This paper explores the feasibility of using High-Speed Laser Cladding technology to apply an enhanced nickel superalloy, Inconel 625, as coating material. This superalloy, which includes Reactive Additive Manufacturing additions, is designed to maintain high strength and corrosion resistance at both room and high temperatures. In this study, the effects of process parameters, such as laser power, powder flow rate and speed, were analysed for producing enhanced Inconel 625 coatings on 42CrMo4 steel cylinders. Single-layer coatings, extending 20 mm along the cylinder’s axis, were produced by High-Speed Laser Cladding process and systematically evaluated through metallographic analysis and defect identification. The coating process was optimized in terms of layer thickness, defect avoidance and powder catchment efficiency. The thickness of the selected coating layers ranged from 190 µm to 205 µm, with an average porosity between 0.16 % and 0.23 %. The powder catchment efficiency ranged from 71 % to 73 %.

Modern arc welding systems equipped with dynamic wire feeders enable the effective cladding of enhancing coatings while minimizing heat input to the substrate material, thus limiting its distortions. The heat input is related to the wire feeding rate through the synergic arc-voltage curves, and it defines the volume of the coating. However, low heat input is associated with rapid cooling, limiting the coating's homogeneity and producing highly quenched microstructures in the heat-affected zone of some steel substrates. An oscillating laser beam was employed as a secondary heat source to improve these aspects unless changing the volume of the coating. Laser-assisted and hybrid approaches in various setups were investigated during the cladding of wear-resistant Co-based alloy onto the martensitic steel substrate. The cladding process was monitored with a high-speed and thermal imaging camera, and the structure and microhardness of beads were evaluated.

Using high-speed laser melt injection (HSLMI), it is possible to generate wear-resistant metal matrix composite (MMC) surfaces on tools with excellent productivity. Since high laser intensities are required for the process, strong interactions can occur between hard particles and the laser beam. For reducing the interaction time and gaining a better understanding of the role of particle transport and incorporation in the HSLMI process, the trajectories of spherical fused tungsten carbide (SFTC) particles were analyzed using high-speed imaging. The trajectories were divided into a transport path and an incorporation path. The identified interaction mechanisms were particle deformation, formation of agglomerates and particle disintegration. The volume flow rate of the feeding gas was found to have a decisive influence on both the transport time and the incorporation time of the particles. Consequently, an increased volume flow rate led to a significant reduction in interactions between SFTC particles and the laser beam.

Cavitation erosion (CE) is detrimental to several engineering components, including ship propellers and pump impellers. Due to deformation and mass loss, CE significantly reduces serviceability, resulting in huge economic losses. This makes it essential to reduce the material damage caused by CE. Material damage can be minimised by using protective coatings to resist CE. Laser melt injection was performed to improve the cavitation erosion resistance. A metal matrix composite is formed by injecting spherical fused tungsten carbide and niobium carbide. The effect of different particle sizes on the CE behaviour of the reinforced surface layers were investigated. The microstructure of the modified surfaces was characterised using optical microscopy and image analysis. CE tests of the produced layers and untreated aluminium bronze were carried out according to ASTM G32-16 and the results were compared. The Niobium carbide coating was found to be the most effective in protecting substrates from cavitation damage.

Continuous market fluctuations, changes on product demand and global policies have led the automotive industry to look for innovative manufacturing solutions to improve manufacturing efficiency. In this sense, laser-based processes lead to shorter cycle times, less maintenance and more cost-effective production. Besides the laser technology is stated as key enabler of flexible, sustainable and reconfigurable manufacturing. In a group related to the authors different laser-based processes are being investigated aiming to modify the mechanical performance of automotive parts according to predefined requirements without any tool change. In this perspective, a multiprocess laser head able to perform laser heat treatment, laser remelting and laser wire cladding has been set up. First tests have been performed in CP800 high strength steel, looking for modifications in the mechanical performance of the material. This work shows the results of the metallographic and mechanical analysis performed on the first trials involving the multi-process tool with fast reconfiguration capabilities.

Laser welding, acknowledged for the low heat input process, was initiated to refurbish a steam turbine rotor. The refurbishment involved applying a superalloy filler metal to the damaged areas on the turbine disk caused by heavy rubbing. The post-weld heat treatment was established to minimize the residual stress after welding. The machining work was performed to remove cracks and finish the welded areas to original dimensions. The liquid penetrant test was conducted and revealed no defects. A notable characteristic of high hardness on the machined weldment was observed and attributed to a significant degree of work hardening. The maximum runout of the rotor was lower than that from the as received condition. The rotor mass unbalance was minimized and accepted according to the standard limit. The rotor then resumed operation for power generation. In addition, the consecutive projects showcased the success of laser welding in repairing critical power plant components.