International Journal of Lightweight Materials and Manufacture最新文献

The results of studies technological processes for obtaining welding wire from alloys of the Al–Mg system with a scandium content of 0.12 (alloy 1580) and 0.25 wt % (alloy 01570) presented. A feature of the technology is the production of a billet for further cold deformation by an energy-efficient method of ingotless rolling-extrusion (IRE). It was found that hot-extruded rods from the investigated alloys obtained by the IRE method have the required level of plastic and strength properties necessary for further cold deformation up to 80%. Thermomechanical processing of hot-extruded rods manufactured by IRE have been developed and experimentally tested, which made it possible to obtain a billet with a square side of 5 × 5 mm by sectional rolling and wire with a diameter of 3 mm by drawing. Studies of the structure and mechanical properties of deformed semi-finished products have shown that the developed modes make it possible to obtain a welding wire from the investigated alloys that meets the requirements of current standards. Studies of the operational properties of the obtained welding wire were carried out. It was found that alloy 1580 with a minimum content of scandium (0.12 wt %) is not inferior to alloy 01570 in terms of corrosion resistance and weld quality. Developed technology for the production of welding wire from alloys of the Al–Mg system with different scandium content can be recommended for industrial use. It is advisable to implement alloy 1580, which has a lower cost compared to alloy 01570.

Incorporating sustainability into Concrete-Filled Steel Tubular (CFST) columns' optimization can enhance efficiency and sustainability in construction. Discrepancies in international standards for ultimate load capacity computation in compact CFST columns under eccentric loading, particularly with lightweight high-strength concrete, pose challenges. This research compile a dataset of compact CFST columns, evaluating design codes (AISC 360-16, Eurocode 4) against experimental results. Besides, a comprehensive finite-element model predicts compact CFST column performance, investigating axial force-moment (P-M) interaction behavior with respect to the material strength ratio ($f_y$/$f_c^{\prime }$). In the second phase of the study, an ANN model, incorporating input parameters, estimates axial load capacity, facilitating multi-objective optimization for optimal CFST column geometry. The results confirmed that Eurocode 4 outperforms AISC 360-16 in experimental axial capacity predictions ($N_{uc}$/$N_{uc,theoretical}$) where, the mean and standard deviation for Eurocode 4 were estimated at 1.07 and 0.22, respectively, compared to 1.21 and 0.29 for AISC 360-16. Besides, statistical metrics confirm the precision of the ANN model, particularly with high-strength concrete, promising efficiency in future computational intelligence-based structural design platforms.

This research explores natural fiber composites (NFCs) as alternatives to traditional materials such as fiberglass. By examining fibers like abaca, bamboo, banana, coir, flax, hemp, jute, kenaf, pineapple leaf (PALF), sisal, and others, we emphasize their lower weight, cost-effectiveness, competitive mechanical properties, commendable specific strength, and potential for biodegradability. NFCs offer practical and eco-friendly substitutes for conventional composite fibers in industries like construction, automotive, and packaging. The article provides a brief overview of NFCs, covering their chemical, physical, and mechanical characteristics, and highlights diverse applications. The comparative analysis underscores the potential of natural fibers as sustainable choices in various industries.

Present study is focused on optimization of WEDM process parameters for increased productivity and improved surface quality of the machined surface of hybrid composite [Al6061 (90 %), SiC (2.5 %) and TiB₂ (7.5 %)] by utilizing the trim cut strategy. Effects of four factors namely, pulse on time (T_on), peak current (Ip), wire offset (WO) and rough-cut history (RCH) have been investigated on response characteristics namely, material removal rate (MRR), surface roughness (SR) and Recast layer (RL) thickness; using Box-Behnken design (BBD) for the experimentation. Three levels of RCH i.e., high, medium and low have been included to investigate the effectiveness of trim cut strategy for dealing with rough-cut surface under varied conditions. The optimized parametric setting has been obtained for multiple responses using desirability function. RCH is found to be most significant factor for MRR, while pulse on time (T_on) is found most significant for SR and RL. WO has been found to play an important role in controlling the thickness of RL. It is observed that after trim cut, surface roughness is improved for experiments conducted under high and medium levels of RCH. However, almost no improvement in SR is obtained for low level of RCH. Trim cut strategy is also found to be effective in reducing the thickness of recast layer, however, it is noticed that the percentage reduction in recast layer thickness for samples machined under high level RCH is greater than that for the other two levels of RCH.

Digital image correlation (DIC) outperforms other strain measurement technologies due to its versatility, accuracy, non-contact nature, and capability to capture full-field strains. However, for aluminium alloys like AA6082 under high-temperature and large-deformation conditions, the shiny effects observed in the gauge area degrade the quality of the captured deformation images, leading to failures in the DIC analyses. In this study, the source of the shiny effects was investigated by analysing the evolution of AA6082 specimen surfaces painted with speckle patterns during hot stamping deformation. It was found that the shiny effects were attributed to the exposure of the reflective base material due to paint peeling and cracking. To overcome these problems, the DIC method was improved by developing a novel procedure for generating more effective speckle patterns and utilising a cross-polarisation optical system (XPOL) to mitigate the shiny effects. The improved DIC method was applied to AA6082 in both uniaxial and biaxial tensile tests under diverse hot stamping conditions, along with applications to boron steel for comparison. These improvements significantly reduced the shiny effects and increased the time over which full-field strains can be measured for AA6082, reaching over 96% (up from 75%) of the fracture time in the uniaxial tests and even 100% in the biaxial tests. The improved DIC method enables the full-field strain measurement for aluminium alloys under hot stamping conditions, allowing for the accurate determination of their thermomechanical properties.

Mica waste, a type of commercial waste produced in bulk quantities by the mica mining industry, was processed and added to Natural Rubber Latex Foams (NRLF) made of centrifuged and creamed latex. Following the Dunlop method, NRLF composites with various Processed Mica Waste (PMW) loadings (0, 2, 4, 6, 8, and 10 Phr) were prepared, and the thermo-physical characteristics were compared. Thermal conductivity, electrical resistivity of NRLF against the latex type and mica loading were compared for the first time. NRLFs prepared using creamed latex exhibit 33 and 50 μm (width and height) cell diameter, 3 ibf hardness, 281 % swelling index improvements and 0.05 Wm⁻¹K⁻¹ thermal conductivity, and 1 °C glass transition temperature (T_g) reductions than centrifuged NRLF and indistinguishable electrical resistivity. With the addition of mica (0–10 Phr), both NRLF types showed a similar ascending trend in hardness (42 ibf), water absorption (16 %), T_g (7 °C), thermal conductivity (0.54 Wm⁻¹K⁻¹), electrical resistivity (69 × 10³ Ω m) with decreasing gel time (3 min) and swelling index (550 %). The key objective of this research was to prepare PMW-filled NRLF and compare structural, electrical and thermo-physical properties, for the first time, against mica content and latex type.