ADDITIVE MANUFACTURING


LASER MESH DEPOSITION: A NEW LASER DED METHOD FOR REPAIR


THOMAS GIRERD ET AL*, UNIVERSITY OF NOTTINGHAM


fixed oscillation amplitude of 5 mm matched the mesh width. Process parameters ensured constant fluence distribution profiles. A simple line oscillation (5 mm amplitude) was used to assess stability, with mesh feed rate and laser power varied to study energy and material input effects. To demonstrate the flexibility of LMD, another mesh with a higher mass density was also deposited (Figure 1(c)). An elliptical oscillation pattern was tested, with a maximum energy concentrated at oscillation extremities rather than the centre (Figure 1(b)).


Figure 1: Experimental setup in this work illustrating the mechanism that was used to realise the mesh deposition


INTRODUCTION


Repair and remanufacturing restore damaged parts to ‘like-new’ condition, reducing waste, saving costs, and conserving resources. Direct Energy Deposition (DED) is particularly suited for on-site repair, as its feeder and heat source can be mounted on robotic arms, allowing high flexibility without dismantling equipment.


Lasers are the preferred heat source for their efficiency and precision, but challenges remain—especially controlling cooling rates and avoiding defects like columnar microstructures or cracks. Laser beam oscillations are emerging as a solution, enabling finer control of energy distribution and improving microstructure quality.


Feedstock choice also limits repair capabilities. Powder-based DED suffers from low efficiency in confined spaces, while wire-based systems are restricted in geometry adaptability. To overcome these trade-offs, this article proposes a novel DED feedstock: metallic woven mesh.


Combining the adaptability of fabric with the strength of metal, meshes can be customised in density, weave type, and material composition.


22 | LASER USER 118 DECEMBER 2025


This allows scalable material input, high geometric conformity, and even multi-material repair. Pairing meshes with laser beam oscillations - Laser Mesh Deposition (LMD) - offers control over fluence (energy density), melt pool stability, and deposition rate. This study explores the stability and feasibility of LMD across different mesh densities and scanning strategies, demonstrating consistent, high-quality deposition and opening new possibilities for complex, flexible repair operations in additive manufacturing. See [1] for the published paper.


MATERIALS AND METHODS


The LMD experiments are described in [1] and shown in Figure 1.


The experiments used a 2 kW CW fibre laser (IPG Photonics YLR 2000S) coupled to an IPG mid-power scanner with a working distance of 350 mm and a laser spot diameter of 3 mm. The mesh delivering system and the scanning head were mounted on a commercial CNC milling machine. The whole system was shielded with argon gas at 0.2 bar.


The feedstock was SS304 woven mesh (40 mm × 5 mm) on SS304 substrate (50 × 25 × 2 mm). A


Line and ellipse patterns were selected for their simplicity alongside two commercially available meshes. Cross sections were prepared by embedding and polishing perpendicular to the track, then examined via scanning electron microscopy (SEM).


RESULTS & DISCUSSION


The mesh feed rate allows modification of the mass input while the laser power will change the average fluence level during the process. As the mesh feed rate and the laser power were varied, two types of mesh depositions were observed: “continuous” deposition and “discontinuous” deposition (Figure 2(a)). The “discontinuous” depositions appear to be semi connected masses instead of one smooth track for “continuous” deposition. Hence, Figure 2(b) shows representative cross- sections in such depositions. At low fluence levels, inferior clads were obtained with either no dilution or discontinuous deposition. When the average fluence levels are high enough, “continuous” depositions were obtained. For “continuous” depositions, a correlation between the dilution and the contact angle can be observed when plotted as a function of the ratio of the energy per mass input (Figure 2(d) and (e)). As this ratio increases, more mesh will be melted into the substrate, leading


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