WReTaMo Refractory High‐Entropy Alloy with High Strength at 1600 °C

Abstract

Structural materials with higher melting temperatures and better mechanical properties than superalloys are in high demand in refractory applications. A promising WReTaMo refractory high‐entropy alloy (RHEA) with high strength at 1600 °C is fabricated by vacuum arc melting. The WReTaMo RHEA has a body‐centered cubic (BCC) structure with a maximal compressive strength of 1140 MPa and Vickers microhardness of 654 HV at room temperature. The alloy displays a strong resistance to high‐temperature softening, showing the high maximal compressive strength of 244 MPa at 1600 °C. The deformation of the WReTaMo RHEA compressed at 1600 °C maybe resulted from the grain boundary sliding, which leads to the propagation of the cracks along grain boundaries. Face‐centered cubic (FCC) phase forms at the surface region of samples annealed above 1800 °C due to the diffusion of carbon atoms by gas carburizing in the graphite crucible at such high temperatures. The increase in hardness at temperatures above 1600 °C results from the solid solution strengthening of dissolved carbon. The forming ability of the WReTaMo RHEA is also discussed. This work presents a promising high‐temperature structural material and fills the vacancy of the mechanical properties of Re‐containing RHEAs at 1600 °C.

A comprehensive review on the deformation behavior of refractory high entropy alloys at elevated temperatures

“…10e) were observed at 800 °C [105]. Rhenium containing WReTaMo RHEA deformed at 1600 °C by Wan et al [82] experienced grain boundary sliding that contributes to the deformation as only intergranular cracks are observed. As shown in Figure 10f, the cracks originate at the grain boundaries initially and then spread along the grain boundaries.…”

“…The yield strength of CrMoNbV is 1062 MPa at 1000 °C. The rhenium containing WRe-TaMo RHEA by Wan et al [82] deformed at 1600 °C and at a strain rate of 0.001 s À1 showed a yield strength of 172 MPa, peak compressive strength of 244 MPa, and plasticity >25%, which is attributed to the high melting temperature.…”

Strategies for Enhanced Optical Performance and Durability of VO2‐Based Thermochromic Windows

“…[ 99,100 ] Therefore, numerous studies of the multilayer systems that fabricate VO 2 thin films under other oxide thin films or in between such films have been conducted, with film thicknesses and refractive indices adjusted to enhance luminous transmission and solar modulation. Additionally, the combination of VO 2 films with additional functional layers not only improves thermochromic performance but also gives smart coatings new capabilities like antifogging, superhydrophilicity, hydrophobicity, and photocatalysis, [ 101,102 ] which can be utilized for the self‐cleaning function. This cleaning capability utilizes two processes: photocatalytic and hydrophilic.…”