Papers by Author: M. Bouabdallah

Abstract: A shape memory alloy with a nominal composition of 84.68 wt.% Cu-11.25 wt.%Al-4.07 wt.%Ni, has been studied. Polycrystalline specimens have been quenched into water at room temperature, after heat treatment of 15 minutes at a high temperature of 1123 K. Two successive cycles from room temperature to 923 K and inversely have been performed on the non equilibrium samples. The microstructural study presented in this work has been performed using TEM (Transmission Electron Microscopy) analysis, STEM (Scanning Transmission Electron Microscopy) analysis, X-ray diffraction analysis at a variable temperature. Nanometric phase precipitation of AlNi type was observed to appear in this alloy.

Abstract: Duplex stainless steels 2205 are widely used in constructional and petrochemical applications because of their good mechanical and corrosion properties. The objective of this work was to study the influence of aging at high temperature on the austenite and d ferrite equilibrium. After welding by TIG process, duplex stainless steel was aged in the range of 800 – 1150 °C temperatures for 60 min. The microstructure was characterized by metallography and X-ray methods. The toughness of welded structure was also measured.