The additive manufacturing of thin-walled components is key to producing complex, high-value hollow designs, particularly in the aerospace industry. To master the fabrication of such parts and limit defects that compromise quality, in situ process monitoring is essential. This work implements an off-axis infrared camera to track thermal behavior during LP-DED manufacturing of 316L single-bead walls. The solidification parameters such as the cooling rate, thermal gradient, and solidification rate were extracted from the thermal images and correlated with the microstructural observations. Although trends were identified between process parameters (laser power and scanning speed) and thermal or microstructural characteristics, some of these relationships diverged from expectations in the literature. Geometrical defects, including stacking irregularities and surface roughness, were found to disrupt heat flow, leading to heterogeneous grain morphologies and local alterations in thermal measurements. These findings emphasize the need to account for geometrical defects to ensure reliable thermal monitoring and effective process control. In addition to highlighting the strong influence of geometrical defects, this study demonstrates the potential of in situ IR-based monitoring to predict the microstructure in LP-DED through a comprehensive experimental methodology.
We report an autopsy case in which broncholithiasis mimicked retained ballistic projectiles in a putrefied body. A medico-legal autopsy was performed on a 76-year-old male found in an advanced state of putrefaction. Macroscopic examination during autopsy revealed small, stony intrapulmonary nodules raising suspicion of retained pellets. Whole-body post-mortem computed tomography (PMCT) allowed us to further characterize these elements. The structures were subsequently analyzed using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS) to determine their elemental composition. PMCT demonstrated multiple hyperdense micronodules within the right upper lobe, arranged in a linear endobronchial pattern without metallic artifacts, strongly suggesting a calcified biological origin. SEM-EDS analysis revealed a predominance of calcium and phosphorus, with no evidence of metallic elements typically associated with ballistic materials. These findings and histopathological examination confirmed the diagnosis of broncholithiasis. Broncholithiasis may closely mimic retained ballistic fragments at the macroscopic level in decomposed bodies, representing a significant forensic diagnostic pitfall. While PMCT is key to orienting the diagnosis, this work highlights the value of a multimodal approach combining post-mortem imaging, histopathology, and elemental microanalysis to provide definitive chemical confirmation and prevent misinterpretation of the cause and manner of death.
The concept of quasi-orthotropic laminates has recently developed thanks to the introduction of so-called Double-Double (DD) laminates by Prof. S. TSAI and his team. We propose here to generate a class of quasi-orthotropic (QO) laminates from a “meta-set” consisting of two well-identified sub-sequences. One of which, isotropic in stiffness in its plane with a ply number equal to 3, can be obtained on a Pre-Plied Tape without crimping, so called NCF (Non-Crimp Fabric) tape. Given the low relative thickness required for each sequence, the following study focuses primarily on high-performance laminates—such as CFRPs—for which the aim is the mass optimization. To do this, we will rely on an underutilized property: « All plane laminates made up of orthotropic (e.g., unidirectional) plies derived from one another by rotation in the plane of π n ( n > 2 ) with identical proportions according to each orientation, are isotropic in stiffness in this plane. They have the same modulus of elasticity and the same Poisson’s coefficient ∀ n > 2 ». The following shows that it is possible to generate quasi-orthotropic laminates that are very easy to design and dimension to meet specific requirements. In terms of strength, they also benefit from concepts developed for quasi-orthotropic DD laminates (Omni Strain Failure Envelopes for Laminates).
Cet article dresse un panorama du rôle central des matériaux céramiques dans les secteurs industriels stratégiques et des innovations qui accompagnent leur développement. Il met en évidence leur adoption croissante dans des domaines tels que l’aérospatial, l’énergie, l’électronique, la mobilité électrique et la santé, où leurs propriétés uniques (résistance thermique, stabilité chimique, performances mécaniques ou fonctionnelles) répondent à des exigences extrêmes. Les composites à matrice céramique (CMC), les matériaux pour batteries ou encore les biocéramiques illustrent la diversité des applications. L’article souligne également les avancées majeures en termes de procédés, notamment dans la fabrication additive, qui permet l’élaboration de structures complexes et optimisées, et dans l’intelligence artificielle, qui accélère la découverte de nouveaux matériaux et l’optimisation des procédés. Les nanotechnologies et les matériaux hybrides offrent par ailleurs de nouvelles possibilités d’ingénierie des propriétés grâce à un contrôle fin des microstructures et des interfaces. Cependant, ces évolutions s’accompagnent de défis importants liés à la mise en œuvre des procédés, à la maîtrise des phénomènes physico-chimiques et à l’industrialisation. La stabilité des nanostructures, la gestion des interfaces solides et la montée en échelle restent des enjeux majeurs. Enfin, l’article met en lumière les défis environnementaux et sociétaux associés à l’industrie céramique, notamment la forte consommation énergétique des procédés thermiques, la dépendance aux matières premières critiques et les difficultés de recyclage. Il insiste sur la nécessité de développer des procédés plus sobres, d’intégrer des approches d’analyse du cycle de vie et de s’inscrire dans une logique d’économie circulaire. Ainsi, les céramiques apparaissent comme des matériaux clés pour les transitions technologiques et environnementales, dont le développement futur reposera sur une approche interdisciplinaire et durable.
Differentiating bladed weapons in sharp force trauma remains a critical forensic challenge. While macroscopic examination offers preliminary clues, it often lacks the precision to identify the specific weapon used. Yet, correctly attributing a wound to a particular blade type can be decisive in legal investigations. This study explores the combined use of morphological analysis using Scanning Electron Microscopy (SEM) with elemental analysis via SEM-coupled Energy-Dispersive X-ray Spectroscopy (EDX), to detect unique signatures left by different bladed weapons.We conducted a prospective experimental study using three smooth-bladed knives: a hunting knife, a ceramic knife, and a common utility knife (Opinel type 8). A custom-built machine created standardized stab wounds on ex vivo specimens with consistent pressure. A total of 30 wounds (10 per knife type) were analyzed.Wounds were first examined using SEM to identify specific morphological criteria like groove depth and width. Simultaneously, EDX was used to identify and quantify trace particles from the blades. Analysis was performed on both bone and soft tissue samples to represent conditions of maximal and more realistic deposition. The elemental composition of each blade was determined as a reference, and negative controls ensured sample integrity.While morphological differences exist between wounds produced by each of the weapons, their distinction remains a challenge. Scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX) provides complementary data. A detailed statistical comparison of particle density and nature was performed. Thus, distinct morphological features and characteristic elemental signatures were observed in the wounds. These results demonstrate that a combined morphological and compositional analysis provides an effective method for differentiating sharp force injuries.This research establishes a comprehensive protocol for characterizing sharp force injuries. The findings will enhance forensic investigations by providing a precise, objective method to identify the type of weapon used, thereby making a valuable contribution to forensic pathology.
