Advanced Engineering Materials最新文献

This study develops a novel melt foaming technique for fabricating aluminum foam-filled tubes (FFTs) with in situ bonding. Through a high-temperature foaming process within a dynamically rotating mold, the foam and tube of FFT are cofabricated. The microstructure of FFT is observed, and the compression performance of FFT is also explored. The results demonstrate that the plateau stress of FFT is 25.50 MPa. The energy absorption and specific energy absorption of FFT are 12.75 MJ m⁻³ and 15.0 kJ kg⁻¹, respectively. Due to the in situ bonding, the energy absorption of FFT is increased by 87.2%. The stress remains stable in the axial compression process, and no macroscopic fracture occurs in FFT. Finite element models based on specimens are reconstructed by X-ray tomography. The tensile test is applied to the tube of FFT to obtain the parameters of the finite element simulation. The results of the finite element simulation also show that the composite structure of FFT deforms cooperatively in axial compression. The purpose of this study is to provide a high-efficiency strategy for achieving a composite structure aluminum foam with superior energy absorption and overcoming bonding failure during the deformation process.

Triply periodic minimal surface (TPMS) lattices are an emerging class of cellular materials with excellent potential for lightweight structural and energy-absorbing applications. In this study, gyroid (G), diamond (D), and primitive (P) architectures were fabricated via fused filament fabrication (FFF) using three material configurations: (i) single-phase polylactic acid (PLA) or polyethylene terephthalate glycol (PETG); (ii) layered PLA-PETG composite structures (50/50), in which the lower half was printed with PLA and the upper half with PETG; and (iii) layered composites with PLA shells and PETG cores. Quasi-static compression tests were combined with finite element simulations to elucidate stress distribution, deformation mechanisms, and collapse progression. The results demonstrate that homogeneous blends delay crack initiation and enhance specific energy absorption through progressive collapse, while layered composites improve stability by redirecting stresses via the PLA shell. Finite element analysis successfully captured shear banding, layer-wise buckling, and localized fracture, confirming the predictive capability of the simulations. The findings highlight the strong interplay between lattice geometry and material configuration in tailoring mechanical performance and provide guidelines for the design of multifunctional polymer-based cellular composites produced by additive manufacturing.

To meet the urgent need for lightweight impact-resistant structures in new energy vehicles battery protection, an aluminum-honeycomb/basalt-fiber composite panel is proposed as a novel protective underbody, offering lightweight design, high specific strength and energy absorption. Drop-weight impact testing was conducted to characterize the dynamic mechanical response, and high-speed three-dimensional digital image correlation (3D-DIC) was used to quantify the influence of the thickness of the aluminum facesheet, basalt fiber ply count, core density of the aluminum honeycomb, and impact energy on the impact resistance. The peak impact force increased by factors of 3.60, 3.98, and 4.85 relative to the aluminum baseline. The dominant failure modes were penetration, tearing, and buckling. The ultimate load-carrying capacity of the panels with aluminum honeycomb core increases by factors of 4.54, 5.62, and 6.71 relative to aluminum. Local indentation and honeycomb crushing are the prevailing deformation modes, and no perforations occur. The aluminum honeycomb significantly enhances the panel stiffness and impact resistance. With increasing impact energy, the delaminationand tearing is delayed by crack bridging in the basalt fiber plies and interlaminar constraint, while progressive core crushing combined with face-sheet plasticity established multiple energy-dissipation pathways.

This study investigates the friction and wear mechanisms of CrN, AlCrN, TiN, and AlTiN coatings deposited on SUS316L stainless steel. The experiments are conducted under 50% humidity and a 5 N normal load, combining tribological tests with numerical simulation. The results show that the TiN coating paired with an Al₂O₃ ball exhibits the lowest wear rate of 8.9 × 10⁻⁴ mm³ (N·m)⁻¹. In contrast, the AlCrN coating with ZrO₂ ball achieves the lowest coefficient of friction of 0.318. The dominant wear mechanism is determined by the coating material. Specifically, TiN shows slight adhesive and fatigue wear, AlTiN experiences abrasive wear, and AlCrN exhibits fatigue wear. Furthermore, oxidative wear occurs in all coatings, with the highest degree in AlTiN and the lowest in CrN and AlCrN. Numerical simulations corroborate these findings, indicating that the stress distribution patterns vary with different ball-coating pairs and that the coating material is the primary factor influencing the stress distribution.

An ultrafine-grained magnesium alloy has been produced through room temperature high-pressure torsion (HPT) of solutionized Mg–1.35 wt% Mn. Dynamic precipitation of nanometer-scale Mn particles occurs during deformation. These particles populate the grain boundaries, acting as pinning sites which allow the alloy to develop a grain size of 140 nm after 0.5 rotations. Further, HPT deformation results in a gradual increase in grain size with no increase in precipitate size. Despite the extensive deformation applied, the alloy does not develop a bimodal grain structure and retains a grain size of 230 nm after 10 complete rotations, demonstrating the stability and effectiveness of these pinning particles.

This study investigates the mechanical performance of three auxetic structures: re-entrant, re-entrant-star hybrid, and S-shape, to identify the most effective design for high-impact applications. Among these, the re-entrant-star hybrid structure demonstrates superior specific energy absorption (SEA), achieving 0.92 ± 0.12 J g⁻¹, attributed to its combination of re-entrant and star-shaped elements, which enhances both energy dissipation and structural integrity. In contrast, the re-entrant and S-shaped structures recorded SEAs of 0.80 ± 0.02 and 0.19 ± 0.05 J g⁻¹, respectively. The hybrid structure also exhibits the highest crush force efficiency (CFE) and equivalent plateau stress (EPS), highlighting its ability to maintain consistent load-bearing capacity and to sustain stress during compression. Flexural and impact tests further validate the hybrid structure's performance, with notable improvements in bending strength and impact resistance. To further enhance its performance, finite element analysis (FEA) simulations are conducted to optimize geometric parameters, specifically strut thickness and inclination angle, to maximize mechanical performance. Postoptimization, the SEA of the re-entrant-star structure increases by 449%, EPS by 3400%, and in-plane flexural modulus by 514%. These results demonstrate the effectiveness of optimizing geometric parameters to maximize the mechanical performance of auxetic structures for applications requiring high-energy absorption.

Silicon anodes are considered to be the most promising new generation materials of Li-ion batteries. However, silicon anode undergoes significant volume expansion during charging, inducing cracking and deteriorating battery capacity and life span. Therefore, investigating the failure behavior and mechanism of silicon film anodes is crucial for ensuring the safety of batteries. In this article, a finite element model of high-capacity silicon anode film bonded copper current collector is established based on mechanical and chemical coupling effect combined with a thermal-analogy method. Volume expansion, Li-ion concentration distribution, and stress evolution of the silicon electrode thin film during the charge process are analyzed. A series of thickness silicon film-current collector models are further established, and the thickness effect of silicon film on state of lithiation at critical interface cracking is studied. The results show that stress changes resulting from Li-ion concentration variations can induce the risk of interface cracking. As the silicon film thickness decreases, its critical fracture strain and critical state of lithiation are higher, resisting interface peeling better and having better chemical and mechanical properties. This research provides a guideline for the dimensional design of silicon thin film electrode.

This article explores the tribological behaviors of Zr_46.5Cu₄₅Al₇Ti_1.5 bulk metallic glass (BMG) during linear reciprocating sliding against WC ball under different loads. The time-dependent coefficient of friction indicates the presence of a significant “Running-in” stage during wear tests, with the duration of this stage extending as the normal load increases. The structural characteristics of the samples are examined using X-ray diffraction, which confirmed their noncrystalline nature. The wear surfaces and debris of the BMG and WC ball are analyzed using scanning electron microscopy coupled with energy-dispersive spectroscopy. The results demonstrate that the predominant wear mechanisms at low loads are abrasive and adhesive wear, accompanied by minimal oxidative wear. Under high loads, adhesive and oxidative wear dominate. A high wear rate is associated with adhesive wear, whereas a low wear rate is linked to oxidative wear.

With respect to process and resource efficiency, semisolid casting processes, such as rheocasting, represent promising technologies for processing lightweight materials in the automotive industry. The reduced temperature of the melt during the casting process allows longer service life for the molds and less production rejects in industrial applications. However, up to now process–microstructure–property correlations have not been investigated in detail. Most studies focusing on these processes are producing simple geometries without a reduction in the cross section. Moreover, mechanical properties are only tested in the quasistatic regime. The present study investigates specimens taken from application-oriented parts. These specimens are examined comprehensively, i.e., from microstructure to the fatigue properties, and are compared to high pressure die cast counterparts. Based on the main findings, the following conclusion can be drawn: Although some differences can be found with respect to the microstructure appearance, under quasistatic loading the results are similar for the die cast and rheocast material (with a yield strength of 125 MPa and ultimate tensile strength of 240 MPa); however, with respect to fatigue properties in the low-cycle fatigue regime, the rheocast material shows reduced scatter: Thus, rheocasting is found to be the method of choice when improved fatigue properties are required.

Magnetic freeze-casting is an up-and-coming method used to fabricate porous structures that are light in weight, yet relatively high in strength for biomedical and aerospace applications. A method has recently been discovered using magnetic fields to create effectively 100% microstructural alignment in freeze-cast scaffolds, resulting in impressive mechanical properties. Unfortunately, these results are limited to materials that are ferrimagnetic in nature. Previously, the magnetic field strength and the magnetic susceptibility of the particles used were thought to be the primary limiting factors to achieving 100% microstructural alignment. Recent work suggests there may be other factors at play that are preventing the microstructure from aligning. This work investigates these factors and identifies the voltage generated by the resistance temperature detector temperature controller, which is often employed in freeze-casting to control the freezing rate, as a significant factor. The voltage generated by the temperature controller affects the ability to align the microstructure of freeze-cast scaffolds using magnetic fields and therefore should be considered when trying to align microstructures.