Intrinsic kink bands strengthening induced by several wrought-processes in Mg-Y-Zn alloys containing LPSO phase

Abstract

The kink bands strengthening effect was investigated using Mg-9at.%Y-6at.%Zn alloys produced by caliber rolling or extrusion at intermediate and elevated temperatures (373 K and more than 673 K). The results of microstructural observations showed that deformation kink bands were induced in all the alloys, regardless of the wrought-processing method and the processing temperatures. Micro-Vickers hardness tests showed that the regions including kink bands exhibited a higher hardness than those without kink bands, which reveal intrinsic kink bands strengthening. Interestingly, the trend of this kink bands strengthening effect could be expressed by an empirical relationship, which was divided into two lines associated with the wrought-processing temperature. This tendency did not appear to depend on the wrought-processing method. The alloys produced at the intermediate temperature showed markedly superior hardness, since, in addition to the kink bands strengthening, the residual strains/dislocations around kink boundaries contributed to obstruct dislocation slips. • Kink bands were induced regardless of wrought processing-method and -temperatures. • Intrinsic kink bands strengthening effect could be expressed by number of kink bands. • The alloys produced at the intermediate temperature showed markedly superior hardness. • Residual strains around kink bands contributed to obstruct for dislocation slips.