Structure and Mechanical Properties of High-Entropy Alcunifeті and Alcunifecr Alloys Produced by Mechanical Activation Followed by Pressure Sintering

 
V.V.Chernyavskii,
  

I. M. Frantsevich Institute for Problems of Materials Science of the NAS of Ukraine, Omeliana Pritsaka str.,3, Kyiv, 03142, Ukraine
Powder Metallurgy - Kiev: Frantsevich Institute for Problems of Materials Science NASU, 2016, #03/04
http://www.materials.kiev.ua/article/2168

Abstract

X-ray diffraction, scanning electron microscopy, and micromechanical tests are employed to study the phase and structural transformations in the Al–Cu–Ni–Fe–Ti and Al–Cu–Ni–Fe–Cr equiatomic powder compositions in the course of mechanical alloying and subsequent pressure sintering. The mechanical properties of the high-entropy alloys are examined. It is revealed that the AlCuNiFeTi and AlCuNiFeCr nanocrystalline high-entropy alloys produced by mechanical alloying consist of supersaturated substitutional solid solutions with bcc crystalline structure. It is established that the alloys become three-phase after sintering and consist mainly of bcc solid solutions and an insignificant amount (to 5%) of two fcc solid solutions with different lattice parameters. It is shown that the sintered AlCuNiFeTi and AlCuNiFeCr alloys are characterized by high strength, and their Vickers microhardness reaches 11.2 ± 0.3 GPa and 9.5 ± 0.25 GPa, respectively.


HIGH-ENTROPY ALLOY, MECHANICAL ALLOYING, MECHANICAL PROPERTIES, PHASE COMPOSITION, PRESSURE SINTERING, STRUCTURE