| Popis: |
With the aid of scanning electron microscope and energy spectrum analysis, the present thesis made a research on the fatigue fracture surface of AA 6A02 with corrosion damage as well as the effect of alloy element Si, Mg and the corrosion damage on the fracture process. Results indicate that the fatigue fracture surface is tough fracture with multiple fatigue sources. Pits introduced by corrosion damage will weaken the material property, which serve as crack nucleation sites. Proper hardening constituent element introduced during alloying process such as Si, Mg, who are in proper ratio of component to form strengthening phase Mg2Si without the excess phase of single crystal Si, will make strength and plasticity match, thus improve fatigue performance of materials. |
