INCLUSION REMOVAL IN CERAMIC GREEN BODY BY ACID TREATMENT - ZIRCONIA CERAMIC CAPILLARY FOR OPTICAL-FIBER CONNECTOR AS AN EXAMPLE

The removal of metallic and/or oxide inclusions in green bodies for PSZ ceramic capillary contaminated in the forming process by nitric acid treatment was investigated. The main inclusions contaminated in the forming process was Fe, and it changed to Fe2O3 and/or Fe3O4 by oxidation in the calcining process. For infiltration of the acid and handling, the specimen with relative density below 70% having open pores and bending strength above 70 MPa was desired. For the ease of removing of inclusions, it was desired that inclusions remained as metallic state. These conditions were achieved by calcining specimens in the temperature range from 600-degrees to 800-degrees-C for 1 h. PSZ ceramic capillaries for optical-fiber connector with Weibull modulus of 10.24 and bending strength of 925 MPa were fabricated by sintering at 1450-degrees-C in air for 12 h and HIP(ping) at 1400-degrees-C and 1000 atm in an Ar atmosphere for 2 h after the acid treatment.