Advanced Engineering Materials最新文献

The advent of biodegradable implants represents a landmark orientation in the biomedical field toward a new generation of medical devices, offering improved patient outcomes, and eliminating the need for subsequent surgeries. FeMn alloys are well-established as promising candidates for such applications. This study analyzes the microstructure, mechanical properties, and degradation behavior of FeMnC alloys produced via pressing and sintering process using water-atomized FeMnC powder. To investigate the impact of pore size and volume fraction on the mechanical properties and degradation rates, two groups of FeMnC samples were prepared, one compacted at 600 MPa (CP 600) and the other at 700 MPa (CP 700). In addition, pure Fe samples compacted at 600 MPa and prepared using the same methodology were used as a reference. Chemical analysis carried out on both the pre-alloyed powder and the resulting sintered samples (CP 600 and CP 700) revealed a significant reduction in the amount of Mn, O, and notably C after sintering. The pure Fe group showed the greatest mechanical strength with an average tensile rupture strength of 446 ± 24 MPa. Among the three groups, CP 600 exhibited the highest degradation rate (−0.339 ± 0.057 mmpy) after 14 days of static immersion degradation test in modified Hanks' solution, demonstrating a degradation behavior characterized by mass gain.

Gradient lattice structures are gaining increased attention due to better meeting the crashworthiness requirements of lightweight structures. This study explores how cell number, configuration, and diameter ratio affect mechanical properties and energy absorption. Three new types of gradient lattice structures are designed. Initially, the mechanical properties, deformation behaviors, and energy absorption capabilities of gradient lattice structures are analyzed through finite element simulations. Subsequently, gradient lattice structures are fabricated using 316L laser powder bed fusion technology, and quasistatic compression tests are conducted using a materials testing machine to validate the effectiveness of the simulation results. The results show that the inner and outer structure diameter ratio gradient strategy has the greatest influence on the mechanical properties and energy absorption capacity of the lattice structure. Among all the gradient structures, the BSF structure (cell number gradient lattice structure-F) is the optimal structure, whose maximum impact force and total energy absorption are 88.8 and 107.9% higher than those of the conventional uniform JYC structure (uniform gradient lattice structure-C), respectively. The three gradient strategies proposed in this study provide insights into the design and optimization of impact-resistant lattice structures, which can be used as potential materials for future impact-resistant applications.

This study investigates the use of bismuth (Bi) as a lubricating additive in laser cladding Co-based composite coatings, addressing the issue of Bi segregation and agglomeration through Ni–Bi alloying. The microstructure, mechanical properties, and tribological properties of composite coatings with varying Ni–Bi contents are systematically evaluated at temperatures between 30 and 800 °C. Analysis reveals that Ni and Bi elemental powders are successfully alloyed to form BiNi and Bi₃Ni intermetallic compounds following vacuum sintering. Incorporation of Ni–Bi alloying powder significantly enhances the friction coefficient and wear rates of the composite coating across the temperature range. Adhesive wear and abrasive wear are identified as primary wear mechanisms. Notably, the formation of BiNi, multiple oxides, and Bi₁₆CrO₂₇ compounds on the surface of the 85:15 (at%) Bi:Ni composite coating at 600 °C created a self-lubricating friction layer, synergistically reducing friction. Consequently, compared to Co-based alloy coatings without Ni–Bi alloying, the composite coating exhibited a three-fold reduction in friction coefficient and a two-order-of-magnitude improvement in wear rate, demonstrating exceptional tribological properties.

Electroplastic effect refers to the role of pulsed current, material plasticity, and microstructural properties change, resulting in an increase in the plasticity of the material, the deformation resistance is reduced, and thus improves the processing performance of the phenomenon. This article summarizes the Joule thermal effect and a variety of nonthermal effects of the electrophysical effect mechanism, of which the nonthermal effects include pure electrophysical effect, magnetic field compression effect, and skin effect. The application of electroplastic-assisted technology in cutting machining, such as turning, milling, drilling, and so on, and the potential application in other manufacturing processes are summarized. The limitations and shortcomings of the electroplastic-assisted technology are analyzed, including the limitations of the required special equipment, machining platforms, and electric pulse parameters. The effects of different electric pulse parameters on the machinability of various types of difficult-to-machine metallic materials are summarized. The electric pulse parameters within a certain threshold range can promote the dynamic recrystallization of the workpiece, enhance the plastic deformation of the cutting zone, reduce the cutting force, improve the surface finish, and reduce tool wear. Finally, this article summarizes and looks forward to the electroplastic-assisted cutting technology.

Titanium-doped ferrite has garnered significant interest as thermoseeds for cancer hyperthermia because of its controllable Curie point near body temperature, which prevents overheating and ensures high biological safety. However, few studies examine the effect of the synthesis conditions on microstructure, magnetic properties, and heat generation in an alternating magnetic field. Herein, Mg_1+xFe_2−2xTi_xO₄ (x = 0.35, 0.45) particles are synthesized by a solid-state reaction and polymerized complex methods, followed by sintering at various temperatures. Their magnetic properties and heat generation behavior in an alternating magnetic field are investigated. Particles with x = 0.45 generate significantly less heat than those with x = 0.35, despite both being single-phase ferrite. Particles synthesized by the polymerized complex method at a sintering temperature of 1200 °C exhibit lower saturation magnetization but higher temperature increases compared with the solid-state reaction method. Additionally, in the sintering temperature range of 800–1000 °C, a temperature increase of more than 10 °C is observed in the polymerized complex method, likely a result of the inclusion of highly crystalline superparamagnetic particles. Furthermore, the ferrite particles form bone-like apatite on their surface in simulated body fluid, suggesting their potential as a novel material combining hyperthermia and bone integration properties.

Cu–Ni–Si alloy is widely used as the main material of lead frame. The process of alloying is an important method to improve the comprehensive performance of the alloy. Herein, Cu–1.8Ni–0.45Si (−0.5Zn) alloys are prepared. The variation trend and mechanism of Zn on the mechanical properties and welding properties are analyzed with scanning electron microscopy and electron backscattering diffraction. The results show that the addition of 0.5 wt% Zn can improve the brazing properties of the alloy while ensuring the tensile strength and conductivity of the material. Further quantitative analysis reveals that Zn addition enhances the contribution of precipitation strengthening to the alloy's mechanical properties, which is due to the reduction of the size of the particles of the precipitated phase by the addition of Zn. In addition, the addition of Zn can form a Zn-enriched layer at the welding interface of the alloy, which has an obstructive effect on the diffusion and growth of the intermetallic compound (IMC) layer, effectively reducing the thickness of the IMC layer, inhibiting the formation of the Cu₃Sn phase, and improving the mechanical properties of the alloy brazed joints.

Understanding pitting corrosion is critical, yet its kinetics and morphology remain challenging to study from X-ray computed tomography (XCT) due to manual segmentation barriers. To address this, an automated pipeline leveraging deep learning for efficient large-scale XCT analysis is developed, revealing new corrosion insights. The pipeline enables pit segmentation, 3D reconstruction, statistical characterization, and a topological transformation for visualization. The pipeline is applied to 87 648 XCT images capturing commercial purity aluminum (1100 Al) wire exposed to sodium chloride (NaCl) salt particles over a period of 122 h. The pipeline achieves complete feature extraction and statistical quantification across the entire XCT dataset, leveraging distributed computing environment for high efficiency. Global growth kinetics such as high-level stepwise sigmoidal volume loss patterns and granular individual pit developments are both captured for 36 detected pits. By combining automation, computer vision, and extensive XCT datasets, this research accelerates precise corrosion assessment to enable materials science discoveries at scale.

The developments in the automotive and aerospace sectors require alternative structures to metals for diverse applications; therefore, lightweight polymer–metal hybrid composites with outstanding mechanical characteristics are synthesized. Herein, the modern nanoperfusion technology, which involves the in situ growth of 3D porous cobalt oxide nanoflakes (Co₃O₄ NFs) on the porous aluminum surface, is used. A rough surface with corresponding surface porosities of 21, 48.1, and 49.8% can be produced by anodization of aluminum at 8, 10, and 12 V, respectively. The samples anodized at 10 V are selected as a structure for the growth of 3D Co₃O₄ NFs at different hydrothermal temperatures (90, 120, and 160 °C). The bond strength and modulus of the toughness of the sample combining aluminum and 3D Co₃O₄ NF growth at 120 °C exhibit a substantial bonding strength, reaching a value of 14.27 MPa and 3.56 kJ m⁻³, respectively. The porous nature of the manufactured cobalt oxide nanoflakes allows the epoxy to penetrate, which enhances the bonding strength and thus improves the mechanical properties of the manufactured joints.

Hydrogen storage materials are critical for sustainable energy applications. Magnesium is a promising material for hydrogen storage due to its high volumetric and gravimetric hydrogen storage capacities. However, its application in fuel cells is hindered by slow hydrogen sorption kinetics. This study aims to investigate the hydrogen absorption of a commercial AM60 alloy catalyzed by Ti and multiwalled carbon nanotubes additives, as well as the microstructural changes induced by high-energy ball milling (HEBM). The results show that the HEBM of the AM60 alloy reduces the particle size to 22 μm, introducing microvoids and porosity between the particles, which increase the total pore volume and hydrogen absorption capacity from 1.5 to 4 wt%. Catalyzing the AM60 alloy with a 5 wt% Ti increases absorption to 4.35 wt%. The AM60-5 wt% MWCNT sample shows higher surface area of 34 m² g⁻¹, highest hydrogen absorption capacity of 6.2 wt%, and the fastest hydrogen absorption rate. The novelty of this study lies in demonstrating the synergistic effects of HEBM and MWCNT additives, thereby establishing a practical approach for optimizing magnesium-based materials for hydrogen storage.

This study systematically investigates the ultraviolet-assisted direct ink writing (UV-DIW) process, focusing on the influence of critical parameters, including UV intensity, the ratio of printing speed to ink extrusion rate ($��v_P�/�v_E�$), and relative nozzle height (H/h), on filament fusion and structural morphology. The rheological behavior of photosensitive resin ink is analyzed, revealing that UV irradiation induces a fluid-to-solid transition critical for shape retention and structural integrity. The results demonstrate that UV intensity plays a pivotal role in controlling filament fusion, with insufficient curing causing filament sagging and excessive fusion, while higher UV intensities improve structural fidelity. Additionally, printability (Pr), calculated from cross-sectional analysis, is used as a quantitative metric to assess filament fusion quality and structure preservation. Parameter phase diagrams are developed to visually map the relationships among printing variables, providing a framework for optimizing UV-DIW conditions. The successful fabrication of dense solid blocks without filament interfaces highlights the potential of UV-DIW for producing high-quality, defect-free 3D structures. This work provides valuable insights into parameter tuning, paving the way for advanced applications in manufacturing, biomedical engineering, and material science.