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arXiv · 2602.06225

Enhanced Elevated-Temperature Strength in Refractory Complex Concentrated Alloys via Temperature-Induced Transition from Screw-to-Edge Dislocation Control

Tamanna Zakia·Ayeman Nahin·Dunji Yu·Jacob Pustelnik·Juntan Li·Mason Kincheloe·Lia Amalia·Yan Chen·Peter K. Liaw·Haixuan Xu·Mingwei Zhang
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Abstract

Refractory complex concentrated alloys (RCCAs) show promise for high-temperature applications but often lose strength due to screw-dislocation-controlled plasticity. We demonstrate a temperature-driven transition from screw- to edge-dislocation-controlled deformation in a single-phase NbTaTiV RCCA. Tensile tests from 298-1573 K reveal a pronounced intermediate-temperature strength plateau and yield strengths surpassing other ductile RCCAs and the Ni-based superalloy CMSX-4 above 1273 K. In-situ neutron diffraction, TEM, and molecular dynamics identify a crossover near ~900 K, where edge dislocation glide stabilized by V-induced lattice distortion dominates, enabling enhanced strength retention and a clear design strategy for ultrahigh-temperature applications.

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Tamanna Zakia, Ayeman Nahin, Dunji Yu, Jacob Pustelnik, Juntan Li, Mason Kincheloe, Lia Amalia, Yan Chen, Peter K. Liaw, Haixuan Xu, Mingwei Zhang. 2026-02-05. Enhanced Elevated-Temperature Strength in Refractory Complex Concentrated Alloys via Temperature-Induced Transition from Screw-to-Edge Dislocation Control. https://arxiv.org/abs/2602.06225

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