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

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

doi:10.3390/ma14216618

Paulina Kozera, Marcin Małek + Show 3 more

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https://doi.org/10.3390/ma14216618

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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 (Sv). The highest value of the Sv 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.

Highlights

As a result of the constantly growing demand for lightweight materials with improved physicochemical, mechanical, and thermal properties, the development of new composites can be observed
The interpenetrating phase composites (IPCs) foam samples in general and the silane coated ones in particular showed significant improvement in elastic modulus, yield stress, energy absorption, and plateau stress values when compared to the corresponding syntactic foam of the same volume fraction of micro balloons
This paper presents the influence of ceramic-elastomer composites microstructure on their energy absorption capability

Summary

Introduction

As a result of the constantly growing demand for lightweight materials with improved physicochemical, mechanical, and thermal properties, the development of new composites can be observed. Composite materials called interpenetrating phase composites (IPCs) or co-continuous composites may have properties that are unattainable by other materials. Many different strategies have been proposed in the literature to process co-continuous composites including powder metallurgy [1], squeeze casting [2,3], and pressure or nonpressure liquid infiltration using open-cell preforms [4,5,6] as well as reactive infiltration [7,8]. The possibility of using different fabrication methods determines the wide range of materials that make up interconnected phases in IPCs and various mechanical and macrostructural characteristics.

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