High-temperature mechanical and thermochemical properties of NbMoTaW refractory high-entropy alloy coatings produced via Nano Particle Deposition System (NPDS). (September 2021)

• Record Type: Journal Article
• Authors: Nam, Seungjin; Song, Yongwook; Son, Minhee; Lee, Kee-Ahn; Yoo, Geun Hee; Park, Eun Soo; Choi, Hyunjoo; Lee, Caroline Sunyong
• Is Part Of: International journal of refractory metals & hard materials. Volume 99(2021)
• Publication Date: 2021-09
• Subjects: Refractory high-entropy alloy -- Coating -- Nanoparticle deposition system -- High-temperature hardness -- Oxidation resistance; Heat resistant alloys -- Periodicals; Refractory materials -- Periodicals; Metallography -- Periodicals; Alliages réfractaires -- Périodiques; Matériaux réfractaires -- Périodiques; Métallographie -- Périodiques; Heat resistant alloys; Metallography; Refractory materials; Periodicals; Electronic journals; 669.73
• DOI: 10.1016/j.ijrmhm.2021.105594
• Languages: English
• ISSNs: 0263-4368

Abstract

Abstract: In this study, we investigated the oxidation resistivity and mechanical properties of NbMoTaW refractory high-entropy alloy (HEA)-based coatings at high temperatures. The coating layers were produced using mechanically alloyed HEA powders via Nano Particle Deposition System (NPDS). The as-milled powder is comprised of W-rich BCC1 and NbMoTa-rich BCC2 phases. After the deposition process, the W-rich BCC1 phase remained, while NbMoTa-rich BCC2 phases were transformed into complex NbMo-rich and Ta-rich oxides. Consequently, the NbMoTaW RHEA composite coating exhibited outstanding oxidation resistivity and high nanoindentation hardness at high temperatures compared to that of commercial coating materials, possibly owing to the combination of the W-rich solid solution phase and internal oxides. Highlights: We produced NbMoTaW RHEA-based coatings at high temperatures by nanoparticle deposition NbMoTaW RHEA composite coating exhibited outstanding oxidation resistivity and high temperatures nanoindentation hardness After high-energy ball-milling, ball milling, W-rich small particles revealed poor mechanical alloying with other elements