Effect of Loading Rates and Surface Conditions on the Flexural Strength of Borosilicate Glass

摘要

This study evaluates the loading-rate and surface-condition dependence of flexural strength of a borosilicate glass. The tensile surfaces of glass bending specimens are subjected to 3 different surface treatments. Four-point bending experiments are performed on those treated samples, at loading rates ranging from 0.7 MPa/s to 4 10(caret)6 MPa/s. The results show that the flexural strength of the borosilicate glass increases with increasing loading rate. When the surface is chemically etched, the flexural strength increases by an order of magnitude and fracture initiates from an edge. The high strength measured in the etched glass is still far less than the intrinsic tensile strength, indicating a flaw-determined failure.