Towards Understanding 16th-Century Metallurgy and Electrochemistry: The Case of Inca Artifacts.

S. Ismat Shah

University of Delaware

Artifacts from the Peruvian Moche culture are examples of highly sophisticated metallurgy. Some of these artifacts have deteriorated through exposure to the local atmosphere and, in many cases, burial in the earth. Much effort has been invested by the Peruvian scientific organizations and heritage conservation institutions to understand the deterioration process and to ultimately protect these objects from further exposure and corrosion. In my talk, I will cover two aspects of the research on gold-coated copper artifacts. The first one will describe a sophisticated electrochemical process that the Moche used to coat Cu substrates. The second part of my talk will describe the results of studies of the diffusion processes that, over hundreds of years, led to the intermixing of the base metal (copper) and the gold/silver coatings and caused the diffusion of copper through the overlayer and eventual oxidation. Surface and interface analyses show how the preferential diffusion of copper through the gold coating is primarily responsible for the deterioration of the artifacts. The diffusion process that occurs at room temperature is seldom studied. In my talk, I will present the results of detailed surface-interface analyses of Inca samples to establish a low-temperature diffusion model that explains the slow, grain-boundary-mediated, short-circuit diffusion process that led to the deterioration of the Moche artifacts.

Konuşmacı hakkında

Prof. S. Ismat Shah holds a joint appointment as Professor of Materials Science and Engineering and Professor of Physics and Astronomy at the University of Delaware, where he also previously directed the Energy and Environmental Policy Program. He earned his Ph.D. in Materials Science from the University of Illinois at Urbana-Champaign in 1986 and spent twelve years as a Senior Research Scientist at DuPont Central Research and Development before joining the University of Delaware in 1999. Prof. Shah’s research focuses on the synthesis, surface and interface characterization, and applications of functional nanomaterials for energy harvesting, environmental remediation, and water treatment. His work spans photocatalysis for green hydrogen generation, band structure modification in wide-bandgap oxide nanoparticles, hybrid and organic photovoltaics, multiferroic thin films, and the materials science of cultural heritage preservation. He is the recipient of two DuPont Accomplishment Awards for his contributions to chemical vapor deposition and nanostructured materials, the Society of Vacuum Coaters Mentor Award, and multiple Fulbright Fellowships. A dedicated international educator, he has also previously served as a TÜBİTAK Visiting Scholar in Ankara.