*2.2. Fatigue Tests*

Samples were tested in two loading conditions, rotating–bending (RB) and tension-compression (TC). For RB, the fatigue behavior was studied with a loading frequency of 10 Hz and a load ratio of R = −1, in air, at room temperature using an R. R. Moore rotating–bending fatigue test bench (Instron, Norwood, MA, USA). The fatigue limit was estimated from the highest stress amplitude at which no failure occurred up to 10<sup>6</sup> cycles.

For TC, fully reversed tension–compression (R = −1) fatigue tests were carried out with a loading frequency of 10 Hz, in air, at room temperature on an 810 MTS (MTS systems, Eden Prairie, MN, USA) servo-hydraulic machine equipped with a dynamic loading cell with a maximum capacity of ±100 kN.
