Discontinuous Basalt Fiber-Reinforced Hybrid Composites

Abstract

1 Introduction Structural materials are usually classified into three groups: polymers, metals, and ceramics. Their combinations are composites, which show unique properties. If the matrix has a multiphase structure or the reinforcement consists of more than one material, the resulting composite is called hybrid composite. Hybrid composites are at the peak of the pyramid in the hierarchy of structural materials due to their special properties. The large-scale and fast growing applications of polymer composites in all industrial fields are characteristic of the modern market-oriented technology and economy. The reason for this development is primarily the favorable pricelweight ratio of composites. The most rapidly developing branch is the automotive industry where traditional metals are continually being replaced by corrosion-resistant polymer composites. This yields a significant reduction in the weight of the automotive parts. Hence, fuel is saved and the impact on environment is reduced. Nowadays, the reinforcing material in polymer composites is usually glass fiber (GF, volume fraction of ca. 85%), which has good strength, ensures a relatively good adhesion to the polymer matrix, and has a low price. Carbon fiber (CF) is used in more demanding applications with special requirements (e.g., aerospace technology, aircraft industry, military applications, sports and leisure). The production expenses of CF are much higher than those of GF and the sufficient adhesion between matrix and CF is also more difficult to obtain. Recently, natural fibers are spreading: flax and