Abstract: A process for the preparation of composite materials consisting essentially of an oxide phase and a metal phase is effected by grinding a mixture of at least one oxide precursor of the metal phase of the composite with at least one reducing agent, the reducing agent being a precursor of the oxide phase. The grinding being performed in a high energy mechanical grinder for a sufficient length of time so that at least 80 percent of the oxide precursor is reduced to metal or to a metal alloy. The process is particularly valuable for the preparation of oxide/metal composite materials which have improved mechanical, electrical or radiation absorption properties.

Abstract: A substantially amorphous or microcrystalline Al-based alloy, wherein said Al-based alloy is represented by the formula:Al.sub.a M.sub.b M'.sub.c X.sub.d Y.sub.ein which:a+b+c+d+e=10050.ltoreq.a.ltoreq.95 atom %0.ltoreq.b.ltoreq.40 atom %0.ltoreq.c.ltoreq.15 atom %0.ltoreq.d.ltoreq.20 atom %0.ltoreq.e.ltoreq.3 atom %wherein at least two of the subscripts b, c or d are strictly positive, and wherein M is at least one metal selected from the group consisting of Mn, Ni, Cu, Zr, Cr, Ti, V, Fe and Co; M' is Mo, W, or a mixture thereof, X is at least one element selected from the group consisting of Ca, Li, Mg, Ge, Si, and Zn; and Y is the inevitable production impurities, with the proviso that when element M is Co, Mn and/or Ni, the total amount of these elements is at least 12 wt % of the alloy.

Abstract: The present invention relates to substantially amorphous or microcrystalline aluminium-base alloys.Such alloys are of the following chemical composition:Al.sub.a M.sub.b M'.sub.c X.sub.d Y.sub.ein which:50.ltoreq.a.ltoreq.95 atom %M representing one or more metals of the group Mn, Ni, Cu, Zr, Ti, V, Cr, Fe and Co with:0.ltoreq.b.ltoreq.40 atom %M' representing Mo and/or W with:0.ltoreq.c.ltoreq.15 atom %X representing one or more elements of the group Ca, Li, Mg, Ge, Si and Zn, with:0.ltoreq.d.ltoreq.20 atom %Y representing the inevitable production impurities such as O, N, C, H, He, Ga, etc . . . , the proportion of which does not exceed 3 atom %.The alloys according to the invention can be produced by means of known methods in the form of wires, strips, bands, sheets or powders in the amorphous or microcrystallized state, the grain size of which is less than 1000 nm, preferably 100 nm.