Abstract
The residual and thermal strains strongly influence the dilatation characteristics of fibre composites. The dilatation characteristics of two fibre composites, AX41-12 vol.% Saffil fibres and AX41-12 vol.% C fibres, were investigated in the temperature range of 20-380 °C. Three fibre orientations were studied; angles between the axis sample and the preferential plane of the fibre distribution were 0°, 45° and 90°. The thermal strains showed strong anisotropy. The smallest influence of the residual and thermal strain on the dilatation characteristics was found in C-45 composites. The thermal strain in CC composites (reinforced by C-fibres) is three times higher than in CS composites (reinforced by Saffil fibres). It is assumed that this is a consequence of the chemical reaction between the matrix and reinforcement in the AX41-C fibre interface. The reaction products strongly influence the matrix properties at the interface, and therefore, micro-plastic deformation in this part of the matrix. This micro-plastic deformation then influences macroscopic physical properties such as thermal expansion. The products of the chemical reactions at the interface of the CC composite also influence the character of the temperature dependence of the residual strain.

Key words
metal matrix composites, fibres, thermal expansion

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