Subcritical Crack Growth in Vitreous Carbon at Room Temperature

Publisher Website
Google Scholar
Abstract
The velocity of crack propagation was measured as a function of stress intensity in vitreous carbon at room temperature. The double‐torsion technique was used. In one vitreous carbon, the relation between crack velocity and stress intensity was image In another vitreous carbon, repeated crack arrest prevented determination of the V‐K1dependence. Vitreous carbon in air is virtually immune to static fatigue, compared with soda‐lime glass in air. The ratio of times to failure when the materials are loaded to equal fractions of the critical stress intensity is log (τvc/τsly)≃33. In addition to subcritical crack growth, other fracture mechanical properties, e.g. the modulus of rupture and critical stress intensity factor, were measured. These measurements confirmed the presence of a compressive surface layer on vitreous carbon.