The Fractographic Analysis of Tensile and Fatigue Fracture Surfaces in Secondary A356 Aluminum Alloy with a Higher Concentration of Iron

Abstract

A significant number of different metals are present in aluminum alloy scrap and waste. Secondary aluminum cast alloys, made by recycling from scrap and waste, have as the main impurity Fe. Fe reduction is a very economically and technologically expensive process and therefore there is a growing interest in researching such materials. Moreover, the higher content of Fe leads to the formation of brittle Fe-rich phases, leading to faster propagation of fracture in castings. Therefore, this study reflected on secondary aluminum cast alloy with a higher concentration of Fe and research their effect on brittle Fe-rich phase formation (in the needle; plate-like form) and propagation of fracture in the castings. This study confirms the increasing amount of needle Fe-rich phases in the melt with higher content of Fe. The increasing amount of such phases leads to the formation of a large number of cleavage fractures on fracture surfaces. Although the cleavage fracture increased, the experimental results show low changes in the properties of all experimental melts.