Microstructure, mechanical and vacuum high temperature tribological properties of AlCoCrFeNi high entropy alloy based solid-lubricating composites

High-entropy alloys (HEAs) that have revolutionized the alloy design of strength-ductility trade-off, provide a pathway for the development of high strength solid-lubricating composites. Herein, a high performance AlCoCrFeNi HEA based composite reinforced with different contents of solid lubricant Ag was prepared by Spark Plasma Sintering technique. The composites retain the structure of nano-coupling network matrix and uniformly disperse Ag particles located at the grain boundaries, thereby exhibiting high strength of above 1917 MPa. Meanwhile, Ag particles render the composites excellent lubricity and significantly reduce the adhesion and wear of the frictional interface at temperature from room temperature to 800 °C in vacuum. •A high performance high entropy alloy based solid-lubricating composite was designed.•This AlCoCrFeNi–Ag composite displays excellent mechanical and tribological properties.•Ag tribo-film significantly reduces the adhesion and wear of the sliding-pairs in vacuum.