Surface Treatment of a Metal Part

Author:  Tony Prezeau et al.
Source:  US Patent 9,382,609
Doc ID:  2016049
Year of Publication:  2016
Abstract:  
A process for the surface treatment of a metal part comprises: exposing a surface of the metal part to a stream of substantially spherical particles, so that any portion of said surface receives said particles along several primary incidences, the primary incidences of the particles on a portion of the surface being essentially distributed in a cone or a conical film which has an outer half apex angle between 10 degrees and 45 degrees, until a surface layer of nanostructures having an average thickness of several tens of microns is obtained, the particles having a diameter of less than 2 mm and greater than 0.1 mm and being projected at a speed between 40 m/s and 100 m/s. A thermochemical treatment is then applied, in particular a low-temperature treatment of the nitriding type or a high-temperature treatment of the low-pressure carbonitriding type.