Impact of gradient microstructure on strain hardening via activation of multiple deformation mechanisms in CoCrNi medium entropy alloy
Peer-Reviewed Publication
Updates every hour. Last Updated: 28-Apr-2025 18:08 ET (28-Apr-2025 22:08 GMT/UTC)
Nanjing University of Science and Technology in collaboration with Liaoning Academy of Materials, Hohai University and City University of Hong Kong revealed a significant strengthening mechanism related to the core region in a gradient CrCoNi MEA. In this study, the microstructure evolution and mechanical strengthening mechanism of CrCoNi MEA were investigated using advanced techniques such as EBSD, TEM and HRTEM. Through the analysis of microstructure before and after uniaxial tensile plastic deformation along the depth direction, It is revealed that the fault energy characteristics of CoCrNi MEA at the lower level trigger the emergence of nanoscale deformation twins, layer faults, L-C dislocation locks and the phase transformation from FCC to HCP at the twin boundary in the core region to enhance the strain hardening ability of the material.
The inertial of the system and the maximum frequency deviation caused by the energy storage batteries when participating in grid frequency regulation need to be improved,virtual synchronous generator control for GSC is expected to improve the performance of storage battery energy participation in grid primary frequency regulation. Therefore, this paper proposes participation of energy storage batteries in primary frequency control for power grid considering dynamic frequency inertia characteristics. In order to utilize the inertial support and primary frequency regulation capability of the energy storage batteries for the grid, the additional active power module is constructed, and the active powers generated by the virtual inertial control and droop control strategies of the energy storage batteries are used as additional power for variable rotor inertial control and output feedback model predictive control, respectively. For the better mismatch between inertia characteristics of the virtual synchronous machine and the grid demand, this paper designs the variable rotor inertia control considering system frequency deviation and system frequency change rate to realize the real-time adjustment of rotor inertia responding to the system frequency. The output feedback model prediction control of VSG is further proposed to achieve dynamic prediction and compensation of system frequency deviation by establishing a feedback channel between rotor angular frequency increment and torque increment. A comparative analysis with three existing control strategies shows that the proposed control strategy can make full use of the frequency regulation capability of the energy storage battery and VSG to effectively reduce the frequency deviation and frequency variation rate of the grid.
Researchers from Northwestern University, University of Virginia, Carnegie Mellon University, and Argonne National Laboratory have made a significant advancement in defect detection and process monitoring for laser powder bed fusion (LPBF) additive manufacturing. By using accessible sensors (such as microphones and photodiodes), along with machine learning, they achieved over 90% accuracy with a temporal resolution of 0.1 milliseconds in detecting keyhole pore formation. This breakthrough paves the way for intelligent, closed-loop control systems for LPBF and a faster qualification and certification process for metal additive manufacturing parts.
Researchers at Karlsruhe Institute of Technology (KIT) have developed novel high-entropy sulfides (HESs) as catalysts for the hydrogen evolution reaction (HER). These materials contain a combination of iron, manganese, nickel, cobalt as a base, combined with either chromium or molybdenum and they are distinguished by their unique layered structures and enhanced electrochemical properties. The researchers demonstrated that introducing molybdenum into the composition creates a layered structure, which increases the material’s surface area and thereby enhances its catalytic efficiency.
In humans, the main molecular energy carrier is adenosine triphosphate (ATP). It is critical for cellular functions all over the body, especially in the brain. Its synthesis, which occurs in the mitochondria, through oxidative phosphorylation (OXPHOS) is a complex, multi-step process. When one or more of the elements of this process malfunction, it may result in imbalances in ATP production or the over production of reactive oxygen species (ROS). This can cause oxidative damage in several cellular biomolecules including proteins and DNA and may eventually end in cell death. In the brain, this imbalance can cause problems which can lead to the loss of neurons, resulting in the damage seen in some degenerative neurological disorders.