The fatigue behaviour of SiC particulate reinforced 2124 aluminium matrix composites

In this investigation paper, the cyclic stress-controlled fatigue response and fracture behaviour of aluminium alloy 2124 discontinuously reinforced with Silicon-Carbide Particulates (SiCp) are presented. The influence of volume fraction (17% and 25% vol.), particle size (2.5 mum and 15 pm), and stress ratio (R = 0.1 and R = 0.5) are examined. In addition, the cyclic fatigue tests were carried out at elevated temperatures (200 degreesC and 250 degreesC). Volume fraction had a significant influence on fatigue lives. An increase in stress ratio and temperature significantly diminished the fatigue life responses of the base alloy and the composites. At elevated temperatures, the tensile properties of the materials decreased, thus, the fatigue lives and their strength diminished. Fracture surfaces revealed that the materials failed in ductile manner, with the evidence of the shallow dimples.