Comparative study of the influence of laser power and machine type on the mechanical performance of advanced alloys in additive manufacturing

The paper aims to analyse the joint influence of laser power and machine type on the mechanical properties of metal parts manufactured by additive manufacturing, in particular via SLM/LPBF (powder bed melting) and DED (direct energy deposition) technologies. The study responds to a growing need to optimise manufacturing parameters for advanced alloys such as Inconel 718, Ti-6Al-4V and 316L stainless steel, particularly in bimetallic applications where mechanical performance is critical.Thie work is based on an in-depth comparative analysis of the data available in the literature concerning the tensile strength, yield strength and hardness of parts produced by different SLM and DED machines operating at various laser powers. The approach highlights the interactions between process parameters and the technical specificities of the machines (optical system, scanning strategy, thermal management), based on a literature study targeting the main alloys used in an industrial context.The results confirm that laser power has a decisive effect on densification and mechanical properties, but only up to an optimum threshold. Beyond this, excessive power can lead to over-melting, internal defects (such as microcracks and porosities), and microstructure degradation. At the same time, the type of machine plays a crucial role: for equivalent parameters, performance can vary considerably depending on factors such as beam quality, gas recirculation system, or thermal stability. Some moderate-power, well-calibrated machines outperform more powerful but poorly controlled systems.The study is based exclusively on a literature review, with no direct experimental validation. Future work is needed to validate the trends observed through controlled tests on bimetallic parts and to support numerical modelling of the process.The results provide concrete recommendations for selecting the optimal machines and manufacturing parameters to enhance the mechanical performance of parts in critical sectors, including aerospace, biomedical, and energy.The work provides an unprecedented cross-sectional reading of the combined impact of laser power and machine type in metal additive manufacturing. It provides a useful comparative basis for process engineers and researchers seeking technological optimisation.