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Correlation of Strength of Glass with Fracture Flaws of Measured Size
Author(s) -
SHAND ERROL B.
Publication year - 1961
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1961.tb13754.x
Subject(s) - borosilicate glass , materials science , composite material , soda lime glass , brittleness , fracture (geology) , pressing , comminution , tungsten carbide , mineralogy , metallurgy , chemistry
The purpose of this study was to develop a method of producing a single small crack on a glass surface which would become the initiating flaw in the fracture process. Techniques for measuring dimensions of this flaw also formed an essential part of the study. The cracks were formed by pressing a wedge‐shaped tungsten carbide point against the glass. Measurements were made from visible patterns found on the fracture surface after the glass was broken. Strict adherence to carefully worked out procedures was found to be essential for obtaining satisfactory cleaved cracks. Based on fracture caused by a semicircular crack 0.002 in. deep, the 1‐second breaking stresses of five different glasses were as follows: lead‐alkali glass 6800, soda‐lime glass 9000, 96% silica glass 11,500, low‐expansion borosilicate glass 12,000, and aluminosilicate glass 13,800 lb. per sq. in. These values are believed to correlate with the intrinsic strengths of the glasses. This method should have definite advantages in the investigation of fracture phenomena in glasses and in other brittle materials, specifically the effects of composition on strength and the causes of stress fatigue