Effect of twist-channel angular pressing on precipitation in Al–Mg–Zn–Ga alloys

Abstract

The influence of severe plastic deformation, namely twist-channel angular pressing on the formation of quasicrystalline precipitates in Al-Mn-Zn-Ga alloy, was investigated. The deformation process was performed at two temperatures: 473 K (200 degrees C) and 433 K (160 degrees C). The microstructure of alloys after the process was analyzed in terms of the number density of formed precipitates, their size, and crystals structure. Mechanical properties including hardness and compression yield strength were determined. The obtained results indicated that at higher temperature (473 K), crystalline precipitates were formed. Additionally, the number density of the formed precipitates decreased with subsequent passes. At lower temperature, 433 K, the formed precipitates have quasicrystalline structure. Alloys processed at 433 K exhibit yield strength two times higher than in the previous case which correlates well with higher number density of precipitates estimated for these samples.