Ness measurements were carried out applying a Micromet 5101 tester (Buehler, Leinfelden-Echterdingen, Germany). The tensile tests were carried out making use of miniature specimens with 12 mm full length and the gage aspect length, width and thickness of five, 1.45, and 1 mm, respectively, using an INSTRON 5966 testing machine (Instron, Norwood, MA, USA). Tensile specimens had been reduce by the electrospark technique, in order that their gage part was positioned around the mid-radius from the disk-like HPT-specimen. To study the thermal stability, the aluminum alloy samples after HPT were heated in an electric furnace at temperatures of 150 and 200 C with holding for 1 h and cooled in air, followed by a tensile test. Fractographic evaluation of specimens following tensile tests was carried out utilizing a JSMIT500 scanning microscope (JEOL Ltd., Tokyo, Japan) at 0000 magnifications. This microscope was also utilised to study the structure of the HPT-processed specimens. The region close to the specimen mid-radius was analyzed. three. Benefits three.1. Effect on the HPT-Deformation on ML-SA1 site microhardness on the Aluminum alloys The HPT-deformation of all aluminum alloys results in a important raise within the values of microhardness and for the appearance of inhomogeneity of their distribution over the specimen diameter: the minimum values of microhardness have been Thromboxane B2 site observed inside the center on the specimen, and the maximum values had been observed at its periphery (Figure 1). The shape in the microhardness value distribution profiles along the specimen diameter differs among all alloys. For example, for the Al0 La alloy specimen, a `dip’ of your microhardness is observed only in the central area 1.5-mm radius, and at a higher distance in the center to the periphery, the microhardness values rapidly reach a maximum and remain at a continual level. For the Al Ce alloy specimen, with distance in the center for the periphery, the microhardness values monotonically boost, reach a maximum at a distance of 4 mm in the center, and remain at a constant level. For the Al Ni alloy specimen, a monotonic boost inside the microhardness values from the center towards the periphery is observed along entire diameter of your specimen (i.e., a gradient of microhardness is observed). Therefore, the homogeneity of your microhardness worth distribution increases within the following series of alloys: Al Ni, Al Ce, and Al0 La.Materials 2021, 14, 6404 Supplies 2021, 14, x FOR PEER REVIEW4 of 18 4 ofFigure Microhardness distribution along the diameter of the on the HPT-processed specimens: (a) Figure 1. 1. Microhardness distribution along the diameter HPT-processed specimens: (a) Al0 Al0 La; (b) Al Ce; (c) Al Ni. La; (b) Al Ce; (c) Al Ni.The maximum microhardness values after HPT improve the following series from the maximum microhardness values soon after HPT boost inin the following series of alloys: Al0 La (10508 HV), Al Ce (14550 HV), and Al Ni (21420 HV). alloys: Al0 La (10508 HV), Al Ce (14550 HV), and Al Ni (21420 HV). The hardening impact right after HPT (the ratio the maximum microhardness worth with the The hardening impact just after HPT (the ratio ofof the maximum microhardness value in the alloy just after HPT the typical microhardness worth from the alloy before HPT) increases in alloy immediately after HPT toto the typical microhardness value with the alloy ahead of HPT) increases in the following series alloys: Al0 La (1.eight occasions), Al Ce (two.eight occasions), and Al Ni the following series ofof alloys: Al0 La (1.eight times), Al Ce (2.8 times), and Al Ni (3.3 tim.