Laser cladding generally achieves a higher hardness than conventional quenching. Laser heating has a very high power density, meaning that each unit area of the laser-irradiated area has extremely high power. Due to the extremely high power density, the heat cannot be immediately transferred through the workpiece's conduction. As a result, the workpiece in the laser-irradiated area rapidly heats up to the austenitizing temperature. The novel ultra-high-speed laser cladding technology achieves rapid heating. If laser heating ends, the large volume of the workpiece matrix remains at a low temperature during rapid heating, thus the heated area is rapidly cooled due to the workpiece's own heat conduction, achieving heat treatment effects such as quenching. Laser heat treatment has a high degree of automation, and the depth and area of the cured layer are controllable. This invention primarily enhances the surface of automotive parts or molds, improving their surface hardness, wear resistance, corrosion resistance, strength, and high-temperature performance. For example, the laser additive manufacturing technology for automotive engine cylinder bores, crankshafts, ultra-high-speed laser cladding powder stamping dies, and casting templates can achieve the forming and manufacturing of complex parts without molds. It can also deposit reinforcing coatings with special properties on selected areas of components, thereby enabling the growth of parts with specific shapes and allowing for the laser remanufacturing of defective areas. Besides adjusting size, it can also improve component performance. New product. Furthermore, the development of high-energy beam heat treatment technology has provided technical support for surface heat treatment of certain areas of our important components and has become an important heat treatment method.
Laser cladding is used in the mining, chemical, metallurgical, power, and cement industries. With long-term use and aging of equipment, such as gas turbine rotor journals and blades, rolling mill journals, and steel mill arches, localized damage occurs requiring repair. Laser cladding technology addresses the failure modes of these large components, primarily including internal metal component breakage and cracking, and severe wear or corrosion leading to localized peeling. These components are subjected to varying degrees of high temperature and pressure from gas, long-term exposure to corrosive media, and mechanical stress caused by volumetric loads. Damage often occurs on the surface or originates from the surface. Therefore, improving the surface properties of components plays a crucial role in extending their service life. Furthermore, surface damage detected through periodic maintenance can be remedied using surface remanufacturing technology. For gas turbines and steam turbines, failure sites often occur in hot-end components such as rotors, blades, and nozzles. Fractures occurring at the blade root are irreparable, while damage at the blade tip or root can be repaired and reused. Furthermore, blades used in generator sets are often extremely expensive; reinstalling and reusing repaired blades significantly reduces power plant costs. Laser cladding is used for surface strengthening of parts before service or for repairing malfunctions after service. Traditional processing methods include surface hardening, surface carburizing or nitriding, thermal spraying, and welding. With continuous upgrades and improvements in processing technology, laser mobile remanufacturing technology (laser cladding) has gradually gained widespread application. This laser remanufacturing technology can not only repair damaged parts but also perform laser surface hardening. Compared to traditional heat treatment methods, laser hardening is a rapid heating and cooling process that can obtain a fine-grained hardened layer on the surface. Moreover, combined with high-end multi-axis machine tools or 6+2 robotic arms, lasers can also repair damaged three-dimensional complex parts, fully demonstrating the flexibility and advanced nature of laser remanufacturing technology.
What are the advantages of laser cladding?
As we all know, many things share commonalities, and the advantages of laser cladding can be cleverly and flexibly applied. Many people are aware of this, so let's briefly discuss the advantages of laser cladding. The focused power density of a laser beam can reach 10¹⁰~12 W/cm², achieving a cooling rate of up to 10¹² K/s when applied to materials. This comprehensive characteristic not only provides a strong foundation for the development of new disciplines in materials science but also offers an unprecedented tool for realizing new materials or new functional surfaces. The rapid cooling conditions created by laser cladding, far from equilibrium under high temperature gradients, lead to the formation of a large number of supersaturated solid solutions, metastable phases, and even new phases in the solidified structure, as confirmed by numerous studies. It provides entirely new thermodynamic and kinetic conditions for manufacturing in-situ self-generated particle-reinforced composite layers with functional gradients. Furthermore, the use of laser cladding technology to prepare new materials is a crucial foundation for the repair and remanufacturing of failed components under extreme conditions and the direct manufacturing of metal parts, attracting high attention and extensive research from the scientific community and enterprises worldwide. Currently, laser cladding technology can be used to prepare metal-based composite materials such as iron-based, nickel-based, cobalt-based, aluminum-based, titanium-based, and magnesium-based materials. Functionally, it can prepare coatings with single or multiple functions, such as wear resistance, corrosion resistance, high-temperature resistance, and special functional coatings. In terms of the material system constituting the coating, it has evolved from binary alloy systems to multi-component systems. The alloy composition design and multi-functionality of multi-component systems are important development directions for the future preparation of new materials by laser cladding. These are the advantages of laser cladding. New research indicates that steel-based metal materials dominate in engineering applications in my country. At the same time, the failure of metal materials (such as corrosion, wear, and fatigue) mostly occurs on the working surfaces of components, requiring surface strengthening.