板状刚玉骨料气孔结构及性能分析

Pore structure and performance of tabular corundum aggregates

为了研究板状刚玉骨料性能与其气孔结构之间的关系,选取市场上两种3~5 mm板状刚玉骨料A和B为研究对象,进行了化学组成、物相组成、显微结构和物理性能分析,同时采用X射线断层扫描(CT)技术对板状刚玉骨料的三维结构和气孔孔径分布进行了表征。结果表明:两种板状刚玉骨料的化学组成相近,晶粒尺寸均为20~100μm;除筒压强度外,两种板状刚玉骨料的其他物理性能无明显区别;板状刚玉骨料B较板状刚玉骨料A的平均气孔尺寸小,大尺寸气孔数量少,气孔分布均匀;结合显微结构和CT结果,平均气孔尺寸和大尺寸气孔数量是影响其强度的主要因素:气孔尺寸越大,大尺寸气孔数量越多,板状刚玉骨料的强度越低。

In order to investigate the relationship between the properties and the pore structure of tabular corundum aggregates,two commercial tabular corundum aggregates(A and B) of 3-5 mm were selected as the research objects.The chemical composition,the phase composition,the microstructure and the physical properties of the two tabular corundum aggregates were analyzed,while their three-dimensional structure and pore size distribution were characterized by X-ray computed tomography(CT).The results show that the chemical composition of the two tabular corundum aggregates is similar,and their grain size ranges from 20-100 μm.There is no significant difference in the physical properties of the two tabular corundum aggregates,except for the cylinder compressive strength.Tabular corundum B has smaller average pore size,less large-sized pores and more uniform pore distribution than tabular corundum A.The microstructure and the CT results indicate that the average pore size and the large pore amount are the main factors to influence the strength of the tabular corundum aggregates:the larger the pore size and the more the large pores,the lower the strength of tabular corundum aggregates.