A process for resurfacing a monocrystalline or directionally solidified metallic piece having a length, a width and a thickness (Ws), wherein said thickness, when measured across a side wall of said metallic piece, varies between 0.2 and 2 mm along said width, said process comprising:
- applying coaxially a laser beam and a flux of metallic powder to said side wall of the metallic piece and along said width, wherein the metallic powder is of a same nature as that of the metallic piece, to produce at least one layer of metal, monocrystalline or directionally solidified, on said side wall and along said width of the metallic piece,
- emitting the laser beam at a power “P” and moving said laser beam along the metallic piece at a speed “v”, and
- adapting a P/v ratio as a function of said thickness (Ws) of said metallic piece as said laser beam moves along said side wall of said metallic piece at said speed, wherein said adapting of said P/v ratio is performed as follows:
- for a thickness Ws between 0.2 and 0.6 mm, maintaining said P/v ratio between two portions of increasing P/v vs Ws curves, one taking values ranging from 0.12 to 0.58 Wmm-1, the other taking values ranging from 0.25 to 0.84 Wmm-1;
- for a thickness Ws between 0.6 and 0.8 mm, maintaining said P/v ratio between two portions of increasing P/v vs Ws curves, one taking values ranging from 0.58 to 0.83 Wmm-1, the other taking values ranging from 0.84 to 1.42 Wmm-1;
- for a thickness Ws between 0.8 and 1 mm, maintaining said P/v ratio between two portions of increasing P/v vs Ws curves, one taking values ranging from 0.83 to 1.08 Wmm-1, the other taking values ranging from 1.42 to 2.05 Wmm-1;
- for a thickness Ws between 1 and 1.2 mm, maintaining said P/v ratio between two portions of increasing P/v vs Ws curves, one taking values ranging from 1.08 to 1.27 Wmm-1, the other taking values ranging from 2.05 to 2.34 Wmm-1;
- for a thickness Ws between 1.2 and 1.4 mm, maintaining said P/v ratio between two portions of increasing P/v vs Ws curves, one taking values ranging from 1.27 to 1.33 Wmm-1, the other taking values ranging from 2.34 to 2.48 Wmm-1;
- for a thickness Ws between 1.4 and 2 mm, maintaining said P/v ratio between two portions of increasing P/v vs Ws curves, a constant one equal to 1.33 Wmm-1, the other taking values ranging from 2.48 to 2.75 Wmm-1,
- wherein the laser beam and the metallic powder are applied by a projection nozzle, and wherein said adapting of said P/v ratio is performed automatically via a program that includes predetermined information about an evolution of said thickness (Ws) along said side wall and that automatically controls said P/v ratio as a function of a position of said nozzle along said side wall of the metallic piece.