Laser cladding is a material surface modification technology. Here are some of the latest research directions and progress in this field:

Preparation of gradient cladding layer: A study first prepared Ti6Al4V alloy by laser powder bed fusion, and then successfully prepared an economical gradient cladding layer on its surface by composition design, gravity segregation, and laser cladding of micron-level Ni powder, nano-level SiC powder and Y2O3 powder. The study systematically analyzed the microstructure of the gradient cladding layer and the reasons for its improved wear resistance and corrosion resistance.

Application in hybrid engines: Laser cladding valve seat technology can directly clad wear-resistant alloys on aluminum alloy cylinder heads, replacing the traditional press-in powder metallurgy valve seat production process. For example, Toyota applies it to the TNGA series models and promotes it as a global standard process. The advantages of this technology include metallurgical bonding between the cladding layer and the aluminum alloy substrate, fast heat conduction and good heat dissipation; the local wall thickness of the aluminum alloy cylinder head blank can be thinned, and the water jacket area can be expanded to facilitate heat dissipation; larger valves can be used to reduce throttling losses; good cooling conditions can improve the wear resistance of the valves, etc. In addition, the use of this technology can reduce the throat height, achieve a double increase in the tumble ratio and flow rate of the intake duct, and bring flexibility to the intake duct design.

Self-lubricating composite coating: Through the design of the composite material system, laser cladding can be used to prepare a series of composite material coatings with wear resistance, friction reduction and oxidation resistance to extend the service life of mechanical components.

Cladding layer alloy material development: Laser cladding valve seat ring materials need to have good wear resistance, high high temperature hardness, corrosion resistance, self-lubrication, cladding performance and machinability. For example, Toyota developed CuLS10, a cladding alloy material for intake valve seats, which uses Cu-Ni alloy and adds hard particles such as Fe2B and Ni5Si2; while the addition of Mo-based hard phases to the exhaust valve seat cladding alloy material CuLS50 can effectively improve the anti-adhesion performance. In the face of different fuel conditions, Toyota has also developed the adaptability of alloy materials. For example, in response to the poor lubricity of ethanol fuel in the South American market, based on CuLS50 alloy material, Cu-Fe alloys are used as a new research basis to explore methods to improve wear resistance and reduce the risk of cladding cracks.

Application in automobile manufacturing:

• Surface coating preparation: It can form high-quality coatings with excellent adhesion and wear resistance, providing longer-term protection.
• Material repair and remanufacturing: It can accurately melt metal powder in the damaged area to achieve local repair, saving resources and costs.
• Customized manufacturing: Directly manufacture parts of the required shape on the substrate according to design requirements, simplify the manufacturing process and improve efficiency.
• Special functional coatings: Such as coatings with functions such as anti-corrosion, anti-wear, and noise reduction to improve the performance and quality of the car.
• Lightweight design: Form a high-strength coating on the surface of lightweight materials to achieve lightweight design requirements.
• Valve seat ring technology: For example, the laser cladding valve seat ring technology of aluminum alloy cylinder head is used to replace the traditional press-in powder metallurgy valve seat ring production process. This technology makes the cladding layer and the aluminum alloy substrate metallurgically combined, with fast heat conduction and good heat dissipation; it can reduce the local wall thickness of the blank and expand the water jacket area; it can use larger valves to reduce throttling losses; improve valve cooling and improve wear resistance. It brings flexibility to the design of the intake duct, and can achieve a double increase in the tumble ratio and flow rate of the intake duct. In addition, Japanese manufacturers have more experience in the development of laser cladding valve seat materials, such as the two-liquid phase separation method developed by Toyota, and the adaptation of corresponding valve seat materials for different temperatures and lubrication conditions.

Laser cladding head: The laser cladding head is a key core component of the laser cladding system, which can realize the transmission, transformation, focusing and synchronous delivery of laser beams and cladding materials. Among them, the shaping, transformation and focusing of the laser beam, the transmission and injection convergence of the material, and the coupling method of the light material are key technologies. The spot shape includes circular, annular, rectangular and linear shapes, and the powder feeding methods include pre-set powder method and synchronous powder feeding method. According to the coupling form of the laser beam and the powder, the cladding nozzle can be divided into a side-axis powder feeding cladding nozzle and a coaxial powder feeding cladding nozzle. At present, the coaxial powder feeding cladding nozzle is mostly used. It has no directional problems and can also be used in laser metal additive manufacturing.

Technology development trends:

• Coating type: from easy-to-clad metal coatings or ceramic-metal composite coatings to difficult-to-clad pure ceramic coatings;
• Coating material structure: from traditional materials to nanostructured materials;
• Coating function: from general mechanical properties to electromagnetic properties and biocompatibility, and the application field is expanded from industrial fields to medical and health fields.

Laser cladding technology involves many disciplines and is still under development and research, with new research results and applications emerging. If you are interested in a specific direction or application field of laser cladding, you can consult HUIRUI-LASER.COM for more detailed and in-depth information.