The low-cycle fatigue performance aluminum matrix composites reinforced with particles AlFeCrMnTi and SiC that are extruded by equal-channel angular pressing

Equal-channel angular pressing was employed to fabricate 12.5 vol% AlFeCrMnTi high-entropy alloy (HEA) particle reinforced 5052Al composite and SiC particle reinforced 5052Al composite. The low-cycle fatigue performance at strain amplitudes of 0.5 %, 0.75 %, 0.85 %, and 1 % was investigated, respectively. The hysteresis loops and cyclic stress response characteristic curves of 5052Al, (AlFeCrMnTi)_p/5052Al and SiC_p/5052Al were analyzed. The Manson-Coffin model was used to benchmark and analyze the fatigue life data of the three tested materials. Under different strain amplitudes of low-cycle fatigue, the 5052Al material exhibits extreme stress asymmetry after adding HEA, and the stress gap gradually decreases along withincreasing cycle times. The fatigue performance of the composite reinforced by HEA particles is much better than that of SiC particle reinforcement. Under a strain amplitude of 1 %, the low-cycle fatigue life of HEAp/5052Al is enhanced by 75 % compared to that of 5052Al, while the low-cycle fatigue life of SiCp/5052Al is reduced by 80 % relative to 5052Al. Furthermore, when the total strain amplitudes are 0.5 %, 0.75 %, and 0.85 %, respectively, the low-cycle fatigue lives of HEAp/5052Al are increased by 11.1 %, 39.9 %, and 47.1 % compared to those of SiCp/5052Al composites. Through the analysis and observation of the fatigue fracture morphology, it was found that the presence of internal hole defects in the composite prepared by extrusion of 5052Al matrix, coupled with the poor interfacial bonding between SiC particles and the Al matrix which is prone to detachment, leads to inferior fatigue performance. Debonding fracture and the fracture of SiC particles themselves are the primary mechanisms of fatigue failure in SiCp/5052Al composites. The excellent interfacial bonding and the high fracture toughness of the HEA particles enable them to withstand significant cyclic loads without failure, resisting the stress at the crack tip and impeding crack propagation. This results in a superior low-cycle fatigue life for the HEAp/5052Al composite.