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Blunt scratch strength of polycrystalline alumina



Robert F. Cook


A model for the fracture strength of brittle materials controlled by blunt (spherical) scratches is developed and compared with measurements on a polycrystalline alumina. The model is based on a residual stress-intensity factor for median cracks at scratches that include a localized plastic deformation zone formed by dragged spherical contacts. The stress-intensity factor depends non-linearly on the normal contact load, P, resulting in a predicted strength variation of P<-3/4>. The strength result validates previous claims and extends the overall indentation-strength framework. However, the result has only limited effectiveness in describing experimental measurements, pertaining only to ideal blunt scratches formed over a limited load domain.
Journal of the American Ceramic Society


alumina, fracture, indentation, mechanical properties, scratch


Cook, R. (2017), Blunt scratch strength of polycrystalline alumina, Journal of the American Ceramic Society (Accessed May 24, 2024)


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Created August 21, 2017, Updated October 14, 2022