Variable width scanning of variable wall thickness twisted blade with laser inside-beam powder feeding

The conventional laser cladding forming process generally uses equal line-width scanning, which can difficultly realize a continuously variable width deposition. A blade model with variable wall thickness was designed. The inside-beam powder feeding nozzle was applied for the variable laser spot deposition. A deposition height control system was used to measure the actual height of each segment. PI-controllers with scanning speed as the control input were designed to guarantee equal deposition heights in different widths. A segmented deposition height control strategy was developed to realize continuous variable width deposition of the variable wall thickness twisted blade. The structure was formed based on methods of continuously varying focus distance and closed-loop control. The test results indicate that the wall thickness varied uniformly from 2.52 mm to 6.18 mm, and the largest error was -0.58 mm. The heights of the segments were in accordance with the largest error of -0.22 mm. The micro-structure in different wall thickness positions were compact and uniform.