The effect of strain rate on the evolution of microstructure in aluminium alloys

Abstract

SummaryIntensive deformations influence strongly microstructure. The very well-known phenomenon is the diminishing dimension of grain size by the severe plastic deformation (SPD) methods. The nanometric features of microstructure were discovered after the SPD deformation of various materials, such as aluminium alloys, iron and others. The observed changes depended on the kind of the deformed material, amount of deformation, strain rate, existence of different phases and stacking fault energy. The influence of the strain and strain rate on the microstructure is commonly investigated nowadays. It was found that the high strain rates activate deformation in shear bands, microbands and adiabatic shear bands. It was observed that bands were places of the nucleation of nanograins in the material deformed by SPD methods. In the work, the refinement of microstructure of the aluminium alloys influenced by the high strain rate was investigated. The samples were compressed by a specially designed hammer to the deformation of ϕ = 0 ÷ 0.62 with the strain rate in the range of · ε = 1.77 × 10 1 ÷ 6.06 × 10 2 s −1 . The highest reduction of microbands width with the increase of the strain was found in the AlCu4Zr alloy. The influence of the strain rate on the microstructure refinement indicated that the increase of the strain rate caused the reduction of the microbands width in the all investigated materials (Al99.5, AlCu4Zr, AlMg5, AlZn6Mg2.5CuZr). A characteristic feature of the microstructure of the compressed material was large density of the shear bands and microbands. It was found that the microbands show a large misorientation to the surrounds and, except Al99.5, the large density of dislocation.

Morphological Changes in the Midface of Beagle Dogs Treated by Trans-Sutural Distraction

“…After many experiments on material properties, we finally chose aluminum alloy as the head ring of traction frame within the reasonable cost range. Aluminum alloy has been widely used by the characteristics of light weight, low melting point, low density, good mechanical properties, corrosion resistance, low cost, easy processing and casting (Leszczynska-Madej & Richert, 2010). Our self-designed aluminum alloy external fixed traction frame is light and stable, weighing about 150g, and the tensile strength is enhanced in the u-shaped area, which can be personalized design.…”

Effect of strain rate on the microstructure and mechanical properties of aluminum alloy AA2B06-O of the Al–Cu–Mg system

“…Ширина полос сдвига составляет от 0,5 до 0,1 мкм для разных материалов и условий деформации. В работах [23][24][25], где исследована деформация сжатия при ε • = 17,7÷606 с -1 технически чистого алюминия Al99.5 (99,5 % Al) и сплавов AlCu4Zr (4 % Cu, 0,5 % Zr), AlMg5 (5,5 % Mg) и AlZn6Mg2,5CuZr (6 % Zn, 2,6 % Mg, 1,5 % Cu, 0,4 % Zr), они названы «микрополоcами сдвига», и их ширина уменьшается с увеличением степени деформации, которая варьировалась в пределах ε = 0÷0,62. В светлых полосах видны мелкие участки диаметром около 100 нм, различающиеся по оттенку и контрастности (см.…”