| 摘要 |
FIELD: technological processes. ^ SUBSTANCE: cutting of sheet materials is realised with the help of cut sheet surface exposure to oxygen jet that flows from supersonic nozzle and laser radiation. Laser radiation is focused so that axis of beam coincides with the nozzle axis, beam focus is located inside the nozzle, and beam diameter on surface of cut plate exceeds output diameter of nozzle. Beam heats the metal to the temperature that is higher than burning temperature but is lower than melt temperature. Thickness of cut sheets is set by condition H/Da<=(0.8-1.2)P/P∞+5, where H is thickness of cut sheet, mm, Da is output diameter of nozzle, mm. Certain selection of cutting parameters, namely value of pressure in nozzle chamber and gap size between output section of nozzle and cut sheet, makes it possible to increase quality of cutting surface. Selection is done based on the following conditions: P/P∞=6.15/(D0/Da-A)-7.7 and delta/Da=1-2, where P is excess gas pressure in chamber, MPa; P∞ is pressure of environment, MPa; A=0.2-0.3; D0 is critical diameter of gas nozzle, mm; Da is output diameter of gas nozzle, mm; delta is gap size between output section of nozzle and sheet surface, mm. ^ EFFECT: higher quality of cutting surface. ^ 1 ex, 3 dwg |
