INFLUENCE OF THERMOMECHANICAL （热机的的影响）.pdfVIP

Association of Metallurgical Engineers Serbia and Montenegro Invited paper AME UDC:669.715’721’782-156.8=20 INFLUENCE OF THERMOMECHANICAL TREATMENT ON PROPERTIES OF Al-Mg-Si ALLOY ZLATANKA MARTINOVA, DIMITAR DAMGALIEV University of Chemical Technology and Metallurgy, Sofia, Bulgaria ABSTRACT The effects of pre-aging conditions (90°C to 140 °C/ 15 min to 4 h) followed by 95% deformation and the final aging time and temperature (130°C to 170°C/1h to 8 h) on strength, elongation and electrical conductivity of a thermomechanically treated 6201 alloy were examined. Regression models were derived for each of the properties. Treatment conditions for maximum strength or conductivity were determined using models and multicriterial optimization procedure. A compromised treatment regime for optimal balance between strength/ conductivity/ ductility of the wires was established. Keywords: pre-aging, deformation, mathematical models, strength and electrical conductivity 1. INTRODUCTION Limited information is available for the Al-Mg-Si alloys, subject to TMT with stepped aging. Conclusions about its effectiveness are based on changes of either hardness or strength, obtained after selected pretreatment conditions or single regimes of TMT. Nevertheless, from the previous works [1-4] it is clear that the main parameters are time and temperature of pre-age, amount of cold work, time and temperature of the final aging. Hence, to establish the beneficial or detrimental effects and optimal regimes of TMT is necessary to have a quantitative relation between the processing parameters and required properties. Besides, for many applications it is importa