# Fabrication of Mesh Patterns Using a Selective Laser-Melting Process
## 1 Introduction
As described above, each manufacturing process is characterized by its own strengths and weaknesses, and because the formed product is significantly influenced by the manufacturing method, a reasonable compromise between process efficiency and product quality is required [32; 33; 34]. Direct manufacturing of metal lattice structures is now possible through the use of laser- and electron beam melting (EBM)-based additive manufacturing systems. Fine-structured 3D porous filter elements [35] and porous titanium implants with a channel structure [36] have been built with SLM. Geometrically complex filters with customized shapes and oriented in the through direction pores were successfully fabricated. The production of porous scaffold structures using additive manufacturing is becoming widespread. There are a number of methods to produce porous components. Of these methods, only additive manufacturing techniques enables the fabrication of anatomically-shaped scaffolds with complex internal architectures, allowing precise control of the  
Figure 1: Four types of metal meshes: (**a**) welded, (**b**) woven, (**c**) perforated, (**d**) expanded. stiffness [37; 38]. EBM process uses an electron beam as the energy source to selectively melt layers of metal powder in vacuum [39]. The electron beam is generated by heating a tungsten filament and accelerating the electron towards the metal powder at the build platform using an accelerated voltage. The electron beam is focused and deflected using electromagnetic coils. [PERSON] et al. [40] reported microstructure, defects and mechanical behavior of porous structures manufactured by EBM. As the peak temperature of EBM is higher than that of SLM, the metallurgical properties of fabricated parts are somewhat different from those of SLM. Although many previous studies using SLM have focused on the manufacturing of porous and lattice-like parts. SLM has demonstrated its potential for manufacturing mesh structure with the desired dimensions. The formation of a mesh pattern has a strong potential to increase the functionality and cost-effectiveness of the SLM process [41]. In this study, the fabrication of a metal mesh using SLM has been investigated as a fast and easy process with a tailored dimensional accuracy. This is very advantageous for the integrated one-step fabrication of small quantity production of various mesh types because the fabrication of a part with a mesh pattern can be easily achieved using a 3D computer-aided design (CAD) solid model. To fabricate a single-layered thin mesh pattern, laser layering was applied on a copper base plate in this study. The high thermal conductivity of copper allows heat to pass through it quickly, and prevents the adhesion of a thin laser-melted layer. The effects of the process conditions such as the laser scan speed and scanning path on the size and dimensional accuracy of the fabricated mesh patterns were characterized experimentally. In order to optimize processing conditions for the laser layering, the effects of process conditions on line instability of the mesh lines were determined. Based on the above experimental results, a thin cylindrical tube with mesh patterns was fabricated to validate the feasibility of the proposed approach.