## 3 Results and Discussion  
### Basic Glass Differential Thermal Analysis  
Figure 2 displays the differential thermal analysis results for the base glass. The glass transition temperature (T\({}_{\text{g}}\)) of the base glass was approximately 697.42 \({}^{\circ}\)C, and the crystallization temperature (T\({}_{\text{c}}\)) was approximately 948.93 \({}^{\circ}\)C. In particular, this differential heat curve obtained through DSC exhibited a heat absorption peak at 958.49 \({}^{\circ}\)C, indicating the melting temperature (T\({}_{\text{m}}\)) of the base glass. Therefore, the maximum crystallization temperature in this experiment was 950 \({}^{\circ}\)C.  
Effects of Heat Treatment Temperature on the Crystal Precipitation of Microcrystalline Glass and Its Properties  
The results of the differential heat curve of the base glass showed that the crystallization exothermic peak of the base glass was 948.93 \({}^{\circ}\)C, that is, the maximum crystallization temperature of the base glass was 948.93 \({}^{\circ}\)C. Therefore, three heat treatment temperatures of 900 \({}^{\circ}\)C, 925 \({}^{\circ}\)C, and 950 \({}^{\circ}\)C were selected to analyze the effects of heat treatment temperature on the crystal precipitation of the microcrystalline glass and its properties. Figure 3 displays the XRD patterns of the microcrystalline glass obtained after holding it at different crystallization temperatures for 3 h each. The base glass was recrystallized at three crystallization temperatures of 900 \({}^{\circ}\)C, 925 \({}^{\circ}\)C, and 950 \({}^{\circ}\)C, and the diffraction peaks of the obtained microcrystalline glass were stronger at 950 \({}^{\circ}\)C than those at 900 \({}^{\circ}\)C, indicating that the higher the crystallization temperature, the greater the recrystallization of the base glass. Within the range of the crystallization temperature from 900 \({}^{\circ}\)C to 950 \({}^{\circ}\)C, the crystalline phases of the microcrystalline glass were all dominated by calcium feldspar (CaAl\({}_{2}\)Si\({}_{2}\)O\({}_{8}\)). The main precipitation phase of the microcrystalline glass within the range of 900-950 \({}^{\circ}\)C was independent of temperature; however, the degree of crystallization of the prepared microcrystalline glass increased with increasing temperature. Figure 4 displays the SEM images of the microcrystalline glass obtained after the heat treatment of the base glass at different crystallization temperatures. The crystallization temperature notably influenced the microstructure of the microcrystalline glass. When the crystallization temperature was 900 \({}^{\circ}\)C, the number of crystalline phases in the microcrystalline glass was small, the degree of crystallization was low, the size of the grains varied, and the number of glassy phases was greater; furthermore, obvious cracks and pores appeared after corrosion by hydrofluoric acid. When the crystallization temperature increased to 925 \({}^{\circ}\)C, the glass phase in the microcrystalline glass disappeared, the number of  
Figure 2: DSC curves of the base glass. crystalline phases sharply increased, the grain size increased, the crystal became spherical, and the density of the microcrystalline structure increased. When the crystallization temperature increased to 950 \({}^{\circ}\)C, some spherical grains transformed into columnar grains and the structure became denser, thereby improving the performance of the microcrystalline glass. With the increase in temperature, the degree of crystallization of the microcrystalline glass rapidly increased, the precipitation of the crystalline phase rapidly increased the viscosity of the microcrystalline glass, and the resistance to crystallization became significant, which inhibited the further sintering process and formed a supercooled liquid that could not be nucleated. At the same time, due to the fastest heat dissipation in the direction perpendicular to the shape wall, the crystal grew in the opposite direction and the anisotropy of crystal growth made part of the grain shape turn into a column.