TY - JOUR
T1 - Dynamic Mechanical Response and Deformation Mechanism of Laser-Directed Energy Deposited AerMet100 Ultra-High-Strength Steel Under Critical Fracture Strain-Rate Conditions
AU - Wang, Cong Rui
AU - Ran, Xian Zhe
AU - Cheng, Xu
AU - Li, Zhuo
AU - Dong, Heng
AU - Wu, Hai Jun
AU - Zhang, Shu Quan
N1 - Publisher Copyright:
© The Minerals, Metals & Materials Society and ASM International 2025.
PY - 2025/11
Y1 - 2025/11
N2 - Superior impact resistance is a critical dynamic mechanical performance characteristic that is essential for maintaining structural integrity of ultra-high-strength steel (UHSS) components under high-strain-rate loading conditions. This study primarily investigates the dynamic mechanical response and deformation mechanisms of laser-directed energy deposited (LDED) AerMet100 steel in both as-deposited and three types of tempered conditions (482 °C for 2 to 10 hours) using Split Hopkinson Pressure Bar (SHPB) tests at critical fracture strain rates. After heat treatment, the critical fracture strain rate of LDED AerMet100 steel increased from 4336 s−1 (as-deposited) to over 5011 s−1. Prolonged tempering time results in a reduction in flow stress (2806 ± 50 MPa for TM-2h specimen vs. 2475 ± 36 MPa for TM-10h specimen) and yield strength of the steel, which is attributed to M2C carbide coarsening and thickening of film-like reverted austenite. Among the tested specimens, the TM-5h specimen demonstrates an optimal combination of strength and toughness, exhibiting a flow stress of approximately 2725 MPa and plastic work of approximately 846 MJ/m3. Notable differences are observed in microplastic deformation behavior and cracking characteristics between the as-deposited and tempered specimens. As-deposited specimens exhibit non-uniform plastic deformation with the appearance of localized deformation bands, while grain boundaries are susceptible to premature cracking prior to the formation of adiabatic shear bands (ASBs). In contrast, the tempered specimens develop ASBs containing dynamically recrystallized nanoscale equiaxed grains, which promote microcrack initiation and propagation. These findings establish a clear correlation between microstructural evolution and dynamic mechanical properties of LDED AerMet100 steel under critical fracture strain-rate conditions, offering valuable design guidelines for the development of strong impact-resistant components.
AB - Superior impact resistance is a critical dynamic mechanical performance characteristic that is essential for maintaining structural integrity of ultra-high-strength steel (UHSS) components under high-strain-rate loading conditions. This study primarily investigates the dynamic mechanical response and deformation mechanisms of laser-directed energy deposited (LDED) AerMet100 steel in both as-deposited and three types of tempered conditions (482 °C for 2 to 10 hours) using Split Hopkinson Pressure Bar (SHPB) tests at critical fracture strain rates. After heat treatment, the critical fracture strain rate of LDED AerMet100 steel increased from 4336 s−1 (as-deposited) to over 5011 s−1. Prolonged tempering time results in a reduction in flow stress (2806 ± 50 MPa for TM-2h specimen vs. 2475 ± 36 MPa for TM-10h specimen) and yield strength of the steel, which is attributed to M2C carbide coarsening and thickening of film-like reverted austenite. Among the tested specimens, the TM-5h specimen demonstrates an optimal combination of strength and toughness, exhibiting a flow stress of approximately 2725 MPa and plastic work of approximately 846 MJ/m3. Notable differences are observed in microplastic deformation behavior and cracking characteristics between the as-deposited and tempered specimens. As-deposited specimens exhibit non-uniform plastic deformation with the appearance of localized deformation bands, while grain boundaries are susceptible to premature cracking prior to the formation of adiabatic shear bands (ASBs). In contrast, the tempered specimens develop ASBs containing dynamically recrystallized nanoscale equiaxed grains, which promote microcrack initiation and propagation. These findings establish a clear correlation between microstructural evolution and dynamic mechanical properties of LDED AerMet100 steel under critical fracture strain-rate conditions, offering valuable design guidelines for the development of strong impact-resistant components.
UR - https://www.scopus.com/pages/publications/105016727888
U2 - 10.1007/s11661-025-07942-x
DO - 10.1007/s11661-025-07942-x
M3 - Article
AN - SCOPUS:105016727888
SN - 1073-5623
VL - 56
SP - 5311
EP - 5330
JO - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
JF - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
IS - 11
ER -