Tribo-mechanical, physical and thermal behaviour of Al/Si₃N₄ composite with and without the addition of Cu, Ni and Cr entropy elements

In the present investigation, a comparative study has been presented between Al/Si₃N₄ and entropy elements (Cu, Ni and Cr) mixed Al/Si₃N₄ composite material. The investigation revealed that the tensile strength and hardness of base material were enhanced by 23.65% and 56.66% respectively with an increase of 10 wt. % of Si₃N₄. The tensile strength of Al and Al/10 wt. % Si₃N₄ composite was enhanced by 46% and 18% respectively after the addition of entropy elements 1.5 wt. % Cu, 1.5 wt. % Ni and 1 wt. % Cr. Further, the same wt.% of entropy elements enhanced the hardness of Al and Al/10 wt. % Si₃N₄ composite by 83.66% and 27%, respectively. The ductility and toughness of the composite were further improved by adding the 1.5 wt. % Cu, 1.5 wt.% Ni and 1 wt.% Cr in Al/10 wt. % Si₃N₄ composite. However, corrosion weight loss, volume thermal expansion and wear of the composite are reduced by adding the entropy elements. The number of grains per square inch for Al/10 wt% Si₃N₄ composite with and without adding the 1.5 wt. % Cu, 1.5 wt.% Ni and 1 wt.% Cr was found to be 3590.57 and 2385.37, respectively. The addition of entropy elements results in a finer grain structure of the composite which shows grain refinement.