Browse Topic: Materials properties

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Forgings, Magnesium Alloy, 5.5Zn - 0.45Zr (ZK60A-T5), Precipitation Heat TreatedAMS4362J (Current)8/18/2026
This specification covers a magnesium alloy in the form of die forgings 3 inches (76 mm) and under in nominal thickness at time of heat treatment, hand forgings 6 inches (152 mm) and under in nominal thickness, and forging stock of any size (see 8.5).
AMS D Nonferrous Alloys Committee
Steel, Corrosion-Resistant, Sheet, Strip, and Plate, 17Cr (SAE 430), AnnealedAMS5503H (Current)8/18/2026
This specification covers a corrosion-resistant steel in the form of sheet, strip, and plate.
AMS F Corrosion and Heat Resistant Alloys Committee
Steel, Corrosion- and Heat-Resistant, Forgings and Forging Stock, 12.5Cr (SAE 410), Enhanced Fracture Toughness, AnnealedAMS5867D (Current)8/17/2026
This specification covers a corrosion- and heat-resistant steel in the form of forgings and forging stock.
AMS F Corrosion and Heat Resistant Alloys Committee
User’s Guide to AMS SpecificationsAIR4779E (Current)8/17/2026
The scope of this SAE Aerospace Information Report (AIR) is to explain the functions of the various sections of the specifications, why some of the terms in AMS specifications are used, and how the specification system works. Starting with Section 4 of this document, the topics are presented in the order they usually appear in AMS specifications.
Aerospace Materials Systems Group
Rings, Flash-Welded, Aluminum and Aluminum AlloysAMS7488H (Current)8/14/2026
This specification covers flash-welded rings made of aluminum and aluminum alloys (see 8.5).
AMS D Nonferrous Alloys Committee
Steel Corrosion-Resistant Investment Castings, Vacuum Melted, Vacuum Cast, 13Cr - 8.0Ni - 2.2Mo - 1.1Al (PH 13-8 Mo), Homogenized, Solution, and Precipitation Heat Treated (Condition H1000)AMS5412C (Current)8/14/2026
This specification covers a corrosion-resistant steel in the form of investment castings.
AMS F Corrosion and Heat Resistant Alloys Committee
Aluminum Alloy, Alclad Sheet (6156-T4) 1.0Si - 0.90Cu - 0.60Mn - 0.90Mg Solution Heat Treated and Naturally AgedAMS4405D (Current)8/14/2026
This specification covers an aluminum alloy procured in the form of sheet 0.078 to 0.197 inch (2.00 to 5.00 mm), inclusive, in nominal thickness, Alclad on both sides (see 8.5).
AMS D Nonferrous Alloys Committee
Reliability Calculation and Analysis of Influencing Factors for Girth Welds in High-Grade Steel Pipelines Based on HMC-SS2026-99-03428/14/2026
Fracture failure of girth welds in high-grade steel pipelines poses a critical threat to pipeline integrity. Leveraging enhanced digitalization in pipeline engineering, a statistical database has been developed to support reliability analysis based on actual operational data. This study utilizes real project data to analyze the failure probability and key influencing factors of girth welds containing crack defects, thereby providing theoretical support for safety design and risk management. To overcome the conservatism of traditional deterministic methods, a probabilistic reliability model was established, incorporating a modified PRCI-CRES ultimate tensile strain criterion. Addressing the inefficiency of standard Monte Carlo (MC) simulation in high-dimensional low-probability contexts, an efficient Hamiltonian Monte Carlo-Subset Simulation (HMC-SS) strategy was introduced. Results show that HMC-SS improves computational efficiency by 99.95% over MC, with only 0.90% relative error. Key findings include: crack depth has the strongest influence – variation from 0.92 mm to 3.68 mm, which increases failure probability by 103 times; the strength matching coefficient is dominant, and higher values reduce failure risk; strain demand exhibits a positive correlation with failure probability and couples with material properties. It is concluded that high- or equal-strength material matching should be emphasized in welding, and reliability-informed design should account for multi-parameter interactions to ensure global safety.
Yang, Kai, Wang, Kaihong, Wang, Bin, Shao, Jia, Yu, Weichao, Zhang, Dong
Carbon Fiber Fabric Repair Prepreg, 120 °C (250 °F) Vacuum Curing, Part 0 - IntroductionAMS3970B (Current)8/10/2026
This document (Technical Specification) gives information about qualification rules and the relation between the different specification parts involved, such as the Technical Specification (TS), Material Specification (MS), and Purchasing Specification (PS). The link to the material qualification and qualified products is presented.
AMS CACRC Commercial Aircraft Composite Repair Committee
Steel, Corrosion-Resistant, Wire, 17Cr - 7.1NI - 1.1Al (17-7 PH®), Cold Drawn, Precipitation-HardenableAMS5678H (Current)8/10/2026
This specification covers a corrosion-resistant steel in the form of wire 0.007 to 0.625 inch (0.18 to 15.88 mm), inclusive, in nominal diameter, cold drawn to Condition C, and capable of being precipitation heat treated to Condition CH900.
AMS F Corrosion and Heat Resistant Alloys Committee
Research on the Cumulative Damage Mechanism of Special Equipment Steel Structures Based on Complex Load2026-99-10118/7/2026
Steel structures subjected to complex loading conditions undergo various types of damage, including fatigue, crack propagation, plastic deformation, and corrosion. As time and loads accumulate, these damages may lead to structural failure. The investigation of the damage mechanisms and constitutive models for special equipment steel structures under complex loading has been a significant challenge in engineering. This study develops a constitutive model for steel structure damage under static and dynamic loads, as well as vibration disturbances, through a normalization approach. The proposed model is validated via simulation to assess its feasibility. The findings offer a theoretical foundation for the design, life prediction, and health monitoring of steel structures in special equipment, aiming to enhance their safety and reliability. This research provides critical insights into damage analysis, failure prediction, and the optimization of repair strategies for steel structures, with significant practical implications in engineering applications.
Wang, Jun, Yu, Zhen, Huang, Yong-qiang, Chen, Wei-bi
Molecular Dynamics Simulation of Temperature Effects on the Hot Deformation and Microstructural Evolution of Al-Mg-Si Aluminum Alloy2026-99-10108/7/2026
In this work, molecular dynamics simulations are applied to systematically examine the influence of varying temperatures (300 K, 500 K, and 700 K) on the Elevated-temperature compression behavior and micromechanical characteristics of polycrystalline Al-Mg-Si aluminum alloy. A nanopolycrystalline model was established to analyze the stress–strain response, dislocation evolution, and crystal structure changes occurring during the deformation process. The simulation results show that the yield strength and elastic modulus both decline as temperature increases, indicating a pronounced thermal softening effect. During the early stage of plastic deformation, dislocations mainly have their nucleation sites at grain boundaries and then propagate into the grain interiors, where they form interconnected networks along with stacking faults and twin structures. This work reveals the thermal deformation mechanisms of Al-Mg-Si aluminum alloy at the atomic scale and provides theoretical guidance for the optimization of its hot-working processes.
Sun, Ruifeng, Liu, Shoukui, Wang, Rui, Sun, Xuemei, Ding, Shuli, Ma, Xiaofei
Research on Corrosion and Friction Behaviors of 8Cr4Mo4V Bearing Steels in Corrosive Medium Environments2026-99-10068/7/2026
Corrosion-wear damage behavior affects the bearing life and reliability seriously in a corrosive environment. The accurate evaluation of the tribocorrosion behavior of 8Cr4Mo4V bearing steel samples is critical for the application and protection of bearings. The present work seeks to establish the relationship between laboratory salt spray accelerated experiments and the corrosion of 8Cr4Mo4V steel samples in real outdoor marine atmosphere exposure, and investigate the tribological behavior in the corrosion-wear process under artificial seawater. Results show that salt spray corrosion tests can well simulate the corrosion of 8Cr4Mo4V steels in marine atmospheric exposure. The tribocorrosion performance of 8Cr4Mo4V steels under artificial seawater conditions is affected by the temperature effect of the corrosive liquid and the working conditions. Increased normal load and reduced rotational speed can improve the anti-friction performance. This work offers the possibility and reference of precise control of corrosion-wear-coupled damage failures for bearings.
Zhao, Chao, Ying, Lixia, Nie, Chongyang, Zhu, Tianlin, Sun, Dong
Experimental and Mechanistic Study on Current Carrying Friction of Sliding Ring Slide in Shaft-Type Oil Distributor under Different Oil Environments2026-99-10058/7/2026
The issue of current-carrying friction wear in the sliding ring slider of a controllable pitch propeller (CPP) oil distributor under shaft current conditions was addressed through the development of a specialized wear test device. Comparative tests were carried out with and without the application of electrical current in order to assess lubrication performance in bio-oil, mineral oil, and gear oil. Under conditions of low electrical current, the device exhibited significant signs of current-induced friction wear, in addition to substantial oil oxidation and the accumulation of deposits within the bio-oil. Conversely, the level of wear experienced was minimal in both mineral oil and gear oil conditions. These results imply that CPP systems utilising bio-oil encounter a considerable risk of wear under current-carrying circumstances. Quantitative analysis revealed that the wear depth of the friction pair in bio-oil under energized conditions reached 0.02 mm, accompanied by the formation of a phase-transformed layer up to 11.2 μm thick, which was approximately twice that observed in mineral or gear oils. Metallographic evidence confirmed severe arc erosion as the dominant wear mechanism, which was significantly exacerbated by the inferior oxidation stability and higher electrical conductivity of the bio-oil. In engineering practice, the utilisation of alternative lubricants is to be given precedence, and the shaft-type oil distributor is to be electrically insulated.
Xia, Miao, Li, Jiyue, Chang, Long, Wu, Rongjia
Analysis of Annular Pressure Drop Resistance across Tubing Joints Based on CFD and Nonlinear Fitting2026-99-09098/7/2026
During well testing and killing operations, tubing couplings with a larger diameter than the tubing body significantly increase the flow friction in the casing-tubing annulus, alter the rheological behavior of the kill fluid, thereby affecting operational accuracy and even leading to operational failure in severe cases. Most existing relevant studies focus on the impact of changes in flow area on flow, but ignore the effect of the coupling’s own structural configuration. Moreover, the research conclusions lack verification by downhole measured data, and there is an urgent need to further improve the analysis accuracy. Taking an ultra-deep well in the Xinjiang Oilfield as the engineering background, this paper conducts targeted research: first, a physical model of the flow field in the casing-tubing annulus passing through the tubing coupling is established, and a method for judging and determining the rheological properties of the kill fluid based on the fitting of the physical model and key parameters is proposed; on this basis, a numerical model including the coupling’s structural configuration is established and solved, and the friction calculation equation for the casing-tubing annulus passing through the tubing coupling is obtained through nonlinear fitting; finally, the calculation results of this equation are compared and verified with the measured data and numerical simulation results. The research results show that: under six working conditions, the flow characteristics of the kill fluid all conform to the characteristics of Bingham fluid, which is also consistent with the general flow regime of kill fluid flow; comparing the numerical analysis results of the target well in the Xinjiang Oilfield with the calculation results of the fitting equation, the maximum error, minimum error, and average error of friction analysis under the six working conditions are 14.46%, 0.39%, and 6.15% respectively; the total friction of the casing-tubing annulus in the entire well section calculated based on the theoretical equation is 12.085 MPa, and the relative error compared with the field measured 13 MPa is 7.57%, which meets the engineering accuracy requirements. The equation proposed in this study provides a universal equation for predicting the pressure drop of non-uniform flow in the wellbore, and also has an important reference value for predicting the wellbore pressure in drilling and oil-gas production operations.
Song, Zhitong, Jiang, Wu, Mi, Hongxue, Cao, Yinping, Dou, Yihua
Steel, Corrosion- and Heat-Resistant, Wire, 17Cr - 12Ni - 2.5Mo (SAE 316), Solution Heat TreatedAMS5690P (Current)8/5/2026
This specification covers a corrosion- and heat-resistant steel in the form of wire.
AMS F Corrosion and Heat Resistant Alloys Committee
Gold-Palladium-Nickel Alloy, Brazing Filler Metal, High-Temperature, 30Au - 34Pd - 36Ni, 2075 to 2130 °F (1135 to 1166 °C) Solidus-Liquidus RangeAMS4785L (Current)8/3/2026
This specification covers a gold-palladium-nickel alloy in the form of wire, rod, sheet, strip, foil, pig, powder, shot, chips, preforms, and a viscous mixture (paste) of the powder in a suitable binder.
AMS F Corrosion and Heat Resistant Alloys Committee
Iron-Nickel Alloy, Strip, 49Fe - 5.3Cr - 42Ni - 2.5Ti - 0.55Al (Ni-Span-C® 902), Solution Heat Treated, Cold Rolled, 50% ReductionAMS5225H (Current)8/3/2026
This specification covers an iron-nickel alloy in the form of strip 0.020 to 0.250 inch (0.51 to 6.35 mm), inclusive, in nominal thickness.
AMS F Corrosion and Heat Resistant Alloys Committee
Nickel Alloy, Corrosion- and Heat-Resistant, Welding Wire, 72Ni - 3.0Mn - 20Cr - 2.5Cb(Nb) (Inconel® FM82)AMS5836F (Current)8/3/2026
This specification covers a corrosion- and heat-resistant nickel alloy in the form of welding wire.
AMS F Corrosion and Heat Resistant Alloys Committee
Steel, Corrosion-Resistant, Bars, Wire, Forgings, Extrusions, Rings, and Forging Stock 5.0Mn - 22Cr - 12.5Ni - 2.2Mo - 0.20Cb - 0.30N - 0.20V (SAE XM-19), Solution Heat TreatedAMS5764G (Current)8/3/2026
This specification covers a corrosion-resistant steel in the form of bars, wire, forgings, extrusions, flash-welded rings, and stock for forging, extruding, or flash-welded rings.
AMS F Corrosion and Heat Resistant Alloys Committee
Nickel Alloy, Corrosion- and Heat-Resistant, Welding Wire, 72Ni - 15.5Cr - 1.0Cb(Nb) - 2.4Ti - 0.70Al - 7.0Fe (Inconel® FM69)AMS5778L (Current)8/3/2026
This specification covers a corrosion- and heat-resistant nickel alloy in the form of welding wire.
AMS F Corrosion and Heat Resistant Alloys Committee
Steel Bars, Forgings, and Mechanical Tubing and Forging Stock, Nitriding, 1.4Cr - 1.2Mo - 0.3V (0.29 - 0.36C) (32CrMoNiV5), Electroslag Remelted or Consumable Electrode Vacuum Remelted, Premium Aircraft-Quality for Bearing ApplicationsAMS6497C (Current)8/3/2026
This specification covers a nitriding grade of premium aircraft-quality, low-alloy steel in the form of bars, forgings, mechanical tubing, and forging stock. AMS6496 and AMS6498 cover UNS K23280 with other quality levels.
AMS E Carbon and Low Alloy Steels Committee
Manganese Bronze, Sand and Centrifugal Castings, 65Cu - 24Zn - 6.2Al - 3.8Mn - 3.0Fe, High Strength, As CastAMS4862G (Current)8/3/2026
This specification covers a manganese bronze alloy in the form of sand and centrifugal castings (see 8.5).
AMS D Nonferrous Alloys Committee
Steel, Corrosion- and Heat-Resistant, Welding Wire, 16.4Cr - 4.8Ni - 0.22Cb (Nb) - 3.6Cu, (17-4 PH), Consumable Electrode or Vacuum Induction MeltedAMS5803J (Current)8/3/2026
This specification covers a corrosion- and heat-resistant steel in the form of welding wire.
AMS F Corrosion and Heat Resistant Alloys Committee
Steel, Corrosion- and Heat-Resistant, Welding Wire, 12.5Cr (SAE 410)AMS5776J (Current)8/3/2026
This specification covers a corrosion- and heat-resistant steel in the form of welding wire.
AMS F Corrosion and Heat Resistant Alloys Committee
Nickel Alloy, Corrosion- and Heat-Resistant, Welding Wire, 70Ni - 2.5Mn - 15.5Cr - 3.0Ti - 7.0Fe (Inconel® FM92)AMS5675K (Current)8/3/2026
This specification covers a corrosion- and heat-resistant nickel alloy in the form of welding wire.
AMS F Corrosion and Heat Resistant Alloys Committee
Generating a New Class of Ultra-High-Strength Ductility Steel for 3D PrintingTBMG-555488/1/2026
A machine-learning strategy has generated a new class of ultra-high strength and ductility steel for 3D printing that costs less, resists rust, and requires only a fraction of the usual processing time.
Conventional Friction Stir Extrusion MachineTBMG-555418/1/2026
NASA Marshall Space Flight Center has developed a new small-scale metal extrusion tool, called a conventional friction stir extrusion (C-FSE) machine that may be attached or added-on to a conventional friction stir welding (C-FSW) system. The C-FSE machine uses the heat generation and plastic deformation processes underpinning C-FSW to perform metal extrusion instead of metal joining.
A Biohybrid Micro Swimmer Unaffected by CoatingTBMG-555368/1/2026
A team of researchers at the Max Planck Institute for Intelligent Systems (MPI-IS) in Stuttgart developed a biohybrid micro swimmer covered with magnetic material, whose swimming ability is largely unaffected by the coating. The team from the Physical Intelligence Department at MPI-IS published their work in the journal Matter, which covers a wide range of materials science research.
Fatigue Life Prediction and Improvement of Supporting Structures under Cyclic Highpressure Impact2026-99-01157/31/2026
Under cyclic ultra-high-pressure impact loads, structures often experience local fractures due to insufficient initial fatigue life (low-cycle fatigue). This article focused on a certain ultra-high-pressure support structure and established a dynamic model based on load transfer characteristics to simulate the transient stress-strain response under impact loads. On this basis, a low-cycle fatigue life evaluation method was used to predict the fatigue life of the structure about 362 times, which was significantly different from the required indicators for structural fatigue life. In response to the problem of high loadbearing capacity on the structural support surface and significant stress concentration at the root, the structural load-bearing method has been optimized. Calculation analysis showed that after optimization, the structural stress was greatly improved, the bearing capacity of the support surface was reduced by 25 %, and the fatigue life of the structure was increased from 362 times to 4208 times, an increase of about 10 times. The optimized structure has been verified through 2000 tests without any fracture, meeting the requirements for the service life of the structure.
Wang, Shuman, Ning, Bianfang, Ma, Amin, Zhang, Fanfan
Seismic Performance and Reinforcement Strategies for ±600 kV Suspended Converter Valves — Part1: Seismic Vulnerabilities2026-99-01457/31/2026
The suspended converter valve constitutes the fundamental equipment essential for the functioning of direct current power transmission infrastructure. The electrical equipment has been severely damaged in historical seismic events, underscoring the earthquake resistance of thyristor valve is critical for maintaining secure and consistent performance of energy delivery systems. Current seismic research focuses on ±800 kV converter valves, while studies on ±600 kV converter valves are lacking. Due to significant differences in the length of suspended insulators between ±600 kV and ±800 kV converter valves, their seismic responses differ considerably. A three-dimensional finite element model encompassing both the ±600 kV suspended converter valve and its supporting valve hall structure was developed to accurately capture their dynamic interactions under seismic excitation. The modal analysis is conducted, and the natural frequencies and mode shapes of converter valve and valve hall system are obtained. The seismic analysis results indicate that under 1 g seismic excitation, the calculated maximum seismic displacement of the suspended valve tower is 421 mm, exceeding the engineering design limit of 400 mm. The calculated minimum stress safety factor for the converter valve suspended insulators is 1.46, failing to meet the specified requirement of no less than 2. Both the swing amplitude of the converter valve and the stress on the suspended insulators exceed design limits. It not only poses a mechanical safety risk to the converter valve, but the excessive seismic displacement can also lead to seismic coupling effects between the converter valve and critical equipment. Therefore, further research on damping measures is required for the seismic vulnerabilities of ±600 kV suspended converter valves.
Lin, Sen, Zhu, Zhubing, Lu, Zhicheng, Sun, Yuhan
Microstructure and Mechanical Properties of Vacuum Laser Welded Joints in 42CrMo Thick Plate2026-99-01327/31/2026
Vacuum laser welding trials were carried out on 42CrMo steel, a material widely utilized in the defense sector. By employing a 30 kW fiber laser system, complete penetration welds were successfully produced on 20 mm thick 42CrMo steel plates. The resulting joints displayed satisfactory surface quality on both the top and bottom sides, with no evident defects such as cracks or porosity. A comprehensive analysis of the joint microstructure and mechanical properties was conducted. Findings reveal that the weld zone (WZ) is predominantly composed of lath martensite, accompanied by minor quantities of plate martensite, organized as columnar crystals. The joints demonstrated high tensile strength at ambient temperature, with fracture consistently occurring within the base metal (BM). Microhardness measurements indicated higher values within the weld relative to the base metal, and no pronounced softening was detected in the heat-affected zone (HAZ). Additionally, the joints exhibited commendable impact toughness, suggesting overall superior mechanical performance.
Shi, Haicheng, Zhang, Guoyu, Li, Wuhong, Cao, Dongxu, Liu, Tianlei
Application of the Coupled Volume of Fluid and Level Set (CVOFLS) Method for Moving Interface Tracking in the Zalesak Disk Problem2026-99-01387/31/2026
Addressing the inaccuracies in interface curvature computation using the Volume of Fluid (VOF) method and the lack of mass conservation in the Level Set (LS) method, a novel interface tracking method, the Coupled Volume of Fluid and LS (CVOFLS) method, is established. This approach synergistically integrates the strengths of both VOF and Level Set methodologies. It simultaneously solves for the VOF and LS functions based on fluid velocity, corrects fluid mass using the surface obtained by the VOF approach, and computes interface normals using the LS function, thereby eliminating the need for LS function reinitialization. This effectively overcomes the shortcomings of both methods. Numerical simulations of interface tracking demonstrate that the CVOFLS method ensures high tracking accuracy of free interfaces, good mass conservation, and improved computational efficiency.
Cui, Liying, Sun, Hui, Xu, Wei
Study on Penetration Damage Characteristics of Honeycomb Non-pneumatic Safety Tiree2026-99-01677/31/2026
To improve the mobility and reliability of special-purpose vehicles that are operated in extreme conditions and to minimize the influence of tire failure on the vehicle’s mobility, this paper investigates how the mechanical properties of honeycomb non-pneumatic tires are affected after high-speed impacts from external projectiles. A prototype of a network non-pneumatic honeycomb tire was initially developed, which was made of polyurethane material. The five parameter model of the Mooney-Rivlin model was selected as its constitutive relation and the experimental study was performed to validate three-dimensional stiffness simulation model for the tire. Secondly, a LS-DYNA-based finite element model was developed to describe the dynamic behaviors of the tire under an external impact at various locations (e.g. tread, single spoke plate and joints), and to investigate the influence of local damage and spoke plate fracture on the stiffness of the tire. The results indicate that the tire has better performance of resisting the impacts at small and medium levels, with the decrease of radial stiffness of the tire less than 4% after experiencing the ultrahigh load; after the spokes plate is broken, the radial stiffness of tire drops significantly by comparing with the intact tire, that is 24.17%, which has a great effect on the support performance of the tire. The findings of this work offer theoretical support and design guidelines for the structural optimization and properties improvement of NPTS.
Yao, Tuzao, Sun, Xiaowang, Zhang, Qiang, Fu, Lei, Huang, Jianbin
Aging and Performance Restoration Mechanisms of Gussasphalt under Thermo-Oxidative Aging and Remelting Conditions2026-99-01817/31/2026
To address the performance degradation of Gussasphalt during thermo-oxidative aging and remelting processes, this study investigates the restoration mechanisms of different additives on the aged and remelted Gussasphalt. Additives including RSS, CAS modifiers, and polymer-modified asphalt were incorporated into aged asphalt to evaluate their effects on performance recovery. The improvement in high- and low-temperature properties, viscosity, and viscoelasticity under remelting conditions was systematically analyzed. Results indicate that the additives significantly increased penetration and ductility, while reducing softening point and viscosity. Among them, a 10% dosage of CAS additive combined with new asphalt exhibited the optimal performance restoration. RSS additive enhanced the plastic deformation capacity of remelted asphalt, whereas CAS and new asphalt improved ductility and softening point, though CAS showed insufficient thermal stability. Viscosity tests demonstrated that 10% CAS addition yielded the most significant reduction in rotational viscosity. Dynamic shear rheometer (DSR) and bending beam rheometer (BBR) tests revealed that CAS notably improved phase angle and decreased rutting factor, while RSS showed superior enhancement in low-temperature crack resistance. Comprehensive analysis confirms that the incorporation of appropriate amounts of RSS, CAS, and new asphalt during remelting effectively enhances the properties of Gussasphalt. In particular, CAS additive and new asphalt exhibit outstanding overall performance, contributing to the improved durability and service performance of Gussasphalt.
Li, Jinmi, Wu, Guorong, Chen, Yunjin, Chen, Huayan, Ying, Hong
Method for Quantitatively Determining Stress Intensity Factors for Complex Metal Structures by Analogy2026-99-02077/31/2026
For the strength verification of metal structures, in addition to fundamental static strength analysis, fatigue analysis is also indispensable for structures subjected to cycle fatigue loads. Notably, accurate calculation of the stress intensity factor (SIF) is a prerequisite for the quantitative evaluation of crack propagation life. For real structures such as civil aircraft or steel bridge, the complexity of geometry, component connections, and mutual constraints makes the determination of SIFs along the crack propagation path both complex and time-consuming. If the cracked structure is simplified into a two-dimensional model for analysis, the beneficial effects of structural constraints on crack opening are often neglected, leading to overly conservative life predictions, which has been confirmed in the full-scale fatigue tests. Alternatively, while finite element analysis (FEA) can be used to estimate SIFs, inaccuracies or non-convergence may arise due to improper meshing around the crack tip, particularly when singular elements are not properly incorporated. To solve these problems, an analogy method for efficient and accurate evaluation of SIFs in complex metallic structures (particularly those used in civil aircraft) is proposed in this study. The method estimates the SIF in a real structure by comparing the crack opening displacement (COD) at the crack tip with that of a reference model (an infinite plate containing a central crack) using the same local mesh refinement. Extensive validation has demonstrated that the SIFs obtained using the proposed analogy method exhibit sufficient accuracy for engineering applications, offering a practical alternative to traditional analytical or finite element-based techniques in crack propagation analysis.
Luo, Yifan, Zhu, Wuxue, Xu, Haisheng, Huang, Fu, Bao, Haisheng, Lan, Xinlei
The 10 th International Conference on Mechanical Manufacturing Technology and Material Engineering (MMTME 2025)2026-99-01007/31/2026
TOC
Tobolski, Sue
Microstructure and Property Evolution of T91 Steel under Deep Peak-Shaving Service Conditions2026-99-01687/31/2026
To address the safety assessment challenges of T91 steel heating surface components in the context of coal-fired power plant transformation toward deep peak-shaving, this study systematically investigates the evolution laws of microstructure and mechanical properties of in-service T91 pipes from different positions in a power plant after peak-shaving operation. Material properties were evaluated in accordance with standards such as GB/T 5310-2017 through metallographic analysis, tensile testing, impact testing, and hardness measurement, while the mechanisms linking microstructure to property degradation were explored. Results show that oxidation and decarburization occur on the outer surface of T91 pipes at all positions, with differences in the thickness of oxide/decarburized layers between the fire-facing and back-fire surfaces; the oxide layer exhibits fracture characteristics. After service, the tensile strength, yield strength, elongation, and hardness of the material still meet national standards. The performance at the platen and final superheater inlet is superior to that at the final reheater inlet, consistent with differences in operating temperature and pressure. This study indicates that the T91 steel provided in this study is in the early stage of its service life, providing a theoretical basis for the safe operation of the unit.
Huang, Liming, Li, Zutao, Zhang, Jie, Liu, Yaoren
Weld Formation, Microstructure, and Mechanical Properties of High-Speed Friction Stir-Welded 6061-T6 Aluminum Alloys2026-99-01267/31/2026
In this paper, 6061-T6 aluminum alloys were subjected to high-speed friction stir welding. The associated weld formation, microstructure, and mechanical properties were systematically examined via combined experimental observation and numerical simulation approaches. At a welding speed of 3000 mm/min and a rotation rate of 3800 rpm, the defect-free weld was simply achieved due to the simultaneous intense thermal input and enhanced material flow. Microstructural analysis further demonstrated a fine equiaxed grain structure featuring a predominant simple shear texture with A/A components. The resultant joint exhibited an ultimate tensile strength equivalent to 80% of the base material, accompanied by excellent fracture elongation. This research provides experimental evidence for designing high-efficiency and high-quality bonding processes for aluminum alloys.
Guan, Yuankai, Wang, Ruiyang, Zhang, Kexin, Lin, Zhicheng, Deng, Jun, Liu, Zhe, Ganushchak, Oleg, Voitenko, Oleksandr, Zhao, Yunqiang, Gao, Shiyi
Development and Experiment of Rolling Friction and Wear Testing Machine Based on LabVIEW2026-99-02457/31/2026
To investigate the friction and wear characteristics of rolling bearings under various operating conditions, this paper develops a ring-block type rolling bearing friction and wear testing machine based on LabVIEW. The device achieves rotational friction by regulating the speed with a motor and applies the test load using a lever and weight loading method to simulate the actual working conditions of rolling bearings. The testing machine integrates a high-frequency response force sensor with a high-sampling rate data acquisition system, and combines with the LabVIEW platform to achieve real-time collection, processing, and display of friction force. Using a rolling bearing with a diameter of 50mm as the test object, continuous testing was conducted for 100 s under the conditions of a speed of 500r/min and a load of 50N. The experimental results show that the friction coefficient fluctuated significantly in the early stage of the test (the first 20s), and then stabilized. After stabilization, the average friction coefficient measured was approximately 0.005, which is highly consistent with the theoretical value, verifying the accuracy and reliability of this machine. The testing machine has a compact structure and is easy to operate. It is suitable for friction performance testing of various types of rolling bearings and provides an effective experimental means for the tribological research of rolling bearings.
Xiao, Supeng, Hu, Rui, Xu, Chunxia, Liu, Yang, Chen, Binhua
Preparation and Characterization of Glycerol-Based Fe3O4 Magnetic Fluids2026-99-02447/31/2026
To optimize the preparation protocol and tribological performance of glycerol-based Fe^3O^4 magnetic fluids, three hybrid agitation systems—(i) chemical co-precipitation coupled with magnetic stirring (H+C), (ii) chemical co-precipitation coupled with mechanical stirring (H+J), and (iii) chemical co-precipitation integrated with mechanical plus ultrasonic agitation (H+J+C)—were systematically investigated with respect to their influence on the physicochemical characteristics and lubricating behaviour of the resulting magnetic nanoparticles. Relative to the H+C and H+J protocols, the H+J+C protocol effectively suppressed intermediate agglomeration, yielding a 15 % increase in Fe^3O^4 productivity and a 15 % reduction in the full-width at half-maximum of the particle-size distribution. A binary surfactant system composed of oleic acid and citric acid achieved complete surface passivation, producing nanoparticles with a saturation magnetization of 59.2 emu g^–1. Under a magnetic flux density of 0.0341 T, tribometric evaluation revealed that the friction coefficient of the fluid prepared via the H+J+C route decreased to 0.041, corresponding to reductions of 7.1 % and 22 % relative to the H+J and H+C counterparts, respectively, thereby demonstrating superior tribological performance. The present work furnishes an experimental foundation for the rational design of high-performance magnetically responsive lubricants and the optimization of magnetic-fluid synthesis protocols.
Hu, Rui, Zhong, Shihao, Xu, Chunxia, Chen, Binhua, Liu, Yang
The Influence of Stator Vane Lean on the Rotor Blade Forced Response of an Axial Turbine2026-99-02107/31/2026
Forced response resulting from rotor-stator interaction is a primary cause of high-cycle fatigue (HCF) failure in axial turbine blades. To investigate the mitigating effect of stator vane lean on the forced response of a downstream rotor blade, this paper conducts a numerical analysis based on a fluid-structure interaction (FSI) method, comparing a baseline radial vane with a leaned vane configuration in a single-stage axial turbine. Unsteady computational fluid dynamics (CFD) was used to analyze the unsteady flow field and aerodynamic excitation, and the resulting harmonic pressures were applied to a finite element (FE) model for harmonic response analysis. The results show that, compared to the radial vane, the leaned vane design effectively weakens the potential field and wake interactions by introducing a spanwise phase difference, which significantly reduces the amplitude of the unsteady pressure fluctuations. The harmonic response analysis further validates the effectiveness of this approach, demonstrating that under the first harmonic excitation, the leaned vane configuration reduces the maximum dynamic stress on the rotor blades by 37.7%. This study confirms that stator vane lean is an effective aerodynamic detuning strategy that mitigates the excitation at its source, leading to a substantial reduction in the rotor’s dynamic stress and thus offering a valuable method for improving turbine blade reliability.
Huang, Zhi, Zhang, Ying, Xiong, Zhonggang
Research on the Erosion and Wear Characteristics of Gathering and Transportation Pipelines by Cyclone Abrasive Process Parameters2026-99-01847/31/2026
Cyclone abrasive pigging technology, with advantages like environmental friendliness, easy construction, and low destructiveness, has broad application prospects. Studying how the process parameters affect the erosion-wear characteristics of gathering pipelines is crucial for improving pigging efficiency and effectiveness. This study adopted numerical simulations based on gas-solid two-phase flow erosion theory to explore such effects and verified the simulations via a self-designed experimental platform. Results showed that within the given parameter range, erosion rate rose significantly with velocity, especially at 20-30 m/s, peaking at 60 m/s; 0.6 mm abrasives and 0.25 kg/s mass flow rate led to higher erosion rates. Experimental data matched simulations with <10% error, confirming accuracy. Thus, cyclone abrasive process parameters significantly influence pigging performance, and the findings can guide practical operations within the studied range.
Wang, Haoran, Zhou, Xianjun, Li, Long, Song, Huifang, Zhang, Jin, Jv, Xiaolong
Microstructure and Properties of 316L Stainless Steels Modified with C and Cr Elements2026-99-02177/31/2026
SiC-based power devices are favored for high-voltage and high-power applications due to their superior material properties. However, the demand for higher breakdown voltages and improved channel mobility presents significant challenges to the etching process, especially the micro-trenching effect. In this study, etching results from inductively coupled plasma (ICP) have been presents, which focused on using various SF6/O2/Ar gas ratios to eliminate micro-trenching effect. The profile analysis of micro-trench was taken by cross-sectional scanning electron microscopy (SEM). The results demonstrate that micro-trenches primarily originate from the coupling effect between ion multi-reflection from sidewalls and redeposition of etch byproducts. Based on this mechanism, we propose a quasi-Bosch process: a combined polymerization and etching step in oxygen-fluorine-rich plasma deposits polymer on exposed SiC and the mask, while removing it from the structure bottom via ion bombardment to enable etching and passivation; then alternates with a short fluorine-plasma step, which consumes sidewall polymer through ion incidence and prevents SiFxOy charge accumulation, cycle etching gradually deepens the structure without micro-trenches. Different gas ratios and etching time not only change the plasma energy distribution but also affect the temporal synchronization between etching and passivation steps. This approach reduces the special demands on ICP equipment capabilities while achieving superior trench profiles. The optimal etching conditions produced a micro-trench-free SiC structure with a vertical sidewall angle and a surface roughness of less than 1 nm. This methodology and resulting structures significantly advance the manufacturability of high-performance SiC power devices, enabling next-generation applications in electric vehicles and grid infrastructure where device yield and reliability are paramount.
Zhao, Yingfan, Dong, Shuang, Sun, Xiaoxu, Chang, Xiangpeng, Liang, Yiwei, Tong, Weiping
Durability Study of Electronic-grade Glass Fibers in Salt-Alkali Environments2026-99-02197/31/2026
Electronic substrates and copper-clad laminates are widely used in modern life, particularly in electronic products such as coastal communication base stations and ship communication and navigation system. In these environments, salt particles carried by sea fog can adhere to the surface of the substrates along with moisture, leading to salt-alkali corrosion of the products. As a core material in electronic components, electronic-grade glass fiber urgently requires investigation into its durability under salt-alkali conditions. Therefore, this study focuses on a specific type of electronic-grade glass fiber and explores its corrosion behavior in three different environments: 2 mol/L NaOH, 1 mol/L cement solution, and 3.5 % NaCl. Soaking durations of 6, 12, 24 hours and 3, 7, and 14days were selected as key parameters. The mechanical properties and surface morphology of the fibers before and after corrosion were observed and analyzed. Experimental results indicate that the glass fiber exhibits higher durability in saline solutions than in alkaline environments. This study provides theoretical support for evaluating the long-term performance of Electronic grade glass fibers in practical applications. It also contributes to the optimization of raw materials and manufacturing processes, enhancing the performance of such fibers in salt-alkali conditions, and offers valuable reference for future research on glass fiber-reinforced composites.
Pu, Qixin, Sun, Siqi, Fang, Qiang, Dong, Shuo, Li, Peng, Wang, Yu, Zhang, Mengxuan, Zhang, Yubo, Yang, Wenfeng, Guo, Peng
Tailored Thermo-Mechanical Behaviour of CNT/Epoxy Nanocomposites via Solvent-Assisted Dispersion2026-99-01897/31/2026
Carbon nanotube (CNT) reinforced epoxy nanocomposites were prepared using a solvent-assisted dispersion method and characterized to evaluate their structural, mechanical, and thermal behaviour. X-ray diffraction (XRD) confirmed the presence of CNTs in the polymer matrix through the characteristic (002) reflection, while scanning electron microscopy (SEM) revealed that CNTs were found to be uniformly embedded within the epoxy matrix, showing limited agglomeration and strong interfacial bonding. Fourier-transform infrared spectroscopy (FTIR) supported these observations by revealing absorption bands associated with C=C stretching, C–O–C ether linkages, and O–H vibrations, indicating chemical interactions between CNTs and the epoxy network. Mechanical testing showed that CNT concentrations of 0.25–0.50 wt.% provided the most effective reinforcement, with notable and measurable improvements in tensile and compressive strength as well as modulus. At higher CNT loadings, however, agglomeration led to reduced tensile performance, despite compressive strength remaining comparatively stable. Thermal conductivity increased steadily with CNT addition, from 0.2143 W/m.K for neat epoxy to 0.2435 W/m.K at 0.75–1.00 wt.%, with the most pronounced improvements observed above 0.25 wt.% due to the formation of more efficient conductive pathways. Overall, these findings suggest that low-to-intermediate CNT loadings achieve a practical and useful balance between strength and thermal conductivity while avoiding the drawbacks of excessive filler content. Effective dispersion of nanotubes is a critical factor that governs the mechanical and thermal behaviour of the composites. These results indicate that CNT/epoxy nanocomposites produced under optimized conditions can serve as lightweight, mechanically reliable, and thermally stable materials, making them attractive candidates for advanced applications in aerospace, automotive, and energy-related sectors where both structural performance and efficient thermal management are required.
Gul, Aysenur, Kamali, Ali Reza
SiO2 Particle Charging Behavior with a Nonionic Surfactant in Low-Permittivity Liquids2026-99-02247/31/2026
Phase angle light scattering (PALS) was chosen to study the charging behaviors of metal oxide SiO2 distributed in nonpolar solvents, including nonionic surfactant, often known as “charge control agents”. Zeta potential was examined systematically in relation to the concentration of Span80 (Sorbitan monooleate) and particle size and concentration. The findings showed that Zeta potential was unaffected by the surfactant concentration of Span80 over the critical micelle concentration (CMC) at various particle concentrations (volume percentages ranging from 10^–4 to 10^–2). Over a considerable range, the charging of the particles was not significantly affected by the particle concentration. Additionally, the particles showed a size-independent zeta potential. A straightforward model based on meanfield Poisson-Boltzmann theory and preferential adsorption was offered to predict SiO2 particles’ charging procedure in Span80-dodecane solution. The experimental data and the simulated findings agreed well. It was shown that the preferential adsorption of micelles that carry a charge is the cause of the charging of the SiO2 particle in Span80-dodecane solution.
Jiang, Liyuan, Chen, Jiayi, Lv, Qunsong, Cao, Huiying
Force-Balance Analysis of Surface Instability in a Tri-Layer Film/Substrate Structure2026-99-02157/31/2026
Driven by increasing engineering demands, the need for high-performance flexible electronics has surged, accelerating the development of stretchable devices within mechanics. Among multilayer structures, the film/substrate architecture serves as a typical example, and its buckling behavior remains a longstanding focus of mechanical investigation. This work examines how an elastic film bonded to a soft tri-layer substrate loses stability, producing wrinkled surface patterns under compression. We first construct a mechanical model, then derive an analytical expression for the wrinkle amplitude using a force-balance approach, and finally employ finite-element simulations and theoretical comparisons, we systematically explore how the middle layer’s stiffness and thickness jointly govern the onset, wavelength and amplitude of surface buckling, revealing quantitative selection rules that have not previously been reported for tri-layer structures. The results show that the tri-layer film/substrate structure exhibits two instability modes: film-intermediate co-buckling and film-only wrinkling. By simply varying the middle layer’s elastic modulus or its thickness, one can move the structure across the boundary that separates the film-only and bi-layer buckling regimes, providing a direct mechanical selection for on-demand mode. In addition, the wrinkle amplitude increases monotonically with the applied initial strain. Those findings offer a theoretical reference for designing flexible electronics based on film/substrate structures.
Chen, Hao, Zhang, Wulin, Song, Yahui
Research on the Influence of Reduction Rate in Asynchronous Rolling on Magnesium Alloy AZ31 Thin Sheet2026-99-02227/31/2026
A finite element analysis was conducted on the plastic deformation of 6 mm AZ31 magnesium alloy thin plates rolled asynchronously. Different reduction rates were adopted to analyze their influences on the bending deformation, rolling force, equivalent stress, and equivalent strain of the plates. The finite element analysis of asynchronous rolling was carried out when the single-pass reduction rates were 66%, 58.3%, 51.6%, 41.6%, and 35%, respectively. The results show that as the reduction rate decreases, the rolling force increases. Furthermore, considering the influencing factors of the rolling process parameters, it is determined that when the optimal rolling process reduction rate is 41.6%, the rolling effects of rolling force, stress, and strain are better, which is conducive to the rolling process.
Liu, Baishun, Li, Li, Wang, Baozhong
Study on the Properties of Waterborne Polyurethane Laminating Adhesives2026-99-02117/31/2026
This paper designs and synthesizes a series of high-performance waterborne polyurethane (WPU) laminating adhesives using polyester, polyether polyols and isophorone diisocyanate as the main raw materials. It focuses on exploring the effects of polyol types and R value (the ratio of polyol to isocyanate) on the properties of the adhesives, including emulsion viscosity, solid content, water absorption rate of the adhesive film, mechanical properties, and bonding performance on different substrates. The results show that WPU2 with polycarbonate diol (PCDL) as the polyol has the best water resistance and the highest tensile strength; WPU1 with polytetrahydrofuran (PTMG) as the polyol has the optimal elongation at break and exhibits outstanding bonding performance on the polar substrate PET; the regulation of R value can optimize the bonding performance of the adhesive on the non-polar substrate BOPP. This type of WPU laminating adhesive features low VOC emissions, no benzene-based solvents, excellent flexibility, and good resistance to high and low temperatures. It not only meets the environmental protection and safety requirements in packaging fields such as food and medicine, but also shows potential application value in high-end fields like aerospace interior compounding and lightweight transportation structure bonding. Its performance is highly compatible with the strict requirements for materials in the modern aerospace and transportation industries. The adjustable strong adhesiveness, compliance with strict emission standards, and adaptability to various substrates make it an ideal choice for a new generation of composite manufacturing, especially suitable for industrial fields pursuing reliability, sustainability and high performance.
Wang, Chengming, Yu, Jiacheng, Wang, Huixia, Huang, Yiqiang, Ren, Xiue
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