Structural and Fractographic Analysis of Aluminum Alloy before and After Fatigue Loading

The article deals with the analysis of structure and fracture surface aluminum alloy samples. Alu-minum AlMg9 was used as an experimental material. material from which samples were made supplied cast without heat treatment, specifically produced by continuous casting method. test examined using a Neophot 32 optical microscope, sample scanning electron microscope (SEM). fatigue life tested three-point bending cyclic loading parameters - frequency f = 100 Hz, temperature T 22 ± 5 ℃ stress ratio R 0.11. showed that alloys are very sensitive to defects, such porosity or content distribution intermetallic phases. If large pores phases present on near sample, this can be dominant cause crack initiation reduction lifetime.