Synthesis and properties of multiprincipal component AlCoCrFeNiSix alloys

By introducing nonmetallic Si element, AlCoCrFeNiSix (x values in molar ratio, x = 0, 0.2, 0.4, 0.6, 0.8 and 1.0) alloys are designed and prepared. One kind of nanoscale cellular structure forms due to the introduction of nonmetallic Si element. The alloy is composed mainly of BCC solid solution and possesses excellent room-temperature compressive mechanical properties. The excessive introduction of Si element leads to the precipitation of δ phase at grain boundary. The improvement of mechanical properties is attributed to the solid solution of Si element and precipitation strengthening of nanoscale cellular structure. The precipitated δ phase at grain boundary should be responsible for transition of alloy from plastic fracture to brittle fracture. Among them, Si0.4 alloy exhibits excellent comprehensive mechanical properties, yield stress of 1481 MPa, fracture strength of 2444 MPa and plastic strain of 13.38%, respectively.