Ti and SmAlO3 co-affected Al2O3 ceramics: Microstructure, electrical and mechanical properties

This work aims to investigate the co-reinforcing effects of Ti and Sm2O3 on Al2O3 ceramics for optimizing electrical and mechanical properties and study the role of elongated SmAlO3 in toughening. For this purpose, 20 vol% Ti dispersed Al(2)O(3 )composites were chosen as matrix and rare earth element oxide of Sm2O3 (0-2.0 at%) was used as the reinforcement to fabricate Sm2O3 added Al2O3/Ti composites and toughening mechanism caused by elongated SmAlO3 was discussed. Results indicated that elongated SmAlO3 with rod-like shape due to the reaction between Al2O3 and Sm2O3 was identified by XRD and EDX analysis. When Sm(2)O(3 )content was below 2.0 at%, all composites exhibited excellent electrical conductivity of similar to 10(-2) Omega cm. Owing to strengthening and toughening effects caused by SmAlO3, 1.5 at% Sm2O3 added composites showed the highest flexural strength and fracture toughness with the values of 567 MPa and 5.53 MPa cm(1/2). Elongated SmAlO3 phase contributed greatly to toughening by crack bridging and particle pull-out mechanisms which were determined by aspect ratio of SmAlO3 particles varying with Sm(2)O(3 )content. (C) 2020 Elsevier B.V. All rights reserved.