Process for surface modification of the surface of a substrate by forming an alloy, application of the process to the manufacture of, in particular, ferrous alloys and catalysts, alloys obtained by the process

摘要

Process for surface modification of the surface of a substrate by forming an alloy with at least one chemical element, called added element, by means of a concentrated energy beam such as a laser beam. The process is characterised in that the surface of the substrate is covered with a film containing at least one salt containing at least the element which is to form the alloy, the film having reductive capacities in the presence of the energy beam, in that the surface thus covered is irradiated with the beam, the parameters linked with this irradiation being adapted so that a substantial thickness of substrate lying immediately below is melted and so that the elements originating from the decomposition of the salt and from the melted part of the substrate are mixed and in that the alloy thus obtained is resolidified. The invention applies to the manufacture of metal components which have improved surface characteristics, such as resistance to wear and/or to corrosion, friction modification and catalytic activity.