Characterization of the Long Crack Propagation Behaviour in a Hardenable Aluminium Alloy in Very High Cycle Fatigue Regime

Effect of Microstructure on High Cycle Fatigue Behavior of 211Z.X-T6 Aluminum Alloy

“…X alloy specimen #6, EDS data showed small amounts of Mn and impurity Fe elements besides the aluminum matrix (Figure 10 and Table 4). Several studies have pointed out the Fe element as an impurity element in aluminum alloys [11,[25][26][27]42]. High amounts of Fe and Mn elements in aluminum alloy could yield coarse and insoluble intermetallic compounds, such as Al 4 (Mn, Fe) Al 20 Mn 3 Cu 2 Al 3 Fe, which can easily form.…”

“…Under the action of cyclic stresses, the microcracks continued to propagate and connect to form cracks. Also, the propagation of long cracks would eventually lead to material fracture [42], thereby decreasing the fatigue strength of structural parts. Moreover, the inclusions in the aluminum alloy usually existed as blocks, needles, and sheets, seriously damaging the continuity of the alloy matrix (Figures 3-5).…”