Severe plastic deformation (SPD) with deformation strain significantly larger than one is effective to strengthen metals and alloys. However, such a method will not work for Mg alloys due to their low deformability. In view of this problem, we propose a new alloy strengthening scheme of low-strain deformation, which is to introduce massive twins and stacking faults in coarse grain interior by rotary swaging (RS) at room temperature. By using this scheme, we successfully prepared an ultra-light bulk Mg-Li alloy with new strength record. GRAPHICAL ABSTRACT IMPACT STATEMENT This paper explored a new strengthening way of low deformation strain for metals and alloys and successfully prepared a strongest ultra-light Mg–Li alloy by low-strain rotary swaging process.

In this paper, the tribological behavior of 316L stainless steel with heterogeneous lamella structure (HLS), prepared through 85% cold rolling technology and subsequent annealing treatment (750 °C, 10 min), were conducted on a ball-on-disc tribometer under different normal loads in dry ambient air conditions. The morphologies, structures, and compositions of the raw and worn surfaces were analyzed by 3D surface profilometer, XRD, SEM, EDS and TEM. Based on this, the results showed that the HLS 316L stainless steel samples exhibited lower and more steady friction coefficients than coarse-grained samples, especially under higher loads, which can be attributed to the existence of numerous oxidative particles across sliding interfaces. However, the wear resistance of HLS 316L stainless steel sample was a little weakened compared to that of the coarse-grained sample under a normal load of 5 N. When the load increases up to 15 N, an obviously decreased wear resistance was found for the HLS of the 316L stainless steel sample, which was 50% lower than that of coarse-grained sample. This can be ascribed to the more severe oxidative and abrasive wear performance of HLS 316L stainless steel sample under dry sliding conditions.