Principles of physical mesomechanics of nanostructural fatigue of metals. I. Model of subsurface fatigue crack nucleation in VT3-1 titanium alloy

Abstract

In the work, we tested VT3-1 titanium alloy for fatigue in the transition from surface to subsurface crack nucleation. In the tests, subsurface crack nucleation was detected by the acoustic emission method. A model of the formation of a fracture nucleus and of an initial fracture zone around the nucleus was proposed starting from the concept of compression of material and rotation of its volumes at the nanostructural level. The origination of an initial fracture facet was considered as saturation of slip planes with gases where superplasticity arises in a local material volume. The proposed model allows physical understanding of many hitherto inexplicable effects in the behavior of metals under cyclic loading.