Yousf Islem Bourezg

Bio: Yousf Islem Bourezg is an academic researcher from University of Science and Technology Houari Boumediene. The author has contributed to research in topics: Differential scanning calorimetry & Materials science. The author has an hindex of 4, co-authored 10 publications receiving 57 citations.

Texture and microhardness of Mg-Rare Earth (Nd and Ce) alloys processed by high-pressure torsion

Abstract: The influence of high-pressure torsion (HPT) processing on the texture and microhardness of two binary Mg-RE (RE=Nd and Ce) alloys was investigated using X-ray diffraction and Vickers microhardness measurements. Disks cut from the alloys were processed by HPT at room temperature for up to 10 turns. The precipitation products of both alloys were identified using synchrotron radiation. The results show that both alloys exhibit a weak basal texture where the c-axis of most grains is shifted 15° from the shear direction. An Mg-1.44Ce (wt. %) alloy showed a continuous decrease in the texture strength which may be due to the effect of second precipitation phases (Mg 17 Ce 2 and MgCe 2). The microhardness of both alloys increased significantly with increasing HPT turns but levelled-off beyond about one HPT turn. Maximum values of ~65 and ~96 Hv were achieved which are significantly higher than the hardness of the undeformed Mg-Ce and Mg-Nd alloys.

An investigation of the stored energy and thermal stability in a Cu–Ni–Si alloy processed by high-pressure torsion

Abstract: The stored energy and activation energy for recrystallization were investigated for a Cu-Ni-Si alloy after high-pressure torsion processing for N = ½, 1, 5 and 10 turns at room temperature....

Investigation of texture, microstructure, and mechanical properties of a magnesium–lanthanum alloy after thermo-mechanical processing

Abstract: The texture, microstructure, and mechanical properties of Mg-1.33La (wt.%) alloy after hot rolling and cold plane strain compression were investigated by using X-ray diffraction, optical microscopy, and micro-hardness measurements. This thermo-mechanical processing resulted in a relative weakening of the texture that was mainly a basal type. The microstructures after hot rolling and cold plane strain compression revealed the presence of a second phase (Mg17La2), mostly at grain boundaries. Twins were profuse, and their morphologies were quite different after hot rolling and cold plane strain compression. The Mg-1.33La (wt.%) alloy exhibited good room temperature formability and an increase in strength. The alloy's hardness increased with increasing deformation strain. Such properties were explained by the effect of both the Mg17La2 phase precipitation and the sample's texture.

Processing Magnesium and Its Alloys by High-Pressure Torsion: An Overview

Abstract: Magnesium and its alloys have attracted significant attention in recent years because they display high strength-to-density ratios, they are biodegradable and they provide a potential for hydrogen storage. Many investigations have examined the effect of high-pressure torsion processing on the microstructures and properties of these materials so that numerous reports are now available. This overview provides a summary of the observations reported to date on the structure and mechanical property evolution including the nature of grain refinement, the grain boundary misorientation distributions, texture evolution and the minimum grain size. For convenience, the mechanical properties are separated into hardness, tensile behavior and superplastic properties. It is shown that the mechanism of grain refinement differs from other metallic materials processed by severe plastic deformation but high strength may be achieved in magnesium alloys and exceptional ductility in pure magnesium. Hydrogen storage and corrosion behavior are also examined together with a discussion of recent attempts to produce magnesiumbased nanocomposites through processing by high-pressure torsion.