Laser cladding is one of the most promising technological processes for the restoration of faulty parts and for changing the properties of the surface of the parts, such as corrosion resistance, hardness and so on. The productivity and quality of laser cladding is determined not only by the technological parameters like laser beam power, focal spot area, laser beam travel speed etc., but also by the parameters of the gas-powder stream that delivers particles into the processing zone. For laser cladding of surfaces with relatively big areas powerful diode lasers with rectangular laser beam profile are used. They require the application of specific flat nozzles that are capable of generating the powder stream with rectangular cross-section.

Development of an efficient system for the delivery of gas-powder mixture into the processing zone is crucial for the increase in the performance of laser-based additive manufacturing. Different powder types could be introduced into the processing zone simultaneously and the required powder distribution and concentration could be reached.

Results of numerical simulation of gas-powder stream behavior were used to design the original configurations of multi-channel nozzles that were manufactured and tested experimentally. Optimal technological parameters for the use of multi-channel nozzles in laser cladding were established.

The observation of multichannel gas-powder stream formation at different working conditions has demonstrated good correspondence between the results of trial cladding and those predicted numerically. The cladded layers had a high level of uniformity since it was possible to control the powder distribution and concentration within the laser processing zone.

An original design of the nozzle for laser cladding that increases the efficiency of technological process was developed during the research.