Evolution of the Fracture Surface of Commercially Pure VT1-0 Titanium Subjected to Multicycle Fatigue in a Constant Magnetic Field

High-cycle fatigue tests of commercially pure titanium of VT1-0 grade in the initial state (without the use of a magnetic field) and in a magnetic field of various magnitudes (in situ) are carried out. It is established that the use of a constant magnetic field with an induction of 0.3, 0.4, and 0.5 T leads to an increase in the number of cycles until the destruction of titanium samples by 64, 123 and 163%, respectively. Fractographic analysis of the fracture surface of titanium under high-cycle loading conditions allows us to conclude that the destruction of the material proceeds by a mixed mechanism; both quasi-cleavage facets and ductile fracture pits are present on the fracture surface. The fracture structure, regardless of the fatigue conditions, has three characteristic zones: the zone of crack initiation, the zone of stable crack growth, and the breakaway zone. In the zone of stable crack growth, obvious fatigue grooves between ridge formations are observed, the distance between which varies depending on the magnitude of the magnetic field.