Ceramic Slabs Prepared Using Different Flux System and Its Properties
In this work,the K-Na and Ca-Mg based raw materials were used to prepare SiO2-Al2O3-K2O(Na2O)(K2O-Na2O)and SiO2-Al2O3-CaO-MgO(CaO-MgO)system ceramics,respectively.The impacts of flux systems(CaO-MgO,K2 O-Na2 O)on sintering characteristic and mechanical properties of ceramic slabs prepared at different firing temperatures(1 110～1 210℃)were investigated systematically,and the evolution rule of phase composition and microstructure was studied by XRD and SEM.The results show that the optimal firing temperatures for CaO-MgO and K2O-Na2O system ceramics are 1 17O and 1 15O ℃,respectively.The introduction of Ca-Mg based raw materials would lead to the lower firing shrinkage and bulk density of CaO-MgO system ceramics compared to K2O-Na2O system ceramics,meanwhile the pore size and content in CaO-MgO system ceramics are larger than those in K2O-Na2O system.The formation of anorthite and α-cordierite in CaO-MgO system ceramics is promoted by the introduction of Ca-Mg based raw materials,and the crystalline phase content of CaO-MgO system ceramics is significantly increased to be 75.66％(mass fraction),which is 56％higher than that of K2O-Na2O system.The dispersion strengthening effect caused by high crystalline phase content is greater than degradation effect of pore on mechanical strength.The flexural strength of CaO-MgO system ceramics is(56.9±2.6)MPa,fracture energy is(183.2±9.5)J/m2,failure strain is(7.4±0.1)x 10-4 and specific strength is(24.9±1.1)kN·m·kg-1,which are 15％,25％,11％,and 23％higher than those of K2O-Na2O system ceramics,respectively,indicating that the CaO-MgO flux system is more suitable for the manufacturing of high strength,toughness,and flexibility ceramic slabs compared with the traditional K2O-Na2O system.
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维普
