不同熔剂体系制备的陶瓷岩板及其性能

Ceramic Slabs Prepared Using Different Flux System and Its Properties

本文利用钾钠质与钙镁质原料配制了SiO_(2)-Al_(2)O_(3)-K_(2)O(Na_(2)O)(K_(2)O-Na_(2)O)与SiO_(2)-Al_(2)O_(3)-CaO-MgO(CaO-MgO)体系陶瓷,系统探究了熔剂体系(CaO-MgO、K_(2)O-Na_(2)O)在不同烧结温度(1 110~1 210℃)下对陶瓷岩板烧结性能和力学性能的影响,并利用XRD和SEM研究陶瓷岩板的物相组成和显微结构演变规律。结果表明:CaO-MgO与K_(2)O-Na_(2)O体系陶瓷的最佳烧结温度分别为1 170、1 150℃,钙镁质原料的引入导致CaO-MgO体系陶瓷的烧成收缩率与体积密度均低于K_(2)O-Na_(2)O体系陶瓷,且CaO-MgO体系陶瓷中气孔尺寸与含量均大于K_(2)O-Na_(2)O体系陶瓷;钙镁质原料的引入会促进CaO-MgO体系陶瓷中钙长石与α-堇青石的形成,且可以大幅度提升CaO-MgO体系的结晶相含量(质量分数为75.66%,较K_(2)O-Na_(2)O体系高56%)。高结晶相含量导致的弥散强化效果大于气孔对强度的劣化作用,CaO-MgO体系的弯曲强度为(56.9±2.6) MPa、断裂功为(183.2±9.5) J/m^(2)、极限应变为(7.4±0.1)×10^(-4)、比强度为(24.9±1.1) kN·m·kg^(-1),较K_(2)O-Na_(2)O体系分别提高了15%、25%、11%、23%,这说明CaO-MgO熔剂体系陶瓷更加适用于高强韧、高柔性陶瓷岩板的制备。

In this work,the K-Na and Ca-Mg based raw materials were used to prepare SiO_(2)-Al_(2)O_(3)-K_(2)O(Na_(2)O)(K_(2)O-Na_(2)O) and SiO_(2)-Al_(2)O_(3)-CaO-MgO(CaO-MgO) system ceramics,respectively.The impacts of flux systems(CaO-MgO,K_(2)O-Na_(2)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 K_(2)O-Na_(2O) system ceramics are 1 170 and 1 150 ℃,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 K_(2)O-Na_(2O) system ceramics,meanwhile the pore size and content in CaO-MgO system ceramics are larger than those in K_(2)O-Na_(2O) 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 K_(2)O-Na_(2O) 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/m^(2),failure strain is(7.4±0.1)×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 K_(2)O-Na_(2O) 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 K_(2)O-Na_(2O) system.