The analysis of a two-dimensional scanner lens based on a triple lens system for a laser with a wavelength of 1.06 μm is performed. The first chapter indicates the scope and features of f-theta lenses. In the second chapter the initial conditions for the design of f-theta lens are given. In the third part, the simulation results, showing the parameters and efficiency of the system for 2 types of construction are given. The parameters and efficiency of the system are demonstrated. For each system, the optimal parameters are calculated, and the technical criteria for the possible application are outlined. The geometrical characteristics of the systems are shown, lens materials are described. A variant with a distortion of 0.0035% with a maximum focal spot of 24.9 μm was obtained.
Keywords: scanning system, f-theta lens, optical design, laser engraving, galvo
Gas-powder dynamics within the off-axis nozzle of the Precitec YC52 laser cladding head (Germany) has been studied using the original Tepler shadow setup, the high-speed tracing system and the laser Doppler anemometer. The length of the laminar part of the gas-powder flow has been optimized for variety of the transport and shielding gas flow, as well as the diameter of the orifice of cyclone. Powder jet at the nozzle’s outlet follows the carrier gas flow structure. In case of 4 mm nozzle’s diameter, the powder stream separates into two stable vortex structures near the surface of the substrate, causing significant losses of powder particles (about 2/3 of the total powder mass) within the melting zone, which finally reduces the efficiency of the deposition process and the powder utilization. Practical recommendations on the application of the optical diagnostic to optimize gas-powder jets for laser cladding are provided.
Keywords: laser powder cladding, shadow method, off-axis nozzle, tracing, laser Doppler anemometry, gas-powder flow optimization
Dynamics of gas and plasma flow in a Fassel type torch for the OPTIMA 2000 optical emission spectrometer (PerkinElmer, USA) was investigated using the original shadow Toepler visualizer. Significant transient instability of plasma’s flow was registered by the high-speed shadow imaging. Observable structure of the plasma torch was described and interpreted. The process of formation of toroidal vortices within the plasma torch was demonstrated, its frequency was estimated. Effect of reverse gas flow back to the plasma torch is revealed, interpreted and experimentally validated. It is noted that ambient air containing residues of the analyzed substances getting into a spectrally pure analytical zone of the plasma torch can lead to deterioration of metrological characteristics of a spectrometer because of “memory effect”. A set of practical recommendations to protect the analytical zone of the plasma torch from the contamination caused by the gas backflow of surrounding gas was formulated.
Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production