Characterizing Brittle Fracture by Modeling Crack Deflection Angles from the Microstructure. Issue 12 (25th August 2015)

• Record Type: Journal Article
• Authors: Porz, Lukas; Wei, Sai; Zhao, Jiamin; Patterson, Eric A.; Liu, Bin
• Is Part Of: Journal of the American Ceramic Society. Volume 98:Issue 12(2015)
• Page Start: 3690
• Page End: 3698
• Publication Date: 2015-08-25
• Subjects: Ceramics -- Periodicals; 620.1405
• DOI: 10.1111/jace.13822
• Languages: English
• ISSNs: 0002-7820

Abstract

Abstract : This study introduces a simple analytical model for fracture toughness to bridge the length scales from grain size to bulk thickness by assembling a virtual crack path from the angles recorded on an unfractured microstructure, which is a great challenge in fracture mechanics due to the high geometrical complexity. Good agreement is found between a crack deflection angle distribution measured from 5764 crack segments and the prediction by the model and the possible influence of residual stress is quasi quantitatively discussed. A total of 7.4% of the crack segments observed acted as crack bridges, while 7.3% was predicted by the model. A quantification of how high an angle needs to be to turn crack deflection into crack bridging is given. The ratio of fracture toughness from grain boundary to grain, G 1c(gb) / G 1c(g), was measured indirectly from all samples to be between 0.3 and 0.35.