Abstract: Strain ageing embrittlement behaviour of X80 self-shielded flux-cored arc welding (FCAW) girth weld metal at different strain ageing conditions (1% prestrain, and aged at 150°C/100°C for 1 –6 h, and 80°C for 1–30 days) was studied. Microstructure of FCAW girth weld generally consisted of coarse granular bainite and lath bainite. After strain ageing, toughness notably decreased, and higher ageing temperature or longer ageing induced lower toughness, until ageing is fully yielded. At initial stage of strain ageing, more dimples were found accompanying with cleavage facet. With the progress of strain ageing, the embrittlement was more obvious, while larger cleavage facet and less dimples were found. Meanwhile, the critical size for cleavage fracture initiation site became smaller. Martensite–austenite constituent (1–2 μm) was found to initiate cleavage fracture when partially strain aged, while submicron inclusions could initiate cleavage facet when fully strain aged.

Abstract: Alloying elements (Ni, Mo) were added to grey cast iron, and the effect of Ni, Mo on microstructure and mechanical properties were analysed in this study. When Ni was added alone, the precipitation of graphite was inhibited at the early stage of solidification, and part of graphite was formed between the dendrites, resulted in an uneven distribution of graphite. Ni played a role of solution strengthening and reduced the pearlite interlammer spacing, improved the mechanical properties. The addition of Mo refined the austenite dendrites and made the carbon unevenly distributed, which led to the abnormal growth of graphite. Mo increased the eutectoid supercooling degree, reduced the pearlite interlammer spacing and improved tensile strength. When Ni and Mo were added together, the elements beneficial to strength (Mo, Sn) were not uniformly distributed, and the influence on graphite size and pearlite interlammer spacing was not obvious, resulted in poor mechanical properties.

Abstract: We elucidate here the temperature and strain rate sensitivity of a duplex stainless steel through the development of deformation maps and by studying the flow behaviour during hot compression tests in the temperature range of 1223–1473 K and at strain rates between 0.01 and 30 s−1. The flow curves exhibited softening after attaining a peak condition and the flow stress increased with the decrease of temperature and increase of strain rate. The observed change in the activation energy is attributed to strain partitioning between the two constituent phases and the deformation maps were characterised by two regions of flow instability. On the other hand, the microstructural evolution indicated that the strain rate and deformation temperature had a significant impact on the flow behaviour. In the flow stability region, the continuous dynamic recrystallisation (DRX) of ferrite was strongly activated, while in the flow instability region, both the continuous dynamic recrystallisation in ferrite and discontinuous DRX in austenite were weak.

Abstract: A Ti3C2 MXene/Ti composite powder was developed through surface modification and powder coating for producing a high-performance titanium matrix composites (TMCs) by laser power bed fusion. Introducing MXene rarely changed the original sphericity and flowability of Ti powder while it slightly enhanced the laser absorption capacity of Ti powder. The printing conditions in turn affected the morphology and distribution of MXene in as-printed composites. At optimised printing parameters, majority of MXene with high structural integrity and uniform distribution remained along the grain boundaries of as-printed composites, and a combination of high surface quality, geometrical accuracy and densification was obtained. The remaining MXene played the synergy of pulling-out effect and load transfer role, which increased the yield strength from 530 to 710 MPa, while retaining good ductility (elongation of 19.8%). Compared with ASTM standard cast Ti64 alloy, our MXene/Ti composites also exhibited superior comprehensive tensile properties and excellent strength-ductility synergy.

Abstract: Magnesium (Mg) alloys are difficult to cold/warm-process due to their hexagonal close-packed (HCP) lattice, which has restricted slip systems and makes plastic deformation at low temperatures a challenging task. Multi-axial forging (MAF) and annealing of as-cast alloys were combined to create a texture-free ultrafine-grained (UFG) structure with a high strength-high ductility combination to address this challenge. The study showed a clear and fundamental change from basal and pyramidal dislocation slip to twinning in the strong and ductile UFG Mg alloy compared to the low strength coarse-grained (CG) Mg alloy counterpart. This implied that the dislocation activity, grain orientation, and particular grain boundary states played an important role in controlling the deformation mechanisms. The potential impact of processing Mg alloys by MAF opens-up a new frontier of strong and ductile low-density materials for light and efficient solutions including energy absorption and formability and provides a perspective in terms of process-structure-property relationship.

Abstract: Grain boundary (GB) segregation was experimentally studied in a bulk high entropy Cantor alloy, which indicated for the first time that Cr strongly segregates to the GBs along with the weak segregation of Mn, implying co-segregation of Cr and Mn to the GBs. The strong segregation of Cr and weak segregation of Mn are explained in terms of the driving forces for GB segregation, where alloy interaction is favourable and stronger in the case of Cr, while elastic strain energy governs Mn segregation.

Abstract: This paper proposes a casting improvement process to enable the casting of Al-Cu alloy cylinder heads to achieve the required quality. The hot tearing defects generated in the fire face of the cylinder head during casting were simulated using MAGMA software. The simulation results show that the large wall thickness transition difference in the fire face of the cylinder head is the reason for the large temperature and stress gradient during solidification. Therefore, the first solution was optimised by forming the fire face as a whole into a flat plate, but the fire face centre area stress is still too high. The second optimisation option optimises the cold iron structure of the fire face, the probability of cracking in the fire face is reduced to 17%. These results have important reference significance for the optimisation of the Al-Cu alloy cylinder head hot tearing problem.

Abstract: Currently, there is a significant interest in magnesium (Mg) alloys for structural and functional applications. Mg alloys are lightweight materials (1.7–2.0 g/cm3), whose density is significantly lesser than that of titanium alloys and stainless steels. Furthermore, from the perspective of biomedical devices, they are biodegradable, bioresorbable and biocompatible. The objective of this work is to investigate the transition from grain boundary precipitation behaviour in the as-cast alloy to nanoscale precipitation during triaxial forging, with particular emphasis on exploring the application of small-angle X-ray scattering technique to investigate nanoscale precipitation and complement with the conventional approach of X-ray diffraction and electron microscopy.

Abstract: In this paper, molecular dynamics simulation method was used to establish the atomic model of high entropy alloy. The effect of strain rate on the microstructure evolution and dislocation motion of FeNiCoCrCu high entropy alloy was studied by applying tension and compression loads at different strain rates. The results show that the stress–strain curve of FeNiCoCrCu high entropy alloy presents three stages of elastic deformation, yield and plastic deformation under high strain rate. Under tensile load, Frank dislocation causes plastic deformation of the material, and the dislocation reaction between Shockley dislocation and Hirth dislocation generates Stair-rod dislocation. The mechanism of stress relaxation of materials under compression load is the formation of stacking faults. One of the mechanisms of strain hardening of materials is the formation of twins. In addition, stacking faults intersect with each other to produce dislocation reactions, which generate Stair-rod dislocations, maintaining the development of strain hardening effect.

Abstract: Bio-artificial organs, commonly referred to as bionic organs, are artificial structures that perform the same functions as natural organs. In regenerative medicine, damaged organs are repaired using biological components including growth factors and stem cells. The advancement of tissue engineering, which aims to harness the inherent regenerative potential of human body organs to rebuild normal biological function, has benefited greatly from the use of biomaterials. The rapidly expanding field of regenerative medicine has brought the usage of biomaterials and their functions in the production of new tissue. Organs-on-chips are seen as a concept performer in tissue engineering with significant potential for future ‘clinical trials on a chip’ and a step towards developing customized medicine. With the advancement of 3D printing technology, the manufacturing constraints of biomedical devices have been solved using cutting-edge biomimetic structures. This review covers the areas on bionic organs such as organ on a chip with tissue engineering, bio grafting, 3D bio-printing and the stem cell techniques that are employed in regenerative medicine.

Abstract: Zinc oxide nano-particles (ZnONPs) were synthesized by the aqueous extract of the betel leaf and characterized by UV-visible spectroscopy, XRD analysis, Zeta potential and SEM studies. The ZnONPs had spherical to irregular shapes ranging from 45.8 to 68 nm with a zeta potential of −22.2 mV. The biogenic ZnONPs are used for plant growth properties in maize and fenugreek. The ZnONPs had more than two to three-fold increase in the plant root, height and yield in the plants. Further, the ZnONPs had no significant changes in levels of antioxidant enzymes in the treated plants but slightly reduced the biofertilizers in the plant rhizospheres and no significant changes in the nodulation of Rhizobium spp. Therefore, the biogenic ZnONPs synthesized exhibited excellent nano-fertilizers in non-nitrogen fixing (maize) and nitrogen-fixing plants (Fenugreek and Red Gram) with multiple modes of fertilization in soil and plants.

Abstract: In this study, Calophyllum inophyllum (CIO) loaded Poly (ε-caprolactone) (PCL) electrospun fibre mats were produced for potential wound healing applications. Physiochemical evaluation and in vitro characterisation of produced mats were evaluated. Average fibre diameters of the mats were determined as 0.9 ± 0.3 μm, 1.2 ± 0.2 μm, 1.3 ± 0.2 μm, and 1.5 ± 0.1 μm for PCL, PCL/CIO−2.5, PCL/CIO−5 and PCL/CIO−7.5, respectively. The contact angle values of the fibre mats were decreased up to 30 ± 5 (°) compared to oil-free PCL fibre mat, indicating improved surface wettability. The incorporation of CIO into fibre mats led to a two-fold increase in the antibacterial activity, as compared to the fibre mats composed of PCL. In vitro cytotoxicity evaluation indicated that all the fibre mats had increased cell viability compared to the control. The findings suggest that CIO-loaded PCL electrospun fibre mats have potential for use in tissue engineering applications.

Abstract: Recently, the application of flexible sensors in mechanical equipment has attracted widespread attention. However, the design of vibration sensor materials and structures for complex mechanical environments still faces challenges. Hence, we proposed an annular structure CCTO/PDMS-based triboelectric nanogenerator (CP-TENG) as self-powered triboelectric automotive bolt tightness sensor. Due to the high dielectric properties of CCTO/PDMS film, the CP-TENG device can obtain high electrical output performance to achieve high sensitivity sensing. Through the annular structure design, CP-TENG devices can be integrated into bolt fittings with good structural compatibility. The output voltage and current of CP-TENG can monitor the different accelerations borne by the bolts from 9 to 60 m/s2. Moreover, by installing on the gasket, the CP-TENG device can also monitor bolt looseness to achieve early warning of the safety status of automotive components. This research can promote the development of self-powered sensor in the field of automotive bolt vibration monitoring.

Abstract: We describe here the structural evolution and optical properties of co-doping of Eu-doped ZnO nanoparticles with lithium synthesized by the sol-gel process. The characterization was carried out via X-ray diffraction (XRD), Fourier transmission infrared (FTIR), UV-Vis spectroscopy, and photoluminescence (PL) techniques. XRD confirmed hexagonal wurtzite phase of ZnO nanoparticles with crystallite size in the range of 22–61 nm. The band gap calculated from UV-vis spectra was in the range of 3.30–3.26 eV for undoped and Li and Eu co-doped ZnO nanoparticles, respectively, while photoluminescence study indicated that Li in Eu-ZnO affected the PL emission intensity, which was attributed to defects present in the crystal lattice. The field emission scanning electron microscopy (FESEM) images revealed the diverse morphology containing, spherical, tri-, tetra-, penta- and hexagonal rod-like nanostructures.

Abstract: Performing wet bench experiments to search for lead molecules for drug delivery is a long and tedious process where computational tools have played a crucial role. Molecular docking studies have been carried out for selecting the nanocarrier, and the results of the computational studies have been validated using the model protein Ova albumin and anticancer drug 5-Fluorouracil (5-FU) with mesoporous silica (MSNPs) and chitosan nanoparticles (CSNPs) as the nanocarriers. Formulated nanocarriers were tested for in-vitro release, which showed a sustained release of the drugs. In-vitro studies on the lung cancer cell line A459 revealed excellent biocompatibility and non-toxic nature of the designed drug delivery system. This chitosan nanoparticle-based drug delivery system could have the potential for chemotherapeutic treatment of cancer.

Abstract: The increased use of medicinal plants has raised questions regarding their safety, efficacy, and utility. Since a result, a thorough understanding of plant phytochemical components is essential, since this information will be useful in the development of innovative therapeutic medications. Copper nanoparticles (CuNPs) have received a lot of interest due to their numerous applications. The physical and chemical features of CuNPs influence their uses. In the current study, CuNPs were synthesised utilising the chemical reduction process, with Tinospora cordifolia extract serving as a reducing agent due to their high phenolic and flavonoid content and their antibacterial and anti-inflammatory properties were also assessed. The majority of the absorption peaks found in the T. cordifolia leaves extract can also be found in the FT-IR spectrum of CuNPs, often at the same locations or with just little variations in the peak’s location and intensity. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) found that the particles were generally spherical, with an average particle size of 15 to 70 nm. Their potential as anti-bacterial and antifungal drugs was demonstrated by the antimicrobial activity, they exhibited against S. aureus (18 mm), L. bacillus (22 mm), S. mutans (24 mm), and C. albicans (15 mm). Studies on the anti-inflammatory properties of biologically produced Cu NPs were determined.

Abstract: The lack of a viable vaccine and the emergence of novel Mycobacterium tuberculosis (MTB) strains that are particularly resistant to treatments, presage a complicated future situation. Biosynthesized nanomaterials are currently proving to be a viable antibacterial therapeutic option, including for MTB infection treatment. The goal of this work is to synthesize silver nanoparticles (AgNPs) from Syzygium aromaticum seeds and investigate their antimicrobial, anti-tubercular, and cytotoxic properties using zebrafish embryos and Artemia salina. The UV spectrophotometer, SEM-EDAX, TEM and FTIR measurements were used to characterize the AgNPs. Antibacterial activity was performed against S. aureus, P. aeruginosa, E. coli and K. pneumoniae and exhibited potential inhibitory activity towards the bacterial cultures. The MABA assay was used to investigate the anti-mycobacterial activity, and the AgNPs showed the highest percentage of inhibition in both test concentrations (250 and 500 µg/ml).

Abstract: Ionic liquid 1,3-dimethylimidazolium dimethyl phosphate (DIDP) is used as a possible green inhibitor for the corrosion control of 6061 aluminium alloy in 0.25 mol/L HCl is described in the study. Study involved electrochemical methods carried out at various temperatures by changing the concentrations of DIDP. Kinetic and thermodynamic parameters were determined using the Arrhenius rate law and transition state equations, respectively. Physisorption of the inhibitor takes place and the adsorption follows Freundlich isotherm. Surface morphology was studied by scanning electron microscopy (SEM), atomic force microscopy (AFM), and energy-dispersive X-ray analysis (EDAX) techniques. Quantum chemical studies were done by the density functional theory (DFT). The maximum inhibition efficiency of DIDP on 6061 aluminium alloy was about 78% for the concentration of 1000 ppm at 303 K. The mechanistic aspects of DIDP adsorption onto the metal surface were supported by quantum chemical studies. HOMO and LUMO of the optimized structure and quantum chemical descriptors confirmed the adsorption of the inhibitor on the metal surface. Mulliken charge population was used to identify the DIDP molecule’s high electron density region, and Fukui indices confirmed the interaction between metal and inhibitor.

Abstract: The usage of copper nanoparticles (CuNPs) is now acknowledged as a promising therapeutic agent in the detection and treatment of cancer. This study aimed to develop a sustainable method for synthesizing CuNPs using Pedalium murex L. and characterization by SEM, FTIR, XRD & UV-Vis methods. The produced CuNPs were primarily spherical and varied in shape, and the average dimension ranged between 20 and 50 nm. The aqueous fruit juice of Pedalium murex L. contained biomolecules that serve as capping and reducing agents for the production of CuNPs, according to the findings of FTIR analysis. Various assays were used to determine the fruit extract’s in vitro antioxidant activity. CuNPs exhibited dose-dependent cytotoxicity and apoptosis promotion in A549 cells. The findings demonstrated that biosynthesized CuNPs using Pedalium murex L. fruit juice have anti-cancer properties and can be used in lung cancer treatment, particularly for early-stage intervention.

Abstract: Degradation behaviour of bioactive glass (bioglass) is one of the most important factors affecting bone repair, because an excellent and controllable degradation rate can match the rate of new bone formation. In this research, the derived borosilicate bioglasses based on the 6Na2O-8K2O-8MgO-22CaO-18B2O3-54SiO2-2P2O5 component were synthesized. The effects of B2O3 on the structure, degradation behaviour and cytocompatibility of borosilicate bioglasses were systematically studied. The results showed that with B2O3 addition, the network-forming units became diversified and part of BO4 units transformed into BO3 units. These factors weakened the chemical durability of borosilicate bioglass, thus accelerating the bioglass shedding and altering the ions release, especially B. This study provides a theoretical basis for designing borosilicate bioglass with adjustable degradation rate and ion release behaviour to meet the diverse needs of clinical bone repair.

Abstract: In this paper, the atomic model of high-entropy alloy is established by molecular dynamics simulation. By applying nano-indentation, the influence of Cu atomic ratio and temperature on the deformation of FeCoCrCuNi high-entropy alloy was studied, and the micro-scale dislocation movement evolution mechanism was obtained. The results show that, with the increase of temperature, the load of FeCoCrCuNi high-entropy alloy under nano indentation decreases. The total length of dislocations in each stage of nanoindentation decreases monotonically, and the types of dislocation reactions decrease. Under the action of high temperature, the number of perfect dislocations decomposed into Shockley partial dislocations decreases, resulting in more Frank dislocations and Stair-rod dislocations, which makes the extended dislocations recombine into perfect dislocations, and the length of dislocations decreases sharply. The dislocation defect is replaced by a cavity at high temperature, which makes the high-entropy alloy lose elastoplastic mechanical properties.

Abstract: Recently, sports monitoring sensors based on flexible wearable technology have attracted much attention. Here, we reported a P(VDF-co-HFP)/MXene-based triboelectric nanogenerator (PM-TENG) to harvest bio-mechanical energy. The introduction of MXene can significantly improve the dielectric constant of P(VDF-co-HFP), thereby achieving higher electron harvesting ability. The PM-TENG can obtain the maximum instantaneous power of 1.68 mW contacted with a resistance of 4 MΩ. Furthermore, the PM-TENG can be also integrated inside the mask to monitor changes in respiratory status before and after basketball exercise. Meanwhile, the PM-TENG installed inside the shoes can be used to distinguish different gaits in basketball, which will be used to assist in basketball training. This flexible sport sensor demonstrates potential application value in basketball training assistance.

Abstract: The Bi2O4/Bi2WO6 composites were synthesized by one step hydrothermal method, which were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transformed infrared spectroscopy (FT-IR), photoluminescence spectra (PL), X-ray photoelectron spectroscopy (XPS) and UV – Vis diffuse reflectance spectroscopy (DRS). The photocatalytic performance of the composite was tested by degrading methyl orange (MO) under visible light irradiation. The results showed that the Bi2O4/Bi2WO6 composites performed better than pure Bi2O4 and Bi2WO6, whose cycle stability was also greatly improved. Among them, S3 sample (Bi2O4:Bi2WO6 = 16:1) could degrade by about 95% methyl orange (MO) within 50 min, and after three cycles the degradation rate could still reach 74%. The enhanced photocatalytic activity and stability was attributed to the formation of heterojunctions. This work provided a promising composite photocatalyst with high performance for organic pollutant degradation.

Abstract: Magnetic and magneto-optical studies were carried out in microwires that had been subjected to the bending annealing. A previously unobserved effect of bending-annealing-induced magnetic bistability was discovered. This effect is observed only in the region of the sample subjected to bending. The length of the longitudinal region of the sample, in which the effect of induced bistability takes place, depended on the bending radius. In contrast to the classical version of this effect, bending-induced bistability was accompanied by the rapid movement of the longitudinal domain wall in the microwire surface.

Abstract: In this study, we designed and synthesised MTX and PEG‒grafted chitosan copolymer nanoparticles (PsCM) to load MAG. We generated MAG@PsCM nanoparticles according to the effective ratio of dual drugs of 1:2.5, achieving 3.73% and 8.95% drug loading for MTX and MAG, respectively. Drug efficiency experiments were conducted on MDA-MB-231 breast cancer cells, and the results showed that when MTX was used alone, the tumour cell survival rate was 43.66 ± 1.77%and when low-dose MAG and MTX were used in combination, the survival rate of tumour cells was significantly reduced to 29.82% ± 2.22%. The nanoparticles enhanced the synergistic tumour therapeutic effect of the two drugs with the cell survival rate was 21.94 ± 1.43%, significantly lower compared with the free drugs. MAG@PsCM nanoparticles were significantly taken up by cells at 3, 6 and 12 h, and the total amount taken up increased significantly with time.

Abstract: Polymethyl methacrylate (PMMA) has been widely used in stomatology to prepare denture bases. However, issues such as a porous structure and high water absorption rate facilitate bacterial growth. This study aimed to synthesize silver nanoparticle/graphene oxide (AgNPs/GO) composites by the chemical reduction method, which was mixed with PMMA by the ball milling method to improve the antibacterial properties of PMMA. Scanning electron microscopy and transmission electron microscopy showed that AgNPs were uniformly dispersed on the GO sheets. AgNPs/GO composite and GO were investigated using x-ray diffraction. The modified AgNPs/GO/PMMA composite demonstrated enhanced antibacterial properties against Streptococcus mutans based on the film adhesion test. Also, the number of bacteria decreased and the morphology of bacteria changed with the increase in mass fraction. Besides, the improved mechanical properties were confirmed by the friction and contact angle tests. Moreover, the composite did not induce cytotoxicity in human gingival mesenchymal stem cells.

Abstract: The characteristics and performance of perovskites are adversely impacted by the presence of a Sn metal at high-temperature conditions. In this study, CASTEP analysis and density functional theory are used to examine the impact of 1-butyl-3-methylimidazolium bromine ionic liquid in enhancing the features of Pb-Sn halide perovskite alloys. According to the study’s findings, the ionic liquid device has better electronic, optical, mechanical, and thermodynamic properties than the control sample because it can anchor the MA cation through hydrogen bonding and can reduce the grain boundaries of the perovskite film, making it tolerable up to high temperatures above 80°C. In comparison to the control device, the ionic liquid perovskites’ photovoltaic characteristics were also improved. This research lays the way for the development of Pb-Sn alloys with enhanced characteristics that are likely to result in the development of stable and effective lead-free perovskite solar cells.