METHOD FOR MODIFYING THE LOCAL GRAIN STRUCTURE AT THE SURFACE OF A MATERIAL BY MEANS OF HIGH-ENERGY RADIATION

摘要

The invention concerns a method and device for modifying the local grain structure at the surface of a material in the solid or liquid phase. The surface in the zone being worked is heated to a given temperature by high-energy radiation. The temperature at this point is measured. The measured values thus obtained are modified to bring them closer to the required target values by using a control unit to modify the rate of emission of energy from the high-energy radiation source. Following the heating phase, the rate of cooling of the material is determined by measuring the temperature of the surface of the material, in the zone being worked, at at least two different points in time as the material cools. The temperature of the material is controlled as it cools further by irradiating it at least once more, in the zone being worked, in such a way that a previously specified rate of cooling of the material in the zone being worked results.