Investigation on the transformations in grinding affected layer of ZTC

A complex transformation may be induced in the grinding affected layer of zirconia-toughened ceramics (ZTC). To explore the characteristics of transformation such as direction, magnitude and depth-dependent distribution under the ground surface of ZTC, Mg-PSZ, Y-PSZ and Si₃N₄+ZrO₂ etc., four kinds of ceramics have been ground using an orthogonal design test. By means of grinding forces, XRD analysis and SEM observation the main causes and mechanism of transformation are discussed for the conventional grinding processes. It is shown that: the ZTC phase would change either from t to m or from m to t, depending on the composition and heat-treatment of the ceramic materials: Transformation due to grinding is noticeable and influenced by the grinding parameters (V_s, a_p, V_w) strongly; The thickness of transformation layer is larger than the depth of wheel cut.