这是由于随着红柱石粗颗粒预烧温度的提高,红柱石粗颗粒与基质的热膨胀系数差值变小,产生的微裂纹尺寸逐渐减小,且在热震过程中能够阻止新裂纹产生和裂纹扩张的微裂纹减少。
This work researches the effect of pre-fired andalusite aggregates on the thermal shock resistance of mullite-corundum refractories. Andalusite aggregates( 5-3 mm) from South Africa( original or prefiring at 1 300 ℃,1 400 ℃,1 500 ℃ and 1 600 ℃ for 3 h) were mixed with mullite particles( 3-1 mm and ≤1 mm),tabular corundum powder,active alumina powder and silica fume. The mixtures were shaped and fired at 1 450 ℃ for 3 h into the mullite-corundum specimens. The linear change rate,elastic modulus and thermal shock resistance of the specimens were tested. The microstructure was analyzed. The results indicate that the cold flexural strength of the specimens increases gradually,but the thermal shock resistance gets worse with the rising preheating temperature of andalusite. The reasons are that with the rising prefiring temperature,the difference between the thermal expansion coefficients of andalusite aggregate and the matrix decreases,so the generated microcracks get smaller,and the microcracks preventing the crack generation and growth during the thermal shock get less.
This work researches the effect of pre-fired andalusite aggregates on the thermal shock resistance of mullite-corundum refractories. Andalusite aggregates( 5-3 mm) from South Africa( original or prefiring at 1 300 ℃,1 400 ℃,1 500 ℃ and 1 600 ℃ for 3 h) were mixed with mullite particles( 3-1 mm and ≤1 mm),tabular corundum powder,active alumina powder and silica fume. The mixtures were shaped and fired at 1 450 ℃ for 3 h into the mullite-corundum specimens. The linear change rate,elastic modulus and thermal shock resistance of the specimens were tested. The microstructure was analyzed. The results indicate that the cold flexural strength of the specimens increases gradually,but the thermal shock resistance gets worse with the rising preheating temperature of andalusite. The reasons are that with the rising prefiring temperature,the difference between the thermal expansion coefficients of andalusite aggregate and the matrix decreases,so the generated microcracks get smaller,and the microcracks preventing the crack generation and growth during the thermal shock get less.
引文
[1]KAKROUDI G M,HUGER M,GAULT C,et al.Anisotropic behaviour of andalusite particles used as aggregates on refractory castables[J].J Eur Ceram Soc,2009,29(4):571-579.
[2]李柳生,廖桂华,徐国辉,等.亚白刚玉对红柱石细粉烧结性能的影响[J].耐火材料,2016,50(2):96-99.
[3]张婷,韩兵强,杨威,等.红柱石加入量对均化矾土基Al2O3-SiC-C浇注料性能的影响[J].耐火材料,2017,51(3):205-208.
[4]喻燕,徐勇,沈明科,等.活性α-Al2O3微粉加入量对红柱石耐火泥浆性能的影响[J].耐火材料,2016,50(3):223-224+227.
[5]贾江议,李谦,曹贞源.红柱石的莫来石化作用及机理[J].河南科技大学学报(自然科学版),2004,25(3):100-104.
[6]文洪杰,苗圃,李文超.红柱石的莫来石化动力学[J].耐火材料,1995,25(3):140-141.
[7]HüLSMANS A,SCHMüCKER M,MADER W,et al.The transformation of andalusite to mullite and silica:partⅠ.transformation mechanism in[001]Adirection[J].American Mineralogist,2000,85(7-8):980-986.
[8]HüLSMANS A,SCHMüCKER M,MADER W,et al.The transformation of andalusite to mullite and silica:partⅡ.Transformation mechanisms in[100]Aand[010]Adirections[J].American Mineralogist,2000,85(7-8):987-992.
[9]李柳生,廖桂华,徐国辉,等.红柱石粗颗粒预烧温度对红柱石基耐火材料性能的影响[J].耐火材料,2016,50(5):321-324.
[10]李柳生,徐国辉,任刚伟.南非红柱石细粉的烧结行为和莫来石化研究[J].耐火材料,2006,40(6):423-425.
[11]廖桂华,徐国辉,李柳生,等.烧成温度和保温时间对红柱石基材料烧结性能的影响[J].耐火材料,2005,39(4):255-258.
[2]李柳生,廖桂华,徐国辉,等.亚白刚玉对红柱石细粉烧结性能的影响[J].耐火材料,2016,50(2):96-99.
[3]张婷,韩兵强,杨威,等.红柱石加入量对均化矾土基Al2O3-SiC-C浇注料性能的影响[J].耐火材料,2017,51(3):205-208.
[4]喻燕,徐勇,沈明科,等.活性α-Al2O3微粉加入量对红柱石耐火泥浆性能的影响[J].耐火材料,2016,50(3):223-224+227.
[5]贾江议,李谦,曹贞源.红柱石的莫来石化作用及机理[J].河南科技大学学报(自然科学版),2004,25(3):100-104.
[6]文洪杰,苗圃,李文超.红柱石的莫来石化动力学[J].耐火材料,1995,25(3):140-141.
[7]HüLSMANS A,SCHMüCKER M,MADER W,et al.The transformation of andalusite to mullite and silica:partⅠ.transformation mechanism in[001]Adirection[J].American Mineralogist,2000,85(7-8):980-986.
[8]HüLSMANS A,SCHMüCKER M,MADER W,et al.The transformation of andalusite to mullite and silica:partⅡ.Transformation mechanisms in[100]Aand[010]Adirections[J].American Mineralogist,2000,85(7-8):987-992.
[9]李柳生,廖桂华,徐国辉,等.红柱石粗颗粒预烧温度对红柱石基耐火材料性能的影响[J].耐火材料,2016,50(5):321-324.
[10]李柳生,徐国辉,任刚伟.南非红柱石细粉的烧结行为和莫来石化研究[J].耐火材料,2006,40(6):423-425.
[11]廖桂华,徐国辉,李柳生,等.烧成温度和保温时间对红柱石基材料烧结性能的影响[J].耐火材料,2005,39(4):255-258.