Application of Laser Cleaning In Metal Welding
Welding is a manufacturing process that joins metals or other thermoplastic materials by heating. It is a commonly used material processing method in engineering, providing a stable and effective way to connect different workpieces. To prevent defects such as porosity, cracks, rough appearance, and uneven structure in the weld, which affect weld quality, it is crucial to clean the surface of the weld joint before welding to remove dirt and rust.
The heat treatment during welding causes oxidation at the interface, forming an oxide layer. Timely cleaning of the oxide scale, slag, and spatter after welding facilitates the observation and flaw detection of weld defects, allowing for timely identification, elimination, and repair, thus ensuring the surface quality of the product.
Current post-weld surface treatment methods mainly involve mechanical grinding and chemical cleaning. Mechanical grinding can easily damage the workpiece, is difficult to handle complex curved surfaces, and generates significant noise pollution and high labor intensity for workers. Chemical cleaning is unsuitable for localized cleaning and can easily cause environmental pollution.
A new laser cleaning technology uses a high-energy pulsed laser beam to irradiate the workpiece surface, causing surface dirt, rust, particles, or coatings to evaporate or expand and peel off instantaneously, thus achieving a cleaning process.
Features of Laser Cleaning Technology
Various problems arise during the treatment of stainless steel welds, such as cracks, cavities, solid impurities, incomplete fusion, incomplete penetration, and shape defects. Common weld treatment methods are cumbersome, difficult to implement, and time-consuming, significantly reducing production efficiency. Laser cleaning machines offer competitive advantages over traditional cleaning methods for metal weld surfaces, primarily in the following aspects:
1) Comprehensive Functions: Laser cleaning can remove rust, oil, oxide layers, and other substances adhering to metal surfaces, as well as dust and impurities. It can efficiently treat stainless steel welds, including pre-weld treatment, offering both high efficiency and saving time and labor.
2) Localized Cleaning: The laser beam can be adjusted in spot size for precise cleaning of specific areas of the metal surface. The laser intensity can also be adjusted to thoroughly clean adhesives of varying strengths.
3) Flexible Operation: Laser cleaning does not contact the material surface, allowing for effective cleaning of complex curved surfaces and areas inaccessible by conventional cleaning methods.
4) No damage to the substrate: Laser cleaning selectively removes contaminants, improving cleanliness and protecting the substrate.
5) Environmentally friendly: Impurities removed by laser cleaning can be directly recycled through dust extraction, generating no noise, waste solutions, or secondary pollution.
Application Case of Weld Cleaning (Post-Welding)
Laser cleaning removes lubricants, ferrous and non-ferrous metal impurities from metals, resulting in high-quality, smooth, and porosity-free welds and brazing seams. It produces visible welds with optimal stability and quality, suitable for cleaning steel and aluminum surfaces. As a pretreatment before and after welding, it is widely used in industries including automotive, precision tool manufacturing, and shipbuilding.
Laser cleaning can not only clean small areas of workpieces but can also be used in automated laser cleaning production lines to clean large batches of workpieces, thereby improving laser cleaning efficiency.