The role of the Mg17Al12-phase in the high-pressure die-cast magnesium-aluminum alloy system

•Non-equilibrium solidification in cast Mg-Al alloys forms brittle Mg17Al12 phase.•Mg17Al12 intermetallic has strong role in performance of Mg-Al based cast alloys.•Alloying additions from trace to a few percent suppresses Mg17Al12 phase formation.•Several different alloying additions can modify performance of cast Mg-Al alloys. The Mg17Al12 β-phase is highly influential to the performance of magnesium-aluminum high-pressure die-casting alloys. Numerous studies have investigated the effect of this phase on the room temperature and elevated-temperature mechanical properties as well as the corrosion, flammability, thermal conductivity and castability performance. This work summarizes the results of these works, as well as the studies that describe control of the Mg17Al12-phase through alloying additions that modify the microstructure and resulting alloy performance. The results of this work can be used as a basis for the development of alloying additions that enable modifications to the performance of high-pressure die-cast magnesium-aluminum-based alloys.