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In the automotive industry, lightweight steel has received much attention because steel comprises a significant portion of a vehicle’s total weight. Fe–Mn–Al–C steel is a representative lightweight steel due to its high performance and low density. However, there is insufficient research into the welding characteristics of Fe–Mn–Al–C lightweight steels. In this study, hot ductility tests were conducted on austenitic Fe–30Mn–9Al–0.9C steel in order to understand the welding characteristics (cracking resistance) of the heat affected zone. During the on-heating thermal cycle, ductility was altered by a decrease in microband induced plasticity (MBIP) (softening) and an increase in dynamic recrystallization (DRX) (softening) as the temperature increased. Specifically, in the range of 773–1073 K, ductility was fairly degraded because neither MBIP nor DRX took place. During the on-cooling thermal cycle, ductility behavior was changed by both softening and hardening factors, including formation of brittle (Fe, Mn)3Al intermetallic compounds with grain growth and re-solidified grain boundaries. However, the hardening effect of precipitated κ-carbide was insignificant and might not play a significant role in the hot ductility behavior of the lightweight alloy used in this study.

Medium- and high-entropy alloys are an emerging class of materials that can exhibit outstanding combinations of strength and ductility for engineering applications. Computational simulations have suggested the presence of short-range order (SRO) in these alloys, and recent experimental evidence is also beginning to emerge. Unfortunately, the difficulty in quantifying the SRO under different heat treatment conditions has generated much debate on the atomic preferencing and implications of SRO on mechanical properties. Here we develop an approach to measure SRO using atom probe tomography. This method balances the limitations of atom probe tomography with the threshold values of SRO to map the regimes where the required atomistic neighbourhood information is preserved and where it is not. We demonstrate the method with a case study of the CoCrNi alloy and use this to monitor SRO changes induced by heat treatments. These species-specific SRO measurements enable the generation of computational simulations of atomic neighbourhood models that are equivalent to the experiment and can contribute to the further understanding and design of medium- and high-entropy alloys and other materials systems where SRO may occur. A method is introduced to quantify short-range order in multicomponent alloys using atom probe tomography, which enables further understanding and materials design related to atomic-scale solute engineering.

In this study, weld solidification cracking behaviour of AA2195 Al–Cu–Li alloy was studied and compared with conventional AA2219 and AA2014 aluminium alloys. Cracking susceptibility was evaluated using varestraint test and Gleeble® hot ductility test and the slope of liquidus temperature as function of liquid fraction was also evaluated. Solidification cracking susceptibility of AA2195, AA2219 and AA2014 alloys was ranked based on the above methods. Consistent trend in cracking susceptibility was observed in all the methods where AA2195 and AA2219 alloys showed highest and lowest cracking susceptibility, respectively.

To limit the cross-sectional size of concrete structures, high-strength, lightweight concrete is preferred for the design and construction of structural elements. However, the main drawback of high-strength, lightweight concrete is its brittleness over normal-weight concrete. The ductility of concrete is a crucial factor, which plays an important role when the concrete structures are subjected to extreme situations, such as earthquakes and wind. This study aims to improve the ductility of high-strength, lightweight concrete by incorporating steel fibers. The palm oil clinker (POC)-based, high-strength, lightweight concrete specimens reinforced with steel fibers were prepared and their ductility was systematically examined. POC was used as aggregates and supplementary cementitious materials. Steel fibers from 0–1.50% (by volume), with an increment of 0.5%, were used in the concrete mix. Compression ductility, displacement ductility and energy ductility were used as indicators to evaluate the enhancement of ductility. Moreover, the compressive strength, flexural strength, stress-strain behavior, modulus of elasticity, load-displacement characteristics, energy absorption capacity and deformability of the concrete samples were investigated. The compression ductility, displacement ductility and energy ductility indexes were found to be increased by up to 472%, 140% and 568% compared to the control specimens (concrete with 0% steel fibers), respectively. Moreover, the deformability and energy absorption capacity of the concrete were increased by up to 566% and 125%, respectively. Therefore, POC-based, high-strength, fibrous, lightweight concrete could perform better than conventional concrete under extreme loading conditions as it showed significantly higher ductility.

The susceptibility of nickel-based superalloys to processing-induced crack formation during laser powder-bed additive manufacturing is studied. Twelve different alloys—some of existing (heritage) type but also other newly-designed ones—are considered. A strong inter-dependence of alloy composition and processability is demonstrated. Stereological procedures are developed to enable the two dominant defect types found—solidification cracks and solid-state ductility dip cracks—to be distinguished and quantified. Differential scanning calorimetry, creep stress relaxation tests at 1000 °C and measurements of tensile ductility at 800 °C are used to interpret the effects of alloy composition. A model for solid-state cracking is proposed, based on an incapacity to relax the thermal stress arising from constrained differential thermal contraction; its development is supported by experimental measurements using a constrained bar cooling test. A modified solidification cracking criterion is proposed based upon solidification range but including also a contribution from the stress relaxation effect. This work provides fundamental insights into the role of composition on the additive manufacturability of these materials.

The massive growth through the trends toward coffee-lover communities has pushed the new revolution of coffee waves in Indonesia, previously from the second wave into the third wave. In the Malang area, this phenomenon at the same time had brought new challenges and opportunities, especially improving the awareness for the lovers, which a major role as the coffee-shop customers. Moreover, this study focused on describing customers and semi-trained testers perspectives towards the taste of available coffee species which is provided by new experiences from simple public cupping. As many 31 customers and 9 semi-trained testers have been chosen for the demonstration which was conducted in Bumi Kopi Coffee Shop, Malang. Four types of coffee samples; including Coffea arabica var typica (arabica), Coffea liberica var liberica (liberica), Coffea canephora var robusta (robusta), and Coffea. liberica var dewevrei (excelsa) have been used during the test. The findings based on the test showed that customers and semi trained testers tend to enjoy fruity coffee such found in arabica and liberica, while the robusta and excelsa also still enjoyed for fewer customers. Based on this research, its hoped if these activities could be improved, such an creative business optimization and could be a part of gastronomic tourism.

Additive manufacturing (AM) is becoming increasingly popular since it offers flexibility to produce complex designs with less tooling and minimum material at shorter lead times. Wire arc additive manufacturing (WAAM) is a variant of additive manufacturing which allows economical production of large-scale and high-density parts. The WAAM process has been studied extensively on different steels; however, the influence of process parameters, specifically wire feed speed (WFS), travel speed (TS), and their ratio on bead geometry, microstructure, and mechanical properties, are yet to be studied. The present work aims at closing this gap by using the WAAM process with robotic cold metal transfer (CMT) technology to manufacture high-strength structural steel parts. For that purpose, single-bead welds were produced from HSLA steel by varying WFS between 5 and 10 m/min and the WFS to TS ratio between 10 and 20. Those variations produce heat inputs in the range of 266–619 J/mm. The results have shown that the wire feed speed to travel speed ratio is the major parameter to control the heat input. Increasing heat input increases characteristic bead dimension, whereas it reduces the hardness. In the second part of experiments, two single-bead walls were deposited via the parallel deposition strategy and one multiple-bead wall was produced using the oscillation strategy. The tensile properties were tested along two directions: parallel and perpendicular to deposition directions. For the yield strength and tensile strength, the difference between horizontally and vertically tested specimens was smaller than the standard deviations. On the other hand, the total and uniform elongation values exhibit up to 10% difference in the test direction, indicating anisotropy in ductility. Those tensile properties were attributed to repeated thermal cycles during the WAMM process, which can cause heat transfer in multiple directions. The yield strength of the multiple-bead wall produced via oscillation was lower, whereas its ductility was higher. The tensile properties and hardness differences were found to correlate well with the microstructure.

Chemical Short-Range Order (CSRO) has attracted recent attention from many researchers, creating intense debates about its impact on material properties. The challenges lie in confirming and quantifying CSRO, as its detection proves exceptionally demanding, contributing to conflicting data in the literature regarding its true effects on mechanical properties. Our work uses high-precision calorimetric data to unambiguously prove the existence and, coupled with atomistic simulations, quantify the type of CSRO. This methodology allows us to propose a mechanism for its formation and destruction based on the heat evolution during thermal analysis and facilitates a precise identification of local ordering in CoCrNi alloys. Samples of CoCrNi (Co 33 Cr 33 Ni 33 ) and CrNi 2 (Cr 33 Ni 66 ) alloys are fabricated in varying ordered states, extensively characterized via synchrotron X-ray diffraction, X-ray absorption spectroscopy, and transmission electron microscopy. Samples with considerably different ordered states are submitted to tensile tests with in-situ synchrotron X-ray diffraction. We demonstrate, despite inducing varied CSRO levels in CoCrNi, no significant alterations in overall mechanical behavior emerge. However, the CrNi 2 alloy, which undergoes long-range ordering, experiences significant shifts in yield strength, ultimate tensile stress and ductility. Here authors use calorimetry to quantify chemical short-range order (CSRO) experimentally, in good agreement with atomistic simulations. Synchrotron in-situ tensile testing showed no effect of varied CSRO levels on mechanical properties.

On February 6, 2023, an M w 7.8 earthquake hit the south of Kahramanmaras prefecture, Turkey, followed by another M w 7.5 earthquake after nine hours in the middle region of the Kahramanmaras prefecture. More than 84,000 buildings collapsed or were severely damaged, and more than 50,000 lives were lost in Turkey and Syria. Some of the authors, as members of Chinese rescue team, entered Antakya, Hatay prefecture, and investigated the damaged buildings. This paper first summarizes the damage patterns of buildings and provides three reasons for the massive number of collapsed buildings; i.e., the lack of seismic measures for better ductility, site effects such as liquefaction and surface rupture, and pronounced low-frequency components of the ground motions. Next, the seismic responses of two typical buildings are calculated based on the geometric data estimated by visual inspection. The results imply that the resonance of the whole structure and the poorer ductility of key members resulted in the collapse of buildings. Finally, some conclusions are drawn. Note that although a large number of buildings were seriously damaged to collapse, the majority of buildings in the areas of extreme shaking were lightly or moderately damaged, which implies that well designed and constructed buildings were able to survive and protect human lives even in over-design earthquakes.

In this paper, different proportions of graphene modifiers were used to double-modify the SBS-modified asphalt. The needle penetration, softening point, and ductility of modified asphalt with different proportions of graphene incorporation were measured by the national standard test method. As affected by adding different proportions of graphene on the three indexes of SBS modified asphalt was studied. Through the analysis and comparison of the experimental results, when the graphene parameter is 0.5%, the performance of graphene-SBS double-modified asphalt reaches the optimum, which provides technical reference for the diversification of modified asphalt materials in the alpine region of Inner Mongolia.