Dopant diffusion at the interface of TiO₂‐MnO‐doped alumina/alumina layers in sintered laminates

Abstract

Alumina is a ceramic oxide with excellent properties, such as high strength, hardness, corrosion, chemical stability, and wear resistance. [1][2][3] High purity alumina bodies usually require high sintering temperatures-usually over 1400°C-to reach relative densities close to 100%. 4 Additives-such as TiO 2 , MnO, MgO, Cu 2 O, ZrO 2 , Y 2 O 3, and Li 2 O 3 -have been employed to increase alumina sinterability and achieve full density while controlling grain growth. 5,6 Sintering aids can enhance sintering due to the formation of lattice defects, solid solutions, or liquid phases. Generally, there is an optimal amount of additives, which varies with the sintering temperature to achieve higher densification. 7,8 TiO 2 is a crystal growth promoter and sintering aid for alumina. Even small amounts (0.2 mol%) can effectively enhance diffusion, 9 particularly at grain boundaries. For submicrometric titania, a gradual change was observed