This invention relates to a metal alloy, comprised of two elements, a solute and a solvent, the solute having a maximum equilibrium solid solubility (at one atmosphere pressure) of less than 1 wt. -% in the solvent, the solvent and the solute dissolved therein forming a matrix phase, the matrix phase having a subgrain structure defined by subgrain boundaries and particles at intersections of the boundaries, the subgrains having an average size of less than 5 microns in diameter, and, within the subgrains a dispersion of particles which are finer than the particles at the subgrain boundaries, both types of particles being harder than the matrix phase.