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Corrosion processes are often discussed as stochastic events. Here, it is shown that some of these seemingly random processes are not driven by nanoscopic fluctuations but rather by the spatial distribution of micrometer‐scale heterogeneities that trigger fast reactions associated with corrosion. Using a novel excitable reaction‐diffusion model, corrosion waves traveling over the metal surface and the associated material loss are described. This resulting nonuniform corrosion penetration, seen as a height loss in modeling, exposes buried intermetallic particles, which depending on the local electrochemical state of the surface trigger or block new waves. Informed by quantitative experimental data for the Mg–Al–Zn alloy AZ31B, wave speeds, wave widths, and average material loss are accurately captured. Morphogenic mitigation based on wave‐breaking microparticles is also simulated. While AZ31B corrosion is identified as a process driven by rare‐wave events, this study predicts several other corrosion regimes that proceed via spots or patchy patterns, opening the door for new protection, design, and prediction strategies. [ABSTRACT FROM AUTHOR]

The development of hybrid agro-metallic alloy and its composites has increased in the last few years to overcome the shortcomings of monolithic alloys. Using hard ceramic reinforcements would enhance the strength of the alloys and its composites during component building. One such ceramic reinforcement is the Titania (TiO2) powder, which possesses more strength than other ceramics materials, but the cost is a little higher. To overcome this, eco-friendly, calcined eggshell (CES) particulates are added to TiO2 reinforcement to enhance the strength of the hybrid composite at a reduced cost. The main novelty of the present study is the employment of CES and TiO2 particulates in the Al 6061 matrix during the development of hybrid Al 6061 composites. This increases the strength of the fabricated composites at a reduced cost and results in the development of eco-friendly agro-metallic composites. Samples were produced individually in groups with varying proportions of CES at 3, 6, 9 and 12 wt% and combined with fixed proportions of TiO2 at 3, 6, 9 and 12 wt% individually with groups such as A (3 wt% of TiO2 + 3, 6, 9 and 12 wt% of CES), B, C and C and D, respectively. Microstructural characterization through FESEM and phase identification through XRD analysis are conducted to justify the uniform dispersion of reinforcements in the matrix. Developed samples were subjected to tensile, flexural and hardness tests, and the results proved that the mechanical properties of composites were enhanced when combining 3, 6, 9 and 12 wt% CES with 3 and 6 wt% of TiO2 compared with unreinforced Al 6061. The enhancement is linked to the uniform dispersion of the particles and good interaction between the particles. However, the 3, 6, 9 and 12 wt% CES with 9 and 12 wt% of TiO2 yielded inferior strength performance relative to the reference mix due to particle clustering and agglomeration formation. This acts as a yielding point for stress concentration. Therefore, it was concluded that a combination of 3, 6, 9 and 12 wt% CES with TiO2 should not exceed 6 wt% of TiO2. [ABSTRACT FROM AUTHOR]

Composites are versatile materials that can be tailored to meet the specific needs of various industries, including aerospace, automotive, and construction. This study focuses on investigating how the amount of titanium-di-boride (TiB2) particles (0%, 3%, 6%, and 9%) affects the physical, mechanical, microstructural, and fracture properties of Al7075/TiB2 composites produced using a liquid-state stir-casting process. The addition of TiB2 particles increases the hardness and tensile strength of the Al7075 alloy. This has been confirmed by X-ray diffraction analysis, which showed that these particles are dispersed throughout the aluminum matrix. The hardness increases from 60 HV to 90 HV and the tensile strength increases from 140 MPa to 211 MPa. The significance of increased wettability brought about by the addition of magnesium powder and the preheating of a ceramic reinforcement before pouring molten metal was revealed by scanning electron micrographs of the cast composites, which showed an even dispersal of reinforcements in the aluminum matrix, establishing the strong connection between the matrix and the reinforcement agents. Fracture surface scanning electron microscopy revealed that micro-void formation and nucleation in Al7075/TiB2 composites resulted in ductile material paves a way for manufacturing innovation. [ABSTRACT FROM AUTHOR]

BACKGROUND: Self‐propagating high‐temperature synthesis was used to create mesoporous CeO2 and MgO powders as well as nanocomposites based on them for efficient degradation of organic dyes. RESULTS: It has been investigated how magnesium oxide and cerium oxide interact to affect the crystal structure, morphology and microstructure of the materials produced. It was assumed that CeO2 forms on the surface of MgO while the material's developed surface is preserved. The values of the specific surface area and average pore diameter of the studied samples depend on the composition and vary in the ranges of 16–41 m2 g−1 and 11.919 nm, respectively. CONCLUSION: It has been established that the sizes of CeO2 crystallites in the composition of nanocomposites change insignificantly and range from 6.5 to 7.4 nm. The photocatalytic activity of the studied samples is at least two times higher compared to analogs. The samples MgO–CeO2 (30 mol%) and MgO–CeO2 (50 mol%) showed the maximum photodegradation efficiency of acid telon blue and direct bright blue dyes at levels of 98.5% and 92.5%, respectively. © 2023 The Authors. Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Laser powder bed fusion (L-PBF) stands out as a promising approach within the realm of additive manufacturing, particularly for the synthesis of CNT-AlSi10Mg nanocomposites. This review delves into a thorough exploration of the transformation in microstructure, the impact of processing variables, and the physico-mechanical characteristics of CNT-AlSi10Mg nanocomposites crafted via the L-PBF technique. Moreover, it consolidates a substantial corpus of recent research, proffering invaluable insights into optimizing L-PBF parameters to attain the desired microstructures and enhanced properties. The review centers its attention on pivotal facets, including the dispersion and distribution of CNTs, the formation of porosity, and their subsequent influence on wear resistance, electrical and thermal conductivity, tensile strength, thermal expansion, and hardness. In line with a logical progression, this review paper endeavors to illuminate the chemical composition, traits, and phase configuration of AlSi10Mg-based parts fabricated via L-PBF, juxtaposing them with their conventionally manufactured counterparts. Emphasis has been placed on elucidating the connection between the microstructural evolution of these nanocomposites and the resultant physico-mechanical properties. Quantitative data culled from the literature indicate that L-PBF-produced parts exhibit a microhardness of 151 HV, a relative density of 99.7%, an ultimate tensile strength of 70 × 10 3   mm 3 N. m , and a tensile strength of 756 MPa. [ABSTRACT FROM AUTHOR]

In this research, the microstructural and mechanical properties of the as-cast and artificially aged Al6061-TiO2 alloy and its composites developed by the double stir casting process were studied. The reinforcements were added in different weight concentrations and artificial aging was done at 200 °C for 2 h. TiO2 particle reinforcement was adopted because of its better grain refining capacity, high elastic modulus and precipitate pinning effect. Heat treatment was performed for the formation of a high density of fine precipitates which was suitable for stress-bearing applications. The results showed an improvement in the tensile strength and hardness of the heat-treated samples up to 195.2 and 43.68%, respectively, compared to the as-cast samples. After TiO2 addition and age-hardening heat treatment, the SEM fractography showed that the small size dimples were evenly distributed which represented the enhanced ductile nature. The as-cast alloy and its composites had better damping properties compared to the age-hardened specimens. Fracture toughness and elongation showed enhancement in the heat-treated samples than in the as-cast samples. This enhancement is associated with the grain refining effect of TiO2 particles and precipitate formation. Artificially aged Al6061 alloy and its composite showed a better balance of properties. [ABSTRACT FROM AUTHOR]

Laser Powder Bed Fusion (LPBF) emerges as a promising technique for manufacturing AlSi10Mg-based composites, particularly those reinforced with graphene (GR-AlSi10Mg). These nanocomposites are known for their distinctive combination of properties. This comprehensive review delves into the development of GR-AlSi10Mg nanocomposites through LPBF. Initially, strategies to achieve uniform GR dispersion within the AlSi10Mg matrix are explored. Subsequently, operational parameters affecting densification, microstructure evolution, and interface behavior are scrutinized. Moreover, this study extensively addresses determining factors influencing physicomechanical characteristics, covering mechanical, thermal, and wear properties. In this regard, key elements like GR concentration, phase formation, and porosity are thoroughly examined. Additionally, challenges in LPBF treatment of GR-AlSi10Mg nanocomposites are identified, and potential areas for future research are proposed. The findings highlight substantial material property advancements due to GR reinforcement, providing valuable insights into strengthening mechanisms and enhanced properties. Finally, this review emphasizes the need to address manufacturing challenges and improve process efficiencies for practical use in producing GR-AlSi10Mg nanocomposites. This review paper serves as a valuable resource for advancing LPBF technology in producing high-performance GR-AlSi10Mg nanocomposites. [ABSTRACT FROM AUTHOR]

On account of their lower densities and distinct properties, lightweight high entropy alloys (LHEA) are gaining prominence in the fabrication of particulate reinforced aluminum composites. In lieu of this, present report was conceived to achieve strength and ductility improvement in aluminum-7068 aerospace alloy by the inclusion of highly flexible Al 30 Li 20 Mg 10 Be 20 Ti 10 Cu 10 LHEA (at 4, 10, and 16 wt%) as reinforcing phase. From the experimental outcome, the X-ray diffraction of the composites depicted BCC and FCC phases derived from LHEA addition. As the LHEA dosage increased, these phases became more prominent. Meanwhile, CuAl 2 , and MgBe 13 intermetallic phases were equally identified in the composites. Based on the microstructure, the particles were sparsely dispersed at 4%, evenly dispersed at 10%, and exhibited both dispersed and clustered particles at 16%. The identified phases and the morphology played significant role in the mechanical characteristics of the fabricated composites ensuing strength improvement. Likewise, the plastic deformability of the composites was enhanced, resulting in a boost in strain hardening sensitivity and a decrease in necking susceptibility. The strengthening mechanism and the micro-models are herein discussed. According to the results, optimal efficacy was deduced at 10% LHEA. • LHEA as substitute to ceramic particles in aluminium matrix. • LHEA are becoming reinforcing phases in aluminium matrix. • LHEA resulted in improvement of hardness of the AA-7068 composite. • Mechanical performance of Al-7068 was improved by the LHEA particles. [ABSTRACT FROM AUTHOR]