利用转炉钢渣作为原料,采用烧结法制备了碱度(CaO/SiO2质量比)分别为0.5、O.6和0.7的微晶玻璃.通过X射线衍射分析、扫描电镜观察和能谱分析等手段,结合样品收缩率与力学强度测试结果,研究了在不同热处理条件下三种微晶玻璃的结构与性能的变化规律.微晶玻璃的力学强度主要受基础玻璃烧结性能和内部晶体组织结构的影响.烧结收缩率高,内部晶体呈方柱状交织形态,则微晶玻璃的力学强度最好.微晶玻璃的晶相主要为黄长石晶体和辉石晶体,高温条件有利于黄长石晶体生长而促使辉石/黄长石比例减少.碱度为0.6的微晶玻璃收缩率最大,其内部的黄长石晶体呈方柱状交织排列,构成晶体骨架,并同残余玻璃相形成力学强度饺高的微观组织,从而使得其具有优异的力学性能.
Using BOF slag as raw materials, glass ceramics with the basicity (w(CaO)/w(Si02) of 0.5, 0.6, and 0.7 were produced by sintering. Their structure and properties were studied under different heat treatment conditions by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), sample shrinkage and mechanical strength testing. Experimental results show that the mechanical strength of the glass ceramics is mainly dependent on the sintering property of parent glass and internal crystal structure. At a higher sintering shrinkage rate, internal crystals in the glass ceramics exhibit a cylindrical intertwined form and the mechanical strength of the glass ceramics performs better. Main crystal phases in the glass ceramics are melilite and pyroxene, and high- temperature conditions are in favor of melilite growth and pyroxene.to-melilite ratio decrease. The maximum shrinkage rate belongs to the glass-ceramic with the basicity of 0.6, in which melilite performs columnar interwoven constituting a crystal skeleton that forms the microstructure of high mechanical strength with residual glass phase. Thereby this glass ceramic has excellent mechanical properties.