Flexural strength of creep feed ground ceramics: general pattern, ductile-brittle transition and mlp modeling

Abstract

Three ceramic materials including two aluminas and one silicon nitride were ground under various creep feed conditions. Flexural strengths of the ground specimens were measured by four-point bending. The experimental data indicates a general flexural strength pattern consisted of three regimes as a function of mean unit load and grit depth of cut (or mean chip cross-sectional area). Defining ductile-brittle transition as the point where strength starts to degrade, it is found that the transition occurs at higher mean unit load, grit depth of cut, or mean chip cross-sectional area for the lower strength material. The percentage of fractured area is found not to be a good indicator of strength for alumina materials. The multi-layer perceptron (MLP) neural network is proposed to establish the strength model. The general form of the MLP-based strength models as well as the fitted parameters are given. The implications of the study are discussed with respect to past studies.