Accelerated vibratory fatigue test by ultrasonic frequency at cryogenic temperature

The fatigue test is a time-consuming experiment. The accelerated fatigue testing technique is a dream for all researchers. In our laboratory, a vibratory fatigue testing machine was built, which works at 20 kHz for R = ?1 and permits to carry out tests at cryogenic temperature. This is an automatic machine controlled by a PC computer. By using this apparatus, it is easy to save time by 400 to 500 times and a lot of liquid air (nitrogen or helium).

A titanium alloy, Ti6A14V (TA6V PQ french mark), was tested in liquid nitrogen (77 K) with this machine for S---N curve. At the same time, other fatigue tests were performed in SEP (Société Européenne de Propulsion) in conventional fatigue for the same material and the same conditions except the frequency. The comparison shows that the results are coherent.