Indentation techniques for assessing fracture toughness are attractive due to the simplicity and expediency of experiments, and because they potentially allow the characterization of both local and bulk fracture properties. Unfortunately, rarely have such techniques been proven to give accurate fracture toughness values. This is a concern, as such techniques are seeing increasing usage in the s...

We have performed a number of experiments to examine the mechanical behavior of amorphous silicon electrodes of lithium-ion batteries. In particular, we have measured the fracture energy of lithiated silicon thin-fi lm electrodes as a function of lithium concentration. The fracture energy is found to be similar to that of pure silicon and essentially independent of the concentration of lithium....

An analysis of chipping fracture in brittle solids is presented. Cracks are introduced into the edges of selected materials, including soda-lime glass and fine-grain ceramics, using a Vickers indenter in monotonic loading. The ensuing chip morphology is examined and shown to exhibit a certain geometrical similarity, independent of material properties. A simple universal relation is derived for ...

We demonstrate the capability of optical coherence tomography (OCT) to perform topography of metallic surfaces after being subjected to ductile or brittle fracturing. Two steel samples, OL 37 and OL 52, and an antifriction Sn-Sb-Cu alloy were analyzed. Using an in-house-built swept source OCT system, height profiles were generated for the surfaces of the two samples. Based on such profiles, it ...

The wide-gap aluminothermic rail welds with root opening of 50-70 mm were produced using plain carbon steel rail and non-alloy aluminothermic charge. Mechanical properties and micro-structure of the weld metal and HAZ as well as the impact energy and the fracture toughness of the welds were investigated. The yield and tensile strength of wide-gap welds were about 98% and 95% of the base metal, ...

In this study, the fractal dimensions of failure surfaces of vinyl ester based nanocomposites are estimated using two classical methods, Vertical Section Method (VSM) and Slit Island Method (SIM), based on the processing of 3D digital microscopic images. Self-affine fractal geometry has been observed in the experimentally obtained failure surfaces of graphite platelet reinforced nanocomposites ...