Using Two Different Laser Cladding Materials Increases Ductility of Joint and Avoids Formation of Cracks

 

Laser cladding refers to a surface modification technique widely used in industrial applications such as rapid manufacturing, parts repair, surface coating, and innovative alloy development. It involves the feeding of a stream of metallic powder or wire into a melt pool that is generated by a laser beam as it scans across the target. Laser cladding can be used to increase corrosion resistance, wear resistance or impact performance of metallic components, using a method of applying a fully dense, metallurgically bonded and virtually pure coating.

Laser cladding materials with different lasers have been used: high power diode laser (848 nm), Nd:Yag laser (1064 nm), CO2 laser (10.64 µm), and excimer laser (248 nm). It is quite different from traditional welding or fusion bonding as a means to permanently bind the metals together by means of high-energy laser beams. Instead, it is usually achieved by injecting two metallic materials through a cryogenic chamber and then pressing or rolling them together using a roll press or other instrument. While lasers have been in existence for decades, their usefulness for industrial applications came into being in the 1970s. They are now commonly used for welding, coating, and powder coating among other applications.

Although use of laser cladding has increased significantly, the process has its own limitations in the form of crack formation. In July 2020, The German state of Hesse, in collaboration with Sigma Laser GmbH and Technical University of Applied Sciences Mittelhessen, researched means to address issues of crack formation while using lasers in welding. The team found that using two different laser cladding materials, such as titanium/aluminum and titanium/stainless steel, increases the ductility of the joint and avoids the formation of cracks.