This study investigates the development and application of a neural network (NN) model to predict hardness characteristics in Cr-Mo steel welded joints, utilizing the SPSS software suite. The model incorporates four key welding parameters; material thickness, welding current, the number of weld passes, and electrode diameter as inputs, with hardness values in the weld zone (WZ) and heat-affected zone (HAZ) as outputs. The neural network features a single hidden layer with eight neurons, using the Softmax activation function for non-linear regression tasks. A comprehensive dataset comprising 18 combinations of the input parameters was employed to train, validate, and test the model, ensuring it could generalize across diverse welding conditions. Results demonstrate the model’s high predictive accuracy, particularly in the HAZ, where an R² value of 0.997 and a low Mean Squared Error (MSE) of 0.94 indicate minimal prediction error. The analysis also reveals that material thickness is the most influential parameter, significantly affecting hardness outcomes, while welding current, number of weld passes, and electrode diameter play secondary roles. However, the model's performance varies between zones, with greater dispersion observed in the HAZ, suggesting complexities in predicting hardness due to microstructural changes in this region. Overall, the study confirms that the SPSS-developed neural network is a robust tool for predicting hardness in welded joints, offering valuable insights for optimizing welding parameters to achieve desired mechanical properties. This approach can reduce the need for extensive physical experimentation, streamlining the welding process in industrial applications.

The extraction of alumina from selected Nigerian kaolin was investigated to assess its viability as a raw material for industrial applications. Kaolin samples from four locations Okpella, Afowa (white and black), and Ado Ekiti, were analyzed for their chemical composition and subjected to calcination and acid-leaching processes. The clays were calcined at 900°C to produce metakaolin, a precursor favorable for alumina extraction. Various concentrations of nitric acid (HNO₃) and hydrochloric acid (HCl) were employed to leach alumina from the calcined samples. The leached alumina was precipitated as aluminum hydroxide and subsequently calcined at 900°C to yield alumina (Al₂O₃). The process efficiency was evaluated through XRF analysis, revealing recovery rates up to 92% under optimal conditions. This study demonstrates the potential of Nigerian kaolin as a sustainable source of alumina for industrial applications and highlights the influence of acid concentration and calcination on extraction efficiency.

In this paper, the study of research on the microstructure and corrosion behavior and mechanical properties of a Mg-5.45Zn-6.63Sn-0.51Ca alloy under different thermal and mechanical states is reported. The cast of the alloy in a mild steel mould took place at 700°C; then, it was homogenized at 400°C for 18 hours and characterized by means of optical microscopy, X-ray diffraction, and scanning electron microscopy. The corrosion behavior was tested in the 3.5% NaCl solution using corrosion potential and linear polarization resistance (LPR) measurements. Post-corrosion analysis of the degraded surface was carried out by SEM. After that, the samples were hot-rolled at 400°C down to 15% of their original thickness and again tested. It was therefore concluded that hot rolling had a major microstructural influence on the properties, an observation consistent with comparison between results in the homogenized and rolled conditions. Hot Rolling tends to improve the corrosion resistance of the alloy and refines the microstructure. Tensile strength, and elongation at failure were obtained using tensile tests, carried out on the hot-rolled samples at temperatures ranging from 200 to 350°C, and two strain rates of 10-4 and 5×10-4 s-1.

Polymer matrix composites (PMC) are prominent structural materials that offer a combination of some extra-ordinary properties, including light weight, high strength, high resistance to chemicals, etc. In this research, the influence of aluminium reinforcement content (5–40 wt%) on the morphological, mechanical, and physical properties (impact strength, tensile strength, elastic modulus, and maximum load-bearing capacity) of Al-high- density polyethylene (HDPE) composites has been studied. We used a customized extruder machine to fabricate the composites, followed by injection molding to prepare test specimens. In comparison to virgin HDPE, the impact strength, flexural strength, elastic modulus, and tensile strength of the composites increased at 5 weight percent of aluminium content and declined with increasing reinforcing quantity. The break point is higher for pure HDPE than composites with any weight of aluminium. Using an optical and scanning electron microscope (SEM), a microstructural study of the composites was carried out to assess the cohesion and distribution of the reinforcement and matrix. Based on the particle loading and uniformity, it was observed that composites with a 5 wt% content of aluminium reinforcement exhibited more efficiency for the enhancement of mechanical properties.

This study investigates the effect of twist factors on the tensile properties of jute yarns with linear densities of 193, 213, and 251 tex. The yarns were twisted to four levels: 1460, 2420, 2820, and 3056 turns per metre x √Tex. Tensile testing was conducted according to ASTM D2256 standards to analyse tenacity, elastic modulus, breaking force, and elongation at break. The results indicate that twist factors significantly influence the tensile properties of the yarns. Notably, yarn SY251T153 exhibited the highest tenacity at 28.4 cN/Tex with an optimal twist factor of 2420, highlighting the critical balance between yarn strength and twist. The findings emphasise the importance of optimising twist factors to enhance yarn performance, providing valuable insights for producing high-quality, durable yarns for natural fibre-reinforced polymer composites in structural applications. Statistical validation through one-way ANOVA confirmed significant differences in yarn tenacity with varying twist factors, with p-values of 0.00197 for SY193, 0.0000137 for SY213, and 0.0000879 for SY251, all below the 0.05 threshold. These results underscore the significant impact of twist factors on yarn strength.

The recycling of car batteries has become a crucial issue in the current context of the transition to electric vehicles. The authors summarise the most critical chemical elements mining and use trends in battery production. Additionally, the issue of the distribution of cobalt, a key material in battery manufacturing, raises ethical and environmental concerns, particularly regarding mining practices in the Democratic Republic of Congo. While traditional lead-acid battery recycling methods are well understood and applied, the appearance of lithium-ion batteries poses new challenges. Indeed, the recycling of lithium batteries presents technical and economic difficulties due to the complexity of the processes and the associated costs. The authors present battery recycling options. Therefore, sustainable recycling practices must be highlighted to ensure the preservation of the environment and promote a circular economy. This research underscores the urgent need for sustainable recycling practices in the context of battery production and use trends.

The Cantor alloy is one of the earliest high entropy alloys to appear. In contrast with its properties at low and cryogenic temperatures, its creep behavior at close to 1000°C is not yet very known. This work aims to explore the behavior of a cast equimolar CoNiFeMnCr alloy in three points bending creep at 1000 and 1100°C for two levels of loading (inducing 10 and 30 MPa tensile stress). The deformation rate increases with temperature and with stress. Duration to test end can reach 100 hours and more for 10 MPa and 50h or much less for 30 MPa. In addition, significant oxidation of the samples was noticed by oxygen impurities in the protective argon atmosphere. These results demonstrate that, in its present state, this alloy is not suitable for service at so high temperature. It must be mechanically strengthened, by precipitates for instance, and its oxidation resistance must be improved.

Titanium and its alloys are amongst the most effective and commonly used biomaterials for the production of dental implants. But, in order to ensure long term success of these implants, surface modification techniques that improve osseointegration and prevent bacterial colonization are highly required. Until now, a variety of surface modification methods were proposed, the most basic ones involving mechanical or chemical processing to increase the roughness coefficient thus favoring osseointegration. However, this is not enough to prevent the common implant-related complications such as peri-implantitis. Therefore, an increased research interest was directed towards the development of functional coatings that can be tailored to both enhance osseointegration and prevent bacterial infections. This review aims to present the currently available titanium-based implants modification methods along with their main benefits and drawbacks. For a better understanding of the subject, the chemical structure and surface characteristics of titanium-based dental implants, and the main causes of implant failure were presented. Moreover, current trends such as nano-scale surface roughening and 3D printing of dental implants were also mentioned.

This research analyzed the mechanical properties of reinforcing steel bars used in Nigeria and compared them to four different standards (AISI 1018, ASTM A706, BS4449, and NST-65-Mn). This was done as a result of frequent building collapses in Nigeria, which has revealed the knowledge gap between what the designers expect and the true mechanical properties of the products they typically receive from manufacturers. Related literature from published articles was collected and analyzed based on the mechanical properties of locally produced and imported steels. Results showed that the tensile strength, yield strength, hardness, percentage elongation, and percentage carbon composition of most products met and exceeded the requirements of AISI 1018, ASTM A706, BS4449, and Nst-65-Mn when compared, while some fell below what these standards required. Federated Steel Mills Limited, Ogun State, has the highest tensile stress value at 799.49 MPa, followed by Real Steel Reinforcing Pty Limited, Auckland, New Zealand, at 726.34 MPa, and Landcraft Industries Limited, Ikorudu, Lagos, at 708.3 MPa, according to a yield and tensile strengths analysis of 16 mm steel bars produced locally and imported. The lowest tensile strengths ever reported are 410 MPa for African Steel Nig. Limited, Ikorodu, Lagos, and 538.51 MPa for steel imported from Brazil. It is hoped that the data from this study will bridge the knowledge gap between the team players in this field, thus preventing catastrophe.