Mechanical properties of Mg-Li-Al alloys reinforced by short Saffil fibres

Composites with a matrix from Mg8Li-xAl (x = 3,5)alloys reinforced by 10 vo l. % of Saffil short fibres were deformed in compression at temperatures fr om room temperature up to 200 degreesC. Flow stresses increase with increas ing Al content and decrease with increasing temperature. Maximum fracture e longation was found at 100 degreesC. Strain hardening is characteristic for deformation at room temperature as well as at 100 degreesC. Recovery proce sses occur at higher temperatures. Contributions to the strength of composi tes are evaluated. The load transfer between the high aspect ratio reinforc ement and the matrix by means of shear stresses on the fibre-matrix interph ase seems to be the most important contribution to the strengthening. A con tribution due to an increase of dislocation density in the composite is als o significant.