SURFACE COATING PROCESS USING HIGH-POWER LASER BEAM TO INCREASE RELIABILITY AND PERFORMANCE OF MATERIALS

• Main Authors: BECHERESCU BARBU DAN NICOLAE, UDREA RADU MIHAIL, UDREA VIRGIL MIRCEA, MIHĂILESCU ION, SELAGEA MIHAI NICOLAE, RISTOSCU CARMEN-GEORGETA
• Format: Patent
• Language: English; Romanian
• Published: 30.01.2023
• Subjects: CHEMICAL SURFACE TREATMENT; CHEMISTRY; CLADDING OR PLATING BY SOLDERING OR WELDING; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; DIFFUSION TREATMENT OF METALLIC MATERIAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR; METALLURGY; PERFORMING OPERATIONS; SOLDERING OR UNSOLDERING; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; TRANSPORTING; WELDING; WORKING BY LASER BEAM

The invention relates to a surface coating process using a high-power laser beam to increase the reliability and performance of the materials. According to the invention, the process is implemented by using a Yb:YAG laser source that emits a laser beam which is transported through optical fiber to a robot with six axes of mobility and processing optics which has a three-channel powder delivery nozzle, the laser beam being focused on the metal sample to be processed within a spot of a diameter of approximately 1 mm, the process of guiding the powder being assisted by a mixture of gases, Ar and He, the powder being transported through hoses to the robot arm, by means of some plates, the laser beam being so directed that the laser beam and the metal particles meet on the substrate at the same point, the distance from the substrate to the powder-injection nozzle being adjustable within the range of 7...16 mm, the process being characterized in that the powder flow rate has to remain constant to maintain a dilution level below 20%, while the laser power and scanning speed can be adjusted to obtain the desired characteristics, and the side angle of the deposited layer should not exceed 120°, in order to provide a uniform structure in the layers overlapping. Invenţia se referă la un procedeu de acoperire a suprafeţelor folosind fascicul laser de mare putere în vederea creşterii fiabilităţii şi a performanţelor materialelor. Procedeul conform invenţiei este implementat folosind o sursă laser Yb:YAG care emite un fascicul laser ce este transportat prin fibră optică la un robot cu şase axe de mişcare şi optică de procesare care dispune de o duză de livrare a pulberii cu trei canale, fasciculul laser este focalizat pe proba metalică de prelucrat într-un spot cu diametru de aproximativ 1 mm, procesul de ghidare a pulberii fiind asistat de un amestec de gaze, Ar şi He, pulberea fiind transportată prin furtunuri la braţul robotului, prin intermediul unor platane, fasciculul laser este direcţionat astfel încât fasciculul laser şi particulele metalice să se întâlnească pe substrat în acelaşi punct, distanţa substrat - duza de injectare a pulberii fiind ajustabilă în intervalul 7...16 mm, procedeul fiind caracterizat prin aceea că debitul de pulbere trebuie să rămână constant pentru a menţine un nivel de diluare de sub 20%, în timp ce puterea laserului şi viteza de scanare pot fi ajustate pentru a obţine caracteristicile dorite, şi unghiul lateral al stratului depus nu trebuie să depăşească 120°, pentru a asigura o structură uniformă în suprapunerea straturilor.