PSI - Issue 10

A. Hein et al. / Procedia Structural Integrity 10 (2018) 219–226 A. Hein and V. Kilikoglou / Structural Integrity Procedia 00 (2018) 000 – 000

226

8

4. Conclusions

The hitherto collected results demonstrate that numerical modeling of typical microstructures, observed in functional archaeological ceramics, can provide essential information about specific manufacturing technologies of the past and their effect on material performance. The modeling complements material testing of archaeological ceramics or of experimental replicates in the assessment of technological choices and strategies to improve the per formance of functional ceramics. The present case study was focused on pore structures intentionally generated by mixing the clay paste with organic materials, which combusted during firing. Experimental results, which had indicated the advantage of fibrous pore structures particularly in terms of suppressing heat transfer, were confirmed and further investigated in terms of mechanical performance. The approach can be applied as well to microstructures on a smaller scale, simulating for example the micromorphology of the vitrified clay minerals, in order to study the effect of firing temperature. This will require, however, the development of digital models with different geometries, simulating the development of the glassy phase. Multi-scale models can be combined by considering effective material properties of small-scale models as input parameters for large-scale models. Furthermore, instead of pores or as supplemental phases non-plastic inclusions of different shapes can be added to the model, in order to simulate the effect of tempering. Digital modeling after all allows for systematic examination of specific material parameters providing reproducible results, which cannot be achieved solely by material testing. Investigations of ancient or forgotten technologies, on the other hand, potentially provide inspiration for the development of new materials exploiting suitable natural sources and rediscovering economical as well as sustainable methods for material processing. Evely, D., Hein, A., Nodarou, E., 2012. Crucibles from Palaikastro, East Crete: Insights into metallurgical technology in the Aegean late bronze age. Journal of Archaeological Science 39(6), 1821-1836. Freestone, I.C., 1989. Refractory Materials and Their Procurement, in Old World Archaeometallurgy (eds. A. Hauptmann, E. Pernicka,and G.A. Wagner) 155 – 162, Der Anschnitt Beiheft 7, Deutsches Bergbaumuseum, Bochum. Hein, A., Kilikoglou, V., 2007, Modeling of thermal behavior of ancient metallurgical ceramics. Journal of the American Ceramic Society 90(3), 878-884. Hein, A., Georgopoulou, V., Nodarou, E., Kilikoglou, V., 2008a. Koan amphorae from Halasarna – Investigations in a Hellenistic amphorae production centre. Journal of Archaeological Science 35(4), 1049-1061. Hein, A., Müller, N.S., Day, P.M., Kilikoglou, V., 2008b. Thermal conductivity of archaeological ceramics: The effect of incl usions, porosity and firing temperature. Thermochimica Acta 480, 35-42. Hein, A., Karatasios, I., Müller, N.S., Kilikoglou, V., 2013. Heat transfer properties of pyrotechnical ceramics used in ancient metallurgy. Thermochimica Acta 573, 87-94. Litovsky, E.Y., Shapiro, M., 1992. Gas pressure and temperature dependences of thermal conductivity of porous ceramic materials: Part 1, Refractories and ceramics with porosity below 30%. Journal of the American Ceramic Society 75(12), 3425-3439. Machado, A.S., Oliveira, D.F., Gama Filho, H.S., Latini, R., Bellido, A.V.B., Assis, J.T., Anjos, M.J., Lopes, R.T., 2017. Archeological ceramic artifacts characterization through computed microtomography and X-ray fluorescence. X-Ray Spectrometry 46, 427-434. Morrell, R., 1998. Biaxial Flexural Strength Testing of Ceramic Materials, Measurement Good Practice Guide No. 12, National Physical Laboratory, Teddington, Middlesex. Müller. N.S., Vekinis, G., Day, P.M., Kilikoglou , V., 2015. The influence of microstructure and texture on the mechanical properties of rock tempered archaeological ceramics. Journal of the European Ceramic Society 35(2), 831-843. Pabst, W., Gregorova, E., 2014. Young’s modulus of isotropic porous materials with spheroidal pores . Journal of the European Ceramic Society 34, 3195-3207. Roberts, A.P., Garboczi, E.J., 2000. Elastic properties of model porous ceramics. Journal of the American Ceramic Society 83(12), 3041-3048. Sillar, B., Tite, M.S., 2000. The challenge of ‘technological choices’ for materials science approaches in archaeology . Archaeometry 42(1), 2-20. Wachtman, J.B., Cannon, W.R., Matthewson, M.J., 2009. Mechanical Properties of Ceramics, 2 nd Edition, John Wiley & Sons, Hoboken. References