Low-temperature sintering performance study of CCTO–Mn–Co series black Al2O3 ceramics by the one-step method

To confer light-blocking properties upon the Al2O3 encapsulation material, this study employed a one-step method using α-Al2O3 as the main raw material to synthesize CaCu3Ti4O12(CCTO)–MnO2–Co2O3 series black Al2O3 ceramics. The research investigated their coloring effect, sintering behavior, dielectric, and mechanical properties. The results indicate that the CCTO–MnO2–Co2O3 series colorants successfully dyed the Al2O3 ceramics black, while their introduction resulted in the formation of various spinel-type compounds and facilitated the sintering of Al2O3 ceramics. The sintering mechanism and performance effects of black Al2O3 ceramics were thoroughly investigated, revealing that with an increase in the colorant content, all properties of the samples improved. When the colorant content reached 15.0 wt.%, the coloring effect reached its optimum, with a relative density of 96.7%, a dielectric constant of 12.5, a dielectric loss of .0081, a flexural strength of 314.4 MPa, and a Vickers hardness of 1254.5 Hv.