MICROSTRUCTURE AND MECHANICAL PROPERTIES OF HOT-DEFORMED AIMg4 ALLOYS WITH THE VARIATIONS OF Mn, Fe, AND Si CONTENTS

초록

This paper aims to investigate the microstructural evolution and mechanical properties of hot-defonned AlMg4 alloys with Mn, Fe, and Si as the main impurities. For this purpose, solidification behavior and microstructural evolution during hot-rolling and heat-treatment processes are investigated by using theoretical calculations and experimental characterization. The crystallization and morphological transformation of intenuctallic Al3Fe, Al6Mn, and Mg2Si phases arc revealed and discussed in feints of the variation in chemical composition. Following a homogenization heat-treatment, the effect of heat treatment on the intennetallic compounds is also investigated after hot-rolling. It was revealed that the Mg2Si phase can be broken into small particles and spherodized more easily than the Al3Fe intennetallic phase during the hot-rolling process. For the Mn containing alloys, both yield and ultimate tensile strength of the hot-rolled alloys increased from 270 to 296 MPa while elongation decreased from 17 to 13%, which can be attributed to Mn-containing intennetallic as well as dispersoid.

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