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Asymmetric rolling (ASR) is a potential process to reach better grain refinement than in conventional rolling, thus, can lead to better mechanical properties. It is not known, however, how the introduction of a shear component will change the ideal orientations of the textures, and consequently, the evolution of plastic anisotropy. To understand the effect of the added shear on texture evolution i
The effect of additional shear on the asymmetric rolling (ASR) of an interstitial-free (IF) steel was studied by modeling and experiments. The asymmetry was introduced by making one roll idle. A 66 pct of total thickness reduction was performed in 6 passes with less than 16 pct reduction per pass. ASR was performed in two ways: monotonically and by rotating the sheet between passes by 180 deg arou
The paper demonstrates the feasibility of upscaling of severe plastic deformation (SPD) techniques using an integrated process that combines conventional extrusion and equal channel angular pressing in a single processing step. The process was applied for production of magnesium ZK60 bars 16 mm in diameter and up to 4 m in length. The processed material exhibited an excellent balance of strength a
Bimodal grain structure was fabricated in a 99.99% purity aluminium by high pressure torsion at ambient temperature in reversal deformation mode at a strain amplitude Δε = 1, strain rate ̇=1.1×10 -1s-1 and hydrostatic pressure P = 5 GPa. Enhanced boundary mobility due to the high purity of the aluminium and homologous temperature coupled with reversal simple shear deformation are found to be respo
It was demonstrated in this work that the corrosion rate of Mg alloy ZK60 can be reduced through the use of an integrated process of extrusion and equal channel angular pressing concomitant with increased strength. The improvement in corrosion resistance, as measured by electrochemical experiments and immersion tests in NaCl electrolytes, was correlated with both grain refinement and the redistrib
As-received hot-rolled 5.6 mm thick IF steel sheet was symmetrically/ asymmetrically cold rolled at room temperature down to 1.9 mm. The asymmetric rolling was carried out in monotonic (an idle roll is always on the same side of the sheet) and reversal (the sheet was turned 180° around the rolling direction between passes) modes. Microstructure, texture and mechanical properties were analysed. The
Among the known severe plastic deformation (SPD) techniques, one particular group can be defined as SPD processing of thin samples. Their distinctive feature is that one of the sample dimensions, namely the thickness, is much smaller than the other two dimensions. Examples include High Pressure Torsion and two recently developed techniques: the Cone-Cone Method and the High Pressure Tube Twisting.
In the present work, effects of loading scheme and strain reversal on structure evolution are studied by using high pressure torsion (HPT) and twist extrusion (TE) techniques. High purity aluminum (99.99%) was processed at room temperature up to a total average equivalent strain of ∼4.8 by TE and HPT with two deformation modes: monotonic and reversal deformation with a step of 12° rotation. It was
The evolution of texture in pure aluminum subjected to monotonous and reversal deformation in high-pressure torsion was first clarified. In a low-strain regime the texture development is similar for both deformation modes, while significantly different behavior is observed at high strain levels. The monotonously deformed materials showed typical torsion textures. In contrast, strain reversal resul
High purity Al (99.99%) was subjected to severe plastic deformation through twist extrusion at room temperature. Microstructures were examined for 1 pass and 4 passes on the cross section perpendicular to the longitudinal axis of billets using optical microscopy and electron back scatter diffraction analysis. It was shown that a vortex-like material flow was observed on the cross section and this
High purity Al (99.99%) is subjected to severe plastic deformation (SPD) at room temperature using a process of twist extrusion (TE). The microstructure evolution and the related change in microhardness are examined with respect to imposed strain. It is shown that subgrains develop after the first TE pass with a size of ∼1.6 μm and this size remains essentially the same for further application of
All the SPD techniques introduce reversal straining principally, but effects of the reversal deformation on structure evolution were not studied directly yet. In the present work, an attempt was made to manage structure in pure (99.99%) Al by strain reversal through high pressure torsion (HPT). Total accumulated deformation up to equivalent strain ∼8 was used. General trend of the grain refinement
Twist extrusion is a recently developed method of severe plastic deformation that principally uses torsion to generate high strains in a repeatedly extruded billet, while maintaining a constant cross-section. The method thus results in a deformation gradient across the billet section. To date, the grain refinement behaviour of alloys deformed by twist extrusion have only been investigated qualitat
Objectives: To assess the health-related quality of life (HRQOL) of patients with mucopolysaccharidosis (MPS) and their caregivers and to quantify the disease-related costs from a societal perspective. Methods: In the context of a multi-country study of rare diseases (BURQOL-RD project), a cross-sectional survey was performed among MPS patients in seven European countries. Data on demographic char
Spread extrusion (SE), proposed by the first author, is a direct extrusion with spread and without elongation. SE does not change the cross-sections of a workpiece so it may be used for multipass deformation in combination with Twist extrusion (TE). We investigate the plastic flow at the TE and SE. We show that a combination of TE and SE leads to mixing of the metal within the specimen.
Twist Extrusion (TE) is a process of severe plastic deformation (SPD) being developed by us during recent 5 years. Upon this time we published few papers on mechanics of the process and influence of the TE processing on materials structure and properties. Here we reported some results on application of the twist extrusion processing and made few general conclusions.
Microstructure and mechanical properties as well as thermal stability of commercially pure titanium VT1-0 subjected to severe plastic deformation by twist extrusion (TE) were studied before and after low-temperature annealing and cold rolling. TE leads to a refinement of structural fragments to sizes of less than 1 μm, enhancement of strength, and the appearance of strong anisotropy of mechanical
It was shown that of a fine α-phase was formed in the Hadfield steel after a cold plastic deformation to E = 50%. Nuclei of the ex-phase of deformed samples reduced the decomposition start temperature of the austenite by 180°C. Fine crystals of an α-phase nearly 30 nm in size, whose concentration was as high as ∼2.3%, were detected in a steel Fe 79.55Mn17Al3Co0.45 after a SPD to ε = 92%. A steel F
It is investigated UFG structure formation in CP Ti bulks processed by SPD (cold Twist Extrusion (TE), true strain e∼5.1, with the following Cold Rolling (CR), true strain e∼0.7). Evolution of microstructure and tensile mechanical properties in the CP Ti were investigated under room temperature. After the TE, in transversal section it is formed structure fragments with size less 1 μm. Strength inc
