Patent ID: 7910854

Claim:
A method of locally colouring a part made of ceramic material of metallic oxide, the method including the following steps: (a) providing a part made of metallic oxide, and a support, (b) arranging the part on the support, (c) providing a laser, wherein the laser and the support are movable relative to each other in an XY plane, (d) performing a plasma treatment on the part using a gas containing one element selected from among nitrogen and carbon, thereby converting, in a surface layer of the part, metallic oxide into a substantially stoichiometric ceramic material chosen from among metal nitrides and metal carbides, (e) illuminating the part locally with a laser beam from the laser, thereby providing sufficient energy to cause a local change in colour in said surface layer of the part of step (d) by altering the stoichiometry of said substantially stoichiometric ceramic material chosen from among metal nitrides and metal carbides, wherein the local change in colour in the surface layer of the part is obtained by alteration of said stoichiometry of the substantially stoichiometric ceramic material chosen from among metal nitrides and metal carbides, and (f) scanning the surface layer of the part using the laser beam, thereby forming a determined pattern on said surface layer of the part.