Abstract
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).
Highlights
It is known that strength and toughness of metallic materials can be improved through decreasing grain size
Asymmetric rolling at cryogenic temperature (ASR-C) provides greater strength tensile properties than rolling at ambient temperature (ASR-A)
The results show that higher values of micro-hardness are after ASR-C for both types of deformation
Summary
It is known that strength and toughness of metallic materials can be improved through decreasing grain size. Asymmetric rolling can be realised in several ways: the angular speed of two working rolls are different; this can be achieved by different rolls diameters at the same speed rotations Fig. 1a) different speed rotations with same diameters of the rolls Fig. 1b) Under these conditions, the material is submitted to an extra shear deformation in addition to compression deformation. With increased shear deformation as well as the compression, it has been suggested that high angle boundaries develop with increasing strain, and ultrafine grains are formed by continuous recrystallization [13,14,15]. Deformation at cryogenic temperature has emerged as a potential route to develop ultrafine grained (UFG) material with improved mechanical properties. As electrolyte was used Electrolyte A2 l and A2 ll mixed together
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