Fatigue damage assessment of recycled metals and alloys

Abstract

Cyclic fatigue tests were conducted on recycled polycrystalline metals and alloys at room and elevated tempera-ures to determine the fatigue strength, endurance limit and endurance ratio. Annealed and polished stainless steel (Fe-18Cr-8Ni), mild steel (Fe-0.25Cr), aluminium (Al), alpha-brass (Cu-30 % Zn) and copper (Cu) speci-mens of respective grain size of 45.0, 63.5, 72.5, 150.0, and 341.2 μm were tested. Fatigue damage assessment obeyed Paris law, fatigue limit was inversely proportional to grain size, fatigue strength decreased as tempera-ture increased, while fatigue life cycles increased with temperature decrease. The fatigue failure resulted from residual stresses which caused crack opening and propagation leading to cup and cone fracture. The fatigue properties of recycled metals and alloys compared satisfactory with primary materials, and could be used to fabricate engineering components in Ghana.

Journal of Applied Science and Technology Vol. 13 (1 & 2) 2008: pp. 86-91