Impact of partial rolling on structural integrity and mechanical properties of AA7075 Tailor Alloyed Blanks

Characterization of the mechanical properties and structural integrity of T-welded connections repaired by grinding and wet welding

Purpose Carbon nanotube-based architectures have increased the scientific interest owning to their exceptional performance rendering them promising candidates for advanced industrial applications in the nanotechnology field. Despite individual CNTs being considered as one of the most known strong materials, much less is known about other CNT forms, such as CNT arrays, in terms of their mechanical performance. The paper aims to discuss these issues. Design/methodology/approach In this work, thermal CVD method is employed to produce VA-MWCNT carpets. Their structural properties were studied by means of SEM, XRD and Raman spectroscopy, while their hydrophobic behavior was investigated via contact angle measurements. The resistance to indentation deformation of VA-MWCNT carpets was investigated through nanoindentation technique. Findings The synthesized VA-MWCNTs carpets consisted of well-aligned MWCNTs. Static contact angle measurements were performed with water and glycerol, revealing a rather super-hydrophobic behavior. Originality/value The structural analysis, hydrophobic behavior and indentation response of VA-MWCNTs carpets synthesized via CVD method are clearly demonstrated.

The study seeks to investigate how the duration of storage of cryopreserved human cadaveric iliac arteries impacts their mechanical, structural and microbiological properties as compared to their fresh sample. Iliac arteries were harvested from 12 human cadavers and divided into 2 groups. One group underwent mechanical stress-strain assessment immediately and another was cryopreserved for a pre-determined time-period (range, 29 to 364 days). Mechanical functionality was assessed with a customised clamping mechanism. The arteries' microbiological properties were studied pre- and post-cryopreservation. The post-thawed arteries were also assessed histologically for structural integrity. Of the 12 pairs, only 7 (58, 119, 150, 252, 300, 332 and 364 days) iliac arteries were included in the final analysis. The other 5 pairs (29, 90, 188, 205 and 270 days) had abundant local calcification and their stress-strain curves could not be characterised. From the curves, pre- and post-cryopreserved arteries had the most similar mechanical properties when stored for 119 days. A trend of increasing relative stiffness with increased duration of storage was noted. The post-thawed arteries demonstrated minimal fragmentation except in atherosclerotic areas. Majority of the arteries were not contaminated by bacterial or fungal infection pre- and post-cryopreservation. Also, 2 arteries (364 and 332 days) which had initial bacterial colonisation showed no bacterial growth on their post-thawed sample. Mechanically, non-atherosclerotic cryopreserved arteries can be a good substitute to their corresponding fresh arterial graft. However, the length of cryopreservation has an effect on the relative stiffness of the pre- and post-cryopreserved arteries. Histological and microbiological findings suggest that cryopreservation have little impact on an artery structural integrity and may possibly have a role in maintaining sterility and sterilising the arteries.

Polymeric binders play a critical role in composite solid propellants by firmly bonding all components, forming the matrix and skeleton, and enhancing toughness to maintain the propellants' structural integrity and mechanical properties. Therefore, developing energetic and tough binders is essential. Glycidyl azide polymer (GAP) is widely used in solid propellants, but its poor flexibility leads to a high glass transition temperature. Introducing fluorine into binders can improve thermal stability, optimize the oxygen balance of solid propellants, reduce oxidizer usage, enhance the utilization of energetic materials, and increase propellant energy. In this study, fluorinated polyether was grafted onto the side chains of GAP 1k via click chemistry to synthesize GAP 1k ‐ g ‐F 3 , which was then dual cured with a multifunctional alkyne‐terminated curing agent and an isocyanate‐based curing agent to prepare GAP 1k ‐ g ‐F 3 ‐PTU. The mechanical properties, thermal stability, and microstructure of the elastomers were characterized by uniaxial tensile testing, dynamic thermomechanical analysis, thermogravimetric analysis, and scanning electron microscopy.

Structural, functional and mechanical performance of advanced Graphene-based composite hydrogels

Osteoarthritis (OA) is a disabling chronic disease involving the gradual degradation of joint structures causing pain and dysfunction. Magnetic resonance imaging (MRI) has been widely used as a non-invasive tool for assessing OA-related changes. While anatomical MRI is limited to the morphological assessment of the joint structures, quantitative MRI (qMRI) allows for the measurement of biophysical properties of the tissues at the molecular level. Quantitative MRI techniques have been employed to characterize tissues’ structural integrity, biochemical content, and mechanical properties. Their applications extend to studying degenerative alterations, early OA detection, and evaluating therapeutic intervention. This article is a review of qMRI techniques for musculoskeletal tissue evaluation, with a particular emphasis on articular cartilage. The goal is to describe the underlying mechanism and primary limitations of the qMRI parameters, their association with the tissue physiological properties and their potential in detecting tissue degeneration leading to the development of OA with a primary focus on basic and preclinical research studies. Additionally, the review highlights some clinical applications of qMRI, discussing the role of texture-based radiomics and machine learning in advancing OA research.

Multiscale enhancement of carbon/carbon composite performance by self-assembly of sulfonated graphene with silane-treated carbon fibers

Influence of temperature and hot corrosion on the micro–nanomechanical behavior of protective mullite EBCs

Structural integrity and mechanical properties of the functionally graded material based on 316L/IN718 processed by DED technology

Correlation between arc mode, microstructure, and mechanical properties during wire arc additive manufacturing of 316L stainless steel

In the context of equipment repair and refurbishment, in situ weld overlay on top of existing cladder is not a common practice. Concerns exist regarding the interface’s ability to withstand stresses induced by the weld overlay. This study aims to comprehensively characterize the DetaClad™ [1] interface and its behavior after simulating a weld overlay repair. When considering weld overlay repair options, preserving the cladding emerges as a highly favorable choice. Weld overlay on top of the cladding offers a cost-effective, time-efficient, and prudent approach to refurbishing critical components. By retaining the cladding, the method minimizes disruption to the base material, preserving its integrity and essential mechanical properties. Moreover, this approach prioritizes safety by mitigating potential hazards during the gouging process. The purpose of this research is to demonstrate that weld overlay build-up on top of DetaClad does not compromise the bond quality, nor the mechanical properties of the steel. The test parameters include analyzing the mechanical properties of the interface before and after welding, along with a detailed examination of the mechanical and structural properties of the base and cladder material. In addition, cross section macro and micro examinations are performed to gain valuable insights into their structural integrity. This study demonstrates that weld overlay on DetaClad-cladded surfaces preserves the interface integrity and mechanical properties of the pressure boundary.

Transition metal carbides have attracted considerable attention and are widely used in machining tools, hard coatings and aerospace components, owing to their excellent mechanical and thermal properties. The Zr–C system is a typical refractory and hard transition-metal carbide, and its structural integrity and stability under extreme conditions are critical for practical applications. Here, a computational study focusing on the structural stability and crystal evolution pattern of Zr2C under ambient and high-pressure conditions was performed using a particle-swarm optimization algorithm, in combination with first-principles calculations. The calculations identified seven viable stable or metastable crystalline phases of Zr2C, exhibiting Fd 3 m, R 3 m, Cmcm, Cmca, Pbcn, Pnma and I4/mcm symmetries; further, a series of structural phase transitions were determined as the pressure increased: Fd 3 m → R 3 m → Cmcm → Cmca. In addition, the mechanical and dynamical stabilities of these phases were verified, and their structural properties were investigated. Overall, this work reveals valuable information concerning the structural, mechanical and electronic properties of Zr2C, providing key insights into the mechanisms underlying its crystal evolution behavior.

Cuckoopint (Arum maculatum), an edible wild plant species, grows in Asia, Europe, and North Africa. The aerial parts of the plant are consumed as food. The plant's tubers are used in traditional folk medicine to treat gastrointestinal disorders. When consumed fresh, the plant's tubers have a toxic effect, and the dried form is safe if it does not exceed a certain amount. Tuber powders can also have a poisonous effect when taken in excessive amounts accidentally and unconsciously. In this study, it was investigated whether it is possible to prepare the powder obtained by drying the tubers of the edible wild plant A. maculatum by encapsulating it with chitosan, an edible, biocompatible, mucoadhesive polysaccharide, in specific doses. A. maculatum-chitosan microcapsules were prepared with A. maculatum tuber powder and chitosan. The effects of medium parameters such as pH, temperature, and ionic strength on the microcapsules' structural integrity and release properties were investigated. Encapsulation of tuber powders prepared in specific formulations into microcapsules can help prevent accidental overdose by the public. Commercial storage, transport, and marketing of cuckoopint tuber powder may be possible through encapsulation.

This article reports research on the development and implementation of new methods for structurally integrated and recyclable polymer based electronic products via multi-head fused deposition modelling (FDM) 3D printing. The focus of this research is to propose an efficient FDM-3D printing process utilising multiple filaments with no interruption of the process to ensure the multi-material electronic product achieved is structurally integrated. Such research is an attempt towards development of recyclable rigid electronic structures via multi-material 3D printing, i.e., multiple conductive nanomaterial embedded thermoplastic and non-conductive thermoplastic layers (in coil forms, herein). Six radio frequency identification (RFID) tag coil geometries were selected for the study. The thermoplastic polymer used in this research was polylactic acid (PLA), and the conductive filament was carbon black nanoparticle embedded PLA at approx. 21 wt.%. The nozzle and filaments diameters examined were 1.75 mm. A MakerBot Replicator 2X 3D printer was partially disassembled to be equipped with a dual head, for our examinations. The research investigated the major challenges ahead of the proposed development, mainly, on the deteriorating effects on the quality of the integrated product (structural integrity, electric and magnetic properties) induced by the 3D printing process parameters (e.g., temperature). The most efficient nozzle and bed temperatures to prevent visible defects were found to be higher than the supplier’s recommendation, attributed to the uncertainties associated with the multi-material composition, and were found to require 248 and 100 °C for reliable and continued FDM printing, respectively. The measurements on the electric and magnetic properties, using 4-wire resistance and Hall effect method, respectively, were conducted to quantify process induced deteriorating effects, quantitatively. It has been examined whether the multi-material electronic structure can be achieved via uninterrupted (continuous) processing of polymer nanocomposite-based identification systems for recyclability purpose whilst maintaining the electromagnetic properties of it, a promising technology for reducing landfill. Recommendations were identified for best practices behind such development.

Graphene nanocoating on titanium maintains structural and antibiofilm properties post-sterilization