Balance Of Toughness Research Articles

An Investigation of the Effects of Flame Straightening Heating on the High-Strength Structural Steels Microstructure

AbstractIn this research, the effects of heating cycles that are performed correctly and excessively—well above the limitations given by the steel manufacturer—on flame straightening are assessed and analyzed. The paper focuses on the microstructural changes caused by the overheating during the flame straightening process. To create geometrical changes in a metal construction, a tiny section of the element or structure is heated to the straightening temperature during the flame straightening process. Strenx® 960 is typically produced through a combination of thermomechanical rolling and quenching and tempering, resulting in a fine-grained martensitic or bainitic microstructure. These processes are designed to achieve a balance of high strength and good toughness. The microstructural changes associated with different working conditions in the case of welding include HAZ softening and grain growth. The study aimed to highlight the influence of flame hardening on the microstructure of the material.

Characterization of PLA/LW-PLA Composite Materials Manufactured by Dual-Nozzle FDM 3D-Printing Processes.

This study investigates the properties of 3D-printed composite structures made from polylactic acid (PLA) and lightweight-polylactic acid (LW-PLA) filaments using dual-nozzle fused-deposition modeling (FDM) 3D printing. Composite structures were modeled by creating three types of cubes: (i) ST4-built with a total of four alternating layers of the two filaments in the z-axis, (ii) ST8-eight alternating layers of the two filaments, and (iii) CH4-a checkered pattern with four alternating divisions along the x, y, and z axes. Each composite structure was analyzed for printing time and weight, morphology, and compressive properties under varying nozzle temperatures and infill densities. Results indicated that higher nozzle temperatures (230 °C and 240 °C) activate foaming, particularly in ST4 and ST8 at 100% infill density. These structures were 103.5% larger on one side than the modeled dimensions and up to 9.25% lighter. The 100% infill density of ST4-Com-PLA/LW-PLA-240 improved toughness by 246.5% due to better pore compression. The ST4 and ST8 cubes exhibited decreased stiffness with increasing temperatures, while CH4 maintained consistent compressive properties across different conditions. This study confirmed that the characteristics of LW-PLA become more pronounced as the material is printed continuously, with ST4 showing the strongest effect, followed by ST8 and CH4. It highlights the importance of adjusting nozzle temperature and infill density to control foaming, density, and mechanical properties. Overall optimal conditions are 230 °C and 50% infill density, which provide a balance of strength and toughness for applications.

Bio-based liquid crystal epoxy resins: Toughening and strengthening of conventional epoxy resins with strategically extended spacer layers

Liquid crystal epoxy resin, as an ideal toughening agent, combines the features of liquid crystal ordering and network cross-linking, which can effectively optimize the comprehensive performance of blended epoxy resins and achieve an ideal balance of rigidity and toughness. Here we successfully synthesized rigid and flexible bio-based liquid crystal epoxy resin (THBR-EP) by finely tuning the length of alkyl side chains. Using aromatic diamine as curing agent, a homogeneous network without phase separation was constructed by taking advantage of the different activity but good compatibility with ordinary epoxy resins, which significantly improved the toughness of the blended system. Specifically, only a small amount of THBR-EP(2.5 wt%) was required to exhibit a maximum impact strength of 48.8 kJ/m2. Moreover, the increase in system toughness was accompanied by a benign improvement in flexural strength, modulus and thermal stability. The ordered structure of the liquid crystals and their good compatibility with the resin matrix enhanced the ability to inhibit crack extension and energy dissipation. The feasibility to simultaneously achieve effective toughening and other property improvements of common resins broadens the application of resins under various demanding scenarios.

Investigating Nanoindentation and Wear Properties of Spark Plasma Sintered Ti48Al48Cr2Nb2 Alloy

This work studied spark plasma sintered Ti48Al48Cr2Nb2 alloy for their nanoindentation and wear properties. Results showed an improvement in nanoindentation properties of the compacts with an increase in holding time from 5min to 7.5min for the heating rate of 50°C/min and 100°C/min. X-ray diffraction (XRD) analysis showed the intensity of diffraction peaks of two major crystalline phases of Ti3Al2.25Nb0.75 and γ-TiAl. Scanning electron microscopy (SEM) images of sintered compacts possessed varied microstructures due to different sintering parameters. The nearly lamellar structure showed a good balance of yield stress and fracture toughness. Wear tracks SEM analysis revealed the worn surface morphologies and the sample sintered for 7.5 min at the eating rate of 50°C/min sustained the least damage evident by the shallow grooves and narrow wear track. Profilometer measurements revealed the wear track depth and width, confirming the degree of wear for the samples sintered at varied conditions.

A Highly Stretchable, Conductive, and Transparent Bioadhesive Hydrogel as a Flexible Sensor for Enhanced Real-Time Human Health Monitoring.

Real-time continuous monitoring of non-cognitive markers is crucial for the early detection and management of chronic conditions. Current diagnostic methods are often invasive and not suitable for at-home monitoring. An elastic, adhesive, and biodegradable hydrogel-based wearable sensor with superior accuracy and durability for monitoring real-time human health is developed. Employing a supramolecular engineering strategy, a pseudo-slide-ring hydrogel is synthesized by combining polyacrylamide (pAAm), β-cyclodextrin (β-CD), and poly 2-(acryloyloxy)ethyltrimethylammonium chloride (AETAc) bio ionic liquid (Bio-IL). This novel approach decouples conflicting mechano-chemical effects arising from different molecular building blocks and provides a balance of mechanical toughness (1.1 × 106 Jm-3), flexibility, conductivity (≈0.29 S m-1), and tissue adhesion (≈27kPa), along with rapid self-healing and remarkable stretchability (≈3000%). Unlike traditional hydrogels, the one-pot synthesis avoids chemical crosslinkers and metallic nanofillers, reducing cytotoxicity. While the pAAm provides mechanical strength, the formation of the pseudo-slide-ring structure ensureshigh stretchability and flexibility. Combining pAAm with β-CD and pAETAc enhances biocompatibility and biodegradability, as confirmed by in vitro and in vivo studies. The hydrogel also offers transparency, passive-cooling, ultraviolet (UV)-shielding, and 3D printability, enhancing its practicality for everyday use. The engineered sensor demonstratesimproved efficiency, stability, and sensitivity in motion/haptic sensing, advancing real-time human healthcare monitoring.

Simultaneously Strengthening and Toughening All‐Natural Structural Materials via 3D Nanofiber Network Interfacial Design

AbstractConstructing structural materials from sustainable raw materials is considered an efficient way to reduce the potential threat posed by plastics. Nevertheless, challenges remain regarding combining excellent mechanical and thermal properties, especially the balance of strength and toughness. Here, we report a 3D nanofiber network interfacial design strategy to strengthen and toughen all‐natural structural materials simultaneously. The introduced protonated chitosan at the interface between the surface oxidized 3D nanonetwork of bacterial cellulose forms the interfacial interlocking structure of nanonetworks, achieving a robust physical connection and providing enough physical contact sites for chemical crosslinking. The obtained sustainable structural material successfully integrates excellent mechanical and thermal properties on the nanoscale of cellulose nanofibers, such as light weight, high strength, and superior thermal expansion coefficient. The relationship between structural design and comprehensive mechanical property improvement is analyzed in detail, providing a universal perspective to design sustainable high‐performance structural materials from nanoscale building blocks.

Simultaneously Strengthening and Toughening All-Natural Structural Materials via 3D Nanofiber Network Interfacial Design.

Constructing structural materials from sustainable raw materials is considered an efficient way to reduce the potential threat posed by plastics. Nevertheless, challenges remain regarding combining excellent mechanical and thermal properties, especially the balance of strength and toughness. Here, we report a 3D nanofiber network interfacial design strategy to strengthen and toughen all-natural structural materials simultaneously. The introduced protonated chitosan at the interface between the surface oxidized 3D nanonetwork of bacterial cellulose forms the interfacial interlocking structure of nanonetworks, achieving a robust physical connection and providing enough physical contact sites for chemical crosslinking. The obtained sustainable structural material successfully integrates excellent mechanical and thermal properties on the nanoscale of cellulose nanofibers, such as light weight, high strength, and superior thermal expansion coefficient. The relationship between structural design and comprehensive mechanical property improvement is analyzed in detail, providing a universal perspective to design sustainable high-performance structural materials from nanoscale building blocks.

Microstructure and mechanical properties of Cu\\Ni-coated α-Al2O3w and graphene nano-platelets co-reinforced copper matrix composites

graphene nano-platelets (GNPs) and α-Al2O3w reinforced laminated Cu matrix composites were successfully prepared by flake powders metallurgy (FPM) and vacuum hot pressing sintering. In order to compare the effects of different coatings on the interfacial and mechanical properties, Cu\\Ni-coated were used for surface modification of reinforcement surface. The microstructure, interfacial bonding and mechanical properties of Cu\\Ni-coated GNPs and α-Al2O3w co-enhanced laminated Cu matrix composites were investigated. The results showed that composites with Cu coating on the surface of reinforcement had poor contact and lower mechanical properties. In contrast, the introduction of Ni coating improved interfacial bonding and also brought about solid solution strengthening of matrix. When the content of Ni coating GNPs was 1 wt%, tensile strength reached 336.12 MPa and elongation was 16.36 %. On the one hand, the Ni coating promoted interfacial bonding, and good interface brings better load transfer and interfacial strength. Meanwhile, α-Al2O3w and GNPs with different aspect ratios showed better strengthening effects through various strengthening modes such as drawing and fracture. On the other hand, the laminated structure allowed crack extension to be transferred to other planes, the crack deflection process consumes more energy, and composite achieves a balance of strength and toughness. This work provides a new idea to improve interfacial bonding of composites and obtain high strength and toughness.

Wear Mechanism of an AlCrN-Coated Solid Carbide Endmill Cutter and Machined Surface Quality under Eco-Friendly Settings during Open Slot Milling of Tempered JIS SKD11 Steel

In the die and mold industry, tempered JIS SKD11 steel is selected to manufacture cold-forming dies that require an optimum balance of toughness, strength, and wear resistance. Therefore, the machinability of tempered JIS SKD11 in the milling machining process is challenging. The use of eco-friendly machining settings is intended to diminish tool wear and enhance the quality of the machined surface as well as the accuracy of the machined components. Adapting to the aforementioned factors for cold-forming dies is a pivotal issue. In this study, the machinability of tempered JIS SKD11 steel was analyzed under dry, MQL, cryogenic cooling with liquid nitrogen (LN2), and liquid carbon dioxide (LCO2) machining settings during open slot milling operations with varying input parameters, including cutting speeds and cutting feeds. An in-depth evaluation of output responses, including tool wear, surface roughness, cutting temperature in the cutting zone, and microhardness of the machined surface, was also conducted. The findings unveiled that the flank wear of the cutters and surface roughness of the machined surfaces obtained minimum values of 0.22 mm and 0.197 µm, respectively, during open slot milling operations at a cutting speed of 100 m/min and a cutting feed of 204 mm/min under cryogenic cooling with liquid carbon dioxide (LCO2). The findings from this study suggest that employing cryogenic cooling with LCO2 could serve as a viable substitute for dry, MQL, and cryogenic cooling with LN2 methods to enhance the machinability of hardened JIS SKD11 steel.

Strength and toughness balance in 7 %Ni steel by formation epsilon martensite, retained austenite and Low matrix strain

In the current study, 7 wt.%Ni alloy steel was prepared, hot rolled, and heat treated according to popular quenching, lamellarization, and tempering treatments. The inter-critical lamellarization temperature was varied and the microstructure-property correlation was evaluated in each stage of heat treatment to understand the metallurgical aspects. Optical and detailed electron microscopic techniques were used to characterize and quantify the microstructures. Mechanical responses under uniaxial and impact loading were also recorded for all the studied samples. Tempered martensite with blocky and lamellar morphology, along with retained austenite and ɛ-martensite, were observed in the microstructures after the above-mentioned heat treatment. The lamellarization at 700 ℃ leads to a more uniform distribution of alloying elements and, therefore, promotes the formation of finer retained austenite with uniform distribution, compared to 650 °C lamellarization temperature. The presence of lower matrix strain and uniformly distributed fine retained austenite provides the highest toughness with moderate strength in the 700 °C samples. ɛ-martensite is expected to provide the necessary strength to balance the softening arising due to tempered martensite and retained austenite. Moreover, the uniformly distributed fine and filmy-shaped retained austenite provides thermal stability, and arrests crack propagation, enhancing toughness. The XRD results after impact toughness show that the γ-ε-α transformation takes place during the -196 °C temperature, and during impact toughness testing, ε-α transformations also provide the toughening in the Ni-700+590 sample.

Microstructure and mechanical property of CoCrFeNiAlxMn(1-x) dual-phase gradient high-entropy alloy coatings prepared by laser cladding

High-entropy alloy (HEAs), known for their balanced strength and ductility, are promising candidates for impact wear-resistant applications. In this study, CoCrFeNiAlxMn(1-x)(x = 0, 0.2, 0.8, 1.0) dual-phase gradient coatings with a layered structure were prepared using laser cladding technology to explore the microstructure evolution, tensile properties and fracture mechanism of gradient coating. As the Al content increased, the single-phase face-centered cubic (FCC) HEA coatings transitioned to dual-phase of FCC+ body-centered cubic (BCC) solid-solution, and finally to a single BCC phase. The remarkable improvement of microhardness is attributed to the dominance of the BCC phase and the impeding effect of the second phase particles on dislocation movement. The gradient coating exhibited a gradual change in internal element composition, microhardness, and structure along the depth direction, with the highest hardness value reaching 530 HV. Compared with the minimum tensile strength (69.03 MPa) and the minimum elongation (0.14 %) of single-layer coating, the gradient coatings exhibited a balance of high tensile strength and good plastic toughness, with a tensile strength of 597 MPa and an elongation of 4.08 %. Fracture analysis indicated a transition from ductile to brittle fracture in single-layer coatings as x values increased. The double-layer and four-layer gradient coatings displayed a mixed mode of brittle and plastic fracture. The study provides valuable insights into the design and fabrication of HEA gradient coatings, offering a novel approach to enhance the durability and performance of laser-clad coatings for various applications.

Preparation, mechanical properties and strengthening mechanisms of T15 particles reinforced Cu matrix composites

High speed steel T15 particle reinforced copper matrix composites were prepared using powder metallurgy. A systematic investigation was conducted into the effects on the microstructure and mechanical properties of the composites of the sintering temperature, T15 hard particle content, and particle size. The results indicate that the grain size is efficiently refined by the addition of T15 hard particles. The decrease in grain size of 10 wt% T15/Cu composite is from 6.87 μm to 1.34 μm at the same sintering temperature, and the grain size is proportional to both the sintering temperature and the size of hard particles. As the sintering temperature increases, the relative density and hardness of the composite gradually increase, while the yield strength initially increases and then declines. When sintered at 790 °C, the 10 wt% T15/Cu composite achieved a maximum yield strength of 160.1 MPa, which is 178.9 % and 30.6 % higher than that of pure copper and 10 wt% TiC/Cu composites, respectively. There are no visible cracks after compression, and a good balance of strength and toughness is achieved. Meanwhile, the primary contributions of strengthening mechanisms such as grain refinement, thermal expansion mismatch and load transfer to the mechanical properties of T15/Cu composites were analyzed. It is anticipated that this will establish a foundation for the preparation and application of high-performance copper matrix composites reinforced with metal particles.

Unleashing the potential of nano-bainite bearing steels: Controllable selection of microstructure evolution enables concurrent improvement of toughness and hardness by pre-cold deformation

In the face of increasingly demanding service conditions for high-end bearings, the need for bearing steels that demonstrate superior mechanical properties, specifically a robust balance of strength and toughness, is growing. The adoption of near-net-shaped cold rolling methods has emerged as a leading international technology to enhance bearing performance. In this study, the effect mechanisms of pre-cold deformation on the phase transformation kinetics, microstructure evolution and mechanical properties of nano-bainite bearing steels are systematically studied. Results reveal that pre-cold deformation treatment effectively reduces the Ac1 temperature of the experimental steel, expedites nano-bainite transformation and promotes strong variant selection during bainite phase transformation. With the increase in pre-cold deformation from 0 % to 50 %, the size of the prior austenite grains decreases from 6.7 μm to 3.3 μm, and the size of carbides in specimens becomes more uniform, whilst the refinement of austenite grains can considerably reduce the thickness of bainitic ferrite plates. The decrease in grain size and the increase in V1–V2 variant pairs lead to an improvement in the toughness of the nano-bainite bearing steel from 64.9 J/cm2 to 114.3 J/cm2. A marginal increase in the hardness of the bearing steel is observed with the increase in pre-cold deformation. Furthermore, this study discusses the evolution mechanism of microstructure in the subsequent phase transformation by different microstructures in the early stage. Results show that pre-cold deformation leads to the transition of the martensite twin substructure in the specimens from {112} <111> twins to twinned variants. These insights offer critical understanding into the microstructural underpinning the enhanced performance of nano-bainite bearing steels subjected to pre-cold deformation treatment.

Super-tough polylactic acid blends via tunable dynamic vulcanization of polyurethanes with ultrahigh bio-based content

Polylactic acid (PLA), a biodegradable plastic derived from renewable resources, is commercially available but has been limited in application owing to its inherent brittleness. To address this, researchers explored a reactive blending strategy using polyurethane (PU) to enhance PLA toughness. This method is straightforward and effective, yet most PUs are derived from petroleum or containing low bio-based content. Herein, we developed a bio-based PU (BPU) with double bonds for dynamic vulcanization to toughen PLA, using 1,3-polypropanediol (PO3G) and 1,5-pentane diisocyanate (PDI) with an ultrahigh bio-based content of 93.8 %. The toughness and tensile strength of the PLA/BPU blends were adjustable by modifying the BPU content. In particular, the toughness of the blends could reach 68.69 kJ/m2 by varying the amount of BPU. In addition, the BPU20–0.1 sample demonstrated an optimal balance of stiffness and toughness, exhibiting a tensile strength of 47.8 MPa and a notched impact strength of 54.86 kJ/m2. This research broadens the scope for toughening PLA using BPUs, thereby diminishing the dependency on petrochemical resources.

On the essential work of fracture of polylactic acid/thermoplastic polyurethane/halloysite

The goal of this work is to investigate the mechanical and fracture characteristics of polylactic acid (PLA)/thermoplastic polyurethane (TPU)/halloysite (HNT). HNT with three levels (0, 3, and 6 wt.%) and TPU with three levels (10, 20, and 30 wt.%) were used as variables. The investigation of tensile properties revealed contrasting effects of TPU and HNT levels. Increasing TPU content to 30 wt.% led to a decrease in strength and modulus by 36% and 42% in turn, however resulted in a remarkable 338% improvement in elongation at break. Conversely, the addition of 3 wt.% HNT enhanced both tensile strength and modulus, although it caused a reduction in elongation at break. The results concerning fracture properties showed by incorporating TPU up to 30 wt.% EWF ( w e) and non-EWF ( βw p) rose by 459% and 178%, respectively. Additionally, the inclusion of 3 wt.% HNT further elevated the EWF compared to the compound containing 10 wt.% TPU without HNT. Through optimization, the compound with 10 wt.% TPU and 3 wt.% HNT was shown to have the optimum strength, stiffness, and toughness balance.

Revealing the mechanical behavior of Ti48-xZrxHf26Nb26 high-entropy alloy through zirconium content variations

Refractory high-entropy alloys (RHEAs) composed of Ti, Zr, Hf, and Nb have emerged as promising materials for high-temperature aerospace applications due to their exceptional balance of strength and toughness, coupled with a reduced density and softening resistance. This study delves into the influence of alloy composition on the mechanical properties, a pivotal aspect in the design of RHEAs. We investigate a series of Ti48-xZrxHf26Nb26 (x = 14, 18, 22, 26, 30, 34) alloys, prepared through suction casting and homogenization treatments. The phases, microstructure, and fracture morphology of these alloys are analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and electron backscattered diffraction (EBSD), subsequent tensile tests provide insights into the strength and elongation characteristics of alloys. The homogenized alloys consistently exhibit one BCC phase with equiaxed grains, whereas the fracture mode shifts from intergranular to transgranular, and return to intergranular as the Zr content increases. Experimental results reveal an asymmetry mechanical behavior, alloys with higher Ti content display superior toughness (elongation 17.83 % for Ti = 34 at%) compared to those with higher Zr content (elongation 16.05 % for Zr = 34 at%). Among them, the Ti22Zr26Hf26Nb26 alloy achieves the peak tensile strength of 695.25 MPa, indicating an inverse relationship between strength and toughness. Solid-solution strengthening and chemical short-range orderings emerge as the predominant contributors to the overall strength of the TiZrHfNb alloys. To gain a deeper understanding of the mechanical behavior at the atomic scale, we performed first-principles calculations to investigate the elastic properties and charge density of Ti48-xZrxHf26Nb26 alloys in the BCC structure. These calculations shed light on the underlying mechanisms governing the strength and toughness behavior. The present work offers valuable insights into the design of mechanical properties of TiZrHfNb RHEAs, serving as a paradigm for future materials development in this field.

A Healable Quasi-Solid Polymer Electrolyte with Balanced Toughness and Ionic Conductivity.

Solid polymer electrolytes (SPEs) have garnered extensive attention as potential alternatives to traditional liquid electrolytes, primarily due to their prowess in curbing lithium dendrite formation and preventing electrolyte leaks. The quest for SPEs that are both mechanically robust and exhibit superior ionic conductivity has been vigorous. However, achieving a harmonious balance between these two attributes remains a significant challenge. In this study, we introduce a novel quasi-solid electrolyte, ingeniously crafted from a poly(urethane-urea) network, enriched with lithium salts and plasticizers. This innovative composition not only boasts remarkable toughness but also ensures commendable ionic conductivity. Our post-gelation method yields gel polymer electrolytes that undergo rigorous evaluation, leading to an optimized version that stands out with its exceptional room-temperature ionic conductivity (2.94×10-4 S cm-1) and outstanding toughness (11.9 MJ m-3). Moreover, it demonstrates a broad electrochemical window (4.73 V), remarkable stability across a 600-hour cycle test, a high capacity retention exceeding 80 % after 100 cycles at 0.2 C, and a noteworthy self-healing capability. This quasi-solid polymer electrolyte emerges as a promising contender to replace current liquid electrolyte solutions.

Polylactic acid/epoxidized linseed oil/polypropylene grafted maleic anhydride: A promising combination of toughness and rigidity

AbstractIncreasing toughness of brittle polymer without losing modulus of elasticity and tensile strength is highly important for enlarging the range of applications. In this study, polylactic acid (PLA) modified with epoxidized linseed oil (ELO) and polypropylene‐grafted maleic anhydride (PPgMA) with a good balance of toughness and rigidity was successfully prepared by melt mixing procedure. The addition of PPgMA/ELO with appropriate proportions (3:1, 5:1, and 5:5 wt%) resulted in PLA modified samples with significant ductility improvement (around 2200% of elongation at break and 1800% of tensile toughness compared to the neat PLA) with low decrease in Young modulus and tensile strength. This feature was attributed to improved interfacial interactions and the formation of crosslinked structures at the interface that also increased viscosity of the melting system and cold crystallization temperature of PLA. The scanning electron microscopy revealed the presence of small domains of modified systems. The effectiveness of reactive compatibilization among the components was also suggested by Fourier transform infrared (FTIR) spectroscopy and thermal degradation analysis. The combination of toughness, modulus of elasticity and good thermal properties make this low‐cost and scalable eco‐friendly material a promising candidate for use as biodegradable plastic in several fields including medical applications and packaging.

A Tough Balancing Act – The Evolving AI Governance in Korea

AI governance began to emerge as a focal point of discourse in Korea from the mid 2010s. Since then, multiple government and public bodies have released guidelines for AI governance, and various tech companies have announced their own AI ethics and governance principles. Beyond its borders, Korea has also actively participated in efforts to establish international norms and guidelines on AI governance. These developments were in part propelled by events that increased public awareness of the importance of trustworthy AI. This has also led to numerous legislative proposals that purport to increase technical and legal checks on such systems. At the same time, Korea has maintained its emphasis on the promotion of new technologies as a fundamental principle of legislative policy. Pursuing the dual goals of spurring innovation in the field of AI while at the same time ensuring its safety has led to confusion and, in some cases, incongruity within the AI governance framework in Korea. The Korean experience sheds light on factors that can influence the trajectory of a jurisdiction's AI governance, including public awareness of AI's potential for both benefit and harm, and the existing legislative and policy framework for governing technology.

Archeometallurgical Investigation of a Fragment from a Medieval Sword Blade

A fragment from a medieval sword blade was investigated by metallography, Vickers microhardness tests and slag inclusions analysis are to extract technological information about its manufacturing process. Optical microscopy observations and microhardness measurements indicated that the sword blade was forged via hammer welding, combining different steel bars for an optimal balance of hardness and toughness. A steeling technique involved wrapping a steel bar around a composite billet, crafted by enclosing a hypoeutectoid steel bar around a near-eutectoid steel core. Moreover, it was found that the hardness of the cutting edges was increased with a quenching heat treatment. After quenching, the blade exhibited martensitic microstructure with Vickers microhardness ranging from 500 to 640 HV0.3. The compositional data of a large set of nonmetallic inclusions were collected by scanning electron microscopy coupled with X-ray dispersive spectroscopy. Slag inclusion analysis and multivariate statistics confirmed the blade's composite nature and revealed distinct smelting and forging-related SI groups. Liquidus temperatures indicated smelting temperatures of at least 1156°C for the external section and 1031°C for the internal. The forging temperature was estimated at a minimum of 1143°C. These findings provide insight into the blade’s metallurgical history.