Dual phase equal-atomic NbTaTiZr high-entropy alloy with ultra-fine grain and excellent mechanical properties fabricated by spark plasma sintering. (10th November 2021)

• Record Type: Journal Article
• Authors: Xiang, Tao; Cai, Zeyun; Du, Peng; Li, Kun; Zhang, Zongwei; Xie, Guoqiang
• Is Part Of: Journal of materials science & technology. Volume 90(2022)
• Page Start: 150
• Page End: 158
• Publication Date: 2021-11-10
• Subjects: NbTaTiZr high-entropy alloys -- Mechanical alloying -- Ultra-fine grain -- Spark plasma sintering -- Mechanical properties -- Corrosion behavior; Metals -- Periodicals; Materials science -- Periodicals; Materials science; Metals; Periodicals; 620.1105
• DOI: 10.1016/j.jmst.2021.03.024
• Languages: English
• ISSNs: 1005-0302

Abstract

Highlights: The bulk TiNbTaZr high-entropy alloys are prepared by mechanical alloying and spark plasma sintering process. The grain size of bulk TiNbTaZr alloys is smaller than that of TiNbTaZr fabricated by vacuum arc melting. The yield strength of bulk TiNbTaZr alloys with plasticity of 12.8% is 2-fold higher than that fabricated by vacuum arc melting. Abstract: Super-high strength NbTaTiZr high-entropy alloys (NbTaTiZr HEAs) have been successfully fabricated by the mechanical alloying (MA) with spark plasma sintering (SPS) technology, which is 2-fold compared with that of NbTaTiZr HEAs prepared by vacuum arc melting (VAM). After the SPS process, the bulk NbTaTiZr alloy samples are provided with dual-phase body-centered cubic (BCC) structure and nanoscale grain size about 500 nm that is obviously smaller than that of NbTaTiZr HEA fabricated by VAM. When the sintering temperature is 800 °C, the compressive fracture strength is the highest reaching at 2511 ± 78 MPa. When the sintering temperature is 1000 °C, the fracture strain is the highest reaching at 12.8%, and compressive fracture strength and yield strength also reach at 2274 ± 91 MPa and 2172 ± 47 MPa, respectively. The excellent mechanical properties of bulk NbTaTiZr alloy samples are attributed to the merits of MA and SPS, and the collaboration effect of ultra-fine grains strengthening, solid solution strengthening and interstitial solid solution strengthening. Graphical abstract: Image, graphical abstract