Search Results (7)

Additive manufacturing of metals is limited by a fundamental tradeoff between deposition rates and manufacturability of fine-scale features. To overcome this problem, a laser-ablated bound metal deposition (laBMD) process is demonstrated in which 3D-printed green-state bound metal deposition (BMD) parts are post-processed via laser ablation prior to conventional BMD debinding and sintering. The laBMD process is experimentally characterized via a full-factorial design of experiments to determine the effect of five factors—number of laser passes (one pass, three passes), laser power (25%, 75%), scanning speed (50%, 100%), direction of laser travel (perpendicular, parallel), and laser resolution (600 dpi, 1200 dpi)—on as-sintered ablated depth, surface roughness, width, and angle between ablated and non-ablated regions. The as-sintered ablation depth/pass ranged from 3 to 122 µm/pass, the ablated surface roughness ranged from 3 to 79 µm, the angle between ablated and non-ablated regions ranged from 1° to 68°, and ablated bottom widths ranged from 729 to 1254 µm. This study provides novel insights into as-manufactured ablated geometries and surface finishes produced via laser ablation of polymer–metallic composites. The ability to inexpensively and accurately manufacture fine-scale features with tailorable geometric tolerances and surface finishes is important to a variety of applications, such as manufacturing molds for microfluidic devices. Full article

Bound metal deposition (BMD) additive manufacturing technique was used to fabricate gears of PH 17-4 stainless steel material. The gears were fabricated with different layer heights (namely 150 μm and 50 μm) and also subjected to post-fabrication machining. Each gear was tested against commercially available gear in a high-precision control test rig. The operational temperature and noise level were measured during the test, while the material loss due to wear was evaluated at the end of the test. The 50 μm layer height gear performed the best with the least wear loss, minimum noise generation, and temperature rise. The 150 μm layer height gear, which was mechanically polished, performed very similarly to it (50 μm layer height gear) and cost 33% less to print; thus, it was considered the best performing when cost was incorporated. The conclusions found that post machining of printed parts greatly impacts their performance, and thus, the post-print conditions should be considered just as much as the printing conditions. Full article

Choosing the right metal AM equipment and material is a highly intricate process that forms a crucial part of every manufacturing company’s strategic plan. This study undertakes a comprehensive comparison of the performance and material properties of three Metal Additive Manufacturing (AM) technologies: Powder Bed Fusion (PBF), Metal Filament Deposition Modeling (MFDM), and Bound Metal Deposition (BMD). An automotive nozzle was selected and manufactured using all three technologies and three metallic materials to understand their respective advantages and disadvantages. The samples were then subjected to a series of tests and evaluations, including dimensional accuracy, mechanical properties, microstructure, defects, manufacturability, and cost efficiency. The nozzle combinations were PBF in aluminum, MFDM in stainless steel, and BMD in hard tool steel. The results underscore significant differences in functionality, material characteristics, product quality, lead time, and cost efficiency, all of which are crucial factors in making equipment investment decisions. The conclusions drawn in this paper aim to assist automotive industry equipment experts in making informed decisions about the technology and materials to use for parts with characteristics like these. Future studies will delve into other technologies, automotive components, and materials to further enhance our understanding of the application of metal AM in manufacturing. Full article

Metal additive manufacturing (AM) technologies can be classified according to the physical process involving the raw material as fusion-based and solid-state processes. The latter includes sintering-based technologies, which are aligned with conventional fabrication techniques, such as metal injection molding (MIM), and take advantage of the freeform fabrication of the initial green part. In the present work, 17-4PH stainless steel samples were fabricated by material extrusion, or rather bound metal deposition (BMD), a solid-state AM technology. The powder-based raw material was characterized together with samples fabricated using different angular infill strategies. By coupling different characterization technologies, it was possible to identify and classify major properties and defects of the raw material and the fabricated samples. In addition, microstructural modifications were found to be linked with the mesostructural defects typical of the BMD solid-state additive manufacturing technology applied to metals. Full article

Currently, metal additive manufacturing (MAM) has been receiving more attention in many sectors for its production of metal parts because MAM effortlessly enables the fabrication of complex metal parts and provides faster and more sustainable manufacturing than conventional processes. Recently, a MAM-using bound metal deposition (BMD) has been proposed as a user-friendly manufacturing method that can provide low-volume production, economical metal parts, and operation safety. Since the BMD technique is new, information on the mechanical properties of MAM parts using this technique has not been sufficiently provided. This paper aims to study the mechanical properties of MAM parts manufactured by the BMD technique, examining the elastic modulus, yield strength, ultimate strength, and fatigue behavior of the parts with different relative densities. The MAM parts made from 316L and 17-4PH stainless steel were investigated using tensile and fatigue tests. Some mechanical properties of the infill parts in this study were validated with formulas from the literature. The weight efficiency is used as an index to assess the efficiency of the infill parts with different densities by examining the relationship between the mechanical properties and the weight of the MAM parts. The experimental results and a discussion of the weight efficiency assessment are presented as a novel information report on MAM products fabricated by BMD technology. Full article

Additive manufacturing is a promising and emerging technology that can transform the global manufacturing and logistics by cutting costs and times of production. Localized corrosion resistance properties of 0°, 45°, and 90° build-up orientations of 17-4 PH as-sintered samples, manufactured by means of Bound Metal Deposition (BMD), have been investigated by electrochemical and morphological investigations. The cyclic potentiodynamic polarization curves and the open circuit potential monitoring, together with potential drop analysis, revealed that the BMD localized corrosion resistance properties were lowered if compared to a wrought 17-4 PH: a characteristic anodic behavior and many drops in potential were recorded for BMD, whilst the wrought specimens presented a typical passive behavior with pitting corrosion. Morphological investigations by scanning electron microscopy and energy-dispersive X-ray analysis revealed the presence of porosities and defects, especially for the 90° build-up orientation, and inclusions of SiO₂. The 45° build-up orientation showed the best corrosion resistance properties among all the BMD specimens, even though defects and porosities were observed, suggesting that their morphology and geometry influenced the overall corrosion behavior. Full article

Bound Metal Deposition (BMD) is an alternative to the most common additive manufacturing (AM) technology for metal parts, Powder Bed Fusion (PBF), since the equipment used is more affordable and there are no risks due to exposure to loose powder and lasers or beams. However, the mechanical properties of parts manufactured by BMD are generally lower than those of PBF, making it necessary to study the process parameters to improve their performance. The aim of this work was to analyse the effect of different process parameters on the mechanical properties of 316L parts manufactured by BMD based on a set of specially designed experiments. The methodology followed in this research was thus based on the manufacturing of a series of samples with variations of the build orientation, infill pattern and chamber temperature followed by subsequent characterization and analysis. The microstructural analysis showed that voids were formed as a consequence of the air gaps generated between rasters during printing. It was observed that the characteristics of these macropores had a significant effect on the mechanical properties. The location, distribution and shape of these macropores depended on the alignment of rasters in each of the conditions, which varied with build orientation and infill pattern. Regarding the build orientation, horizontal parts exhibited lower porosity and considerably higher ultimate tensile strengths (UTS), approximately 160 MPa higher, than vertical samples. With respect to the infill pattern, horizontal parts with a concentric infill pattern showed triangular voids and a total porosity higher than 5%. However, samples with line infill patterns presented elongated macropores and a total porosity lower than 5%, properties that resulted in an improvement in UTS of 20 MPa, approximately. Overall, the results presented here offer a better comprehension of the effect of the BMD process parameters on mechanical properties and serve as a guideline for future work. Full article