Mechanical Properties and Failure Behavior of 7075Al Matrix Composites Hybrid Reinforced by Carbon Fibers-FeCoCrNiAl High-Entropy Alloy Particles

Abstract:

To investigate the effects of double-scaled reinforcements on the tensile properties and failure behavior of aluminium matrix composites, Ni-Co-P coated carbon fibers reinforced 7075Al matrix composites (CF/Al), FeCoCrNiAl high-entropy alloy particles reinforced 7075Al matrix composites (HEA_p/Al) and Ni-Co-P coated carbon fibers and FeCoCrNiAl high-entropy alloy particles hybrid reinforced 7075Al matrix composites (CF-HEA_p/Al) were fabricated by vacuum hot pressing sintering under the pressure of 30 MPa at 580 °C for 10 min. The microstructure and the fracture morphologies of the composites were observed, and the tensile properties of composites were characterized. Results show that the yield strength (YS) and ultimate tensile strength (UTS) of CF-HEA_p/Al composites are firstly increased and subsequently decreased with increasing the CFs content from 0vol% to 40vol%, while the elongation is decreased. Owing to the hybrid reinforcing effects of Ni-Co-P coated carbon fibers and FeCoCrNiAl high-entropy alloy particles, the YS and UTS of CF-HEA_p/Al composites have larger improvement compared with those of CF/Al and HEA_p/Al composites, and the fracture morphology is characterized by mixed rupture modes of ductile rupture of 7075Al matrix and fiber pull-out and fracture.