OBRABOTKAMETALLOV Vol. 26 No. 2 2024 technology a b Fig. 10. Presence of cracks in the fused layer: a – power 1.000 W, scanning speed 15 mm/s, powder flow rate 24 g/min; b – power 1.250 W, speed 15 mm/s, powder flow rate 24 g/min Coefficient of effective materials consumption Determination of the coefficient of useful consumption of materials was carried out according to the equation [25]: = u m K P , where m is the mass of the surfaced layer determined by the volume of surfaced material per minute, g/min; P is the powder consumption in the build-up process, g/min. The mass of the surfaced layer was determined by the cross-sectional area of the obtained tracks. The obtained values are presented in Table 3. The average coefficient of effective materials consumption in the process of direct laser deposition was 20–23 %. A similar result was obtained in [26]. Analyzing Fig. 11, we can conclude that with increasing the speed and power of laser radiation, the powder mass loss during the build-up process changes insignificantly, thus indicating the absence of influence of these two parameters on the build-up performance. Increasing the powder flow rate increases the material consumption ratio (Fig. 12) due to the interaction of more particles with each other. However, changing the laser beam diameter during the growing process showed a significant increase in the coefficient of useful consumption (Fig. 13). This is explained by the increase in the spot diameter on the material. Ta b l e 3 Surfacing efficiency coefficient Power, W Speed, mm/s Powder consumption, % Beam diameter, mm Coefficient, % 1.000 15 8 2.9 21.1 1.000 25 8 2.9 21.4 1.000 35 8 2.9 20 1.250 15 8 2.9 24.8 1.250 25 8 2.9 26.5 1.250 35 8 2.9 24.6 1.500 15 8 2.9 23.3 1.500 25 8 2.9 23.7 1.500 35 8 2.9 21.9 1.250 25 4 2.9 24.6 1.250 25 12 2.9 28.5 1.250 25 4 4.1 32.2 1.250 25 4 5.6 43.1
RkJQdWJsaXNoZXIy MTk0ODM1