Thermal Effects on the Surface-Interface During Laser Cleaning and Substrate Damage Control
摘要
Laser cleaning technology removes contaminants from the surface of an object by irradiating a high-energy laser beam [1]. Laser cleaning technology, in comparison to conventional cleaning methods like mechanical friction, high-pressure water jet cleaning, chemical reagent cleaning, and ultrasonic cleaning, offers superior advantages such as high efficiency, non-contact operation, and environmental friendliness. This technology is primarily utilized for various applications including the removal of oxides from metal surfaces [2], the remanufacturing of coatings [3], the eradication of microorganisms [4], and the cleaning of micron and nanoscale particles [5]. When the laser irradiates on the surface of cleaned material, the laser energy can be divided into three parts according to the law of conservation of energy [6]: reflection from the material’s surface, absorption within the material, and conduction between the materials. The absorption of laser energy by materials results in interactions where thermal effects are indispensable for the efficacy of dry laser cleaning in removing contaminants. However, the aggregation of thermal effects may result in damage to the surface of the substrate, and non-destructive laser cleaning has always been a focus of research. The non-uniformity in the thickness of the adherent material, the irregularity of the object’s surface, and the high laser energy density employed to ensure cleaning efficiency, inevitably subject the substrate’s surface to thermal effects during the laser cleaning process. However, some studies have indicated that the slight remelting of the substrate after laser cleaning may improve the surface properties of the substrate under thermal effects, which is beneficial for secondary processing and utilization.