Selective Laser Melting (SLM) is a particular rapid prototyping, 3D printing, or Additive Manufacturing (AM) technique designed to use high power-density laser to melt and fuse metallic powders. A component is built by selectively melting and fusing powders within and between layers. The SLM technique is also commonly known as direct selective laser sintering, LaserCusing, and direct metal laser sintering, and this technique has been proven to produce near net-shape parts up to 99.9% relative density. This enables the process to build near full density functional parts and has viable economic benefits. Recent developments of fibre optics and high-power laser have also enabled SLM to process different metallic materials, such as copper, aluminium, and tungsten. Similarly, this has also opened up research opportunities in SLM of ceramic and composite materials. The review presents the SLM process and some of the common physical phenomena associated with this AM technology. It then focuses on the following a...

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Review of selective laser melting : materials and applications

A review on selective laser sintering/melting (SLS/SLM) of aluminium alloy powders: Processing, microstructure, and properties

Selective laser melting (SLM) is widely gaining popularity as an alternative manufacturing technique for complex and customized parts. SLM is a near net shape process with minimal post processing machining required dependent upon final application. The fact that SLM produces little waste and enables more optimal designs also raises opportunities for environmental advantages. The use of aluminium (Al) alloys in SLM is still quite limited due to difficulties in processing that result in parts with high degrees of porosity. However, Al alloys are favoured in many high-end applications for their exceptional strength and stiffness to weight ratio meaning that they are extensively used in the automotive and aerospace industries. This study investigates the windows of parameters required to produce high density parts from AlSi10Mg alloy using selective laser melting. A compromise between the different parameters and scan strategies was achieved and used to produce parts achieving a density of 99.8%.

https://nottingham-repository.worktribe.com/preview/734538/1-s2.0-S2214860414000062-main.pdf

Reducing porosity in AlSi10Mg parts processed by selective laser melting

3D printing of Aluminium alloys: Additive Manufacturing of Aluminium alloys using selective laser melting

https://onlinelibrary.wiley.com/doi/pdf/10.1002/jor.23075

Laser and electron-beam powder-bed additive manufacturing of metallic implants: A review on processes, materials and designs.

Rapid manufacturing is an advanced manufacturing technology based on layer-by-layer manufacturing to produce a part. This paper presents experimental work carried out to investigate the effects of scan speed, layer thickness, and building direction on the following part features: dimensional error, surface roughness, and mechanical properties for DMLS with DS H20 powder and SLM with CL 20 powder (1.4404/AISI 316L). Findings were evaluated using ANOVA analysis. According to the experimental results, build direction has a significant effect on part quality, in terms of dimensional error and surface roughness. For the SLM process, the build direction has no influence on mechanical properties. Results of this research support industry estimating part quality and mechanical properties before the production of parts with additive manufacturing, using iron-based powders.

Influence of process parameters on part quality and mechanical properties for DMLS and SLM with iron-based materials

Selective laser melting (SLM) is an advanced manufacturing technology based on layer by layer building to produce solid parts from metallic powder (Kruth et al., CIRP Ann Manuf Technol 56:730–760, 2007). Commercial SLM machines are configured to use specific parameters to process different metallic powder grades. This paper proposes a methodology that makes it possible to analyze the effect of energy density on the formation of single tracks from CoCrMo powder, using a noncommercial machine to select process parameters with open source technology. Full factorial experimental work was carried out to produce single tracks under different combinations of process parameters. A major application of this research work is to develop more flexible machine configurations applicable to different materials.

Energy density analysis on single tracks formed by selective laser melting with CoCrMo powder material

Study of the Pore Formation on CoCrMo Alloys by Selective Laser Melting Manufacturing Process

Scanning Space Analysis in Selective Laser Melting for CoCrMo Powder

Electro discharge machining process (EDM) is frequently used when machining of high complex and accurate features is required. Indeed, it is specially recommended for hard materials and micro-machined features. However, due to the process nature, there is still incomprehension on process parameters influence at the final quality features, ending up by lower productivity and quality ratios. On the other hand, fashioning and re-shaping of required electrodes for each feature are time consuming phases and the number of stored electrodes is very high. Therefore, in order to increase the global EDM process productivity, quality and flexibility, standardized simple electrode shapes, capable to machine different features, must be found. This study presents the influence of the main EDM process parameters and different tool geometries on basic process performance measures. A set of designed experiments with varying parameters such as pulsed current, open voltage, pulse time and pulse pause time are carried out in H13 steel using different geometries of copper electrodes. In addition, material removal rate , surface roughness and different dimensional and geometrical micro-accuracies are analyzed through statistical methods. Results help to select appropriate EDM process parameters to machine parts depending on product requirements.

Tool electrode geometry and process parameters influence on different feature geometry and surface quality in electrical discharge machining of AISI H13 steel

Jordi Delgado

Papers

Influence of process parameters on part quality and mechanical properties for DMLS and SLM with iron-based materials

Energy density analysis on single tracks formed by selective laser melting with CoCrMo powder material

Study of the Pore Formation on CoCrMo Alloys by Selective Laser Melting Manufacturing Process

Scanning Space Analysis in Selective Laser Melting for CoCrMo Powder

Tool electrode geometry and process parameters influence on different feature geometry and surface quality in electrical discharge machining of AISI H13 steel