Ultrahigh strength TiCnp/Mg–2Zn-0.8Sr-0.2Ca magnesium matrix composite processed by combining multidirectional forging with extrusion. (October 2021) - Zhang, J.H.
Abstract: A TiCnp /Mg–2Zn-0.8Sr-0.2Ca magnesium matrix composite was processed by the combination of multidirectional forging (MDF) with extrusion (EX). The composite exhibited ultrahigh mechanical properties (yield strength of ~500 MPa and ultimate tensile strength of ~544 MPa) after 6 passes of MDF at 300 °C, followed by EX at 0.1 mm/s and 200 °C. The grain boundary strengthening effect caused by grain refinement and high recrystallization rate, dislocation strengthening effect originated from the severe plastic deformation, as well as the Orowan strengthening effect inspired by the dynamically precipitated MgZn2 phases and the added TiCnp were considered as the main contributors to the substantial increase in strength. Highlights: TiCnp /Mg–Zn–Sr–Ca was fabricated by the ultrasonic-assisted semi-solid stirring. The composite was processed by multidirectional forging with extrusion. The composite exhibited YS of ~500 MPa and UTS of~544 MPa. The improved strength was attributed to grain refinement and Orowan strengthening.