THE IMPACT OF HIGH PRESSURES ON THE EXPANSION OF PROCESS WINDOW
Journal: Frontiers in Manufacturing Engineering (FME)
Author: Josh Kent
This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
Laser chemical processing (LCM) is an unconventional removal process based on precise thermal activation of heterogeneous chemical reactions between electrolytes and metal surfaces. Due to local overheating during this process, boiling bubbles will be generated, which will impair the removal quality. In order to reduce the amount of bubbles, laser chemical treatment is carried out under different processing pressures. Under the conditions of various process pressures, processing speeds and laser powers, the removal experiment of grade 1 titanium was carried out using electrolyte phosphoric acid in order to determine the limit of the process window by evaluating the characteristics of the removal cavity. As a result, at higher process pressures, the process window for interference-free laser chemical processing is widened. The process pressure has no effect on the geometry removed. The enlargement of the process window is due to the fact that at higher process pressures, the saturation temperature of the electrolyte rises, so the bubble boiling starts from the higher surface temperature on the workpiece caused by laser power. By increasing the process pressure from ambient pressure to 6 bar, the removal rate can be increased by 2.48 times, thus taking an important step towards the economic efficiency of laser chemical processing.