The Influence of the Microstructure of Ceramic-Elastomer Composites on Their Energy Absorption Capability

Paulina Kozera; Anna Boczkowska; Rafał Kozera; Marcin Małek; Włodzimierz Idczak

doi:10.3390/ma14216618

The Influence of the Microstructure of Ceramic-Elastomer Composites on Their Energy Absorption Capability

Materials (Basel). 2021 Nov 3;14(21):6618. doi: 10.3390/ma14216618.

Authors

Paulina Kozera¹, Anna Boczkowska¹, Rafał Kozera¹, Marcin Małek², Włodzimierz Idczak²

Affiliations

¹ Faculty of Materials Science and Engineering, Warsaw University of Technology, ul. Woloska 141, 02-507 Warsaw, Poland.
² Faculty of Civil Engineering and Geodesy, Military University of Technology, ul. Gen. Sylwestra Kaliskiego 2, 00-908 Warsaw, Poland.

Abstract

The paper presents the experimental results of static and dynamic compressive tests conducted on ceramic-elastomer composites. The alumina ceramic preforms were fabricated by the four-step method: ceramic mixture preparation, consolidation under pressure, presintering, and sintering under pressure, respectively. To obtain ceramic preforms with a similar volume fraction of open pores, but with different pore sizes, alumina powder with different particle size and a ceramic binder were used, as well as pore-forming agents that were evenly distributed throughout the volume of the molding mass. The composites were obtained using vacuum pressure infiltration of porous alumina ceramic by urea-urethane elastomer in liquid form. As a result, the obtained composites were characterized by two phases that interpenetrated three-dimensionally and topologically throughout the microstructure. The microstructure of the ceramic preforms was revealed by X-ray tomography, which indicated that the alumina preforms had similar porosity of approximately 40% vol. but different pore diameter in the range of 6 to 34 µm. After composite fabrication, image analysis was carried out. Due to the microstructure of the ceramic preforms, the composites differed in the specific surface fraction of the interphase boundaries (S_v). The highest value of the S_v parameter was achieved for composite fabricated by infiltration method of using ceramic preform with the smallest pore size. Static and dynamic tests were carried out using different strain rate: 1.4·10^-3, 7·10^-2, 1.4·10^-1, and 3·10³ s^-1. Compressive strength, stress at plateau zone, and absorbed energy were determined. It was found that the ceramic-elastomer composites' ability to absorb energy depended on the specific surface fraction of the interphase boundaries and achieved a value between 15.3 MJ/m³ in static test and 51.1 MJ/m³ for dynamic strain rate.

Keywords: ceramic preform; energy absorption capability; interpenetrating phase composites; specific surface fraction of the interphase boundaries; static and dynamic tests; strain rate; stress at plateau zone.