Optimization Design And Manufacture Of The Nozzle For Laser Cladding By Powder Feeding

Laser cladding is a new material processing and surface modification technology, the technology can be made of high-performance low-cost steel instead of a large number of advanced alloys on the material surface, in order to save precious, rare and strategic metals, improve overall performance of materials, to achieve the quick green fix of the vital parts. After years of research and development, at present, the technology has been with a high technical level and the application of considerable scale.Powder feeding nozzle is one of the key components of laser cladding system, it has significant impact on the quality of laser cladding, coaxial powder feeding nozzle has become a hot research due to the characteristics of its powder feed stream isotropic and suitable for 3D cladding, so there are important theoretical significance and practical value for depth research on three-dimensional coaxial powder feeding nozzle.The subject's main work is carried out around the design and manufacture of carrier gas type coaxial powder feeding laser cladding nozzle. Firstly, in accordance with the functional requirements of laser cladding powder feeding nozzle, referencing to the relevant theoretical knowledge of mechanical design, innovatively designed its structure, and drawn parametric geometry model of the laser cladding powder feeding nozzle with a free assembly structure. Designed an orthogonal experiment, and did CFD simulation experiment on the airflow carrying powder of the designed new nozzle with multi-physics coupling analysis software COMSOL Multiphysics. Statistic and analyze results of each experiment, mainly research changing regularity of the powder feeding nozzle's powder stream parameters(focal length and focus radius) in laser cladding process under the circumstance of different combinations of level of three factors(axial cone angle of powder feeding channel, radius of laser outlet and width of powder outlet), reached the following two important conclusions:(1) Optimal combination of the nozzle's geometry size are that and the axial cone angle of powder feeding channel is 25°, radius of laser outlet is 2.2mm and width of powder outlet is 1.3mm.(2) The primary and secondary sequence of factors which affect powder stream's convergence properties are the width of powder outlet, the axial cone angle of powder feeding channel and the radius of laser outlet. Finally, manufactured the free assemble laser cladding powder feeding nozzle which has been optimized on structure and size with the method of Selective Laser Melting Rapid Prototyping, and carried out relevant performance test after its post-processing.