Materials Science Forum Vol. 1195

Abstract: Now a day’s bushes are made from nylon and steel. During the production of nylon, the nitrous oxide which is a green-house gas causes global warming. During moulding process shrinkage problem is high in nylon. The primary goal of this study is to develop an environmental friendly bush and to analyze mechanical properties such as tensile, flexural, and impact strength. We can use the natural fibre composites which will be the replacement for nylon bush. We prepared three samples which is of different combinations and different proportion. Sample 1 consists of coconut shell powder (CSP) with epoxy resin, sample 2 consists of neermuli seed powder with epoxy resin and sample 3 consists of CSP, neermuli seed powder with epoxy resins. The samples are prepared by using hand lay-up technique and compression moulding. From the analysis of three samples, sample 3 have good mechanical strength than other two samples. Sample 3 have almost near tensile value (47.77Mpa) to nylon 6 (50 MPa) and have 26% more flexural strength than nylon 6. The cost of the industrial nylon bush is around rupees 65 for 30 x 30 dimensions and the prepared composite for the same dimension cost only 25 rupees and hence the prepared sample 3 is the best replacement for nylon bushes.

Abstract: The tribological behavior of an aluminum metal matrix composite with TiC particles was investigated in this study. Composite specimens were prepared using the stir casting method, with the weight percentage of TiC particles with 2.5% Experiments were designed employing the Taguchi technique, with applied load, sliding velocity and sliding distance considered as control parameters with varying levels. Wear rate and coefficient of friction were determined using a Magnum pin-on-disc machine. ANOVA was then applied to assess the impact of each factor on wear rate and coefficient of friction. The results showed a significant effect of TiC reinforcement weight percentage on both specific wear rate and coefficient of friction. Increasing TiC reinforcement led to enhanced wear resistance of the composite material. Mathematical models were subsequently developed via regression to predict specific wear rate and coefficient of friction.

Abstract: Nanoparticles have become widely utilized in various industries, such as electronics, environmental science, cosmetics, material science, and medical systems, due to their diverse applications. In dentistry, researchers have shown significant interest in exploring the potential of calcium carbonate (CaCO₃) and zinc oxide (ZnO) nanomaterials, primarily because of their biocompatibility. This article specifically focuses on the integration of zincate nanoparticles (NPs) into poly (methyl methacrylate) (PMMA) resin at different concentrations (0%, 0.15%, 0.25% and 0.35%). The aim is to assess the impact of introducing calcite-zincate NPs on the mechanical properties of PMMA and compare them to PMMA without NP reinforcement. The specimens are created using the open mold method, both with and without NPs, through the auto-polymerization process of PMMA. Subsequently, these specimens undergo mechanical testing, while SEM images are analyzed to gain microscopic insights. The evaluation and comparison are made based on tensile strength. The results clearly indicate that the specimens reinforced with calcite-zincate NPs outperform those without NP addition, displaying superior mechanical properties.

Abstract: Sandwich composites with architected cores are increasingly sought after in aerospace applications where weight efficiency must be combined with reliable impact resistance. Conventional vertical cores, however, exhibit limited energy dissipation during High Velocity Impact (HVI), often leading to localized collapse and reduced structural integrity. This work presents a comparative investigation of Aluminium 2014-T6 sandwich composites reinforced with three distinct cores: a primitive vertical, a re-entrant auxetic, and a hexagonal auxetic chiral configuration. Evolution of core architecture is metamaterial inspired. Explicit dynamic simulations were performed in LS-DYNA at impact energies of 11.7 J, 26.32 J, and 46.78 J, with a power-law plasticity model capturing high strain-rate material response. The transient histories of kinetic energy (KE) and internal energy (IE) were extracted to characterize energy transmission and absorption, respectively, establishing an energy-based framework for impact performance. Results show that primitive vertical cores transmit a substantial fraction of incident energy, indicating poor protective efficiency, while re-entrant auxetic cores achieve higher IE absorption through negative Poisson’s ratio-induced lateral expansion. The chiral auxetic cores consistently outperform both, exhibiting the steepest KE decay and the highest IE accumulation across all impact energies. The enhanced performance arises from the synergistic coupling of re-entrant densification and chiral node rotation, enabling progressive deformation, stress delocalization, and smoother energy dissipation. This study provides new insight into the mechanics of hybrid auxetic–chiral cores under High Velocity Impact (HVI), demonstrating their superiority over conventional geometry and establishing a pathway for designing next-generation lightweight, damage-tolerant sandwich composites for aerospace impact applications.

Abstract: The growing electronic waste crisis and demand for sustainable materials have intensified the need for eco-friendly dielectric composites. While coconut shell (CS) waste shows promise as a renewable filler, the quantitative relationships between its filler percentage and dielectric properties remain unexplored, limiting its practical application. This study employs both computational and experimental approaches to investigate CS-reinforced epoxy composites, aiming to establish regression models for permittivity optimization. Ten baseline composites were fabricated with CS particles (0–95 wt.%). Permittivity was measured at 5 GHz via waveguide transmission, and a Python-based polynomial regression model was developed to correlate filler loading with dielectric performance. Permittivity ranged from 2.65 to 3.42, with higher filler content enhancing polarization. The model achieved an R² of 0.9577 for filler percentage. CS-epoxy composites offer tunable permittivity for green electronics, while the regression model enables efficient material design. This work bridges the gap between the valorization of agricultural waste and the development of high-performance dielectrics.

Abstract: In composite materials, interfacial thermal resistance (ITR) occurs between the matrix and the reinforcement, which is thought to deteriorate effective thermal conductivity (ETC). However, measurement of ITR is difficult, and few measurements have been reported. In this study, the ITR between Al and TiB₂ was evaluated by comparing the ETC calculated by image-based thermal conduction simulation using microstructure images with the measured ETC. Al-TiB₂ composites were prepared under different sintering conditions and the relationship between sintering conditions and ITR was investigated. Three different volume fractions of TiB₂, three different sintering conditions, a total of nine different samples were fabricated with spark plasma sintering (SPS). The Relative density (RD) and ETC of samples with longer holding time is relatively higher than those of samples with shorter holding time, and the ITR at the Al-TiB₂ interface decreased in the samples with longer holding time. The samples pressurized after reaching the holding temperature had relatively higher RD, ETC, and ITR at the Al-TiB₂ decreased in the samples pressurized after reaching the holding temperature.

Abstract: In this study, monolithic samples and 3% SiCp/6061 composite samples were fabricated using spark plasma sintering. A comparative analysis of the microstructure, ageing response, and mechanical properties of these materials revealed that the addition of SiCp induced thermal mismatch dislocations, which accelerated the ageing kinetics. As a result, the time required to reach peak ageing decreased from 8.5 hours to 8 hours, and the peak ageing hardness increased from 102.7 HV to 113.5 HV. The tensile strength of the peak-aged composite sample improved from 315.5 MPa to 352.4 MPa, while the elongation decreased from 11.8% to 8.8%. These findings provide valuable insights for optimizing the properties of the composite, ultimately enhancing its performance and applicability in demanding engineering applications.

Abstract: Polypropylene is a versatile thermoplastic that finds applications in automotive, aerospace, chemical and domestic industries due to its excellent mechanical and chemical properties and cost-effectiveness. Epoxy is a thermoset polymer that is often reinforced with various types of fibers like carbon fiber, glass fiber etc. to tailor its properties for specific applications. Epoxy Composites Market in 2023 was valued around USD 38.1bn and is estimated to attain a market worth of over USD 74bn by 2032 due to rapid replacement of conventional materials in automotive and aerospace applications. Major portion of the disposed epoxy composites parts after their service life goes to land filling which leads to soil pollution. In this novel study an attempt is made to fabricate the polypropylene composite by reinforcing micro particles of cross linked epoxy. The Flexural strength, Hardness and Izod impact behavior of polypropylene composite was studied at 5%, 10%, 15% and 20% of cross linked micro epoxy particles. The proportions of cross linked micro epoxy particles have positive impact on Hardness and Yield Flexural strength but negative impact on Izod – Impact resistance. The Yield Flexural strength increases with increase in proportion of cross linked epoxy particles, flexural strength increases about 26.3% for 20% reinforcement of cross linked Epoxy particles. The Izod Impact resistance is unaltered upto 10% of cross linked micro epoxy particles and then decreases with increase in proportion of cross linked epoxy particles, Izod - Impact strength decreases about 36.12% for 20% reinforcement of cross linked Epoxy particles. X-ray diffraction and Scanning Electron microscopy at specimen fracture surface ensures that the micro epoxy particles dispersed uniformly in the matrix material.