Superplastic Behavior in High-Pressure Torsion-Processed Mo 7.5 Fe 55 Co 18 Cr 12.5 Ni 7 Medium-Entropy Alloy
- PDF / 4,500,170 Bytes
- 7 Pages / 593.972 x 792 pts Page_size
- 1 Downloads / 146 Views
Superplastic Behavior in High-Pressure Torsion-Processed Mo7.5Fe55Co18Cr12.5Ni7 Medium-Entropy Alloy NHUNG THI-CAM NGUYEN, PEYMAN ASGHARI-RAD, JAE WUNG BAE, PRAVEEN SATHIYAMOORTHI, and HYOUNG SEOP KIM In the present study, superplasticity of high-pressure torsion-processed non-equiatomic Mo7.5Co18Cr12.5Fe55Ni7 medium-entropy alloy with nanograins was investigated. The superplastic elongation of 505 pct was achieved at a temperature of 800 C and a low strain rate. The precipitation of the l phase enriched with Mo hinders the grain boundary migration and also acts as the origin for cavity and crack formation. https://doi.org/10.1007/s11661-020-06033-3 The Minerals, Metals & Materials Society and ASM International 2020
THE initial work on multiprinciple elemental alloys from Yeh et al. and Cantor et al., published in 2004, is the cornerstone of alloy development for future advanced engineering applications.[1–4] The multiprinciple elemental alloys are widely called as compositionally complex alloys (CCAs), and they are further categorized into high-entropy alloys (HEAs) and medium-entropy alloys (MEAs) based on their configurational entropy.[5–7] The CCAs possess outstanding mechanical performance over conventional alloys such as a good combination of high strength and high ductility, high strength retention at high temperature, and fracture toughness.[8–12] Some CCAs exhibit exceptional superplastic behavior at high temperatures.[13,14]
NHUNG THI-CAM NGUYEN, PEYMAN ASGHARI-RAD, and PRAVEEN SATHIYAMOORTHI are with the Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, South Korea and with the Center for High Entropy Alloys, Pohang University of Science and Technology (POSTECH), Pohang 37673, South Korea. JAE WUNG BAE is with the Max-Planck-Institut fu¨r Eisenforschung, Max-PlanckStraße 1, 40237 Du¨sseldorf, Germany. HYOUNG SEOP KIM is with the Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH) and with Center for High Entropy Alloys, Pohang University of Science and Technology (POSTECH) and also with the Graduate Institute of Ferrous Technology, Pohang University of Science and Technology (POSTECH), Pohang 37673, South Korea. Conatact e-mail: [email protected] Manuscript submitted March 26, 2020, and accepted September 14, 2020.
METALLURGICAL AND MATERIALS TRANSACTIONS A
Superplasticity is the ability of a material to exhibit significant tensile elongation of over 400 pct at elevated temperatures, typically above the half of absolute melting temperature.[15,16] The primary mechanism of superplasticity is established as grain boundary sliding (GBS), where the individual grains slide over each other in response to the applied stress.[17] Materials with fine grain sizes, often smaller than 10 lm, and high testing temperatures are prerequisites for achieving superplasticity. The fine grains offer a high fraction of grain boundaries, and therefore, the GBS is promoted in the fine-grained structure, lead
Data Loading...
