Evaluation of Hight Purity Aluminium After Asymmetric Rolling at Ambient and Cryogenic Temperatures

Abstract

<p class="AMSmaintitle"><span lang="EN-US">Ultrafine grained materials are capable of superplastic elongation at strain rates faster than those currently employed for commercial superplastic forming operations. However, such operations require the material in the form of thin sheets. Asymmetric rolling (ASR), as one of severe plastic deformation (SPD) methods, was used to make ultra-fined grain materials with enhanced performance. This work show effect of the deformation paths on micro-hardness and mechanical properties changing during asymmetric rolling of pure aluminium. In our case, the asymmetric condition was introduced by using different diameters with a ratio of upper and bottom roll 2,4. The thickness of samples was reduced about 20% - 40% at ambient temperature and at cryogenic temperature. Asymmetric rolling at cryogenic temperature (ASR-C) provides greater strength tensile properties than rolling at ambient temperature (ASR-A). </span></p>

The Influence of Severe Plastic Deformation and Subsequent Annealing on the Microstructure and Hardness of a Cu–Cr–Zr Alloy

“…According to the previous reports, when materials are pre-processed by non-SPD methods such as rolling, followed by subsequent SPD processing, more pronounced grain refinement could be observed [11][12][13][14]. Conventional rolling at the very low temperature of liquid nitrogen causes the suppression of dynamic recovery in the dislocation structures [15], which could behave as potential recrystallization sites, and the occurrence of grain growth during deformation. Thus, cryorolling is considered as an efficient non-SPD method for achieving a small grain size [6].…”

Case Study of the Tensile Fracture Investigation of Additive Manufactured Austenitic Stainless Steels Treated at Cryogenic Conditions

“…Due to the still low number of studies on microstructures after deformation, it is still unclear why AM 316L has a good elongation, which is reported to be as good as that made by other processes [9], despite some residual porosity and the high residual stresses in AM samples [6].…”

“…AM shows the potential to substitute conventional metal manufacturing processes, such as casting and forging [3,4], mainly in the aerospace and biomedical fields. Thanks to improved reliability and reproducibility of the processes, AM competes with other progressive processes such as severe plastic deformation (SPD) [3][4][5][6][7] with substantial advantages such as the absence of constraints in the manufacturing design, shape freedom, high complexity of the components, combination of multiple parts into one part, production of functionally graded materials, reduced tooling requirements, and the possibility of production on demand [8][9][10].…”

“…The laser powder bed fusion process (LPBF), also known as selective laser melting (SLM), directly produces homogenous metal objects, layer by layer, from 3D Computer Assisted Drawing (CAD) data, by selectively melting fine layers of metal powder with a laser beam [1][2][3][4][5][6][7][8]. A considerable amount of material can be saved by designing properly for additive manufacturing with no loss in terms of mechanical properties [11][12][13].…”

“…Especially, in AM products, cryogenic treatment is still very rare. The austenitic 316L grade is a popular steel for cryogenics as demonstrated by the vast literature, with special applications in the field of liquid gas confinement and storage [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 ]. Mechanisms governing tensile properties at cryogenic temperatures for wrought materials have been extensively and deeply investigated [ 25 ].…”