Laser-Based Metal Deposition Techniques and Processes

Laser-based metal deposition encompasses a suite of directed-energy deposition methods in which a focused laser beam is used to fuse metal feedstock—commonly powder or wire—onto a substrate, building near-net-shape components layer by layer. Core process parameters include laser power, scan speed, feedstock flow rate and focal position, which collectively govern melt-pool dynamics, heat-affected zones and solidification microstructures. Powder-fed systems deliver metal particulates coaxially or via multi-jet nozzles, enabling complex geometries, repair operations and functionally graded materials. Wire-fed variants offer reduced porosity and higher deposition rates at the expense of geometric flexibility. Key challenges include spatter formation, porosity control, thermal distortion and real-time process monitoring. Recent advances in computational modelling, high-speed imaging and closed-loop control have improved predictability of melt-pool behaviour and powder trajectory, yielding enhanced dimensional accuracy and mechanical performance. Applications span aerospace, automotive, energy and biomedical sectors, where tailored microstructures and the capacity for in situ repair or bespoke alloy design are of growing significance.

Research from Nature Portfolio

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Research from all publishers

Recent investigations have illuminated the influence of process parameters on part quality and microstructure. A study on stainless-steel powder deposition demonstrated that variations in laser power, scanning speed and powder feed rate govern porosity levels, melt-pool geometry and tensile performance, indicating that consistent mechanical behaviour requires holistic consideration of thermal input and feedstock delivery. Numerical and experimental analyses of gas/powder flow for different laser metal deposition nozzles have elucidated how carrier, shaping and axial gas flows shape powder stream density, focal-plane position and particle velocity distribution, leading to guidelines for nozzle design that optimise powder catchment and minimise overspray. In a computational study of coaxial nozzles, coupled Euler–Lagrange and turbulence models accurately predicted powder-stream convergence and velocity fields, revealing the critical role of nozzle geometry, particle size distribution and inner shielding gas in defining powder trajectory and melt-pool interaction. These collective insights are advancing process robustness and extending the range of feasible alloys and component geometries.

Laser-Based Metal Deposition Techniques and Processes publication trend

The graph below shows the total number of articles in laser-based metal deposition techniques and processes across all publications each year (not limited to Nature Index journals).

Technical terms

Directed Energy Deposition (DED): An additive manufacturing process in which a laser beam melts metal feedstock as it is deposited to build parts layer by layer.

Laser Metal Deposition (LMD): A powder-fed variant of DED in which metal powder is delivered to the melt pool via a nozzle.

Melt pool: The localized pool of molten metal created by the laser, whose size and dynamics determine the final microstructure.

Coaxial nozzle: A powder-delivery system in which feedstock is aligned concentrically with the laser beam to improve powder–laser interaction.

Porosity: The presence of voids within the deposited material, which can reduce mechanical strength and lead to structural defects.

References

1. State of the Art in Directed Energy Deposition: From Additive Manufacturing to Materials Design. Coatings (2019).
2. Directed Energy Deposition of AISI 316L Stainless Steel Powder: Effect of Process Parameters. Metals (2021).
3. Experimental and Numerical Analysis of Gas/Powder Flow for Different LMD Nozzles. Metals (2020).
4. Numerical Study on Powder Stream Characteristics of Coaxial Laser Metal Deposition Nozzle. Crystals (2021).