Ferrosilicon (FeSi), a metallic alloy of iron (Fe) and silicon (Si) has been a critical component in Dense Medium Separation (DMS) processes since the 1950s in the mineral processing industry. Since then, FeSi has been utilized to separate various minerals such as diamonds, gold, tin, tungsten, and iron from less valuable material, i.e. gangue. The use of FeSi as a separation medium remains prominent today. This review provides a comprehensive analysis of FeSi’s lifecycle in DMS, from production using the electric submerged arc furnace to its role in ensuring separation efficiency, medium stability, and loss mitigation strategies. Key factors affecting FeSi performance, such as viscosity, stability, contamination, and corrosion, are explored, along with emerging techniques for improving its sustainability and cost-effectiveness. Additionally, this paper proposes a case study on the potential for FeSi production in Botswana, leveraging local raw materials such as iron ore and silica to support economic growth. Future advancements in FeSi recovery and process optimization are also discussed. By addressing quality standards, environmental considerations, and economic feasibility, this review aims to provide a valuable reference for researchers and industry professionals seeking to enhance the efficiency and longevity of FeSi in DMS applications.

The persistent degradation of Pipeline steels in acidic environments demands effective, low-toxicity inhibitors that are deployable at industrial scale. Plant-based extracts have emerged as promising candidates, but their mechanistic understanding, especially when applied to high-grade pipeline steels under realistic service conditions, is limited. This study aims to evaluate the corrosion inhibition performance and adsorption mechanism of Sclerocarya birrea (marula) ethanolic leaf extract on API 5 L X42 pipeline steel in 1 M H2SO4. A combined experimental-computational approach was adopted, integrating gravimetric analysis, Open Circuit Potential, Electrochemical Impedance Spectroscopy, and Potentiodynamic Polarization at 303, 313, and 323 K with inhibitor concentrations of 0, 10, and 20 g·L-1, applying rigorous error analysis to ensure reproducibility. Spectroscopic and chromatographic analyses (FTIR, UV–Vis, GC–MS, XRD, Raman) revealed oxygen-bearing and π-rich phytoconstituents as active adsorption centers. Maximum inhibition efficiency of 93% (weight-loss) was achieved at 20 g·L⁻¹ and 303 K, with electrochemical data showing increased charge-transfer resistance (1489 → 6359 Ω·cm2) and decreased corrosion current density, consistent with mixed-type inhibition dominated by anodic suppression. Thermodynamic analysis revealed ΔG ads values of -9.2 to -10.2 kJ·mol⁻¹, indicating predominantly physisorption, and positive ΔH (up to +47.99 kJ·mol-1), suggesting endothermic adsorption. Adsorption followed the Temkin model (R² up to 0.985), implying lateral molecular interactions. Density Functional Theory and Monte Carlo simulations confirmed favorable adsorption geometries on Fe(110) surfaces and highlighted phytol derivatives as the strongest adsorbates. The study demonstrates that S. birrea extract forms a robust, eco-friendly protective layer capable of mitigating acid-induced corrosion of pipeline steel.

In this study, we investigated the corrosion behaviour of heat-treated biomedical grade 316L Stainless Steel (SS 316L) in simulated body fluids. SS 316L is widely used in biomedical applications due to its excellent mechanical properties and biocompatibility. Nonetheless, concerns about its susceptibility to corrosion in physiological environments persist. To mitigate these concerns, heat treatment was employed to enhance the material's corrosion resistance by modifying its microstructure. Specimens underwent heat treatment at varying temperatures (1050–1200 °C) for 1 h, followed by rapid water cooling. The corrosion behaviour of both untreated and heat-treated samples was assessed using electrochemical techniques, including potentiodynamic polarization and electrochemical impedance spectroscopy, in simulated body fluids with 0.9 % NaCl. The specimen exhibiting optimal corrosion resistance in this solution was further evaluated in Hanks Balanced Salt Solution enriched with Mg2+ and Ca2+ ions (HBSS+). The results highlighted that the specimen subjected to heat treatment at 1200 °C, followed by water quenching (HT1200 °C/1hr/WQ), experienced deterioration due to galvanic effects between the γ-austenite and δ-ferrite phases. Conversely, the specimen heat-treated at 1100 °C, followed by water quenching (HT1100 °C/1hr/WQ), demonstrated the highest corrosion resistance in 0.9 % NaCl, even surpassing the untreated sample. This improved corrosion resistance was attributed to the combination of moderate and uniform grain size and complete transformation to the austenitic phase during heat treatment. However, when the (HT1100 °C/1hr/WQ) specimen was immersed in a more aggressive HBSS+ solution, its corrosion resistance deteriorated, suggesting the influence of the medium despite microstructural improvement.

T he growing emphasis on environmentally friendly corrosion inhibitors has attracted substantial interest within academic circles, driven by the goal of addressing the persistence issue of corrosion. The application of plant leaf extracts as agents to mitigate metal degradation in harsh environments has emerged as a significant area of study. As the use of mild steel, pipeline steel, and stainless steel becomes more prevalent in corrosive settings like acidic and seawater environments across various industries, demand for environmentally benign and relatively efficient corrosion inhibitors has grown. A comprehensive review of existing literature reveals that plant leaf extracts contain phytochemical compounds such as tannins, polyphenols, and glycerides, which form strong bonds with metal surfaces, effectively obstructing active sites and reducing the ingress of corrosive agents. Functional groups and heteroatoms such as oxygen (O), sulfur (S), nitrogen (N), and phosphorus (P), along with aromatic rings, enrich these extracts, adhering to metal surfaces and inhibiting corrosion. Analysis of the surveyed literature demonstrates that inhibition efficiency rises with increasing inhibitor concentration, with the Langmuir model emerging as the dominant absorption model. Researchers employed electrochemical and weight loss techniques to investigate corrosion mechanisms and absorption models. Notably, most leaf extracts exhibit inhibition efficiencies surpassing 90

This study evaluates the thermodynamic behavior and adsorption mechanism of methanolic Acacia mearnsii bark extract (MAMBE) as a green corrosion inhibitor for stainless steel (SS304) in synergy with KI in 1 M HCl solution. Using weight loss measurements, thermodynamic calculations, and adsorption studies, the study assesses both the individual and combined effectiveness of MAMBE and potassium iodide (KI). MAMBE alone achieved a maximum inhibition efficiency of 62.2 % at 1.2 g/L, which dramatically increased to 98.2% when supplemented with 0.3 g/L KI, indicating a strong synergistic effect (s > 1). Thermodynamic parameters, including activation energy (Ea), enthalpy change (ΔH°), entropy change (ΔS°), and Gibbs free energy change (ΔG°), were analyzed to understand the nature of adsorption and spontaneity. MAMBE and KI alone showed Ea values below 80 kJ/mol with positive ΔH°, indicating endothermic adsorption. The MAMBE and KI combination presented a higher Ea of 105 kJ/mol, suggesting a more robust corrosion barrier. The ΔG° values (-6.653 to −21.765 kJ/mol) confirmed spontaneous, predominantly physical adsorption. Adsorption followed the Langmuir isotherm model, and thermogravimetric analysis revealed MAMBE's thermal stability up to 110°C, highlighting its excellent thermal resistance and potential as an effective eco-friendly corrosion inhibitor.

This study explores the thermodynamic behavior and adsorption mechanism of Sclerocarya birrea leaf extract as a sustainable corrosion inhibitor for mild steel in simulated seawater (3.5 % NaCl). Corrosion inhibition efficiency and corrosion rate were assessed using the weight-loss method over a temperature range of 303–323 K. Thermodynamic parameters such as activation energy (Ea), enthalpy (ΔH°), entropy (ΔS°), and Gibbs free energy (ΔG°) were calculated to evaluate the adsorption nature and spontaneity of the inhibition process. Adsorption isotherms (Langmuir, Temkin, and Freundlich) were applied to model the inhibitor-metal surface interactions. The results show that increasing extract concentration enhanced inhibition efficiency, while increasing the temperature reduced it, indicating a temperature-sensitive physisorption process. Inhibited samples exhibited Ea values below 80 kJ/mol and positive ΔH° values, confirming endothermic adsorption. ΔG° values ranged from -6.653 to -21.765 kJ/mol, consistent with spontaneous physical adsorption. Among the isotherm models evaluated, the Temkin isotherm best described the adsorption behavior (R² = 0.932 at 303 K). These findings demonstrate that Sclerocarya birrea extract offers a viable, eco-friendly approach to corrosion mitigation through thermodynamically favorable physisorption.

This study investigates the laser cladding of Co and Ni powders onto Ti–6Al–4 V substrates, varying the admixed percentages while adjusting laser processing parameters. The influence of nickel and cobalt contents on the microstructure, phase composition, and electrochemical behavior of the laser-clad Ti–6Al–4 V coatings were analyzed. Coating morphology and phases were characterized using scanning electron microscopy (SEM) equipped with energy dispersive spectrometry (EDS), and X-ray diffractometry (XRD), respectively. The corrosion resistance of Ti–6Al–4 V, both with and without Ni–Co additions, in 0.5 M H 2 SO 4 was evaluated using potentiodynamic polarization technique. Results indicated that the coatings exhibited excellent metallurgical compatibility with the substrate. Additionally, the high scan speed laser-clad samples showed enhanced corrosion resistance compared to those processed at low speeds. The potentiodynamic polarization analysis revealed passive behavior in all specimens, with higher cobalt content notably enhancing passivity and corrosion resistance by suppressing the anodic reaction.

The influence of solution treatment on the phase evolution and tensile properties of Ti-Mo alloys was investigated to assess their potential use in biomedical applications. Phase formation and microstructural evolution were studied using X-ray diffraction (XRD), optical microscopy (OM), scanning electron microscopy (SEM), and electron backscatter diffraction (EBSD). The mechanical properties were characterized by means of tensile tests and bending strength. XRD analysis showed that solution treatment increased the volume fraction of ß phase and supressed the α" phase. The microstructures of the as-cast alloys consisted of ß equiaxed grains with sub-grain structures of different sizes, while the solution treated alloys comprised ß equiaxed grains only except for Ti-10.02Mo, which comprised needle-like a" structures. EBSD showed an increase in the volume fraction of the ω and α" phases in all the alloys after solution treatment. The elastic modulus and UTS of all the alloy significantly decreased after solution treatment, except for Ti-15.05Mo, whereas the elongation significantly increased. The fracture surfaces of all the alloys after solution treatment indicated more ductile behaviour than brittle.

The present study investigated the influence of adding FeTi as supplementary reinforcement to B4C in an aluminum–silicon (Al-12Si) matrix for automobile applications. The FeTi alloy was introduced at 3, 6, and 9 wt.

The goal of this work is to improve the Ti–6Al–4V alloy's hardness and tribological behavior. Coaxial laser surface cladding was used to develop intermetallic layers of nickel (Ni), cobalt (Co), and titanium (Ti). Laser power of 900 W, beam spot size of 3 mm, powder feed rate of 1.0 g/min, and gas flow rate of 1.2 L/min are the optimized parameters used for laser depositions. The laser scan speeds were adjusted between 0.6 and 1.2 m/min. Investigations were conducted into the effects of powder admixture and laser parameters on the fabricated coatings' microstructure, tribological behavior and hardness. X-ray diffractometry (XRD), energy dispersive spectroscopy (EDS) with Scanning electron microscopy (SEM) was employed for the characterization of the microstructural evolution and phase identification, respectively. Additionally, the tribological experiment was conducted via UMT-2 –CETR reciprocating tribometer, and the coatings’ micro-hardness characteristics were examined using EmcoTEST DURASCAN. The micrographs exhibit no signs of porousness, cracks, or stress introduction, according to the results. For every manufactured sample, good metallurgical adhesion was obtained. By comparing the hardness of the ternary coating (Co–Ni–10Ti deposited at a scan speed of 1.2 m/min, with a hardness of 980 HV) to the substrate (Ti–6Al–4V, with a hardness of 330 HV), a hardness increase of approximately 2.96 times was observed. Furthermore, the Co–Ni–10Ti coating, deposited at a scan speed of 1.2 m/min, demonstrated a 51.1

This research explores the impact of variations in laser scanning speed and the incorporation levels of SiC-Ni-Co powders on Ti-6Al-4V alloy using laser surface cladding technique. Key parameters, including a consistent laser power of 700 W, a 4 mm beam spot size, a powder feed rate of 1.0 g/min, and a gas flow rate of 3 L/min, along with fixed powder compositions, were maintained. The laser scanning speeds were adjusted to 0.4 m/min, 0.8 m/min, and 1.2 m/min. Microstructural analyses were carried out using scanning electron microscopy (SEM) while Vickers microhardness was employed to assess coating hardness, and corrosion properties were evaluated using a linear potentiodynamic polarization technique. Following the corrosion attack, the protective oxides formed were identified through SEM and X-ray diffractometer (XRD). The results revealed a strong metallurgical relationship between the clad layer and the substrate, demonstrating the effectiveness of the laser-clad technique. Particularly, the highest laser scan speed exhibited the most significant improvements in hardness and corrosion resistance. The coatings displayed an average hardness value of 1269.20 HV0.1, a notable fourfold increase compared to the substrate's value of 334 HV0.1. Concerning corrosion, a clear correlation emerged between scan speed and polarization resistance, confirming that higher scan speeds could lead to enhanced polarization resistance.

Background: Owing to the promising characteristics— high strength-to-weight ratio, acoustic and thermal insulation, renewable and biodegradable, sisal fiber-based composites have been explored. Including patents, interesting literature is available on sisal fiber-based composites. Method: The materials under investigation were sisal fiber (SF), polypropylene (PP), and sisal- fiber- reinforced polypropylene composite (SFR-PC). Three different samples of SFR-PC were fabricated via injection molding. Their morphological-, mechanical-, thermal-, and water absorptionproperties were analyzed. Results: The untreated sisal fiber (USF) sample showed a network microstructure with micro-void; however, the alkali (NaOH)-treated sisal fiber (TSF) sample envisages surface roughness morphology. The C-O stretching vibration of the acetyl groups of lignin in the USF vanished after the alkali treatment of SF. The degree of crystallinity index, thermal stability, weight loss, and water resistance improved with the alkali (NaOH) treatment of SF. The tensile modulus (E) for SFR- PC showed an increasing trend with the addition of TSF at all weights % envisaging a better interaction between polymer matrix and reinforcement; however, the 90PP-10TSF sample exhibited the highest storage modulus (Eˈ) at all temperatures due to the TSF distribution and agglomeration in the polymer matrix. The addition of TSF improved the loss modulus (E˝) for the SFR-PC sample as compared to the PP sample. Conclusion: The 90PP-10TSF sample showed the optimum distribution of TSF in the PP matrix. DSC secondary heating thermograph depicted that the addition of TSF did not affect the melting temperature of SFR-PC samples, and the cooling thermograph showed that the addition of TSF in the polymer matrix gradually increased the crystallization temperature, suggesting a better packing of the cellulose chain. The 70PP-30TSF sample showed the highest absorption, followed by 80PP- 20TSF and 90PP-10TSF samples, whereas the PP sample showed the lowest absorption.

Polymer nanocomposites have been of great interest to packaging, energy, molding, and transportation industries due to several favorable properties including a higher resistance to stress and cracking even under flexed conditions, and also a chemical resistance to water, acids, and alkalis. The current work disseminates the studies on the mechanical and thermal properties of the polypropylene HHR102 polymer reinforced with nano dispersoids of silicon dioxide at varied weight fractions. The nanocomposites, fabricated via melt processing followed by injection molding, were tested for tensile strength, % elongation, tensile modulus, and impact toughness. Further, the samples were also subjected to dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) to determine the dynamic storage modulus and thermal stability. The addition of nano-silica in polypropylene HHR102 resulted in enhanced ductility and well-balanced tensile modulus; however, the tensile strength and impact toughness were found to be decreased. On the other hand, the storage modulus was significantly increased for all nano-silica (NS)-containing polypropylene HHR102 matrices. With the increased nano-silica content, the storage modulus was optimal. Further, with the lower weight loss of 30% and 50%, the thermal stability of the increased silica content PP nanocomposites was much affected. However, it improved at a weight loss of 30% for the lower silica content PP nanocomposite (PP-1%NS). The imbibition was found to increase with the increase in NS. The increase in imbibition is attributed to the micro-voids generated during ageing. These micro-voids act as channels for water absorption. Further, the degree of crystallinity of the nanocomposites was decreased as a result of inhibition by the nano-particles on the regular packing of polymer molecules. The structure–property correlations were explicated based on the achieved mechanical properties.

Abstract The brittle nature of ceramic reinforcement in metal matrixes has initiated a gap in the utilization of metal-based particles as supplementary reinforcement. This present study investigated the influence of adding FeTi as supplementary reinforcement to B 4 C and FeTi in an aluminum-silicon (Al-12Si) matrix for automobile applications. The FeTi alloy was introduced at 3, 6, and 9 wt.% alongside the 5 wt.% B 4 C particles. The effect of such an addition on the morphology, physical, and mechanical properties was examined. The X-ray diffraction pattern identified the presence of B 4 C and FeTi reinforcing phases alongside Al 3 Fe and Ti 5 Si 3 phases. The examined morphology revealed that the particles were well dispersed in the matrix, with consequent effects on their properties. Porosity was reported to reduce linearly with a rise in FeTi dosage, consequently engendering a linear rise in density and relatively high density. Inclusive of the hardness, the yield and ultimate strength were enhanced progressively upon a progressive rise in FeTi dosage, with a contrary reduction in ductility. The result revealed that the inclusion of FeTi reinforcing fillers in the matrix is capable of causing an appreciable improvement in the mechanical properties of the composite.

Abstract The brittle nature of ceramic reinforcement in metal matrixes has initiated a gap in the utilization of metal-based particles as supplementary reinforcement. This present study investigated the influence of adding FeTi as supplementary reinforcement to B4C and FeTi in an aluminum-silicon (Al-12Si) matrix for automobile applications. The FeTi alloy was introduced at 3, 6, and 9 wt.% alongside the 5 wt.% B4C particles. The effect of such an addition on the morphology, physical, and mechanical properties was examined. The X-ray diffraction pattern identified the presence of B4C and FeTi reinforcing phases alongside Al3Fe and Ti5Si3 phases. The examined morphology revealed that the particles were well dispersed in the matrix, with consequent effects on their properties. Porosity was reported to reduce linearly with a rise in FeTi dosage, consequently engendering a linear rise in density and relatively high density. Inclusive of the hardness, the yield and ultimate strength were enhanced progressively upon a progressive rise in FeTi dosage, with a contrary reduction in ductility. The result revealed that the inclusion of FeTi reinforcing fillers in the matrix is capable of causing an appreciable improvement in the mechanical properties of the composite.

Wear properties of Al–Mg–Si alloy matrix hybrid composites made with Si-based refractory compounds (SBRC) derived from bamboo leaf ash (BLA) as complimentary reinforcement with alumina have been studied. The experimental result indicate that optimum wear loss was obtained at higher sliding speed. The wear rate of the composites increased with an increase in BLA wt. %, with the composites having 4%SBRC from BLA + 6% alumina (B4) showing the least wear loss for the different sliding speeds and wear loads considered. With increasing BLA weight percent, the composites' wear mechanism was mostly abrasive wear. Numerical optimization results using central composite design (CCD) reveal that at a wear load of 587.014N, sliding speed of 310.053 rpm and B4 hybrid filler composition level respectively, minimum responses in wear rate (0.572mm 2 /min), specific wear rate (0.212cm 2 /g.cm 3 ) and wear loss (0.120 g) would be obtained for the developed AA6063 based hybrid composite. Perturbation plots indicate that the sliding speed have more impact on wear loss, while wear load have significant impact on the wear rate and specific wear rate.

Current research is focused on development of β-type titanium alloys for biomedical applications as substitutes of the undesirable Ti6Al4V alloy. Ti6Al4V alloy has a higher elastic modulus (110 GPa) than that of the human bone (10-30 GPa) and this mismatch in elastic moduli can cause stress shielding effect, which can cause bone resorption and implant failure. Moreover, the dissociation of vanadium and aluminium can cause long term diseases including Alzheimer, neuropathy. β-type titanium alloys are potential substitute materials due to their good biocompatibility and the β phase has a lower elastic modulus. The aim was to study the microstructure and tensile properties of heat-treated Ti-xMo alloys (x= 8 & 10wt%). Phase analysis was conducted using X-ray diffractometer, while the microstructure was observed using an optical microscope. The tensile properties were examined using a tensile test machine. Acicular structures of α" phase precipitated in the β matrix in Ti-8Mo alloy, while Ti-10Mo alloy showed predominant β phase. The theoretically predicted phase constituents were not consistent with the experimental findings. Ti-10Mo alloy possessed superior yield and tensile strengths, larger elongation, and lower elastic moduli than that of Ti6Al4V alloy. Based on the obtained findings, the Ti-10Mo alloy can be a potential candidate for orthopaedic application. acicular structures of α" phase.

The effect of Nb in the glue site of the cluster-plus-glue atom model formula on the microstructure and mechanical properties of Ti-Mo alloy was investigated. Phase and microstructural analysis were performed by X-ray diffraction and electron backscatter diffraction. Tensile properties were also examined. A small amount of secondary martensitic α” and ωath nano particles were precipitated in the β matrix of both alloys, due to to the inhomogeneous distribution of Mo and/ or Nb caused by segregation, which formed local regions with high- and low-stability of the β phase. The elastic modulus was significantly reduced to 56.9 ± 3.08 GPa, while the elastic admissible strain was substantially improved. The increased β stability and suppression of the ωath phase led to no significant change in both the yield and ultimate tensile strengths, and the brittle fracture behavior. The alloy can be a potential alternative of the conventional orthopedic implant materials in orthopedic applications.

Spark plasma sintering (SPS) in situ degassing process of copper reinforced with TiC powder was examined on densification and wear behavior of copper and copper composite samples. Pure Cu and Cu-10 vo l