Fig 1.
The standard sample dimension (millimeters) for pure and fretting fatigue testing.
Fig 2.
The rotary bending fatigue testing machine with the fretting module.
Fig 3.
The XRD pattern for the AM60 magnesium alloy.
Fig 4.
The SEM image of the AM60 magnesium alloy.
Table 1.
The EDS result in Fig 4 for the elemental analysis in the AM60 magnesium alloy.
Fig 5.
The data of pure fatigue (PF) and fretting fatigue (FF) for the bending stress versus the fatigue lifetime: (a) all raw data and (b) average values.
Table 2.
Fatigue properties of the studied AM60 magnesium alloy.
Fig 6.
The fracture surface under pure fatigue at the stress level of (a) 80 MPa and (b) 120 MPa and under fretting fatigue at the stress levels of (c) 80 MPa and (d) 120 MPa.
Fig 7.
The fracture surface under pure fatigue conditions (the stress level: 80 MPa).
Fig 8.
The fracture surface under pure fatigue conditions (the stress level: 120 MPa).
Fig 9.
The fracture surface under fretting fatigue conditions (the stress level: 80 MPa).
Fig 10.
The fracture surface under fretting fatigue conditions (the stress level: 120 MPa).
Table 3.
The micro-crack characteristics on 2000X-FESEM images (in crack propagation regions).
Fig 11.
FESEM images with the EDS analysis of sample fracture surfaces for (a) pure fatigue at 80 MPa and (b) 120 MPa of the stress level, (c) fretting fatigue at 80 MPa) and (d) 120 MPa of the stress level (Notes: The arrows start with the crack initiation and their directions show the crack propagation paths.
Moreover, the symbol “X” depicts the concentration of the related Al or Mn intermetallic phases in the Mg matrix near the region of the crack initiation).