Abstract

Because aluminum oxide ceramics have excellent properties, such as high strength, high hardness, good resistance to chemical corrosion, and chemical stability, aluminum oxide ceramics have been used widely in the fields of machinery, chemical industry, environment protection, electronic engineering, metallurgy, and composite materials. During the preparation of aluminum oxide ceramics, an appropriate composite system is important because it is effective for decreasing the sintering temperature and improving the properties of aluminum oxide ceramics. In the present work, powders of alumina, calcium oxide, zirconium dioxide, titanium dioxide, and silica sand were used as the main raw materials to design different composite systems, and then aluminum oxide ceramics were prepared via a semi-dry pressing method. Effects of different composite systems on the sintering property of aluminum oxide ceramics were studied. The results indicate that the CaO–SiO₂–TiO₂ system effectively improves the composition and structure of the aluminum oxide ceramic and significantly enhances the flexural strength of the aluminum oxide ceramic; the optimal formulation of adding CaO, SiO₂, and TiO₂ in the CaO–SiO₂–TiO₂ composite system is 4%, 2%, and 3%, respectively, and this formulation leads to a maximum flexural strength of 146.48 MPa; adding an appropriate amount of TiO₂ can promote the formation of a corundum phase and refined grains and therefore enhances the fracture toughness of aluminum oxide ceramics.

摘要

由于氧化铝陶瓷具有高强度、高硬度、良好的耐化学腐蚀性和化学稳定性等优良性能，氧化铝陶瓷在机械、化工、环保、电子工程、冶金、和复合材料。在氧化铝陶瓷的制备过程中，合适的复合体系很重要，因为它可以有效地降低烧结温度，改善氧化铝陶瓷的性能。本工作以氧化铝、氧化钙、二氧化锆、二氧化钛和硅砂为主要原料，设计不同的复合体系，然后采用半干压法制备氧化铝陶瓷。研究了不同复合体系对氧化铝陶瓷烧结性能的影响。结果表明，CaO-SiO_2- TiO ₂体系有效改善了氧化铝陶瓷的成分和结构，显着提高了氧化铝陶瓷的抗弯强度；CaO-SiO ₂ -TiO ₂复合体系中CaO、SiO ₂和TiO ₂的最佳添加量分别为4%、2%和3%，该配方的最大抗弯强度为146.48 MPa；添加适量的TiO ₂可以促进刚玉相的形成和细化晶粒，从而提高氧化铝陶瓷的断裂韧性。