Improvement of mechanical properties of cryorolled LM6 alloy

Abstract Mechanical properties and fracture behavior of bulk UFG LM6 alloy processed through cryorolling (CR) is investigated in the current work. LM6 Al alloy is reduced through CR upto thickness reduction of 50%, 75% and 90% at liquid nitrogen temperature. Mechanical properties of bulk and deformed alloys were investigated through tensile and three-point bend test. These properties are correlated with microstructural features by the help of optical microscopy and scanning electron microscopy. The significant improvement in strength (UTS: 64.18% and YS: 125.16%) of CR upto 90% deformed sample were recorded. This enhancement is attributed due to the formation of ultrafine grained (UFG) structure resulting grain boundary strengthening. However, the fracture mode of tensile tested samples is transformed from ductile to brittle nature with the increment in thickness reduction from ST to 90% CR sample substantiating the lack of strain hardening ability of the UFG LM6 alloy.