Fatigue behavior of aluminium alloy

Abstract

The present project deals with study of fatigue life of Aluminium alloy treated at two different temperatures. This temperature is above and below the recrystallisation temperature of Aluminium alloy. The specimen is commercially available Aluminium alloy which is annealed, tensile testing is done and then fatigue life of the specimen is determined. Failure of the specimen at different stress applied is determined and number of cycles to failure is noted. Fatigue has become progressively more prevalent as technology has developed a greater amount of equipment, such as automobiles, aircraft, compressors, pumps, turbines, etc., subject to repeated loading and vibration. A fatigue failure can usually be recognized from the appearance of the fracture surface, which shows a smooth region, due to the rubbing action. In our experiment we have done the annealing of aluminum alloy above and below recrystallisation temperature in the recovery range. The tensile testing of the specimen was done in INSTRON 1195. The results obtained from this test says that yield strength of the aluminum alloy was found to be more below recrystallisation temperature then that above recrystallisation temperature. The failure of the specimen here occurs at a very large number of cycles. This of the order of 10 5.this number of cycles decreases with an increase in the applied stress. As the load increases the failure of the specimen would occur at a less number of cycles. This alloy used fails at a large number of cycles. Also no endurance limit is obtained here. So for use of this alloy large number of cycles is required and also a lower yield stress. This aluminum alloy can be used for a large number of uses. Aircraft application, gas pipelines, oil tanks, pistons, etc.