Surface metallization of alumina ceramics: Effects of sintering time and substrate etching

Surface metallization of alumina ceramics was prepared by a screen-printing process. The effects of sintering time and substrate etching on the morphology, surface resistivity and mechanical properties of Ag films were studied by scanning electron microscopy-back-scattered electron imaging (SEM-BSI), four-point probe method and tensile test, respectively. The lowest surface resistivity and the highest adhesion strength of Ag films were achieved in the samples sintered at 600 °C for 20 min. Moreover, the Ag films still remained the lowest surface resistivity and the highest adhesion strength after the alumina substrate was etched with 30 wt% sodium hydroxide aqueous solution. Based on the obtained experimental results, a model was proposed for the formation of glass network within the interpenetrating Ag at the interface of Ag film/alumina substrate during the sintering process.