Materials Science Forum

Preface

Thu, 25 Jun 2026 00:00:00 +0200

Publication date: 25 June 2026
Source: Materials Science Forum Vol. 1195

Multi–Objective Optimization of Flame Scarfing Parameters in Low-Carbon Steel Slabs for Enhanced Process Performance

Thu, 25 Jun 2026 00:00:00 +0200

Publication date: 25 June 2026
Source: Materials Science Forum Vol. 1195
Author(s): Anistasia Milandia, Vitaloka Dwi Maharani, Kustiaditya Wiguna, Reza Moezzi
Surface defects in hot-rolled steel slabs, particularly EN 10025-2 S235JR, are commonly addressed through manual flame scarfing. However, variability in operator technique and uncontrolled parameters often lead to inconsistent results. This study investigates the effects of inner oxygen nozzle length and scarfing path width using Taguchi experimental design and Response Surface Methodology. Key performance metrics—slag mass, removal depth, and processing time—were analysed. Results show that longer nozzles combined with narrower paths minimize slag without sacrificing efficiency. Regression models (R² > 0.95) validated by MATLAB simulations confirmed strong predictive accuracy. The findings offer a statistically optimized approach to improve surface treatment consistency, presenting a practical framework for enhancing manual scarfing operations in steel manufacturing.

Novel Non-Destructive Approach for Heat-Affected Zone (HAZ) Boundary Identification in Cold-Formed A 240 TP 304L Stainless Steel Using Magnetic Measurements

Thu, 25 Jun 2026 00:00:00 +0200

Publication date: 25 June 2026
Source: Materials Science Forum Vol. 1195
Author(s): Nandang Abdul Holik Nurjalal, Hamdan Akbar Notonegoro, Hendra Hendra, Paulo Maria de O. Silva
The cold forming of A 240 TP 304L stainless steel, as used in pressure vessel dish heads, introduces significant plastic deformation and internal stress-strain, which can lead to microstructural defects like hairline cracks. While plasma cutting is an efficient fabrication method, it creates a Heat-Affected Zone (HAZ), where thermal effects can obscure the stress-strain state, making it difficult to accurately identify defects. The study compared two methods for identifying the HAZ boundary: hardness measurements and magnetic measurements. Hardness measurements proved to be an unreliable method for defining the HAZ boundary, as the hardness values at the edges of the specimen showed insignificant and inconsistent differences compared to the central region. This is likely because the rapid heating from plasma cutting did not allow sufficient time for grain relaxation. In contrast, the magnetic measurement method proved to be a highly effective and relevant approach. Microstructural deformation resulting from shear forces during metal forming and plasma cutting causes a shift in the steel’s properties from paramagnetic to weakly ferromagnetic. This change creates a distinct magnetic remanence signature that clearly differentiates the HAZ from the parent material. Therefore, the induced magnetic property serves as a reliable, indirect indicator for the HAZ boundary. The non-contact and non-destructive nature of this magnetic measurement technique makes it a superior alternative to traditional methods that are often destructive, such an involve sectioning, or may fail to detect subsurface defects that are not visible during an inspection. This method holds significant potential for application in the manufacturing industry to enhance quality control and ensure the integrity of A 240 TP 304L stainless steel components.

Mechanical Properties and Microstructural Analysis of AISI 304 and Duplex 2550 Welded by GTAW and SMAW Techniques

Thu, 25 Jun 2026 00:00:00 +0200

Publication date: 25 June 2026
Source: Materials Science Forum Vol. 1195
Author(s): Syukran Syukran, Winarto Winarto, Muhammad Anis
This study investigates the mechanical properties and microstructure of dissimilar welds between AISI 304 and Duplex 2550 using GTAW and SMAW processes with filler metals ER309 and E309-16. The weld joint exhibited a tensile strength of 508.7 MPa, lower than AISI 304's minimum of 515 MPa and Duplex 2550's 760 MPa, primarily due to the heat-affected zone (HAZ). Significant differences in hardness were observed, with the weld metal averaging 194.8 HV, compared to 181.9 HV and 229.9 HV for the HAZ of AISI 304 and Duplex 2550, respectively. Charpy tests indicated reduced impact energy and absorption in the weld metal and HAZ compared to the base metal. XRD analysis revealed the formation of intermetallic phases, including chi (χ), sigma (σ), and carbides in the weld metal, which compromised mechanical properties and corrosion resistance.

Effect of ERNiCr-3 and ER70S-G Filler Metals on Mechanical and Microstructural Properties of TIG-Welded SS 409–Cu C11000 Joints

Thu, 25 Jun 2026 00:00:00 +0200

Publication date: 25 June 2026
Source: Materials Science Forum Vol. 1195
Author(s): Yusuf Eko Nurcahyo, Yudy Surya Irawan, Oyong Novareza, Sugiarto Sugiarto
Welding ferritic stainless steel to copper is well known to be challenging because of the large mismatch in their thermal conductivities and metallurgical behaviors. Dissimilar joints are required in a range of energy, automotive, and metallurgical applications. In this study, TIG welding of SS 409 to copper C11000 was performed using ERNiCr-3 (Ni-based) and ER70S-G (Mn-based) filler metals under controlled DCEN conditions to evaluate their mechanical and microstructural performance. Tensile testing, microhardness mapping, and microstructural observations using scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectroscopy (EDS) were performed after the welding process. The results show that the joints welded with ERNiCr-3 exhibited a higher ultimate tensile strength, reaching approximately 220 MPa, along with an elongation of approximately 10%. In comparison, ER70S-G joints achieved a tensile strength of approximately 160 MPa and exhibited lower ductility, with an elongation of approximately 6%. A smoother hardness transition across the weld interface was observed for ERNiCr-3, whereas ER70S-G produced a more localized hardness peak close to the fusion boundary. SEM-EDS analysis indicated sound fusion for both filler metals, with limited formation of interfacial compounds. Based on these results, ERNiCr-3 remains the preferred filler when a higher mechanical performance is required. However, ER70S-G can be considered a practical and economical alternative to TIG-welded SS 409–Cu C11000 joints in applications where moderate strength is sufficient.

Generalized Regression Neural Network-Based Analysis of the Effectiveness of Cryogenic Machining on SS316

Thu, 25 Jun 2026 00:00:00 +0200

Publication date: 25 June 2026
Source: Materials Science Forum Vol. 1195
Author(s): Muhamad Nur Rohman, Dony Perdana, Wiji Lestariningsih, Luki Trihardani
This study develops a generalized regression neural network (GRNN) model to analyze the effectiveness of cryogenic machining compared to dry and wet machining. The model was trained using datasets derived from face milling experiments on SS316 stainless steel, involving variations in spindle speed, feed rate, and depth of cut, with surface roughness (Ra) as the measured output. Cryogenic machining consistently produced lower Ra values, as confirmed by Interval Plot analysis. The GRNN model accurately predicted Ra, achieving low Mean Absolute Percentage Error values (2.31% for training and 2.05% for testing), along with high coefficients of determination (R² = 0.9957 for training and 0.9956 for testing). The GRNN model was then utilized for sensitivity analysis and response surface analysis. Perturbation-based sensitivity analysis identified the machining technique as the most influential parameter. Response surface analysis further confirmed the superiority of cryogenic machining across all parameter settings.

Experimental Study of Pin Profile Effects on Microstructure, Mechanical and Fatigue Properties of Friction Stir Welded AZ31B-H24 Magnesium Alloy Joints

Thu, 25 Jun 2026 00:00:00 +0200

Publication date: 25 June 2026
Source: Materials Science Forum Vol. 1195
Author(s): A.E. Rahmani, M.N. Ilman
Friction stir welding (FSW) has risen to prominence recently due to its ability to join alloys having low weldability such as magnesium alloys. This paper aims to enhance mechanical properties of FSW joints of AZ31B-H24 by varying pin profiles. In this work, four different tool pin profiles were investigated, namely cylindrical, conical, square, and triangular. The FSW processes were conducted at tool rotation speed of 1500 rpm and tool traveling speed 30 mm/min. Afterwards, several experimental works were conducted, i.e. microstructure observations, hardness measurements, tensile tests, and fatigue crack growth rate (FCGR) tests combined with scanning electron microscopy (SEM) fractographic study. Results showed that the square pins produced the best FSW joints with the ultimate tensile strength (UTS), typically of 212.3 MPa respectively. Fractographic analysis showed that the fracture occurred in weld nugget zone (WNZ) close to advancing side (AS). It seemed that the high strength of FSW joints produced by the square pin was likely attributed to the proper frictional heat and material flow which gave the best dynamic recrystallization in WNZ. The present investigation also revealed that FSW joint under the the square pin had better fatigue performance than AZ31B-H24 base metal as indicated by its lower FCGR.

Effect of Zn Addition on the Physical and Mechanical Properties of Sn 0.7Cu1.5Ag Lead-Free Solder Alloy

Thu, 25 Jun 2026 00:00:00 +0200

Publication date: 25 June 2026
Source: Materials Science Forum Vol. 1195
Author(s): Leo Hermanus Kasi, Andromeda Dwi Laksono, Hizkia Alpha Dewanto, Muhammad Ramanda Putra, Alvian Toto Wibisono, Fasih Bintang Ilhami
The growth of the electronics industry highlights the need for lead-free solder materials that balance environmental safety and performance. This study examines the effect of Zn addition on Sn-0.7Cu-1.5Ag solder alloys containing 7, 8, and 9 wt.% Zn. The alloys were synthesized through melting and solidification, followed by characterization using SEM-EDX, DSC, Vickers hardness, wettability, and density tests. Results indicate that Zn promotes the transformation of Ag3Sn into SnZn3 phases, which dominate with higher Zn levels. The melting point decreased from 223.19 °C to 221.27 °C with a narrower transition range, suggesting improved thermal properties. However, Zn reduced wettability (7.43 mm2 to 5.87 mm2), density (7.33 g/ml to 6.49 g/ml), and hardness (16.1 Hv to 15.4 Hv). Overall, Zn addition lowers the melting point but compromises mechanical strength and spreading ability, indicating the need for optimization to achieve reliable solder performance.

Solvent-Driven Flux Deposition Behavior and Weld Pool Response in A-TIG Welding of Aluminum 5083-H116

Thu, 25 Jun 2026 00:00:00 +0200

Publication date: 25 June 2026
Source: Materials Science Forum Vol. 1195
Author(s): Wisnu Yulianto Nugroho, Yusuf Eko Nurcahyo, Pongky Lubas Wahyudi, Dian Setiya Widodo, Ahmad Jabir
Activated Tungsten Inert Gas (A-TIG) welding is widely used to enhance penetration in aluminum alloys; however, inconsistent weld performance is often reported even when similar active-flux chemistries are applied. This indicates that factors beyond flux composition alone influence weld stability, highlighting the importance of understanding flux delivery during welding. The scientific objective of this study is to clarify how solvent characteristics govern active-flux transport, surface retention, and weld pool response in A-TIG welding of Aluminum 5083-H116. Rather than optimizing flux chemistry, this work focuses on isolating the solvent effect using a TiO₂–SiO₂ active-flux system dispersed in methanol–isopropanol solvent mixtures. A-TIG welding experiments were carried out under identical welding parameters and flux chemistry, while varying the solvent composition. Weld penetration depth, penetration-to-width ratio, microhardness distribution, and grain structure were evaluated to assess the metallurgical response. The results show that solvent composition significantly influences penetration behavior, with penetration depth varying from approximately 3.5 mm to 5.0 mm and the penetration-to-width ratio increasing by up to 30% under more stable solvent conditions. Microhardness in the weld metal ranged between 70 and 90 HV, accompanied by observable differences in grain morphology. More stable flux retention associated with methanol-rich solvent mixtures produced smoother penetration profiles and finer, more uniform grains, whereas higher isopropanol content tended to result in less stable penetration and coarser grain structures. These findings provide new understanding that solvent selection plays a governing role in A-TIG welding by controlling flux transport and arc–pool interaction. The study extends conventional flux-centric A-TIG knowledge and offers a practical framework for improving weld stability and reproducibility in aluminum alloy welding through solvent-controlled flux delivery.

The Effect of the Combination of Vibration and Mold Temperature on the Characteristics of Remelted Aluminum

Thu, 25 Jun 2026 00:00:00 +0200

Publication date: 25 June 2026
Source: Materials Science Forum Vol. 1195
Author(s): Souha Nadala, Putu Hadi Setyarini, Teguh Widodo, Alban Naufal, Dovian Iswandi
This study investigates the coupled influence of vibration frequency and mold temperature on the solidification behavior and mechanical performance of recycled aluminum derived from automotive wheel scrap. Investment casting was conducted at mold temperatures ranging from 150 to 350 °C while applying mechanical vibration at frequencies between 100 and 250 Hz. Hardness testing, tensile characterization, optical metallography, and multi-scale SEM analysis were employed to evaluate the evolution of microstructure and defects under varying thermo-mechanical conditions. The results show that mechanical properties exhibit a non-linear dependence on vibration frequency, with an optimum window at 100–150 Hz where dendrite fragmentation, eutectic segmentation, and reduced microporosity contribute to enhanced hardness and tensile behavior. Frequencies above 150 Hz induce turbulent melt flow, promoting pore clustering and intermetallic agglomeration that significantly degrade strength. Mold temperature further modulates these effects, where temperatures above 300 °C suppress vibrational refinement due to reduced thermal gradients and grain coarsening. The combined findings demonstrate that microstructural refinement in recycled aluminum can only be achieved when vibration and thermal conditions are simultaneously optimized. This work establishes a clear processing window for vibration-assisted casting of recycled aluminum and provides practical guidance for industrial remelting operations targeting improved sustainability and mechanical reliability.

Design and Testing of Load Bearing Bushes Using Natural Fibre Composites

Thu, 25 Jun 2026 00:00:00 +0200

Publication date: 25 June 2026
Source: Materials Science Forum Vol. 1195
Author(s): S. K. Thangarasu, A. Shanmugam, N. Muralidharan, S. Mathankumar, K. M. Shrinidhi, S. V. Nandhaa, Nadeem K. Pasha
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.

Wear and Friction Behaviour of Stir-Cast Al7075 Metal Matrix Composites Reinforced with TiC Particles

Thu, 25 Jun 2026 00:00:00 +0200

Publication date: 25 June 2026
Source: Materials Science Forum Vol. 1195
Author(s): Mahesh R. Jadhav, Pramod V. Mulik, Prashant J. Patil, S.V. Lingaraju, G.S. Kamble
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.

Strength Analysis of Precipitation-Synthesized Calcite-Zincite Composite Nanoparticles

Thu, 25 Jun 2026 00:00:00 +0200

Publication date: 25 June 2026
Source: Materials Science Forum Vol. 1195
Author(s): L. Sampath Kumar, D. Chethan, Prashant S. Hatti, Ayub Ahmed Janvekar, S. Karthik
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.

Metamaterial-Inspired Auxetic and Chiral Aluminium Composite Sandwich Cores under High Velocity Impact: Comparative Analysis

Thu, 25 Jun 2026 00:00:00 +0200

Publication date: 25 June 2026
Source: Materials Science Forum Vol. 1195
Author(s): Arun Babu, M.S. Ganesha Prasad, S. Raghavendra, Sachin Prabha, Arun Kumar
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.

Effect of Filler Weight Percentage on the Permittivity of Coconut Shell–Epoxy Composites

Thu, 25 Jun 2026 00:00:00 +0200

Publication date: 25 June 2026
Source: Materials Science Forum Vol. 1195
Author(s): K.B. Mekha, K. Sudhakar, Norazwina Zainol, Mohamad Shaiful Abdul Karim, Mohammad Fikry, Nurhafizah Abu Talip Yusof
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.

Interfacial Thermal Resistance of Al-TiB2 Particle Dispersed Composites with Different Sintering Conditions

Thu, 25 Jun 2026 00:00:00 +0200

Publication date: 25 June 2026
Source: Materials Science Forum Vol. 1195
Author(s): Kenjiro Sugio, Haruki Matsuura, Gen Sasaki
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.

Influence of SiCp Addition on the Microstructure, Ageing Response and Mechanical Properties of Aluminum Matrix Composites

Thu, 25 Jun 2026 00:00:00 +0200

Publication date: 25 June 2026
Source: Materials Science Forum Vol. 1195
Author(s): Lin Zeng, Kenjiro Sugio, Gen Sasaki
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.

An Experimental Investigation of Impact Resistance, Hardness and Flexural Behavior of Polypropylene Augmented with Recycled Epoxy Powder for Automobile Applications

Thu, 25 Jun 2026 00:00:00 +0200

Publication date: 25 June 2026
Source: Materials Science Forum Vol. 1195
Author(s): H. S. Kumara Swamy, G. Narasimhaiah, C. K. Umesh
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.