Study On The Laser Rapid Prototye Revolved Body Accumulate Based On Inside-laser Coaxial Powder Feeding

LCRM (Laser Cladding Rapid Manufacturing) is a laser cladding technology and rapid prototyping technology, which combines the advantages of laser cladding and rapid prototyping technology, has become an important researching direction in the advanced manufacturing technology. At present, use the solid laser as the focus laser in the process of coupling of the powder and laser, the way of powder feeding in this technology is the outside-laser coaxial powder feeding with many lateral powder tubes. This method has some defects, laser beam and powder couple badly, the accumulated parts have rough surfaces , the heat efficiency is low , forming high-level high-precision parts are more difficult, the utilization of metal powder is very low. In response to these deficiencies,we incomes a new optical coaxial powder forming process, the emphasis of this pape are the research on the surface's planeness of the clad and the accumulation of complex components.Based on the coaxial inside-laser powder feeding nozzle developed by the group,we improve the powder nozzle's function. The new nozzle can adjust the directions on both horizontal direction and vertical direction. We have better powder centering, coupling of laser beam and metal powder in the inside-laser coaxial powder feeding, powder efficiency and utilization of laser energy. Because of less flying powder, less pollution. There is less melt particle in the surface, so we can receive better coatings.Use the new nozzle, we finished several monolayer line scanning cladding experiment,Through the analysis on the coatings'feature,microscopic structure,hardness and the size of shaped metallic parts, we summarized the factors which contain the power of the laser,speed of scanning and powder's carry,diameter of the facula make great difference to the coatings'quality. For receiving better coatings, We changed the clearance between focal point and the surface. The result of the experiment shows that if we want to receive flat clad,the beam would better be bigger than the powder's diameter,also, need a average power distribution.Based on the parameters of the monolayer line scanning cladding experiment, we finished overlapping scanning cladding experiment and high-level complex components successfully. The result of the analysis shows the 3D part which has variable cross-section has good quality: its internal structure is very compact, hardness is uniform and harder than the basal body, surface roughness is good. All of the results indicated the advantages of the improved coaxial inside-laser powder feeding nozzle.