Laser cleaning has emerged as a highly efficient, non-polluting, and consumable-free method of industrial cleaning. Its applications in rust removal, paint removal, and metal surface technology have garnered significant attention. However, the cleaning of high-temperature oxide layers has presented a formidable challenge due to their stubborn nature. In this article, we explore the advancements in laser cleaning technology and how they have addressed the challenges associated with cleaning high-temperature oxide layers. We also delve into the market potential of laser cleaning as a green alternative to the traditional pickling process in the manufacturing industry.
Understanding High-Temperature Oxide Layers
High-temperature oxide layers are formed when metal materials react with oxygen at elevated temperatures, resulting in the corrosion of metal and the formation of oxides. These layers possess distinct characteristics that make their laser cleaning more difficult than ordinary oxide layers. Firstly, they are considerably thicker, measured in microns, compared to the tens of nanometers thickness of ordinary oxide layers. This increased thickness significantly reduces the cleaning efficiency.
Challenges in Laser Cleaning High-Temperature Oxide Layers
The cleaning of high-temperature oxide layers poses several challenges due to their unique characteristics. Firstly, the higher concentration of oxygen defects within the metal substrate promotes atom diffusion and leads to an increased density of the oxide layer. This elevated density makes it harder to clean as the oxygen and carbon atoms bond stronger to the surface, further complicating the laser cleaning process.
Secondly, laser cleaning involves a complex process of physical and chemical changes on the material’s surface, including ablation, decomposition, ionization, and gasification. However, high-temperature oxide layers exhibit a stronger resistance to high temperatures, making it more challenging for laser cleaning to effectively remove them based on the ablation and gasification mechanisms. Consequently, the efficiency of laser cleaning high-temperature oxide layers is generally limited to around 1-1.5 square meters per hour, which falls short of industrial cleaning requirements.
Market Opportunity for Overcoming Challenges
The difficulty of cleaning high-temperature oxide layers presents a significant market opportunity, particularly in replacing the pickling process used in the treatment of rolled sheet metal. The pickling process involves immersing hot-rolled plates in chemical solutions to remove oxide layers and other films on the metal surface, serving as a pre-treatment or intermediate treatment for subsequent processes such as electroplating, enamel coating, and rolling.
Despite its widespread use due to mature technology, low cost, and fast cleaning speed, the pickling process has several drawbacks. Issues such as iron oxide scale pressing, oxygen spots, yellow spots, and environmental pollutants have raised