Advanced Engineering Materials最新文献

Drop-Weight Impact Resistance

In article number 2400035, Douglas S. Galvao, Chandra S. Tiwary, and co-workers show that as the impactor (metallic tip) hits the complex 3D-printed porous structures, the impactor experiences multiple stress concentration regions throughout the porous structures; as a result, efficient stress concentrates around the pores, causing local deformation. During penetration of the impactor, the impact energy is absorbed in various events such as the tearing of layers, delamination, bulging, and densification of the structure.

Direct Ink Writing

In article number 2400630, Yarjan Abdul Samad and co-workers use direct ink writing to fabricate an additively manufactured vision based tactile sensor, which cuts down the fabrication time, allows more control of the design, and reduces the feature complexities. The mechanical characteristics of the DIW sensor, robotic normality estimation, and finite element analysis are at par with those of molded Ecoflex, hence providing a fast, scaleable method to produce such sensors.

Conformal Electronics

In article number 2400220, Shuo Zhang, Yuhang Li, and co-workers introduce a facile approach to print completely conformal liquid metal circuits on arbitrary curved surfaces by a conformally attached 3D-printed customized conformal mask (CCM). Via CCM, conformal liquid metal circuits can be printed on the complex surfaces of aircraft, serving as intelligent skin. This work offers fabrication strategy for arbitrary curved surface conformal electronics in aeronautics and wearable devices.

Acoustic Emission

In article number 2400317, Abdulkadir Gulsen and co-workers present a novel ensemble feature selection methodology to rank features relevant to damage modes on AE signals in CFRP sandwich composites. Subsequently, ranked features are utilized in unsupervised clustering models to identify damage modes. The comparative results demonstrate that, in addition to the commonly used features, other features, like partial powers, have a robust correlation with damage modes.

Electrically Assisted Solidification

In article number 2401025, Hyun-Do Jung, Moon-Jo Kim, and co-workers present a method to refine primary Si in hypereutectic Al-Si alloys using electrically assisted solidification with phosphorus (P). Electric currents create flow in the melt, increasing cooling and nucleation, while phosphorus disperses AlP, enhancing silicon refinement.

Texture-Controlled Titanium Alloys

In article number 2400876, Jin Cui and co-workers explore the intricate relationship between processing techniques and the resulting texture and microstructure in α-Ti and β-Ti alloys, materials of choice in aerospace and biomedical sectors. This review delves into the effects of cold rolling, hot rolling, and annealing on the evolution of these properties. The study highlights the significant role texture plays in defining the mechanical properties, such as strength, fatigue resistance, and fracture toughness in α-Ti alloys, and the lower elastic modulus demanded by β-Ti alloys for biomedical applications.

Liquid Metal-Printed Semiconductors

In article number 2400029, Bangdeng Du, Jing Liu, and co-workers present emerging strategies for liquid-metal semiconductors manufacturing; these are expected to revolutionize electronic engineering and show potential for the use of liquid-metal printers to build semiconductors and functional devices as desired.

Ultrafast Lasers

In article number 2302262, Mindaugas Gedvilas, Andrius Žemaitis, and Paulius Gecˇys present a novel precision fabrication method for the creation of 3D cavities in metal. Fresnel lens molds designed for LED diffusers are created utilizing the state-of-the-art layer-by-layer laser milling technique and femtosecond burst irradiation. The findings open new opportunities for industrial applications of ultrafast lasers.

The in situ WC-reinforced Ni60 laser cladding layer-assisted electromagnetic field is prepared on the H13 steel surface. The microstructure and phase of the cladding layer are analyzed by scanning electron microscope, energy disperse spectroscopy, and X-ray diffractometry, the hardness and wear resistance of the coating are tested by microhardness tester and ring-block friction and wear tester. The results indicate that more WC particles are generated with the increase in the magnetic field strength and current value, and many uniformly distributed eutectic carbides are formed in the coating, which makes the structure more uniform and dense. The average microhardness of the coating reaches 786.5HV when the electromagnetic intensity is 20 mT-9 A, and the wear amount after 90 min is 35.2 mg, which is 65.7% of the nonelectromagnetic-assisted WC/Ni60 coating and only 28.6% of the substrate, the wear resistance is obviously improved. The change in the structure and the improvement in microhardness and wear resistance are the result of the combined action of the directional Lorentz force generated by the electric field and the inductive Lorentz force generated by the magnetic field.

A silicon-containing arylacetylene resin (PSA)/SiO₂ syntactic foam was prepared through a chemical foaming approach, with PSA serving as the matrix, quartz sand (QS) and nanosilica (nSiO₂) acting as fillers, and their structures and properties were characterized. The results show that the incorporation of appropriate amounts of QS and nSiO₂ can reduce the cell size and apparent density of the syntactic foam, and improve its heat resistance, dielectric properties and wave transmission properties. The addition of QS can increase the compressive strength of the syntactic foam, while the addition of nSiO₂ decreases the compressive strength. The apparent densities of the PSA/9QS and PSA/9nSiO₂ syntactic foams with 9% filler addition are 0.242 g cm⁻³ and 0.157 g cm⁻³, respectively, and the temperatures at 5% weight loss (T_d5) under a nitrogen atmosphere were 692 °C and 658 °C, respectively. The dielectric constants were 1.59 and 1.25, respectively. The wave transmittance within the frequency range of 8.2–12.4 GHz was 98.5% and 96.8%, respectively. PSA/SiO₂ syntactic foam can be used as a lightweight and high-temperature-resistant wave-transmission material in aerospace and other fields.