This paper examined the room temperature mechanical properties of a mixed conducting perovskite Sm1-xSrxCo0.2Fe0.8O3 (x = 0.2-0.8). Density, crystal phase, and microstructure were characterized. It was found that the grain size increased abruptly with increasing Sr content. Mechanical properties of elastic modulus, microhardness, indentation fracture toughness, and biaxial flexure strength were measured. Young's modulus of 180~193 GPa and shear modulus of 70~75 GPa were determined. The biaxial flexure strength was found to decrease with increasing Sr content from ~ 70 MPa to ~ 20 MPa. The drop of strength was due to the occurrence of extensive cracking. Indentation toughness showed a similar trend as the strength that it decreased with increasing Sr content from ~ 1.1 MPa.m1/2 to ~ 0.7 MPa.m1/2. In addition, fractography was used to characterize the fracture behavior in these materials.
Revised: July 21, 2000 |
Published: July 1, 2000
Citation
Chou Y.S., J.W. Stevenson, T.R. Armstrong, J.S. Hardy, K. Hasinska, and L.R. Pederson. 2000.Microstructure and mechanical properties of Sm1-xSrxCo0.2Fe0.8O3.Journal of Materials Research 15, no. 7:1505-1513.PNNL-SA-32329.