In 1974, Gnanamuthu from ACVO EVERETT RES LAB INC in the United States introduced the first laser cladding patent (US3952180A), marking the beginning of foundational research into laser cladding technology. However, due to limitations in laser technology, the industrial development of laser cladding was slow for a long time. It wasn’t until the 21st century, with the maturity of high-power laser technology, that the industrialization of napawanie laserowe technology began to accelerate.

Laser cladding technology offers numerous advantages, such as low dilution, minimal heat input, and material versatility. Over time, various types of napawanie laserowe technologies have been developed, widely applied in fields like additive manufacturing, remanufacturing, and surface engineering. The common types of napawanie laserowe technologies can be classified based on the material type and the coupling form of the laser beam and material. These include coaxial powder laser cladding, off-axis powder laser cladding (also known as lateral powder feeding laser cladding), napawanie laserowe o dużej prędkości (also known as ultra-high-speed laser cladding), and high-speed wire laser cladding.

Coaxial Powder Laser Cladding

Coaxial powder laser cladding typically uses a semiconductor fiber laser and a disc-type air-fed powder feeder. The cladding head uses a circular light spot with a central output, where powder is delivered around the laser beam or in multiple streams. A special protective gas channel is set up to ensure that the powder flow, laser beam, and protective gas flow meet at a single point. This forms a molten pool at the focus, and as the cladding head moves relative to the workpiece, the cladding layer is formed on the surface.

Advantages of Coaxial Powder Laser Cladding:

• High Freedom, Easy Automation: Since the cladding can be performed in any direction, it is easy to automate the process. The cladding head can move freely over any part of the workpiece, enabling surface cladding of parts with complex shapes. When used as a 3D printing head, coaxial powder laser cladding can perform 3D laser printing.
• Inert Gas Protection for the Molten Pool: The powder is carried by gas and is protected by inert gas, minimizing oxidation. The cladding process in a controlled inert atmosphere ensures a higher-quality coating with fewer oxides.
• Small Molten Pool, Uniform Heating, Good Crack Resistance: The coaxial powder laser cladding process ensures an even heating of powder, resulting in a smaller molten pool. This makes the cladding layer resistant to cracking, even when working with tough materials like tungsten carbide.

Zastosowania: Coaxial powder laser cladding is commonly used for precision parts like shafts, gears, housings, and complex-shaped components for surface modification and additive remanufacturing. In metal 3D printing, it is often used for large part near-net-shaping and the preparation of gradient materials.

Off-Axis Powder Laser Cladding

Off-axis powder laser cladding (also known as lateral powder feeding laser cladding) typically uses a direct-output semiconductor laser or a semiconductor fiber laser with a gravity powder feeder. The cladding head uses a rectangular light spot with lateral wideband powder feeding. During operation, alloy powder is delivered to the surface of the workpiece, where it is scanned by the laser beam to form a molten pool, which cools to create the cladding layer.

Advantages of Off-Axis Powder Laser Cladding:

• Wysokie wykorzystanie materiału: Compared to coaxial powder laser cladding, the material utilization of off-axis powder laser cladding can reach over 95%. The powder is pre-positioned on the workpiece, and the laser beam melts it without wasting powder as often seen in coaxial feeding methods.
• Higher Cladding Efficiency: By using a rectangular light spot, this method increases the cladding efficiency. With higher laser power and larger spot width, it can achieve cladding widths up to 30mm, with a cladding efficiency of up to 1m/h or 12Kg/h.
• No Inert Gas Consumption: Off-axis powder laser cladding uses gravity powder feeding and does not require the use of inert gas, saving material costs. However, the technique does require compressed air and may not be as effective for materials prone to oxidation.

Applications: This technique is typically applied in larger, simpler parts like hydraulic cylinders, rollers, and other large parts in surface cladding and additive remanufacturing.

Bardzo szybkie napawanie laserowe

Developed by the Fraunhofer Institute for Laser Technology (Fraunhofer ILT) in Germany, ultra-high-speed laser cladding is a breakthrough technology that has been promoted in China since 2017. This technology uses high-quality fiber lasers and precision-designed high-speed laser cladding heads along with high-speed or high-velocity motion systems. The laser beam and powder flow are precisely coupled, allowing the powder to melt before entering the molten pool, resulting in significantly faster cladding speeds—up to 200 meters per minute, compared to traditional speeds of 2 meters per minute.

Advantages of Ultra-High-Speed Laser Cladding:

• High Laser Energy Utilization Efficiency: The design of the laser beam, powder flow, and inert gas coupling significantly reduces reflection and scattering losses, improving energy efficiency. While traditional napawanie laserowe technologies like coaxial and off-axis methods have energy utilization rates of around 35%, ultra-high-speed laser cladding achieves energy utilization rates of about 65%.
• High Cladding Efficiency: Due to its higher energy efficiency, ultra-high-speed laser cladding enables extremely high cladding speeds and thin layers, leading to very high cladding efficiency (up to 0.7m/s or more).
• Niski współczynnik rozcieńczenia: The short time the molten pool exists due to the high scanning speed results in a low dilution rate, ensuring the cladding layer’s quality.
• Good Surface Roughness and Crack Resistance: The cladding produced by this technology has low roughness and excellent crack resistance.

Zastosowania: Ultra-high-speed laser cladding is ideal for high-throughput cladding of large parts and those requiring minimal dilution, such as for surface protection in new parts or high-performance coatings for existing components.

High-Speed Wire Laser Cladding

Ten high-speed wire laser cladding technology is a next-generation laser cladding technique developed to meet market demands for eco-friendly, high-efficiency, and high-quality manufacturing. This technology uses high-precision wire feeding systems with fiber lasers to perform cladding with metal wire as the feed material.

Advantages of High-Speed Wire Laser Cladding:

• Environmentally Friendly: Unlike traditional powder-based laser cladding, high-speed wire laser cladding generates no dust, fumes, or metal powder waste, making it more environmentally friendly.
• Wysokie wykorzystanie materiału: Metal wire is fully melted and forms the cladding layer without spillage or waste, achieving material utilization rates of up to 99%.
• High Cladding Efficiency: Due to the pre-heating of the wire, the energy and time required to melt the material are significantly reduced, resulting in higher cladding efficiency compared to traditional powder laser cladding.
• Low Heat Input, Minimal Deformation: This method requires lower energy and offers a lower heat input, minimizing workpiece deformation. The technology is ideal for delicate components like thin-walled or elongated parts.

Zastosowania: High-speed wire laser cladding is widely used for surface protection, additive remanufacturing, and cladding of parts that are prone to deformation, such as long shafts or thin-walled components.

Wniosek

The evolution of napawanie laserowe technologies, from traditional to ultra-high-speed methods, has significantly enhanced industrial manufacturing capabilities. These advancements in napawanie laserowe offer high material utilization, improved efficiency, and environmentally friendly processes, making them ideal for various applications across industries such as aerospace, automotive, and heavy machinery.

Nakładanie laserowe technology continues to evolve and will play an increasingly pivotal role in the development of advanced manufacturing, offering substantial economic and environmental benefits. As the technology becomes more widely adopted, it is set to revolutionize how industries approach surface treatment and additive manufacturing, providing a powerful tool for modern manufacturing needs.