Abstract: The invention relates to a composite material combining a magnesium alloy containing zirconium with a carbon reinforcement, as well as to its production process.According to the invention, such a composite material is prepared by the infiltration of a reinforcement formed from graphite or carbon fibres by a liquid magnesium alloy containing 0.3 to 1% by weight zirconium at a temperature of 650.degree. to 850.degree. C.Under these conditions, on said fibres is formed a zirconium carbide layer containing magnesium in solid solution and e.g. complying with the formula ZrC.sub.x Mg.sub.y with 0.3<x<1 and 0.02<y<0.12, which leads to the wetting of the fibres by the melted magnesium and to a good adhesion between the fibres and the matrix, without any deterioration to the mechanical characteristics of the fibres.

Abstract: The invention relates to a composite material comprising a matrix mainly constituted by an intermetallic compound of the AlNi type containing in solid solution 1.5 to 30 atom % silicon and a reinforcement formed from silicon carbide (SiC) particles dispersed in said matrix.In said material, the presence of silicon leads to a thermodynamic equilibrium system no longer evolving by SiC reinforcement/matrix chemical reaction when raised to a high temperature.This material can be prepared by conventional processes by adding the silicon to the starting material or by carrying out a limited reaction during the preparation between an AlNi matrix and the silicon carbide particles.

Abstract: According to the present invention, a composite material including a magnesium alloy containing zirconium with a graphite or carbon fiber reinforcement is provided. The material is prepared by infiltration of the reinforcement by a liquid magnesium alloy containing 0.3 to 1% by weight zirconium at a temperature of 650.degree. to 850.degree. C. Under these conditions, a zirconium carbide layer containing magnesium in solid solution is formed on the fibers. This results in wetting of the fibers by melted magnesium and good adhesion between the fibers and the matrix, without any deterioration in the mechanical characteristics of the fibers.

Abstract: A grid (10) for the plate of an electrical storage cell, eg. a lead-acid accumulator, comprises two orthogonal sets of conductive bars (7, 8) together with a current collector tab (9). The grid is made from a loosely-woven cloth comprising both bundles of conductive threads outlining the bars and the current collector of the plate, and bundles of non-conductive threads (6) serving to position said conductive threads relative to one another and to maintain them in position. Said bundles of conductive threads are embedded in a metal matrix comprising at least one of the metals in the group constituted by: lead, copper, cadmium, and nickel.