Design of fatigue test apparatus for etial-141, 145 and 160 type cast aluminium and plate aluminium materials and investigation of bendind fatigue behaviour

In this study, the first the bending fatigue behaviour of 1XXX series 3mm thickness aluminium plate which bought from market samples which have been cut the way of rolling and vertical on the way of rolling is examined. The second the bending fatigue behaviour of sand cast aluminium samples which have ET?AL 141 (4XXX.X series), ET?AL 145 (9XXX.X series) and ET?AL 160 (3XXX.X series) is examined. The aim of this study is to find the ways to decrease the damage caused by bending fatigue in using turbine and its axis fan blades made of aluminium alloy. To create a similar fatigue as to loading and stress type in these elements, a plane bending stress fatigue machine is projected and produced in order to reach the goal of the study. Before all else, samples which in the all material groups tensile and three points bending tests are done and the results are evaluated. Afterwards experimental data which is got from fatigue test results that are done different gaps in 10 steps is use and S ? N diagrams (Wöhler curves) are drawn. The bending stress which is equivalent to an average of N = 107 cycle is accepted as damage criteria and fatigue limit. The Weibull dispersion with two parameters is used to evaluate the numerical data of experiments. The 20X and 40X enlarged pictures of the fracture surfaces are taken by means of an optical microscope in macro level and the 30X ? 1000X enlarged pictures of the fracture surfaces are taken by means of SEM apparatus in micro level is examined. According to the fatigue test results, the longest fatigue life is determined of samples which is got from sand cast ET?AL 160 (3XXX.X series Al ? Si ? Cu) materials. The test results which are affected from the rolling direction in aluminium plate and casting defects in cast samples are seen. KEY WORDS: aluminium / bending fatigue / bending fatigue test apparatus / Weibull dispersion / aluminium cast defects