In this study, to improve the fatigue strength of the LDED (laser-directed energy deposition) 316L stainless steel, an in situ ultrasonic rolling technology is developed to assist the laser-directed energy deposition process (LDED-UR). The microstructural characteristics and fatigue behavior are comprehensively discussed. The results show that the average size of pores of the LDED-UR alloy is about 10.2 μm, which is much smaller than that of the LDED alloy (34.1 μm). Meanwhile, the density of the LDED alloy is also enhanced from 98.26% to 99.27% via the in situ ultrasonic rolling. With the application of the in situ ultrasonic rolling, the grains are transformed into fully equiaxed grains, and their average grain size is greatly reduced from 84.56 μm to 26.93 μm. The fatigue limit of the LDED-UR alloy is increased by 29% from 210 MPa (LDED alloy) to 270 MPa, which can be ascribed to the decreased porosity and the fine grains. In particular, the crack initiation site of the LDED alloy is located at the surfaces, while it is nucleated from the sub-surface for the LDED-UR alloy. This is mainly attributed to the compression residual stress induced by the in situ ultrasonic rolling. This research offers a valuable understanding of the failure mechanisms in additively manufactured metals, guiding the development of effective strategies to improve their fatigue threshold under severe operating conditions.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC11313255 | PMC |
| http://dx.doi.org/10.3390/ma17153693 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Catalyst-Free Nitrogen Fixation by Microdroplets through a Radical-Mediated Disproportionation Mechanism under Ambient Conditions.
J Am Chem Soc
January 2025
State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, College of Chemistry and Chemical Engineering, Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen 361005, China.
Nitrogen fixation is essential for the sustainable development of both human society and the environment. Due to the chemical inertness of the N≡N bond, the traditional Haber-Bosch process operates under extreme conditions, making nitrogen fixation under ambient conditions highly desirable but challenging. In this study, we present an ultrasonic atomizing microdroplet method that achieves nitrogen fixation using water and air under ambient conditions in a rationally designed sealed device, without the need for any catalyst.
View Article and Find Full Text PDFAssembly of 3-(Tetrazol-5-yl)triazole Complexes with Ammonium Perchlorate for High-Performance Energetic Composites.
ACS Appl Mater Interfaces
January 2025
Department of Mechanical Engineering, City University of Hong Kong, 83 Tat Chee Avenue, Hong Kong, SAR, China.
Advanced energetic composites possess promising properties and wide-ranging applications in explosives and propellants. Nonetheless, most metal-based energetic composites present significant challenges due to surface oxidation and low-pressure output. This study introduces a facile method to develop energetic composites Cutztr@AP through the intermolecular assembly of nitrogen-rich energetic coordination polymers and high-energy oxidant ammonium perchlorate (AP).
View Article and Find Full Text PDFStrongly Coupled Interface in Electrostatic Self-Assembly Covalent Triazine Framework/BiSBr for High-Efficiency CO Photoreduction.
ACS Nano
January 2025
School of Chemistry and Chemical Engineering, National Special Superfine Powder Engineering Research Center, Nanjing University of Science and Technology, Nanjing 210094, China.
Constructing a strong bonded interface is highly desired to build fast charge-transfer channels and tune reactive sites for optimizing CO photoreduction. In this work, a covalent triazine framework (CTF) combined with a BiSBr heterojunction is designed using an electrostatic self-assembly process. Due to the oppositely charged states between two components and ultrasonic treatment, a strong coupled interface is realized with the formation of Bi-C/N/O bonds, leading to robust interfacial polarization.
View Article and Find Full Text PDFLignin Particle Size Affects the Properties of PLA Composites Prepared by In Situ Ring-Opening Polymerization.
Polymers (Basel)
December 2024
Laboratory of Polymer and Colors Chemistry and Technology, Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
The present work focuses on the synthesis and characterization of biobased lignin-poly(lactic) acid (PLA) composites. Organosolv lignin, extracted from beechwood, was used as a filler at 0.5, 1.
View Article and Find Full Text PDFDevelopment of Amniotic Epithelial Stem Cells Secretome-Loaded Inverse Electron Demand Diels-Alder-Cross-Linked Hydrogel as a Potential Immunomodulatory Therapeutical Tool.
ACS Appl Mater Interfaces
January 2025
Drug Research Program, Division of Pharmaceutical Chemistry and Technology, University of Helsinki, 00014 Helsinki, Finland.
Article Synopsis
- Amniotic epithelial stem cells (AEC) have regenerative potential, particularly through their conditioned medium (AEC-CM), which shows immunomodulatory and regenerative effects.
- A novel hydrogel made from hyaluronic acid and polyethylene glycol was developed to encapsulate AEC-CM, with features like fast cross-linking and sustained growth factor release over 14 days.
- Studies demonstrate that the encapsulated AEC-CM significantly enhances the suppression of peripheral blood mononuclear cells and promotes a shift towards the beneficial M2 macrophage phenotype, suggesting its viability as an immunomodulatory treatment for tissue regeneration.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!