Nano silica was synthesized using the Stober process with ammonia, ethanol, and tetraethyl orthosilicate (TEOS) solution. Equiatomic titanium-nickel pre-alloyed particles were reinforced with silica nanoparticles of constant volume percent with sizes varying as proceeding 50, 100, 250, and 500 nm. The weighed compositions were mixed in a planetary ball mill, followed by compaction via uniaxial compression of 50 MPa. The resultant green pellets were sintered in an argon atmosphere at 1223K for a period of 4 hrs. Following that, by using EDM, the composite pellets were sectioned, soldered, and cold-mounted. Microstructure was analyzed by optical microscopy, mechanical properties by micro-Vickers hardness testing, and electrochemical analysis by Tafel curves, whereas the effect of particle size at constant volume on the densification was determined via Archimedes' Principle. The reinforcement showed increasing hardness up to 120HV and an increase in phase distribution, in addition to the effect complemented by the transformation of silica, whereas the electrochemical evaluation was affected by both reinforcement and phase distribution. Electrochemical corrosion resistance was measured at 6.88mpy in pure TiNi and 10.93mpy in TiNi nano-silica composite.

Effect of Heat Treatment Processes on Microstructure and Mechanical Properties of the Ultra-low Carbon 11.3Cr–1.7Mn–0.8Ni Steel

The effects of V addition on the microstructure and compression properties of NiAl-Cr alloys were investigated. V does not change the constituent phases but significantly changes the microstructure morphology. With increasing V content, the microstructures change to be Cr(V) dendrites and NiAl + Cr(V) eutectic. V addition markedly enhances the compression strength due to solid solution strengthening and second phase strengthening. At room-temperature, weak interfacial bonding between Cr(V) dendrites and eutectic as well as the deterioration of eutectic microstructure degrade properties. The room-temperature compression strength initially rise and thereafter decline. The NiAl-28Cr-10V alloy has the highest compression strength of 2350 MPa. At high-temperature, microstructural roughening improves strength, leading to the highest compression strength of 411 MPa in NiAl-28Cr-18V alloy.

The effects of rolling deformation on microstructure and mechanical properties of cold spraying Ti

Influence of deposition strategy on the microstructure and mechanical properties of CMT + P WAAM-based 205C aluminum alloy

This study systematically investigated the effects of cooling rates on the morphology, size, distribution, and microstructural properties of MnS inclusions in 46MnVS5 non-quenched and tempered steel through three cooling methods: water quenching, air quenching, and furnace cooling. Results indicate that cooling rate significantly regulates MnS precipitation behavior: under furnace cooling, MnS forms coarse particles that aggregate along grain boundaries, leading to reduced properties; air cooling produced spherical or short rod-shaped MnS with uniform distribution and optimal comprehensive properties; water cooling resulted in fine, dispersed MnS with a martensite/bainite microstructure, enhancing toughness but requiring tempering treatment. A nonlinear relationship between cooling rate and average MnS diameter was established, providing theoretical support for optimizing air cooling processes.

The Pb4/5Sr1/5 (Z r11/20Ti9/20)O3-Pb(M n1/3Sb2/3)O3-Pb(W1/3Nb2/3)O3 (PSZ T-PM S-PWN) ceramics were prepared via the solid-state reaction method. The effect of sintering temperatures on PSZ T-PM S-PWN phase formation, microstructure and electrical properties were investigated. The X-ray diffraction study confirmed pure perovskite structure formation in the prepared ceramics and the coexistence of rhombohedral and tetragonal phases has been detected in all ceramics at room temperature. Scanning electron micrographs of fractured PSZ T-PM S-PWN ceramics revealed equiaxed grains and the presence of both transgranular and intergranular fracture modes. Optimal electrical properties were obtained at a sintering temperature of 1175oC, characterized by a high dielectric constant (ϵr=12735), a Curie temperature (TC) of 630 K, a dielectric loss (tanδ) of 0.03, a piezoelectric charge constant (d33) of 341 pC/N, an electromechanical coupling factor (KP) of 0.624, and a mechanical quality factor (Qm) of 1260. These properties indicate strong potential for applications in piezoelectric-related fields, especially under demanding or extreme conditions.

Abstract With the increasing utilisation of scrap in metallurgical processes due to recycling to reduce CO 2 footprint, the content of tramp elements in the base material is increasing. In order to quickly investigate the influence of tramp elements on the weld nugget microstructure and mechanical properties during resistance spot welding (RSW), a method has been developed to introduce tramp elements into the weld nugget. By making an indentation in one of the two sheets to be welded and inserting the desired quantity of tramp element before welding, the weld nugget can specifically be alloyed. This allows to quickly analyse the influence of individual tramp elements on the microstructure and its influence on the resulting mechanical properties. The applicability of the method was investigated using Cu as tramp element material. As part of the investigations, a targeted Cu content of 0.4 wt% was set, which was confirmed using energy-dispersive X-ray spectroscopy (EDS). The spot welds alloyed according to the method were compared with spot welds without the Cu addition and spot welds of an already Cu-alloyed material. The weld nugget microstructure of all steels analysed by light optical microscopy (LOM) and scanning electron microscopy (SEM) was martensitic with similar grain size and morphology, regardless of the Cu content. In tensile shear (TS) and cross tension (CT), testing plug failure occurred in all samples. The results from the TS tests with peak forces of 11.4–12.2 kN and absorption energies between 14.3 and 18.5 J were very close to each other. The CT results with peak forces of 6.7–8.5 kN and energies between 46 and 69 J showed a similar picture. The average weld nugget hardness of all three weld configurations was in between 383 and 398 HV1. The microstructural and mechanical results showed no significant differences. The presented method for a targeted weld nugget alloying during resistance spot welding allows a repeatable, easy and quick investigation of the influence of alloy modification by tramp elements such as Cu on the weld nugget properties and offers a practical approach to assess material changes due to an increased tramp element content.

This study investigates the influence of graphitic flux interlayers on the microstructure, mechanical behaviour, tribological performance, and corrosion resistance of low‐carbon steel fabricated using cold metal transfer‐based wire arc additive manufacturing (CMT‐WAAM). Multi‐layered graphene (MLG) powder was introduced as an interlayer flux between successive deposited layers to fabricate the GR‐IL specimen, while a standard ER70S6 specimen was produced without an interlayer. A systematic comparison was conducted covering microstructural features, mechanical properties, wear behaviour, and corrosion resistance. The MLG interlayer enhanced the deposition process, resulting in grain refinement and improved functional performance. Grain size decreased from 12 to 8 µm, while pearlite content increased from 39.79% to 45.15%, indicating altered phase transformation behaviour. Hardness increased from 178 to 184 HV, improving resistance to plastic deformation. Tensile testing revealed comparable ultimate tensile strength in the horizontal and diagonal orientations, whereas the vertical orientation exhibited lower strength, indicating anisotropy. Pin‐on‐disc testing demonstrated superior tribological performance for the GR‐IL specimen, with a reduced specific wear rate of 2.0 × 10 −6 mm 3 /N·m compared to ER70S6 (4.5 × 10 −6 mm 3 /N·m). Corrosion testing revealed a reduced corrosion rate of 0.07251 mm/year for the GR‐IL specimen compared to 0.07401 mm/year for ER70S6, confirming enhanced corrosion resistance.

The main application scenarios of thermosetting epoxy asphalt binder are currently restricted to steel bridge deck pavement and airport pavement. Up to 50% of the epoxy system (ES) content limits its wider application because of its high cost. To explore a more economical ES range, 20%, 30% and 40% ES were added to virgin asphalt-epoxy system, aged asphalt-epoxy system and aged asphalt + rejuvenator-epoxy system. The effects of ES content on the mechanical properties, microstructure and molecular behaviour were investigated by macroscopic and microscopic experiments. Results show that the curing reaction is the fastest in the first 40 min for all systems, regardless of ES content. The addition of rejuvenator can reduce the viscosity of aged asphalt-epoxy system and improve tensile and low-temperature properties. With the decrease of ES content, the cross-linked network gradually loosens until it disappears. Aged asphalt is more conducive to ES curing and cross-linked structure formation than virgin asphalt. For aged asphalt + rejuvenator-epoxy system, the optimal ES content is 30%, which enables it to have good macro- and micro-properties while reducing material costs.

This study demonstrates the valorization of bone waste from different animal sources as a sustainable approach to produce high-value hydroxyapatite (HA) powders, supporting circular economy principles. The findings provide a scientific basis for selecting bone waste sources depending on desired material properties, promoting resource-efficient recovery and reuse of biowaste. Three different types of bone-bovine, ostrich, and porcine-were selected for this research to compare species-dependent differences in HA derived from animal sources. Bovine bone served as a common reference, ostrich bone represented a non-mammalian source, and porcine bone was chosen for its close structural similarity to human bone. The HA powders were characterized in terms of particle size, specific surface area, crystallite size, phase composition, and porosity. X-ray diffraction (XRD) analysis revealed variations in crystallite size with calcination temperature. Mechanical testing revealed that bovine-derived HA exhibited the highest compressive strength (17MPa) and porcine-derived HA showed the highest hardness (0.5 GPa). These findings highlight the significant influence of the bone source on the microstructural and physicochemical properties of HA, providing a foundation for selecting optimal HA sources for targeted applications. With the results obtained in this paper, it is possible to select the animal of origin of the bones to be used based on the desired characteristics of the powder to be developed.

This study examines in situ induction-heating thermal field assistance during laser cladding of Stellite 6 on 17-4PH stainless steel. Single-layer, multi-track coatings (~2.3 mm) were produced at induction powers of 0, 300, 600, and 900 W while keeping laser parameters constant. Surface morphology, phase constituents, and microstructures were characterized by LSCM, OM, XRD, SEM, EDS, and EBSD, and nanoscale features were probed by TEM for the 600 W condition; microhardness and coating-only tensile properties were evaluated. Thermal assistance improved surface finish (minimum Sa = 16.67 μm at 600 W) and suppressed hot cracking. XRD/EBSD revealed a γ-Co matrix with interdendritic carbides and an increased ε-Co fraction under thermal assistance; TEM further showed stacking-fault lamellae and a distinct FCC/HCP interface, supporting a fault-assisted, diffusionless γ → ε transformation. Increasing induction power coarsened the microstructure (larger DE and SDAS), decreasing hardness from 537.1 to 461.5 HV0.1 and lowering yield/ultimate strengths from 1046 MPa and 1512 MPa to 849 MPa and 1423 MPa, while elongation increased from 4.37% to 6.27%. Considering crack-free valve hardfacing with acceptable strength loss and improved ductility, 600 W provides the best overall performance.

Molybdenum is used as a plasma-facing component (PFC) in tokamaks, where it is exposed to high-energy neutrons and plasma particles (He and H ions). It is also proposed as a nuclear fuel cladding material for future nuclear reactors. This study examines the effects of copper ion beam with varying doses (0.108, 1.08, and 10.8 dpa) on the microstructure, surface morphology and mechanical properties of molybdenum samples, to emulate the impact of high-energy particle cascade damage. Following exposure to high-energy copper ion beams, changes in microstructure, crystal size, lattice constant, microstrain (%), and surface morphology were observed. Lower ion dose (0.108 dpa) resulted in severe cracking as shown in SEM images, attributed to a high dislocation density because of increased microstrain (%) and decreased crystal size. Features like dents, melt craters, and a rough surface were observed at high ion doses of 1.08 and 10.8 dpa. Initially, crystal size decreased (fragmentation) at low ion doses of 0.108 and slightly increased at ion dose of 1.08 dpa. However, at higher ion doses of 10.8 dpa decrease in crystal size (refinement) and the microstrain (%) was observed. A decrease in lattice constant seems linear with the ion dose, as clear from XRD results, indicating the progressive radiation damage. The change in hardness with increasing dose was nonlinear. Hardness was observed to increase first at lower ion dose (0.108 and 1.08 dpa); however, at higher ion doses of 10.8 dpa, a decrease in hardness is observed due to radiation induced structure recovery/recrystallization effects.

Abstract Experimental characterization of brain white matter (BWM) using Magnetic Resonance Elastography (MRE), Diffusion Tensor Imaging (DTI), and numerical modeling is expensive, time-consuming, and constrained by computational limitations and model approximations. To address the scarcity of high-fidelity data, this study develops a machine learning (ML) workflow to predict single-frequency viscoelastic properties, specifically the homogenized storage modulus, of BWM. The dataset originates from a sensitivity study conducted in house where BWM was modeled as a 2D triphasic composite of axons, myelin, and glial matrix. The triphasic unidirectional composite only considers 2D mechanics and diffusion in the transverse plane (perpendicular to axonal direction). Microstructural properties such as fiber volume fraction, intrinsic phase moduli, and axonal geometry were used as features for the ML model. Ensemble of regression and decision tree-based models, coupled with hyperparameter optimization, were explored, with model interpretation performed using SHAP analysis. Decision trees yielded the best predictive performance, with SHAP highlighting the importance of glial moduli and fiber volume fraction. This ML framework offers a surrogate to expensive in vivo characterization, provides insight into BWM mechanical dependencies, and can serve as a foundation for future inverse models aimed at understanding aging, dementia, and traumatic brain injury mechanisms in neuroimaging studies

This study conducts a systematic comparison of binary Ni-P, ternary Ni-W-P, and ternary Ni-Ce-P electroless coatings on 6061-T6 aluminum alloy, focusing on the effects of post-plating heat treatment at 300, 350, and 400 °C. The originality of this work lies in its direct comparison of W and Ce doping under identical conditions and its identification of a critical brittle transition that decouples hardness from wear resistance. All coatings achieved peak hardness at 350 °C, with Ni-W-P reaching approximately 1691 ± 45 HV0.1 due to Ni3P precipitation and solid-solution strengthening. However, a key finding is the severe embrittlement of the Ni-P coating at 300 °C, where its wear rate increased by over 50 times despite a hardness increase. Treatment at 400 °C degraded wear performance across all systems, likely due to precipitate coarsening and substrate over-aging. The best overall performance within the tested window was achieved with the Ni-Ce-P coating heat-treated at 350 °C for 1 h, which exhibited a fine nodular structure and reduced the wear rate by 98.9% compared to the bare substrate. These results highlight the importance of balancing hardness and toughness, identifying an optimized processing window for enhancing the tribological performance of lightweight aluminum components.

Abstract In an effort to acquire harder and more wear-resistant FeCoCrNiMn high-entropy alloys, the Cr3C2-reinforced FeCoCrNiMn HEA composite coatings were fabricated by laser cladding, and their microstructure, hardness, and tribological properties were characterized. The results indicate that the coatings are composed of face-centered cubic (FCC) matrix and Cr3C2 phase, and the addition of Cr3C2 enhances the microhardness, with values ranging from 371.1 to 559.2 HV0.5. When paired with Si3N4 ceramic, the average friction coefficient first decreases from 0.77 to 0.59, and then increases to 0.64. When coupled with 440C steel, the average coefficient of friction first decreases from 0.71 to 0.50, and then rises to 0.62. However, the addition of Cr3C2 carbide can significantly improve the wear resistance, and the wear-rate of the coatings paired with Si3N4 ceramic is always much lower than that paired with 440C steel. When paired with 440C steel, the minimum wear-rate of 1.44 × 10−5 mm3/Nm can be achieved. When paired with Si3N4 ceramic, the minimum wear-rate reaches 9.24 × 10−7 mm3/Nm (FeCoCrNiMn/20Cr3C2 coating), which is only 4.91% of the FeCoCrNiMn coating without Cr3C2 reinforcement. The superior wear resistance stems from a cooperative effect of Cr3C2 enhancement and tribo-oxidization. The main wear mechanism against 440C steel is abrasive and adhesive wear, and the main wear mechanism against Si3N4 ceramic shifts from abrasive-adhesive to oxidative wear as the Cr3C2 content increases.

Effect of Polyol Plasticizers on the Physicochemical, Mechanical, and Microstructural Properties of Films from Chayote ( <i>Sechium edule</i> ) Peels

In the context of spent fuel recycling and the valorization of plutonium, (U,Pu)O2 mixed oxides (MOX) have been developed for use in French Pressurized Water Reactors (PWR). They are also leading candidates for some GEN IV reactor concepts, such as sodium-cooled fast reactors (SFR). One of the critical challenges in the nuclear industry is the mastery of the nuclear fuel cycle, specifically plutonium multirecycling. In order to achieve this goal, it is crucial to identify the secondary phases created during irradiation. In this work, (U,Pu)O2 MOX have been doped with 11 stable fission products (FP) (Sr, Y, La, Nd, Ce, Zr, Mo, Pd, Rh, Ru, Ba) to reproduce FP-based precipitates existing in the real spent fuel. The structural and microstructural properties of these secondary phases were characterized by coupling scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), Electron Probe MicroAnalysis (EPMA), and synchrotron techniques such as X-ray Absorption Spectroscopy (XAS) and Synchrotron Powder X-ray Diffraction (SP-XRD). This analysis highlights the relationship between the partial segregation among metallic FP (Mo, Pd, Rh, Ru) and their crystallographic structures, as well as the speciation shift of several FP induced by the addition of Ba. The synthesized SIMMOX samples present a secondary phase representative of irradiated MOX and can be used as an effective model material to study spent nuclear fuel and its reprocessing.

ABSTRACT Despite the growing demand for sustainable construction materials, limited research has evaluated the performance of bio-based adhesives, such as castor-oil-based polyurethane (PU), compared with conventional polyvinyl acetate (PVA) in glued-laminated bamboo (GLB) for structural use. This study assessed the physical, mechanical, and microstructural properties of GLB bonded with PU and PVA. PU-bonded samples showed higher mechanical performance (18% improved modulus of rupture and 37% improved shear strength); however, these differences were not statistically significant (p > 0.05). In terms of moisture-related properties, PVA exhibited higher water absorption (72% vs. 65%) and slightly lower thickness swelling (9.1% vs. 9.9%) after 168 h of immersion, indicating comparable dimensional stability between the two adhesives. Scanning electron microscopy (SEM) and image analysis confirmed PU’s deeper penetration and stronger inter-fiber cohesion, whereas PVA showed limited penetration and more interfacial failure. These findings indicate that PU is more suitable for load-bearing applications, while PVA is more appropriate for non-structural uses, emphasizing the critical role of adhesive penetration in GLB structural integrity.

Fe-rich phases are unavoidable intermetallic compounds in aluminum alloys, particularly in recycled aluminum. Their needle-like morphology not only impairs the mechanical performance of the alloy by disrupting the continuity of the matrix but also significantly reduces the allowable addition of recycled aluminum materials. Based on this, this study focuses on the Al-7Si-0.35Mg-0.35Fe alloy with a high Fe content. The Cr was introduced to modify the characteristics of the Fe-rich phase, and the microstructural evolution and mechanical properties of the aluminum alloy with different Cr content (0–0.25 wt.%) were investigated. Experimental results show that the secondary dendrite arm spacing of the alloy is significantly refined after Cr addition. Meanwhile, the Fe-rich phase gradually transitions from β-Al5FeSi with needle-like morphology to α-Al15(Fe,Cr)3Si2 with short rod-like or blocky morphology as the Cr content increases. Notably, the Fe-rich phase in the 0.20Cr alloy exhibits an approximately 65% increase in sphericity and an 84% reduction in equivalent diameter compared to those in the 0Cr alloy. The morphological blunting and dispersed distribution of Fe-rich phases lead to a broad effective Cr addition range of 0.05–0.20 wt% in the alloy. Among them, the 0.20Cr alloy exhibited the best comprehensive mechanical properties, with its ultimate tensile strength and elongation approximately 19% and 107% higher than those of the 0Cr alloy, respectively. Furthermore, the fracture morphology and the relationship between the Fe-rich phase and microcracks in Al-7Si-0.35Mg-0.35Fe alloys with different Cr contents were also analyzed.