基于灰色系统理论的高铝砖孔结构与强度的相关性

Correlation Between Pore Structure and Strength of Alumina Brick Based on Grey System Theory

采用灰色关联理论对烧成高铝砖内部孔结构与其抗折和抗压强度的相关性进行了研究。采用扫描电子显微镜、压汞仪和万能强度试验机等对高铝砖显微结构、孔结构参数和强度进行表征,结果表明:高铝砖的体积密度沿砖的压制方向上密下疏,材料显气孔率由上到下逐渐增大。显气孔率增大时,先是小孔径(<10μm)量增加,然后小孔增量消失,稍大孔径(10~15μm)量增加。小孔比例增加有利于材料抗折强度增大,其中1~10μm的孔所占比例对抗折强度影响更大。大孔径比例增加,材料的常温强度下降;材料的抗折强度与材料内部的小孔比例以及孔的复杂程度关联系数较大,而材料的抗压强度与材料内部大孔所占比例的关联系数更大。

Influence of pore structure of alumina brick on its modulus of rupture （MOD） and cold crushing strength （CCS） at room temperature was investigated based on the grey system theory. The pore structure of specimens was characterized by scanning electron microscopy, mercury intrusion porosimetry （MIP） and universal strength test, respectively. The results show that the alumina brick appears inhomogeneous, and the bulk density decreases and the apparent porosity increases along the pressing direction. The content of micro pores with the sizes of 〈10 μm first increases, and then the content of greater pores with the sizes of 10-15 μm increases. The micro pores disappear when the apparent porosity increases. The existence of micro pores favors the MOR, especially for the pores with the sizes of 1-10 μm. Also, the increase of greater pores content affects the MOD and the CCS negatively. The correlation coefficients between the MOR and the content of micro pores and between the CCS and the content of greater pores are greater than other pore structure parameters.