Abstract:
High Entropy Alloys (HEAs) are new class of materials. Recent Studies on HEAs have
attracted much attention in the field of scientific research and industry. There has been a
lot of interest in HEA compositions having a BCC structure. However, analysis of deep
cryotreated Ti-Al-Ni-Cr-Co-Fe-based alloys on the structure and mechanical behavior of
these BCC HEAs has not been performed so far. This project aims to determine the
impact of deep cryogenic treatment on those factors by investigating the phase
composition, microstructure, and characteristics of the TiAlNiCrFe and TiAlNiCrCo
high-entropy alloys. Through the ball milling of elemental powders and Spark Plasma
Sintering, multicomponent alloys of TiAlNiCrFe and TiAlNiCrCo were effectively
created. XRD patterns showed that both materials had substantial two-BCC phases after
Spark plasma sintering. In the TiAlNiCrFe and TiAlNiCrCo samples, SEM BSE images
of the microstructure samples showed a fine dispersion of the two BCC phases coupled
with a fine dispersion of TiC nanoparticles. The impact of deep cryogenic treatment on
the phase composition, crystallite sizes, microstructure, and mechanical characteristics
of TiAlNiCrFe and TiAlNiCrCo high-entropy alloys were successfully investigated. The
XRD patterns say that the 4 and 8-hour treated TiAlNiCrFe and TiAlNiCrCo samples
show major BCC peaks similar to as-sintered alloys, and small TiNI3 peaks are also
present in both 4,8-hour treated alloys. Hardness seemed to rise initially before
decreasing as the duration of the cryogenic treatment increased. At 4-hourly treated
samples have finer crystallite sizes and maximum hardness was attained. The hardness
value of TiAlNiCrFe alloy after 4-hour treatment rises from 755 HV to 840 HV by
11.25%.
