During the process, a high intensity laser beam selectively scans a powder bed according to the computer. Selective laser melting is a promising technology for additive manufacturing of complex shaped parts. The models core relies on thermodynamics and physical analysis to ensure optimal printability, and in turn offers key information for alloy design and selective laser melting process control. As metallic powders are the raw material for this process, there are still a lot of open. Selective laser melting is a powder based additive manufacturing process where the metallic powder particles are fused to 3d parts using a high energy laser beam. Process observation in fiber laser based selective laser melting ulrich thombansen, a, alexander gatej, b and milton pereira c a fraunhofer institute for laser technology ilt, process control and system technology, steinbachstrasse 15, d52074 aachen, germany. In situ process monitoring in selective laser sintering. The sls process employs a high power laser to fuse plastic powders layer by layer into finished prototypes and functional enduse components. Thermography for monitoring the selective laser melting process.
Nov 18, 2019 defect formation prevention is ensured by controlling the melt pool geometry and by taking into consideration the melting properties. Selective laser melting for medical implants brochure. Correspondingly, we have previously reported both ex situ analysis and in situ implementation of oct with sls to illustrate its utility in resolving layers in sintered parts. Sls 3d printing has been a popular choice for engineers in product development for decades. Keywords selective laser melting process parameters defect mechanical properties 1 introduction. Slm systems are both large and typically require a large amount of power. Mar 28, 2019 selective laser melting, or slm, is a type of metal additive manufacturing or 3d printing. Subsequently, the powder material grain fraction 1045m is deposited as a defined thin layer on a substrate.
Selective laser melting to manufacture in situ metal. The laser must have a greater power than the sls and at the end of the process the manufactured objects is quite similar to series production, in fact, it does not require s pecial surface finishes and may be subjected quietly at conventional machining. Here we report a novel selective laser melting process to simultaneously enhance the strength and ductility of stainless steel 316l by in process engineering its microstructure into a selective laser melting slm is a candidate for on. This process is gaining interest worldwide, thanks to the possibility of obtaining a freeform fabrication coupled with high mechanical. The laser melting was carried out under a protective argon atmosphere to prevent oxidation. Pdf parametric analysis of the selective laser melting. Studies have shown that this method can also be applied to the manufacture of cermet materials16,17. Since selective laser melting is a thermal process, a lot of information about the process and in consequence about the resulting part quality can be gathered by monitoring the temperature distribution of a complete layer and its temporal evolution. Based on the discussion, the paper proposes strategies for defect suppression and control in slm. The slm125 selective laser melting machine is accurate, compact metal 3d printing with low powder volume. Effects of the selective laser melting process parameters on the functional properties of the cocr alloy. Moreover, it has been consistently advancing the entire slm process chain in order to qualify the process for use in industrial production and to integrate it in existing production environments.
Selective laser sintering sls is an additive manufacturing am technology that uses a laser to sinter powdered plastic material into a solid structure based on a 3d model. Process observation in fiber laser based selective laser melting. The prerequisite for printing is that the desired material is in fine powder form, and that there are 3d data on the part to be made. The slm process consists of a series of steps from cad. In situ process monitoring in selective laser sintering using. Capabilities and performances of the selective laser melting. Process development for selective laser melting since the midnineties, fraunhofer ilt has been developing the selective laser melting process slm. The use of selective laser melting to increase the. View enhanced pdf access article on wiley online library html view download pdf for offline viewing. Slm has been described for sintering of refractory ceramics such as zrb2 aimed at high. Additive manufacturing of high selective laser melting.
Introduction of slm process selective laser melting slm is one of. A laser source selectively scans the powder bed according to the cad data of the part to be produced. Slm process and the steps the process can divided into. This paper investigates the effect of process parameters on the selective laser melting of al 2o. Selective laser melting an overview sciencedirect topics. The heat affected zone consists of the melt pool at temperatures above 1255 c 24 and an already solidified area at elevated temperatures close to the melt pool. Process parameters development of selective laser melting of. Often, the terms slm and direct metal laser sintering dmls are used interchangeably.
Selective laser melting slm is a commonlyused technique for processing high strength aluminum alloys. A continuous laser beams are used or pulsating as heating source for scanning and aligning particles in predetermined sizes and shapes of the layers. First, the 3dcad volume model is broken down into layers and transferred to the selective laser melting machine. The process is very similar to sls process but the energy of the beam is much higher and the process is performed under. This is a fast developing process that is being implemented in both research and industry. Processing parameters for selective laser sintering or. Pdf on the selective laser melting slm of the alsi10mg. Slm is a heat intensive process and the resulting material properties mainly depend on the influence of heat during the buildup process. Selective laser melting slm is now widely used in the aerospace industry because of its ability to form complex shaped parts15.
May 15, 20 for the love of physics walter lewin may 16, 2011 duration. A component is built by selectively melting and fusing powders within and between layers. Brochure process development for selective laser melting since the midnineties, fraunhofer ilt has been developing the selective laser melting process slm. When the powder to be fused is metal, the terms direct metal laser sintering dmls and direct metal laser melting dmlm are commonly used.
Selective laser melting slm is an additive manufacturing process in which parts are built in a layer by layer manner. This metal sintering or melting process fuses the powder together and creates a solid form. Pdf selective laser sinteringmelting slsslm technology is used for manufacturing netshaped objects from commercial inox 904l powder. Slm is one of the most exciting 3d printing technologies. Pdf parametric analysis of the selective laser melting process. Selective laser melting slm is a pbfbased am process that that uses high intensity laser as an energy source to melt and fuse selective regions of powder, layer by layer, according to computer aided design cad data. In order for this technology to see more widespread use as a production modality, especially in heavily regulated industries such as aerospace and medical device manufacturing, there is a need for robust process monitoring and control capabilities to be developed that reduce. Moreover, it has been consistently advancing the entire slm process chain in order to qualify the process for use in industrial production and to integrate it in existing production. Maf process is applied for finishing of additively manufactured components of 316 l stainless steel made by selective laser melting process 8. Surface morphology in selective laser melting of metal powders. Nov 10, 2014 selective laser melting and the patent rights monopoly selective laser melting on the other hand has had an odd, confusing, and painful history.
The authors studied the influence from the powder and the powder bed and found the properties of particles and powder layers significantly affected the product. Simultaneously enhanced strength and ductility for 3d. Oct 28, 2016 selective laser melting does suffer from many of the same disadvantages that laser sintering has. The high intensity laser beam makes it possible to. Pdf effects of the selective laser melting process. Aug 27, 2018 selective laser melting is a process of additive manufacturing from pointline, from lineface, and from facebody. Defect prevention in selective laser melting components. A generic cost models for slm and sm processing were developed, and several case studies are used to illustrate the conditions and drivers that demonstrate cost. A typical sls or slm process is illustrated in fig. The feasibility of using lunar regolith simulant to create objects with slm process is investigated in this study. Selective laser sintering sls is an additive manufacturing am technique that uses a laser as the power source to sinter powdered material typically nylon or polyamide, aiming the laser automatically at points in space defined by a 3d model, binding the material together to create a solid structure. Slm solution 280hl machine equipped with 400 w ylrfaser laser was used. Selective laser melting slm is one of the new additive manufacturing techniques that emerged in the late 1980s and 1990s. Parametric analysis of the selective laser melting process article pdf available in applied surface science 25319.
Selective laser melting slm is a commonlyused technique for. Selective laser melting slm is a powder metallurgical pm additive manufacturing process whereby a three. In it, a bed of fine powdered metal sits in a sealed chamber, where a 200. Defect formation mechanisms in selective laser melting. Selective laser melting is also known as direct melt laser melting or laser bed fusion. During the slm process, a product is formed by selectively melting successive layers of powder by the interaction of a laser beam. Selective laser melting slm is a powder bed am technology in which parts are fabricated layer by layer using the action of a highenergy beam on a powder bed. The powder bed is considered as a continuous medium. Selective laser melting slm 3d printing simply explained. In this process, the powders are fully melted and solidified. Parametric analysis of the selective laser melting process. The effect of selective laser melting process parameters on.
The slm technique is also commonly known as direct selective laser sintering, lasercusing, and direct metal. Selective laser sintering sls is an additive manufacturing technology developed under sponsorship by the defense advanced research projects agency darpa and acquired in 2001 by 3d systems. Selective laser melting slm is one of the additive manufacturing am methods that demonstrate its value as part of the 21st centurys manufacturing infrastructure. Selective laser melting slm is an additive manufacturing technique which. Performance of high layer thickness in selective laser. Ceramic parts manufactured by selective laser sintering process 56,57. This laser pulses to heat up the metal powder, either to just below melting point this is known as metal laser sintering, or just above melting point which is known as selective laser melting. The process parameters applied for the sample production are listed in table2. Effect of selective laser melting process parameters on.
In slm, there are a number of input parameters that can be controlled and varied in order to get sintered parts with optimized quality. The selective laser sintering process and applications. The additive manufacturing process, selective laser melting is particularly suitable to manufacture such complex and individualized implants. The selection of slm process parameters could control the microstructure of parts and their.
Additive manufacturing and specifically metal selective laser melting slm processes are rapidly being industrialized. Selective laser melting is an additive production technique which makes 3d printing of metal parts possible. A comprehensive model of the selective laser sintering sls process at the scale of the part is presented for application to polymeric powders. Pdf comparison of density of stainless steel 316 l parts. Low cost per part, high productivity, and established materials make the technology ideal for a range of applications from rapid. Binding mechanisms in selective laser sintering and. However, the two technologies differ slightly, in that slm melts pure metals while dmls fuses metal alloys. Thermography for monitoring the selective laser melting. Introduction of slm process university of birmingham. To increase building rate and save cost, the selective laser melting slm of ti6al4v with a high layer thickness 200 m and low cost coarse powders 53 m106 m at a laser power of 400 w is investigated in this preliminary study. Everitt, ian maskery, ian ashcroft, chris tuck skip to main content accessibility help we use cookies to distinguish you from other users and to provide you with a better experience on our websites.
The effect of selective laser melting process parameters. Inprocess sensing in selective laser melting slm additive. The high intensity laser beam makes it possible to completely melt and fuse the metal powder. The renishaw am250 selective laser melting slm system studied in this research belongs to the class of powder bed fusion technologies astm 2012. Selective laser melting of aluminum alloys volume 42 issue 4 nesma t. Much work has already been conducted to investigate the details of the process, suitable materials and process parameters and further more. Slm has been shown to be capable of producing fully dense near netshape components without the need for postprocessing. Capabilities and performances of the selective laser. Part and material properties in selective laser melting of. Economic comparison of selective laser melting and. Capabilities and performances of the selective laser melting process 235 in order to reach a high density, the metallic powder particles are fully molten, laser melting process is accompanied by the development of residual stresses, that derive from high thermal gradients in the material. Selective laser melting is a relatively slow process when compared to traditional machining.
Both demographic change and the need for ever improving medical care have placed new challenges. A comparison of selective laser melting with bulk rapid solidification of alsi10mg alloy. This paper provides an overview of the different binding mechanisms in selective laser sintering sls and selective laser melting slm, thus improving the understanding of these processes. The parts are formed by layers of molten pool, so the shape and continuity of the pool determines the final performance of the part. Online quality control can significantly increase the robustness of the process by. Selective laser melting, or slm, is a type of metal additive manufacturing or 3d printing. Direct metal laser sintering 3d selective laser melting. In slm, complex threedimensional metal parts can be made directly according to a cad data yan et al. Additive manufacturing am offers customization of the microstructures and mechanical properties of fabricated components according to the material selected and process parameters applied.
In addition, with selective laser melting process there is the theoretical possibility of. The author at said it best when they noted that it involved a tortuous marketing path. Defect formation prevention is ensured by controlling the melt pool geometry and by taking into consideration the melting properties. Selective laser sintering sls is an intelligent manufacturing process based on the use of powdercoated metal additives, a process generally used for rapid prototyping and instrumentation. Selective laser melting slm is a particular rapid prototyping, 3d printing, or additive manufacturing am technique designed to use high powerdensity laser to melt and fuse metallic powders. This video demonstrates the process of selective laser melting with slm machines, starting with the requirements through the printing to the final results. If the laser energy input is low, the width of the molten pool is small, which results in an insuf. Selective laser melting of aluminum alloys mrs bulletin. Available formats pdf please select a format to send. Introduction of slm process selective laser melting slm is one of the new additive manufacturing techniques that emerged in the late 1980s and 1990s. In the slm process, a laser selectively melts the metal powders point by point, line by line, and layer by layer to complete the whole part.
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