Sliding Wear of Spark Plasma Sintered CrFeCoNiCu High-Entropy Alloy Coatings: Effect of Aluminum Addition

摘要

High-entropy alloys (HEAs) are considered as attractive coating materials due to their high hardness, good wear and corrosion resistance. AlxCrFeCoNiCu (x=0, 1, 2, 3) high-entropy alloy coatings were fabricated on carbon steel substrate using spark plasma sintering. The microstructure evolved from FCC to FCC-BCC mixed structure. Al3CrFeCoNiCu coating possesses an average hardness of approximately 682 HV0.2, which is the highest hardness in all of the HEA coatings. The dry sliding wear behavior of the HEA coatings was investigated using a ball-on-disk sliding tribo-meter with a silicon nitride ball. In all of the HEA coatings, Al3CrFeCoNiCu presents the lowest wear rate 8.81x10(-5)mm(3)m(-1) and Al2CrFeCoNiCu has the lowest coefficient of friction 0.195 during 1000m sliding distance at 0.1ms(-1) sliding velocity under 20N normal load. Comparing with AISI 52100 steel, spark plasma sintered Al2CrFeCoNiCu and Al3CrFeCoNiCu HEA coatings exhibit outstanding sliding wear resistance and extremely low friction coefficient. The wear resistance of Al3CrFeCoNiCu HEA coating is approximately four times better than the bearing steel, showing a promising application as a wear-resistant material.