Sintering, Microstructure, and Mechanical Properties of TiTaNbZrHf High-Entropy Alloys Prepared by Cold Isostatic Pressing and Pressure-Less Sintering of Hydrides

Yubing Chen; Peidong Liu; Zhaowang Dong; Hanning Liu; Junjie Wang; Xueyi Guo; Yang Xia; Qinmeng Wang

doi:10.3390/ma16051759

Sintering, Microstructure, and Mechanical Properties of TiTaNbZrHf High-Entropy Alloys Prepared by Cold Isostatic Pressing and Pressure-Less Sintering of Hydrides

Materials (Basel). 2023 Feb 21;16(5):1759. doi: 10.3390/ma16051759.

Authors

Yubing Chen^{1

2}, Peidong Liu^{1

2}, Zhaowang Dong^{1

2}, Hanning Liu^{1

2}, Junjie Wang^{1

2}, Xueyi Guo^{1

2}, Yang Xia¹, Qinmeng Wang^{1

2}

Affiliations

¹ School of Metallurgy and Environment, Central South University, Changsha 410083, China.
² National and Regional Joint Engineering Research Center of Nonferrous Metal Resources Recycling, Changsha 410083, China.

Abstract

A TiTaNbZrHf refractory high-entropy alloy (RHEA) was synthesized through a cold isostatic pressing and a pressure-less sintering process in a hydrogen atmosphere using a powder mixture of metal hydride prepared either by mechanical alloying (MA) or by rotating mixing. This study investigates how differences in powder particle sizes impact the RHEA's microstructure and mechanical properties. HCP (a = b = 3.198 Å, c = 5.061 Å) and BCC2 (a = b = c = 3.40 Å) phases were observed in the microstructure of coarse powder TiTaNbZrHf RHEAs at 1400 °C. In contrast, fine powder RHEAs were found to possess two-phase structures of HCP and BCC1 (a = b = c = 3.36 Å) with a higher hardness of 431 HV, compression strength of 1620 MPa, and a plasticity of >20%.

Keywords: element diffusion; high mechanical properties; powder metallurgy; powder size; refractory high-entropy alloys.

Abstract

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