The Study of Evolution of Physical and Mechanical Properties of Metals Under Very High Cycle Fatigue

This work is devoted to experimental investigation of Armco iron fracture under very high cycle fatigue. The tests were carried out using ultrasonic test machine USF-2000 manufactured by SHIMADZU. The frequency of tests was 20 kHz. The specimens were tested under two cooling conditions: air stream and water tank. The water cooling provides better cooling of material and exclude overheating. The fracture surfaces were investigated using SEM microscope. It was show the strong influence of cooling condition on fracture behavior of the specimen. The peculiarity of PDM signal was compared with different types of fracture on the surfaces of specimens.