Investigating the elastic modulus and hardness properties of a high entropy alloy coating using nanoindentation

• Main Authors: M. Dada, P. Popoola, N. Mathe, S. Adeosun, S. Pityana
• Format: Article
• Language: English
• Published: KeAi Communications Co., Ltd. 2021-09-01
• Series: International Journal of Lightweight Materials and Manufacture
• Subjects: Additive manufacturing; High entropy alloys; Nanoindentation; Laser parameters
• Online Access: http://www.sciencedirect.com/science/article/pii/S2588840421000159

Using a focused ion beam TTX-NHT3 Nanoindentation tester with a load of 500 mN, we study the micromechanical properties of laser-deposited AlCoCrFeNiCu high entropy alloy coatings. The indentation tests conducted were used to examine the influence of laser power and scan speed on the elastic modulus and hardness of the alloy coatings using the Oliver & Pharr method. There were several indentation points impressed and used to extract the mechanical properties of the alloys, and the results of the alloy were compared with that of the A301 steel substrate. The results showed the mean value of the NanoHardness and Elastic modulus of the high entropy alloy were 2.769 GPa and 149 GPa, respectively. The Vickers hardness showed a 60% decline as the laser power increased from 1200 W to 1600 W. The hardness and the elastic modulus were proportional to each other, both increasing with a decrease in the indentation depth and laser power. The laser-deposited high entropy alloys were more resistant to plastic deformation and had improved mechanical properties than the steel substrate attributed to the solid-solution hardening and lattice distortion effect of the BCC phase structure and aluminium contents, respectively.