Preparation of Bulk TiZrNbMoV and NbTiAlTaV High-Entropy Alloys by Powder Sintering

Yaqi Wu,Yong Zhang,Peter Liaw

doi:10.3390/met11111748

Abstract

The refractory HEAs block material was prepared by powder sintering, using an equal atomic proportion of mixed TiZrNbMoV and NbTiAlTaV metal powder raw materials. The phase was analyzed, using an XRD. The microstructure of the specimen was observed, employing a scanning electron microscope, and the compressive strength of the specimen was measured, using an electronic universal testing machine. The results showed that the bulk cubic alloy structure was obtained by sintering at 1300 °C and 30 MPa for 4 h, and a small amount of complex metal compounds were contained. According to the pore distribution, the formed microstructure can be divided into dense and porous zones. At a compression rate of 10−4s−1, the yield strengths of TiZrNbMoV and NbTiAlTaV alloys are 1201 and 700 MPa, respectively.

Highlights

High-entropy alloys (HEAs) are alloys containing several elements that violate the usual design constraints of one or two alloying components
The related HEAs preparation technology has been continually improved in response to meet the needs of alloys, and the preparation of eutectic HEAs, for hydrogen storage, high-entropy cemented carbides and coatings, refractory high-entropy alloys (RHEAs), irradiation-resistant HEAs, corrosion-resistant HEAs, and other special properties of HEAs [6,7,8]
Multi-component TiZrNbMoV and NbTiAlTaV HEAs with equal atomic ratio were prepared by mixing high purity metal powder with particle size of 10 microns homogeneously and hot pressing sintering at 30 MPa for 4 h at 1300 ◦C in high purity argon environment

Summary

Introduction

High-entropy alloys (HEAs) are alloys containing several elements that violate the usual design constraints of one or two alloying components. They are distinguished by multi-component and multi-principal components that combine to produce nanoscale composite materials. The general SPS method is utilized in powder metallurgy to produce TaNbVTi series refractory HEAs. SPS with low temperature, short sintering time, and quick cooling speed may produce an alloy with fine grain and uniform structure. The microstructure of the alloy reveals compact, fine, and homogeneous grains, a tensile strength of 750 MPa, an elongation of more than 50%, and mechanical characteristics superior to those of FeCoCrNi HEAs formed by conventional melting [25]. Powder metallurgy typically gets fine powder by mechanical alloying, and the chemical sequence of mechanical alloy is complicated and time-consuming, with contaminants injected into the process

Experimental Procedures

Results

Compressive Properties

Conclusions