On the Repeated Tension Impact Test of Aluminum Alloys

In the previous paper, we reported on our experiments about carbon steels under the repeated tension impact and the discontinuity of their E-N curves. This paper describes about the results of studies on aluminum alloys (17S and 56S) under the repeated tension impact. The followings are the results obtained; (1) The repeated tension impact test discontinuously changes from impact test to fatigue test. In the diagram of the relation between repeated tension impact energy and number of impacts to failure, two curves come out as shown in Fig. 2 and they are discontinuous. The upper curve is associated with large scale plastic deformation, whereas the lower curve stands more truly for a fatigue failure. (2) By measuring the deformation of specimens, we have found the descontinuous change of α, β and ψ with impact energy as shown Figs. 3, 4 and 5. (3) There exists a liner relation between the impact energy and the ratio of Af/A0, where Af is the area of fatigue fracture on the lower curve and A0 is original area of specimens.