Search Results (106)

High-Bandwidth Memory (HBM) enables the bandwidth required by modern AI and high-performance computing, yet its three dimensional stack traps heat and amplifies thermo mechanical stress. We first review how conventional solutions such as heat spreaders, microchannels, high density Through-Silicon Vias (TSVs), and Mass Reflow Molded Underfill (MR MUF) underfills lower but do not eliminate the internal thermal resistance that rises sharply beyond 12layer stacks. We then synthesize recent hybrid bonding studies, showing that an optimized Cu pad density, interface characteristic, and mechanical treatments can cut junction-to-junction thermal resistance by between 22.8% and 47%, raise vertical thermal conductivity by up to three times, and shrink the stack height by more than 15%. A meta-analysis identifies design thresholds such as at least 20% Cu coverage that balances heat flow, interfacial stress, and reliability. The review next traces the chain from Coefficient of Thermal Expansion (CTE) mismatch to Cu protrusion, delamination, and warpage and classifies mitigation strategies into (i) material selection including SiCN dielectrics, nano twinned Cu, and polymer composites, (ii) process technologies such as sub-200 °C plasma-activated bonding and Chemical Mechanical Polishing (CMP) anneal co-optimization, and (iii) the structural design, including staggered stack and filleted corners. Integrating these levers suppresses stress hotspots and extends fatigue life in more than 16layer stacks. Finally, we outline a research roadmap combining a multiscale simulation with high layer prototyping to co-optimize thermal, mechanical, and electrical metrics for next-generation 20-layer HBM. Full article

Carbon-based nanomaterials have emerged as a promising strategy for bitumen modification to enhance the mechanical and thermal performance of pavements. This review evaluates the present advancements in the inclusion of coke and carbon nanomaterials (CNMs) such as carbon nanotubes (CNTs) and graphene into bituminous systems. The findings and limitations of recent experiments in synthesis procedures along with dispersion methods are deeply explored to determine their impact on the rheological properties of bitumen as well as aging resistance and durability characteristics. Petroleum coke enhances bitumen softening points by 10–15 °C and causes up to 30% improvement in rutting resistance while simultaneously prolonging material fatigue life and aging resistance. Bitumen modification through petroleum coke faces challenges in addition to mixing difficulties due to its high viscosity. Moreover, the incorporation of CNTs and graphene as CNMs shows significant enhancements in rutting resistance with improved tensile strength, lower additive requirements, and enhanced dispersion. Both the superior mechanical properties of carbon nanomaterials and processing advancements in nano-enhanced bitumen have the capability to solve technical issues including material costs and specialized mixing processes. Combining coke with CNMs to enhance performance is a future research direction, which could result in economic and scalability considerations. This review comprehensively explores insights into physicochemical interactions, performance outcomes, and processing techniques, crucial for the development of sustainable, high-performance bitumen composites tailored for next-generation infrastructure applications. Full article

Oxide dispersion-strengthened (ODS) steels are emerging as leading candidate materials for next-generation nuclear reactor components due to their exceptional resistance to creep, fatigue, and irradiation, combined with high strength at elevated temperatures. This paper investigates the microstructural mechanisms underpinning these superior properties, with a particular focus on the critical role of nano-oxides in enhancing performance. Various manufacturing techniques, including powder metallurgy and additive manufacturing, are reviewed to assess their impact on the structural and mechanical properties of ODS steels. Recent case studies on their application in nuclear environments highlight the potential of ODS steels to significantly extend component longevity without necessitating major reactor redesigns. Nevertheless, further research is necessary to assess their reliability under extreme environmental conditions and to determine optimal, scalable manufacturing processes for large-scale production. Full article

This review paper investigates the comprehensive impact of various nanomaterials on the mechanical properties and durability of pavement-quality concrete (PQC) with a specific focus on compressive strength, flexural strength, split tensile strength, permeability, abrasion resistance, fatigue performance, and crack relief performance. Despite significant advancements in the use of nanomaterials in concrete, existing research lacks a comprehensive evaluation of their comparative effectiveness, optimal dosages, and long-term durability in PQC. While conventional PQC faces challenges such as low fatigue resistance, high permeability, and susceptibility to abrasion, studies on nanomaterials have largely focused on individual properties rather than a holistic assessment of their impact. Nano SiO₂ and graphene oxide (GO) emerged as the most effective, with optimal dosages of 2% and 0.03%, respectively, leading to substantial improvements in compressive strength (up to 48.88%), flexural strength (up to 60.7%), and split tensile strength (up to 78.6%) through improved particle packing, reduced permeability, and refined microstructure. Nano TiO₂, particularly at a 1% dosage, significantly enhanced multiple properties, including a 36.30% increase in compressive strength, over 100% improvement in abrasion resistance, and a 475% increase in fatigue performance. However, a critical research gap exists in understanding the combined effects of multiple nanomaterials, their interaction mechanisms within cementitious systems, and their real-world performance under prolonged environmental and loading conditions. Most studies have been limited to laboratory-scale investigations, with minimal large-scale validation for pavement applications. The findings indicate that nanomaterials like nano TiO₂, nano CaCO₃, nano Al₂O₃, nano clay, and carbon nanomaterials play crucial roles in improving characteristics like permeability, abrasion resistance, and fatigue performance, with notable gains observed in many cases. This review systematically analyzes the influence of these nanomaterials on PQC, identifies key research gaps, and emphasizes the need for large-scale field validation to enhance their practical applicability. Full article

Despite the significant economic and environmental advantages of friction stir spot welding (FSSW) and its amazing results in welding similar and dissimilar metals and alloys, some of which were known as unweldable, it has some structural and characteristic defects such as keyhole formation, hook defects, and bond line oxidation. This has prompted researchers to focus on these defects and propose and investigate techniques to treat or compensate for their deteriorating effects on microstructural and mechanical properties under different loading conditions. In this experimental study, sheets of AA6061-T6 aluminum alloy with a thickness of 1.8 mm were employed to investigate the influence of reinforcement by graphene nanoplatelets (GNPs) with lateral sizes of 1–10 µm and thicknesses of 3–9 nm on the static and fatigue behavior of FSSW lap joints. The welding process was carried out with constant, predetermined welding parameters and a constant amount of nanofiller throughout the experiment. Cross-sections of as-welded specimens were tested by optical microscope (OM) and energy-dispersive spectroscopy (EDS) to ensure the incorporation of the nanographene into the matrix of the base alloy by measuring the weight percentage (wt.%) of carbon. Microhardness and tensile tests revealed a significant improvement in both tensile shear strength and micro-Vickers hardness due to the reinforcement process. The fatigue behavior of the GNP-reinforced FSSW specimens was evaluated under low and high cycle fatigue conditions. The reinforcement process had a detrimental effect on the fatigue life of the joints under cyclic loading conditions. The microstructural analysis and examinations conducted during this study revealed that this reduction in fatigue strength is attributed to the agglomeration of GNPs at the grain boundaries of the aluminum matrix, leading to porosity in the stir zone (SZ), the formation of continuous brittle phases, and a transition in the fracture mechanism from ductile to brittle. The experimental results, including fracture modes, are presented and thoroughly discussed. Full article

To enhance the erosion resistance of typical Cr₃C₂-NiCr coatings, the Cr₃C₂-TiC-NiCrCoMo (NCT) coating was developed and deposited by high-velocity oxygen fuel spray (HVOF). The erosion resistance and mechanisms of the coating were investigated using numerical simulations and experimental methods. A comprehensive calculation model for the coating erosion rate was developed, incorporating factors such as the properties of the eroded particles, the characteristics of the coating, and the conditions of erosion. The erosion rate of the NCT coating was calculated and predicted by the model, and the accuracy of these predictions was validated through experiments. The NCT1 (87.3 wt.% Cr₃C₂-NiCrCoMo/3 wt.% TiC)coating demonstrated exceptional erosion resistance compared to the original Cr₃C₂-NiCrCoMo (NCC) coatings with reduced erosion rates of 23.64%, 20.45%, and 16.22% at impact angles of 30°, 60°, and 90°, respectively. The addition of nano-TiC particles into the NCT1 coating enhances the yield strength, impeding the intrusion of erosive particles at low angles and supporting the metal binder phase, eventually reducing fatigue fracture under repeated erosion. However, excessive nano-TiC content degrades the erosion resistance due to the increase in pores and cracks within the coating. Full article

This paper presents a comprehensive review of quality control (QC) and reliability research in micro–nano technology, which is vital for advancing microelectronics, biomedical engineering, and manufacturing. Micro- and nanotechnologies operate at different scales, yet both require precise control to ensure the performance and durability of small-scale systems. This review synthesizes key quality control methodologies, including statistical quality control methods, machine learning and AI-driven methods, and advanced techniques emphasizing their relevance to nanotechnology applications. The paper also discusses the application of micro/nanotechnology in quality control in other technological areas. The discussion extends to the unique reliability challenges posed by micro–nano systems, such as failure modes related to stiction, material fatigue, and environmental factors. Advanced reliability testing and modeling approaches are highlighted for their effectiveness in predicting performance and mitigating risks. Additionally, the paper explores the integration of emerging technologies to enhance and improve reliability in micro–nano manufacturing. By examining both established and novel techniques, this review underscores the evolving nature of quality control and reliability research in the field. It identifies key areas for future investigation, particularly in the adaptation of these methods to the increasing complexity of micro–nano systems. The paper concludes by proposing research directions that can further optimize quality control and reliability to ensure the continued advancement and industrial application of micro–nano technologies. Full article

The inadequate resistance of traditional asphalt binders to aging, temperature fluctuations, and fatigue cracking underlines the necessity for innovative modifications to boost pavement durability. This study aims to state the inadequate exploration of the direct application of composite nanomaterials in asphalt binders by assessing their direct effects on physiochemical and durability properties without the inclusion of additional additives. The composite nanomaterials, combined with different amounts of Nano-Silica, Nano-Alumina, and Nano-Copper oxide, were incorporated into the binder at 2%, 4%, and 6% by weight. A series of conventional and rheological tests were conducted, including penetration, temperature susceptibility, Dynamic Shear Rheometer (DSR), Rolling Thin Film Oven Test (RTFOT), and Bending Beam Rheometer (BBR). The results demonstrated that the addition of 2% nanomaterials improved penetration by 34% and 41% for unaged and aged samples, respectively, while a 4% addition reduced temperature susceptibility by 64% for aged binders in a mix containing equal amounts of combined nanomaterials. DSR analysis indicated enhanced stiffness and viscoelastic properties, with increased complex shear modulus (G*) and reduced phase angle (δ). Aging resistance was enhanced as established by RTFOT, and acceptable low-temperature performance was attained per BBR results. These results found composite nanomaterials as a capable key for advancing asphalt binder performance. Full article

This study investigates the tribological effects of nano-sized metal oxides (ZrO₂, CuO, Y₂O₃ and TiO₂) in Group III type base oil containing 0.3% pour point depressant (PPD) and 5% viscosity modifier (VM) to enhance friction and wear performance. The homogenized lubricant samples with varying concentrations of oxide nanoparticles (0.1–0.5 wt%) on a linear oscillating tribometer performed static and dynamic frictional tests. Optical and confocal microscopy surface analysis evaluated the wear of the specimen, and SEM and EDX analyses characterized the wear tracks, nanoparticle distributions, and quantification. The cooperation between PPD and nanoparticles significantly improved friction and wear values; however, the worn surface suffered extensively from fatigue wear. The collaboration between VM and nanoparticles resulted in a nanoparticle-rich tribofilm on the contact surface, providing excellent wear resistance that protects the component while also favorably impacting friction reduction. This study found CuO reduced wear volume by 85% with PPD and 43% with VM at 0.5 wt%, while ZrO₂ achieved 80% and 63% reductions, respectively. Y₂O₃ reduced wear volume by 82% with PPD, and TiO₂ reduced friction by 20% with VM. These nanoparticles enhanced tribological performance at optimal concentrations, but high concentrations caused tribofilm instability, highlighting the need for precise optimization. Full article

The effect of dispersing multiwalled carbon nanotubes (MWCNTs) and graphene nanoplatelets (GNPs) in the matrix on the low-velocity impact resistance and post-impact residual tensile strength of the carbon fiber reinforced epoxy composite laminates has been experimentally analyzed in this study. The composite specimens with the matrix reinforced by different nanoparticle types and various nanoparticle concentrations (0.1, 0.3, and 0.5 wt.%) were prepared and impacted. The post-impact tensile quasi-static and fatigue tests were performed on the specimens with different configurations to study the influence of aforementioned factors on the impact resistance and damage tolerance. Experimental results show that adding nanoparticles in the matrix increases the maximum impact force, reduces the damage area, and alleviates the dent depth of the laminates remarkedly. Moreover, the improvement in these impact resistances increases with the applied nanoparticle concentrations. The nano-modified composite laminates present higher post-impact static strength and longer fatigue life than the specimens with a neat epoxy matrix. Furthermore, both the post-impact static tensile strength and fatigue life increase with the applied nanoparticle concentrations. The damage areas measured using infrared thermography were found to increase linearly with the applied fatigue cycles for all the studied specimens with various configurations. The damage area growth rates of nano-modified composite laminates decrease significantly as the applied nanoparticle concentrations increase. The MWCNTs present better performance than GNPs in improving post-impact static strength and extending the residual fatigue life, however the effect of applied nanoparticle type on the fatigue damage growth rate is slight. Full article

Foamed rubber asphalt has attracted wide attention in cold-recycled pavement projects due to its excellent performance, strong construction performance and resource conservation, but the mechanism of its performance improvement after foaming is still unclear. In order to explore the difference in the performance of rubber asphalt before and after foaming, this study systematically analyzed the performance improvement mechanism of asphalt from nano, micro and macro perspectives. Molecular dynamics simulation results show that the density and modulus of rubber asphalt decrease after foaming. After foaming, the glass transition temperature of rubber asphalt decreased by 4.4 K, and the free volume fraction decreased by 4.7%, which indicated that its low-temperature toughness was enhanced. The simulation results also illustrate the performance enhancement mechanism of rubber asphalt. Rubber and asphalt are physically mixed and do not undergo chemical reactions. However, foaming makes the rubber particles more evenly distributed, helping to improve the toughness and fatigue properties of asphalt. Macroscopic test results show that the high-temperature performance and fatigue performance of foamed asphalt are reduced, while the low-temperature performance is improved. The molecular simulation results are consistent with the experimental results, providing a comprehensive explanation for the improvement mechanism of rubber asphalt performance. Full article

To improve the service life of continuous casting crystallizer, the NiCo-ZrB₂ coating was prepared using nanocomposite plating technology. Uniformly dispersed nano-ZrB₂ particles significantly enhanced the hardness and wear resistance of the coating. Upon testing, the hardness of the coating exceeded 700 HV, with a friction coefficient below 0.2, which was superior to those of pure NiCo or other nanocomposite NiCo coatings reported previously. Microscopic analysis revealed that the addition of dispersants and ultrasonic vibration treatment had facilitated the homogeneous distribution of nano-ZrB₂ within the matrix, thereby promoting the formation of numerous nano-twins. Due to dispersion strengthening, fine grain strengthening, and twinning strengthening, the wear behavior of the coating changed from fatigue wear to abrasive wear, and the wear volume was significantly reduced by 82%. The above findings could potentially extend the service life of the coating, reduce the cost of steel loss per ton, and have broad application prospects in other surface protection fields. Full article

Herein, we fabricated a low-melting-point Zr-16Ti-6Cu-8Ni-6Co eutectic filler based on a Zr-Ti-Cu-Ni filler to achieve effective joining of a Ti6Al4V (TC4) titanium alloy. The temperature at which the brittle intermetallic compound (IMC) layer in the seam completely disappeared was reduced from 920 °C to 900 °C, which broadened the temperature range of the Zr-based filler, brazing the TC4 without a brittle IMC layer. The shear strength of the Zr-16Ti-6Cu-8Ni-6Co brazed joint increased by 113% more than that of the Zr-16Ti-9Cu-11Ni brazed joint at 900 °C. The proportion of β-Ti in the seam of the Zr-16Ti-6Cu-8Ni-6Co brazed joint increased by 21.31% compared with that of the Zr-16Ti-9Cu-11Ni brazed joint. The nano-indentation results show that the elastic modulus of the β-Ti (143 GPa) in the interface is lower than that of the α-Ti (169 GPa) and (Ti,Zr)₂(Ni,Cu,Co) (203 GPa). As a result, the β-Ti is subjected to a greater strain under the same stress state compared with the α-Ti and (Ti,Zr)₂(Ni,Cu,Co), and the Zr-16Ti-6Cu-8Ni-6Co brazed joint can maintain a higher strength than the Zr-16Ti-9Cu-11Ni brazed joint under a middle–low erosion area of the TC4 base metal. This provides valuable insights into the use of high-strength, fatigue-resistant TC4 brazed joints in engineering applications. Full article

Moisture accelerates the degradation of asphalt properties, significantly impacting the service life of roads. Therefore, this study uses simplified viscoelastic continuous damage theory and employs frequency scanning, linear amplitude scanning, and fatigue–healing–fatigue tests with a dynamic shear rheometer. The objective is to investigate the effects of aging time, moisture conditions, and aging temperature on the fatigue and self-healing performance of SBS (Styrene–Butadiene–Styrene block copolymer)-modified asphalt, nano-SiO₂-modified asphalt, and nano-SiO₂/SBS composite modified asphalt in a moisture-rich environment. The results indicate that nano-SiO₂ powder enhances the low-temperature performance of modified asphalt, whereas the SBS modifier reduces temperature sensitivity and increases the recovery percentage after deformation. Compared to SBS-modified asphalt, the deformation resistance of nano-SiO₂/SBS composite modified asphalt has increased by about 30%, while nano-SiO₂-modified asphalt shows relatively poor deformation resistance. The fatigue performance of SBS-modified asphalt deteriorates under moisture, whereas the addition of nano-SiO₂ powder improves its fatigue life. Nano-SiO₂/SBS composite modified asphalt exhibits strong self-healing capabilities. Although self-healing can enhance the fatigue life of modified asphalt, moisture inhibits this improvement after self-healing. Full article

The dual nature of asphalt binder necessitates improvements to mitigate rutting and fatigue since it performs as an elastic material under the regime of rapid loading or cold temperatures and as a viscous fluid at elevated temperatures. The present investigation assesses the effectiveness of Nano Alumina (NA), Nano Silica (NS), and Nano Titanium Dioxide (NT) at weight percentages of 0, 2, 4, 6, and 8% in asphalt cement to enhance both asphalt binder and mixture performance. Binder evaluations include tests for consistency, thermal susceptibility, aging, and workability, while mixture assessments focus on Marshall properties, moisture susceptibility, resilient modulus, permanent deformation, and fatigue characteristics. NS notably improves binder viscosity by about 138% and reduces penetration by approximately 40.8% at 8% nanomaterial (NM) content, significantly boosting hardness and consistency. NS also enhances Marshall stability and decreases air voids, increasing the mix’s durability. For moisture resistance, NS at 8% NM content elevates the Tensile Strength Ratio (TSR) to 91.0%, substantially surpassing the 80% standard. Similarly, NA and NT also show improved TSR values at 8% NM content, with 88.0% and 84.1%, respectively. Additionally, NS, NA, and NT reduce permanent deformation by 82%, 69%, and 64% at 10,000 cycles at 8% NM content, illustrating their effectiveness in mitigating pavement distress. Notably, while higher NM content generally results in better performance across most tests, the optimal NM content for fatigue resistance is 4% for NS and 6% for both NA and NT, reflecting their peak performance against various types of pavement distresses. These results highlight the significant advantages of nanoparticles in improving asphalt’s mechanical properties, workability, stability, and durability. The study recommends further field validation to confirm these laboratory findings and ensure that enhancements translate into tangible improvements in real-world pavement performance and longevity. Full article