High Temperature Performance of Spark Plasma Sintered W0.5(TaTiVCr)0.5 Alloy

Abstract

The phase stability, compressive strength, and tribology of tungsten alloy containing low activation elements, W0.5(TaTiVCr)0.5, at elevated temperature up to 1400 °C were investigated. The spark plasma sintered W0.5(TaTiVCr)0.5 alloy showed body centered cubic (BCC) structure, which was stable up to 1400 °C using in-situ high temperature XRD analysis and did not show formation of secondary phases. The W0.5(TaTiVCr)0.5 alloy showed exceptionally high compressive yield strength of 1136 ± 40 MPa, 830 ± 60 MPa and 425 ± 15 MPa at 1000 °C, 1200 °C and 1400 °C, respectively. The high temperature tribology at 400 °C showed an average coefficient of friction (COF) and low wear rate of 0.55 and 1.37 × 10−5 mm3/Nm, respectively. The superior compressive strength and wear resistance properties were attributed to the solid solution strengthening of the alloy. The low activation composition, high phase stability, superior high temperature strength, and good wear resistance at 400 °C of W0.5(TaTiVCr)0.5 suggest its potential utilization in extreme applications such as plasma facing materials, rocket nozzles and industrial tooling.

An Overview of High-Entropy Alloys Prepared by Mechanical Alloying Followed by the Characterization of Their Microstructure and Various Properties

“…Nakajo et al concluded that increases in sintering time and temperature do not affect the thickness of the ceramic layer [43]. Alvi et al prepared W0.5(TaTiVCr)0.5 HEAs followed by consolidation by SPS at 1000, 1200, and 1400 °C sintering temperatures [44]. They studied the phase stability, compressive strength, and tribology of the consolidated HEAs.…”

“…They also carried out tribology experiments at 400 °C and found an average friction coefficient and exceptional wear-resistant properties; this was attributed to the formation of solid solution strengthening. Therefore, the authors claimed the possible use of the fabricated HEA, even at a Alvi et al prepared W 0.5 (TaTiVCr) 0.5 HEAs followed by consolidation by SPS at 1000, 1200, and 1400 • C sintering temperatures [44]. They studied the phase stability, compressive strength, and tribology of the consolidated HEAs.…”

“…Therefore, the authors claimed the possible use of the fabricated HEA, even at a high temperature of 400 • C with a greater degree of stability, high-temperature strength, and excellent wear resistance. These high-temperature properties of fabricated HEAs have enabled their use in plasma-facing materials, rocket nozzles, and industrial tooling [44]. Kakimoto and Nishimoto fabricated CoCrFeMnNi HEAs through an SPS technique at 1173 K for 10 min under 50 MPa load followed by plasma nitriding to improve their mechanical properties, as shown in Figure 14a [45].…”

A Review on the Tribological Performances of High‐Entropy Alloys

“…Avli et al prepared a spark plasma sintered W 0.5 (TaTiVCr) 0.5 HEA and evaluated its tribological behavior at 400 °C using a Al 2 O 3 ball as a mating material. [ 33 ] The XRD result showed that the HEA was composed of the BCC phase and in situ TiC nanoparticles. The wear results showed a stable COF of 0.55 and a low wear rate of 1.37 × 10 −5 mm 3 Nm −1 at high temperature.…”

Recent Advances in W-Containing Refractory High-Entropy Alloys—An Overview

“…The development of W-containing RHEAs has made great progress in overall performance when compared with other HEAs and RHEAs. The W-containing RHEAs have high hardness and melting points [ 29 , 30 , 31 , 32 ], in particular, they demonstrate excellent mechanical properties at high temperature [ 33 , 34 , 35 ], which makes them ideal materials for future aerospace and nuclear fusion reactors [ 36 , 37 , 38 ]. Therefore, in this paper, the development, manufacturing technology, performance and application prospects of W-containing RHEAs are summarized, and the future research directions of the W-containing RHEAs are also prospected.…”