Deformation and fracture behavior of Ag-based metal-matrix composites

Title : Deformation and fracture behavior of Ag-based metal-matrix composites

Abstract:

As metal-matrix composites (MMCs), the materials are usually considered, containing soft matrix and hard particulates of various shapes. Accordingly, they can well serve for numerous practical applications. From the viewpoint of understanding detailed mechanisms of deformation, it is also interesting to study MMCs containing not only soft matrix, but also the particulates. We refer to the microstructure and plastic deformation of both types of MMCs – Ag-Cu and Ag-W, both produced by spark plasma sintering of the Cu@Ag and W@Ag core-shell powders and characterized by spherical particulates. Both MMCs exhibit dual structures – nanocrystalline Ag matrices and particulates with the grain size of about 10 ?m. While the deformation of the Ag-Cu MMC is characterized by simultaneous deformation of Ag matrix and Cu particulates, in the Ag-W MMC only Ag matrix deforms plastically. It is shown that plastic deformation in Ag-Cu MMC is distributed between both structural components non-homogeneously with higher deformation of the particulates. Compression of Ag-W MMC provides an unexpected course of the stress-strain curve due to fracture and densification processes.

Biography:

Dr. Pavel Lejček is senior researcher at the Institute of Physics of the Czech Academy of Sciences and professor at the University of Chemistry and Technology in Prague/Czechia. He spent several years at the Max-Planck-Institute for Metals Research in Stuttgart/Germany under the A. von Humboldt and Max-Planck-Society fellowships. His field is grain boundary properties with primary focus on solute segregation. He published more than 200 original research papers in impacted journals and several review papers in journals such as Progress in Materials Science. He is author of the Book Grain Boundary Segregation in Metals (Springer, 2010) translated into Chinese (Tsinghua University Press, 2020). His h=30.