- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Design Concepts for the Integration of Electronic Components into Metal Laser-based Powder Bed Fusion Parts
摘要： Additive manufacturing (AM) stands out from other manufacturing processes because it enables covering the functionality of an assembly by one single component only. In order to further increase the functional density in AM parts, it is of interest to integrate sensors in metal components during the Laser-based Powder Bed Fusion manufacturing process. This paper presents design concepts that facilitate an automated integration process of electronic components by using specific and individual criteria. In consideration of an automated embedding process, a standardized solid is outlined to unify different sensor types in a design space.
关键词： design concepts,embedded electronics,laser-based powder bed fusion,additive manufacturing,sensor integration
更新于2025-09-19 17:13:59
-
Additive Manufacturing of Three-dimensional Metal-glass Functionally Gradient Material Components by Laser Powder Bed Fusion with In situ Powder Mixing
摘要： Existing commercial three-dimensional (3D) printing systems based on powder bed fusion approach can normally only print a single material in each component. In this paper, functionally gradient materials (FGM) with composition variation from a copper alloy to a soda-lime glass were manufactured using a proprietary nozzle-based multi-material selective laser melting (MMSLM) system. An in situ powder mixing system was designed to mix both metal and glass powders at selective ratios and the mixed powders were dispensed with an ultrasonic vibration powder feeding system with multiple nozzles. From the cross section analysis of the gradient structures, glass proportion increased gradually from the metallic matrix composite (MMC), transition phase to ceramic matrix composite (CMC). The pure copper alloy joined the MMC part and the pure glass phase penetrated into the CMC part during laser processing, which anchored the glass phase, as the main mechanism of combining pure metal and pure glass by FGM in 3D printed parts. From results of indentation, tensile and shear tests on the gradient material samples, it showed that mechanical properties of the FGM gradually changed from ductility (metal side) to brittle (glass side). The weakest part of the FGM structure occurred at the interface between transition phase and the CMC, which was also the interface between the ductile and brittle phases.
关键词： copper-glass,Powder Bed Fusion,horizontal gradient structure,multi-material selective laser melting,functionally gradient materials
更新于2025-09-19 17:13:59
-
On the Relevance of Volumetric Energy Density in the Investigation of Inconel 718 Laser Powder Bed Fusion
摘要： Laser powder bed fusion (LPBF) can fabricate products with tailored mechanical and surface properties. In fact, surface texture, roughness, pore size, the resulting fractional density, and microhardness highly depend on the processing conditions, which are very difficult to deal with. Therefore, this paper aims at investigating the relevance of the volumetric energy density (VED) that is a concise index of some governing factors with a potential operational use. This paper proves the fact that the observed experimental variation in the surface roughness, number and size of pores, the fractional density, and Vickers hardness can be explained in terms of VED that can help the investigator in dealing with several process parameters at once.
关键词： additive manufacturing,surface roughness,laser powder bed fusion
更新于2025-09-19 17:13:59
-
Contribution of cellulosic fibre filter on atmosphere moisture content in laser powder bed fusion additive manufacturing
摘要： Cellulosic materials are commonly used to manufacture the particulate filters used in laser powder bed fusion (LpBf) additive manufacturing (AM) equipment. An experimental approach has been used to calculate the moisture quantity and kinetics of sorption in a cellulosic filter at varying relative humidity (RH) levels. A prediction of the amount of moisture which can be theoretically held within a filter during storage before its use has been obtained. Subsequently, the quantity and the rate of moisture desorption which can be transferred into the build chamber during LpBf is presented. this work highlights the importance of filter storage and conditioning prior to use in additive manufacturing processing.
关键词： laser powder bed fusion,cellulosic fibre filter,atmosphere moisture content,additive manufacturing
更新于2025-09-19 17:13:59
-
The role of side-branching in microstructure development in laser powder-bed fusion
摘要： In-depth understanding of microstructure development is required to fabricate high quality products by additive manufacturing (for example, 3D printing). Here we report the governing role of side-branching in the microstructure development of alloys by laser powder bed fusion. We show that perturbations on the sides of cells (or dendrites) facilitate crystals to change growth direction by side-branching along orthogonal directions in response to changes in local heat flux. While the continuous epitaxial growth is responsible for slender columnar grains confined to the centreline of melt pools, side-branching frequently happening on the sides of melt pools enables crystals to follow drastic changes in thermal gradient across adjacent melt pools, resulting in substantial broadening of grains. The variation of scan pattern can interrupt the vertical columnar microstructure, but promotes both in-layer and out-of-layer side-branching, in particular resulting in the helical growth of microstructure in a chessboard strategy with 67° rotation between layers.
关键词： microstructure development,additive manufacturing,thermal gradient,side-branching,epitaxial growth,laser powder bed fusion,3D printing
更新于2025-09-19 17:13:59
-
Technological Feasibility of Lattice Materials by Laser-Based Powder Bed Fusion of A357.0
摘要： Lattice materials represent one of the utmost applications of additive manufacturing. The promising synergy between additive processes and topology optimization finds full development in achieving components that comprise bulky and hollow areas, as well as intermediate zones. Yet, the potential to design innovative shapes can be hindered by technological limits. The article tackles the manufacturability by laser-based powder bed fusion (L-PBF) of aluminum-based lattice materials by varying the beam diameter and thus the relative density. The printing accuracy is evaluated against the distinctive building phenomena in L-PBF of metals. The main finding consists in identification of a feasibility window that can be used for development of lightweight industrial components. A relative density of 20% compared with fully solid material (aluminum alloy A357.0) is found as the lowest boundary for a 3-mm cell dimension for a body-centered cubic structure with struts along the cube edges (BCCXYZ) and built with the vertical edges parallel to the growth direction to account for the worst-case scenario. Lighter structures of this kind, even if theoretically compliant with technical specifications of the machine, result in unstable frameworks.
关键词： additive manufacturing,lattice,aluminum alloy,laser-based powder bed fusion
更新于2025-09-19 17:13:59
-
Mesoscopic-scale simulation of pore evolution during laser powder bed fusion process
摘要： Laser powder bed fusion (LPBF) is an advanced manufacturing technology that uses data-driven, layer-by-layer accumulation of materials to form metal components and has been widely applied in aerospace and other fields. Effectively controlling pore defects is a key scientific problem and technical difficulty in LPBF industrial production. Based on the open-source discrete element method code Yade, the particle distribution of the powder bed was obtained. Based on the open-source computational fluid dynamics code OpenFOAM, the pore evolution during the LPBF formation process at the mesoscopic scale was predicted. The thermal–force factors affecting the molten pool included the surface tension, Marangoni effect, gasification recoil force, and mushy drag force. The laser energy model used a body heat source based on interface tracking. First, dimensionless analysis of the molten pool evolution in the case of LPBF single-track formation was carried out. The molten pool evolution was mainly influenced by the gasification recoil force, Marangoni effect and surface tension, and the main influencing factors on different zones of the molten pool were different. To examine the influences of the laser power, scanning speed, powder bed thickness, and hatch space on the pore defect in the LPBF formation process, simulations were carried out and compared with experimental results. When the volumetric energy density was too small, pore defects occurred due to insufficient fusion of metal particles, and when the volumetric energy density was too large to cause the “keyhole” effect, pore defects occurred because the entrained gas could not escape in time. This paper is expected to provide theoretical guidance for the scientific regulation of pore defects in LPBF production.
关键词： OpenFOAM,Volumetric energy density,Dimensionless analysis,Pore defect,Laser powder bed fusion,Numerical simulation
更新于2025-09-19 17:13:59
-
In-situ optical emission spectroscopy of selective laser melting
摘要： The variances in local processing conditions during Selective Laser Melting (SLM), a powder bed Additive Manufacturing (AM) process, can cause defects that lead to part failure. The nature of SLM permits in-situ monitoring of radiometric signals emitted from the part surface during the process, including optical emission from excited alloying elements. Using Optical Emission Spectroscopy (OES) to measure the spectral content of light emitted gives insight into the chemistry and relative intensities of excited species vaporized during SLM processing. The contribution from investigating the use of in-situ OES to gain information about local processing conditions during SLM is reported in this paper. A spectrometer is split into the SLM system laser beam path to measure visible light emitted from the melt pool and plume during the processing of 304L stainless steel. The in-line configuration allows signal collection regardless of the laser scan location. The spectroscopic information is correlated to the melt pool size and features of SLM samples for various build conditions (i.e., process parameters, build chamber atmosphere type, and pressure).The limitations that exist in OES implementation for certain build chamber conditions are discussed. The results in this paper are initial progress towards the use of OES in SLM part qualification and controls applications.
关键词： Metal additive manufacturing,Optical emission spectroscopy,In-situ monitoring,Powder bed fusion
更新于2025-09-19 17:13:59
-
Processability of Atypical WC-Co Composite Feedstock by Laser Powder-Bed Fusion
摘要： Processing of tool materials for cutting applications presents challenges in additive manufacturing (AM). Processes must be carefully managed in order to promote the formation of In this study, for the ?rst time, a satelliting process is used to prepare a WCM-Co (12 wt.% Co) composite. Melting trials were undertaken to evaluate the consolidation behaviour of single tracks within a single layer. Tracks with continuous and relatively uniform surface morphology were obtained. These features are essential for high-quality AM builds in order to encourage good bonding between subsequent tracks within a layer which may reduce porosity within a 3D deposition. This study elucidates the formation of track irregularities, melting modes, crack sensitivity, and balling as a function of laser scanning speed and provides guidelines for future production of WCM-Co by laser powder-bed fusion.
关键词： WCM-Co,satelliting,melt mode,single tracks,laser-powder bed fusion (L-PBF)
更新于2025-09-16 10:30:52
-
Effect of Selective Laser Melting Process Parameters and Heat Treatment on Microstructure and Properties of Titanium Alloys Produced from Elemental Powders
摘要： This work investigates Selective Laser Melting (SLM) process as a method of in-situ synthesis of Ti-5Al and Ti-6Al-4V alloys using elemental powder mixture. Elemental spherical powders were used to prepare a powder mixture and the samples were produced by SLM process using different volume energy densities. The effects of volume energy density on the samples’ relative density, chemical composition, microstructure and microhardness before and after heat treatment have been studied. It was shown that volume energy density significantly effects the density and microstructure of Ti-5Al and Ti-6Al-4V alloys, as well as, the microhardness of obtained Ti-6Al-4V.
关键词： additive manufacturing,in-situ synthesis,titanium alloy,powder bed fusion,elemental powders
更新于2025-09-16 10:30:52