what is the Working principle rust descaling machine
Author: zixu Time: 2020/02/15
The cleaning process of pulsed Nd: YAG laser depends on the characteristics of the optical pulse generated by the laser, which is based on the photophysical reaction caused by the interaction between high-intensity beam, short pulse laser and pollution layer. Its physical principle can be summarized as follows:
a) The laser beam is absorbed by the pollution layer on the surface to be treated.
b) The absorption of large energy forms a rapidly expanding plasma (highly ionized unstable gas), which produces shock wave.
c) Shock waves fragment and remove pollutants.
d) The optical pulse width must be short enough to avoid the heat accumulation which will damage the treated surface.
e) Experiments show that when there are oxides on the metal surface, the plasma is produced on the metal surface.
The plasma is produced only when the energy density is higher than the threshold value, which depends on the removed pollution layer or oxide layer. This threshold effect is very important for effective cleaning under the condition of ensuring the safety of substrate materials. There is a second threshold for the appearance of plasma. If the energy density exceeds this threshold, the substrate material will be destroyed. In order to ensure the safety of the substrate materials, the laser parameters must be adjusted according to the situation, so that the energy density of the light pulse is strictly between two thresholds.
Each laser pulse removes a certain thickness of pollution layer. If the contaminated layer is thick, multiple pulses are needed for cleaning. The number of pulses required to clean the surface depends on the level of surface contamination. An important result of the two thresholds is the self-control of the cleaning. The light pulse with the energy density higher than the first threshold will eliminate the pollutants until it reaches the substrate material. However, because its energy density is lower than the failure threshold of the substrate material, the substrate will not be damaged.