摘要:
以唐钢高炉渣为主要原料,辅以其他化学试剂,采用高温熔融法制备了含不同CaO/SiO2质量比的CaO-MgO-SiO2-Al2O3系微晶玻璃,并借助综合热分析仪、X射线衍射仪和扫描电子显微镜分析了CaO/SiO2的质量比对微晶玻璃析晶行为的影响规律.结果表明CaO/SiO2的质量比直接决定微晶玻璃主晶相的形成.随着质量比的变化,微晶玻璃会形成不同比例的透辉石、普通辉石和钙镁黄长石.经过不同的热处理制度,晶相与玻璃相的比例、颗粒形状、晶粒的均匀致密性等均会发生不同程度的变化.CaO/SiO2的质量比为0.30时,主晶相是透辉石,晶体呈颗粒状,有较多玻璃相残余;CaO/SiO2的质量比为0.44时,主晶相是透辉石,颗粒均匀致密,只有少量玻璃相分散在晶相中;CaO/SiO2的质量比为0.63时,钙镁黄长石含量显著增加,晶体呈雪花状,颗粒粗大,玻璃相增多.综合考虑DSC曲线、XRD图谱和玻璃的微观形貌结构可知,CaO/SiO2的质量比为0.44时最为合理,该配比下微晶玻璃析出的主晶相为透辉石,晶粒细小均匀致密,适宜的热处理制度为核化温度775℃,晶化温度920℃,保温时间均为1.5 h.
Abstract:
CaO-MgO-SiO2-Al2O3 glass ceramics with different mass ratios of CaO to SiO2 were prepared with the blast furnace slag from Tangshan Iron and Steel Company as the major raw material,mixed with other reagents by melting method.The effect of mass ratio of CaO to SiO2 on the crystallization behavior of glass ceramics was investigated by using differential scanning calorimetry,X-ray diffraction and scanning electron microscopy.The results show that the type of phase formation in the crystallization process depends on the mass ratios of CaO to SiO2.The dominant crystalline phase can be formed as diopside,augite and calcium akermanite with the different mass ratio.The proportion of crystal glass facies,particle shape and grain size of uniform density are different changes after different heat treatment system.The main crystal phase is diopside,crystal granular and have more residual glass phase when the mass ratios of CaO to SiO2 is 0.30.The main crystal phase is diopside,particles uniform and only a small amount of glass phase disperses in the crystal phase when the mass ratios of CaO to SiO2 is 0.44.The content of calcium akermanite increases significantly,crystal snowflake,particles coarsening and glass phase increases when the mass ratios of CaO to SiO2 is 0.63.Considering DSC curves,XRD pattems and microstmcture of the glass,the most suitable mass ratio of CaO to SiO2 in CMSA glass ceramics is 0.44,and the main crystalline phase of the glass ceramics is diopside with uniform fine grain.The appropriate heat treatment process is:nucleating at 775℃,crystallizing at 920℃,and heat preservation for 1.5h.
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