Waste-derived aluminium matrix composites (AMCs) are increasingly promoted as circular, low-cost alternatives to conventional ceramic-reinforced aluminium systems, yet their engineering relevance cannot be established from hardness improvement or isolated dry-sliding results alone. Durable service requires simultaneous evidence of wear resistance, corrosion tolerance, interface stability, defect control, reproducibility and benchmark competitiveness. This review critically evaluates waste-derived AMCs through a durability-centred framework that links tribological performance, corrosion response, wear-corrosion trade-offs, test standardization, conventional AMC benchmarking and application readiness. Evidence from agricultural ashes, biomass-derived carbonaceous residues, shell-derived powders, industrial residues, mineral wastes, waste glass and hybrid reinforcement systems shows that waste-derived particles can improve hardness and wear resistance when they are clean, thermally stable, uniformly dispersed, strongly bonded and incorporated with low porosity. Corrosion resistance is more conditional: pores, particle clusters, galvanic heterogeneity, weak interfaces, unstable reaction products and discontinuous passive films can accelerate localized attack even when hardness increases. The review therefore interprets reported performance through a mechanism-weighted lens that prioritizes worn-surface validation, post-corrosion evidence, microstructural quantification, uncertainty reporting and comparison with unreinforced aluminium and conventional SiC or Al2O3 AMCs. The synthesis identifies practical durability windows in which moderate reinforcement loading, controlled particle size, dense processing and stable interfaces support balanced wear and corrosion performance. It also defines reporting and testing requirements needed to move waste-derived AMCs from promising laboratory demonstrations toward reproducible, benchmarkable and application-ready lightweight materials.
Amino acids derived from renewable agro-based feedstocks are emerging as sustainable precursors for green corrosion inhibitors and biodegradable functional materials. Herein, we present a systematic density functional theory (DFT) investigation of the adsorption behavior of four aromatic amino acids as L-phenylalanine, L-tyrosine, L-histidine, and L-tryptophan on a (ZnO)12 nanocluster model. Unlike previous studies focused primarily on metal surfaces, this work uniquely elucidates the molecular-level adsorption mechanism of aromatic amino acids directly on ZnO, the principal constituent of galvanized steel passivation layers. Global reactivity descriptors reveal that amino acids containing multiple N/O heteroatoms exhibit enhanced reactivity toward ZnO. Interfacial analysis shows the formation of strong Zn–N and Zn–O coordinative bonds, reinforced by hydrogen bonding and π-mediated interactions involving aromatic rings. The calculated adsorption energies (− 48.1 to − 60.1 kcal mol⁻¹) and Gibbs free energies (− 64.1 to − 83.1 kcal mol⁻¹) confirm spontaneous and exothermic chemisorption. These findings establish a clear structure–adsorption relationship and provide fundamental mechanistic insights for the rational design of bio-inspired, eco-friendly anticorrosive coatings and functional ZnO-based interfaces.
This study presents a comprehensive experimental investigation into the corrosion behaviour and surface degradation mechanisms of AISI 316L stainless steel in prolonged contact with beer, simulating realistic brewery service conditions. Six polished 316L stainless steel specimens (100 × 30 × 4 mm) were immersed in different commercial beer products for 163.5 days (3892.5 h) at ambient temperatures (19–25 °C), following ASTM G31-21 immersion testing guidelines. Corrosion performance was evaluated using gravimetric weight loss measurements, optical microscopy (OM), scanning electron microscopy (SEM), three-dimensional surface profilometry, surface roughness analysis, and advanced image processing techniques. Gravimetric results revealed measurable material degradation across all samples, with corrosion rates ranging from 0.0006 to 0.0078 mm y−1. The maximum corrosion rate of approximately 0.008 mm y−1 was observed in samples exposed to more aggressive chemical environments, indicating that the exposure medium influences corrosion severity (one specimen per medium, no replicates). Surface characterization indicated that corrosion was dominated by localized attack rather than uniform dissolution. SEM and OM observations were consistent with pitting and crevice attack and showed features suggesting intergranular and galvanic effects; microbiologically influenced corrosion was not verified. Three-dimensional profilometry showed a pronounced deterioration of surface integrity, with average surface roughness (Ra) increasing from 1.009 µm (unexposed control) to 11.45 µm after immersion. Maximum pit depths reached approximately 9.8–10.3 µm, while peak-to-valley height (Rpv) increased to 69.1 µm, indicating severe localized material loss. Image-based quantitative analysis further revealed heterogeneous pit distribution and progressive surface roughening. Beer pH and electrical conductivity were measured before and after immersion and compared qualitatively with corrosion intensity; the roles of acidity, chloride ions and dissolved oxygen in passive film breakdown are proposed rather than directly demonstrated.
In this study, the therapeutic peptide afamelanotide (AFAM) is computationally investigated as a sustainable corrosion inhibitor for carbon steel through an integrated multiscale theoretical approach combining density functional tight-binding (DFTB), molecular electrostatic potential (MEP) analysis, Monte Carlo (MC) adsorption simulations, and radial distribution function (RDF) analysis. Geometry optimization and frontier molecular orbital calculations reveal a relatively small HOMO-LUMO energy gap (3.338 eV), low chemical hardness (1.669 eV), and high electrophilicity (3.855 eV), suggesting a notable intrinsic electron-donating and electron-accepting capability of the isolated AFAM molecule. MEP mapping identifies oxygen- and nitrogen-rich functional groups as the likely adsorption centers that may participate in interfacial charge transfer with the Fe(1 1 0) surface. Force-field-based Monte Carlo simulations predict an energetically favorable, nearly parallel adsorption configuration with a large negative adsorption (interaction) energy of -127.047 kcal mol⁻¹, considerably more negative than that of water (-15.774 kcal mol⁻¹), suggesting a strong tendency to displace interfacial water molecules and cover the surface. RDF analysis of selected heteroatoms further indicates that, within the non-reactive force-field model, adsorption is predominantly of the physisorption type, with electrostatic interactions and possible donor–acceptor contributions involving protonated heteroatoms and aromatic π-electron systems that are inferred from the electronic-structure analysis rather than directly computed. The combined computational evidence supports a plausible molecular-level inhibition mechanism and identifies AFAM as a promising candidate peptide-based green corrosion inhibitor with a strong predicted adsorption affinity for acidic environments; experimental validation is required to confirm its inhibition efficiency.
The present study addresses the need for sustainable multifunctional polymer composites by developing vinyl ester biocomposites reinforced with Wrightia tinctoria seed microfibers and Himalayan Cydonia oblonga pomace filler. The composites were fabricated using the hand lay-up technique with a constant Wrightia tinctoria microfiber loading of 40 vol
