Structure and Phase Composition of a W-Ta-Mo-Nb-V-Cr-Zr-Ti Alloy Obtained by Ball Milling and Spark Plasma Sintering.

Ivan A Ditenberg,Vyacheslav I Mali,Maksim A Esikov,Dina V Dudina,Yuriy P Pinzhin,Ivan V Smirnov,Alexander I Gavrilov,Vladlen V Melnikov,Konstantin V Grinyaev,Michail A Korchagin

doi:10.3390/e22020143

Abstract

In this paper, the structural characteristics of a W-Ta-Mo-Nb-V-Cr-Zr-Ti non-equiatomic refractory metal alloy obtained by spark plasma sintering (SPS) of a high-energy ball-milled powder mixture are reported. High-energy ball milling resulted in the formation of particle agglomerates ranging from several tens to several hundreds of micrometers. These agglomerates were composed of micrometer and submicrometer particles. It was found that, during ball milling, a solid solution of A2 structure formed. The grains of the sintered material ranged from fractions of a micrometer to several micrometers. During SPS, the phase transformations in the alloy led to the formation of a Laves phase of C15 structure and ZrO and ZrO2 nanoparticles. The microhardness of the ball-milled alloy and sintered material was found to be 9.28 GPa ± 1.31 GPa and 8.95 GPa ± 0.42 GPa, respectively. The influence of the processing conditions on the structure, phase composition, and microhardness of the alloy is discussed.

Highlights

In recent years, multicomponent alloys and high-entropy alloys have received much attention, and currently represent a rapidly developing direction of materials science [1,2,3,4,5,6,7,8,9]
Ball milling of the powder mixture was conducted in a high-energy planetary ball mill AGO-2 with two water-cooled vials, each having a volume of 160 cm3
The patterns show broadened reflections of the phases, which is due to the crystallite size refinement and lattice strain; the concentration gradients in solid solutions can contribute to line broadening [35]

Summary

Introduction

Multicomponent alloys and high-entropy alloys have received much attention, and currently represent a rapidly developing direction of materials science [1,2,3,4,5,6,7,8,9] The interest in these alloys is due to unique combinations of mechanical properties that they can offer when properly designed. Multicomponent refractory alloys are interesting materials for nuclear power engineering as well as for aviation and space industries [2,7,10,13,16,24,25,28] Investigations of these alloys are aimed at finding compositions that would ensure stable mechanical performance at elevated temperatures.

Objectives

Methods

Results

Discussion

Conclusion