Laser cladding, a cutting-edge surface modification technique for metals, offers a novel approach to enhancing the wear and corrosion resistance of substrates due to its rapid heating and cooling capabilities, precise control over coating thickness and dilution rates, and non-contact processing characteristics. However, disparities in the physical properties between the coating material and the substrate, coupled with the improper utilization of process parameters, can lead to coating defects, thereby compromising the quality of the coating. This paper examines the effects of material systems and process parameters on laser cladding composite coatings and shows that cracking is mainly caused by thermal and residual stresses. This article summarizes the methods for crack improvement and prevention in five aspects: the selection of processes in the preparation stage, the application of auxiliary fields in the cladding process, heat treatment technology, the use of auxiliary software, and the search for new processes and new structural materials. Finally, the future development trends of laser cladding technology are presented.

As a revolutionary advanced manufacturing technology, the core of laser-assisted machining technology lies in the innovation of traditional machining technology. It uses a laser to precisely modify the surface of the workpiece material through clever integration. This process can lead to significant changes in the microstructure, thermodynamic properties, and physical properties of the workpiece’s cutting layer, greatly facilitating the removal of material by the cutting tool. Especially for difficult-to-process materials, this technology can effectively solve the processing problems they face. This not only improves the processing accuracy, but also ensures the processing quality, making it possible to process difficult-to-process materials with high precision and high quality. This article comprehensively summarizes the latest research progress in laser-assisted precision machining technology and deeply summarizes the specific mechanism of laser-assisted machining technology on the surface of workpiece materials. The influence of laser-assisted machining technology on the cutting characteristics of machining materials is elaborated in detail, providing a theoretical basis for the application of this technology. Finally, the future development direction of laser-assisted machining technology is prospected.

This paper deals with laser-arc hybrid welding of high nitrogen stainless steel (HNS) with 1.2 mm diameter of austenitic stainless steel (ASS) filler wire. The welding was carried out with different shielding gas mixtures like 100%Ar, 95%Ar+5%N2, 90%Ar+10%N2, 94%Ar+5%N2+1%O2 and 89%Ar+10%N2+1%O2. The effects of shielding gas composition on the welding stability, microstructure and mechanical properties were analyzed. The results show that the weld seam forming and welding stability are improved when 1%O2 is added to the mixture of Ar+N2, and the nitrogen content in the weld increases significantly. The pore ratio is the lowest in 90%Ar+10%N2 shielded weld, when 1%O2 is added to 90%Ar+10%N2, the pore ratio increases slightly. The ferrite percentage is the lowest in 89%Ar+10%N2+1%O2 shielded weld. The 89%Ar+10%N2+1%O2 shielded welded joints feature better mechanical properties.