Electron Beam Melting (EBM) is a metal powder bed fusion (PBF) process in which the heat source is an electron beam. Differently from other metal PBF processes, today, EBM is used for mass production. As-built EBM parts are clearly recognisable by their surface roughness, which is, in some cases, one of the major limitations of the EBM process. The aim of this work is to investigate the effects of the orientation and the slope of the EBM surfaces on the surface roughness. Additionally, the machine repeatability is studied by measuring the roughness of surfaces built at different positions on the start plate. To these aims, a specific artefact was designed. Replicas of the artefact were produced using an Arcam A2X machine and Ti6Al4V powder. Descriptive and inferential statistical methods were applied to investigate whether the surface morphology was affected by process factors. The results show significant differences between the upward and downward surfaces. The upward surfaces appear less rough than the downward ones, for which a lower standard deviation was obtained in the results. The roughness of the upward surfaces is linearly influenced by the sloping angle, while the heat distribution on the cross-section was found to be a key factor in explaining the roughness of the downward surfaces.
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http://dx.doi.org/10.3390/ma12132211 | DOI Listing |
J Colloid Interface Sci
January 2025
State Key Laboratory of New Pharmaceutical Preparations and Excipients, Key Laboratory of Medicinal Chemistry and Molecular Diagnosis of the Ministry of Education, Key Laboratory of Analytical Science and Technology of Hebei Province, College of Chemistry and Materials Science, Hebei University 071002 Baoding, PR China. Electronic address:
In this study, a Co doped polyhedral carbon skeleton (Co CN) was prepared by nitrogen carbonization using ZIF-67 as a precursor. The Co CN features a rough surface with excellent electrical conductivity, and the Co atoms exhibit unique catalytic properties. Based on these characteristics, we used Co CN as a carrier to load Au nanoparticles (NPs) onto its surface through the linkage and reduction effects of polyoxometalates (POMs).
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Department of Food Science, Federal University of Lavras (UFLA), Lavras 37200-000, Brazil.
The use of active packaging made from biodegradable polymers can contribute to the environment and to the food industry by increasing the shelf life of their products. This study aimed to produce chitosan-based films incorporated with the invertase enzyme (1, 2, 5, 9, and 10 %) as an alternative to avoid sucrose crystallization in the confectionery industry. The optimum activity of the invertase enzyme was observed at 55 °C and pH 5, thus, the films made with the film-forming solution adjusted to pH 5 and dried at 55 °C were compared with those without pH adjustment and dried at room temperature.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Department of Chemistry, State University of Maringá, Maringá, PR, Brazil; Laboratory of Materials, Macromolecules, and Composites, Federal University of Technology - Paraná, Apucarana, PR, Brazil; National Institute for Materials Advancement, Pittsburg State University, Pittsburg, KS, USA; Department of Chemistry, Pittsburg State University, Pittsburg, KS, USA. Electronic address:
Polyelectrolyte multilayers (PEMs) based on hyaluronic acid (HA) and poly (diallyldimethylammonium chloride) (PDDA) were deposited on oxidized polystyrene (PS) via the layer-by-layer (LbL) method. The X-ray photoelectron spectroscopy (XPS) confirmed the PEM deposition on PS, and atomic force microscopy (AFM) indicated that the surface roughness of PS also increased after PEM deposition. The PEMs significantly enhanced PS wettability, reducing the contact angle from 73° on PS to 24° on PDDA-terminated (PDDA/HA) PEM (2.
View Article and Find Full Text PDFCureus
December 2024
Medical Affairs, Dr. Reddy's Laboratories Ltd., Hyderabad, IND.
Background Toothbrush manufacturers commonly use bristle materials such as nylon, polybutylene terephthalate, polypropylene, polyethylene terephthalate, boar hair, bamboo, carbon fiber, silicone, polylactic acid, or their modifications such as Curen. Nylon filaments have long been demonstrated to be durable and are widely used, but not much is known regarding the performance of Curen filaments compared to nylon filaments. This in vitro study compared the stiffness, abrasion potential, abrasion resistance, and bristle surface changes of Curen and nylon filaments.
View Article and Find Full Text PDFSci Rep
January 2025
College of Mining, Guizhou University, Guiyang, 550025, Guizhou, China.
Acid fracturing fluids can effectively improve the microporous structure of coal, thereby enhancing the permeability of coal seam and the efficiency of gas drainage. To explore the effects of acid fracturing fluids on the pore structure modification of coal samples from different coal ranks, hydrochloric acid-based acid fracturing fluids were prepared and used to soak four types of medium to high-rank coal in an experiment. High-pressure mercury intrusion and liquid nitrogen adsorption techniques results demonstrated that the acid fracturing fluid can effectively alter the pore structure of coal.
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