A key parameter that affects dislocation motion, deformation mechanisms, and the overall mechanical response of face-centered cubic (FCC) metals is stacking fault energy (SFE). The study aims to investigate the effect of stacking faults (SF) on the mechanical properties of copper (Cu) using molecular dynamics (MD) simulations. In this work, the Embedded Atom Method (EAM) interatomic Cu-Cu (Mishin et. al.) potential is employed to model the interactions in Cu, while a combination of tensile testing and the introduction of stacking faults allows for the simultaneous analysis of mechanical behavior and SFE. The results reveal a direct correlation between various parameters like stacking fault, temperature, and system size which subsequently influences the material's ductility, stress-strain response, and failure mechanisms. This study provides insights into the temperature and size dependent mechanical behavior of Cu, with potential implications for understanding deformation in other FCC metals.
INCONEL 600 is extensively employed across various industries due to its remarkable resistance to both corrosion and elevated temperatures. The alloy’s superior high-temperature performance and extended service life are largely attributed to its stable single-phase microstructure, which remains intact up to 1703 K (1430 ℃). In this study, the microstructural evolution of INCONEL Alloy 600 was systematically examined under a range of thermal and thermomechanical treatments. These microstructural analyses were complemented by mechanical property assessments, including tensile and creep tests. Specimens were solutionized at 1200ºC for 1 h, resulting in a microstructure characterized by an average grain size distribution between 45–60 μm. Additionally, primary and secondary carbides rich in Cr, Nb, and Ti were observed within the γ matrix. The alloy was subsequently subjected to cold forging at room temperature, with varying levels of strain ranging from 20
Many critical process parameters affect the fatigue performance of super alloys produced by Selective Laser Melting (SLM). These parameters affect the microstructure, surface roughness, and defect formation and play a significant role on the fatigue life of the super alloys. Optimizing these parameters in combination with appropriate post-processing techniques is crucial to extending fatigue life by decreasing defects. In the present work two set of Inconel718 (IN718) samples were prepared under two different energy densities. According to ASTM E606, a low cycle fatigue test is conducted to assess fatigue performance. Samples with lower energy density showed better fatigue life (Nf) of 858 number of cycles under strain amplitude of 0.8
The hydrogen electric coupling system (HECS) is an indispensable component of next generation power systems, with safety being a prerequisite for its deployment. However, existing studies have conducted limited analysis on the safety of HECS. This study comprehensively investigated the safety risks and accident consequences of HECS. 75 potential failure modes were identified by Failure Mode and Effects Analysis (FMEA), with electrical issues and sealing problems emerging as key contributors to medium and high-risk accidents, respectively. Event Tree Analysis (ETA) were employed to elucidate the main causes and logical chains leading to combustion. Results showed that ignition sources in the environment are the primary triggers, and the hydrogen compression system had a high accident frequency. Numerical simulations of hydrogen leakage and dispersion in confined spaces were conducted, enabling quantitative evaluation of jet fire, flash fire, and explosion consequences. The simulations revealed that hydrogen initially dispersed along the leakage direction, spread laterally upon encountering walls, and finally accumulated near the ceiling. Integrating consequence analysis with risk assessment standards, we found that the greatest injury distance (15.2 m ignition at 5.01 s) caused by the hydrogen storage system explosion, followed by the hydrogen production system (9.5 m ignition at 8.01 s). The maximum injury distances for the compression system and fuel cell system are 7.5 m and 6.7 m, respectively. This research provided critical insights into hazard sources and injury distances in HECS, laying the foundation for safety measure development.
To investigate the mechanism of formation damage induced by clay-free reservoir drilling fluids, a clay-free oil reservoir drilling fluid system was selected as the research object. Core displacement experiments and filter cake mechanical property tests were conducted by regulating the filter cake composition and varying the differential pressure during core displacement. The effects of filter cake composition, filter cake strength, and invasion depth on formation damage were then systematically analyzed. The results show that the filter cake composition has a significant effect on formation damage. In particular, the bridging and plugging structure formed by ultrafine calcium carbonate particles at pore throats is the main cause of formation damage. The influence of different components on formation damage follows the order ASP1250 > XCD > ASR-1. As the polymer effect in the drilling fluid system becomes stronger, the filter cake structure gradually changes from particle packing to a polymer network structure. The maximum load of the filter cake increases from approximately 15 N to more than 25 N, while the filtration volume increases from approximately 11–48 mL, indicating a positive correlation between filter cake strength and filtration volume. As the displacement pressure increases from 500 to 1500 psi, the core damage rate increases from 90.58 to 99.64
