Abrasive machining in general and grinding in particular are processes, which increase their importance with high demands on accuracy of surface finish. The chip thickness is an evaluating variable to describe the quality of ground surface as well as the performance of the overall grinding system. A significant characteristic that distinguishes ceramics from metals is their low fracture toughne...

The fracture toughness of the refractory hardmetal TisSi3, with a grain size between 5 and 6 lam, was measured using the controlled-flaw method in conjunction with the miniaturized disc-bend test. The specimens used in these experiments were 3 mm diameter and varied in thickness from 150-450 lam. They were indented using a Vickers pyramid indentor to indention loads varying from 2.9-79.2 N. Ind...

The increasing need in the mechanical testing of sub-sized samples motivated the present study focused on the effect of the size of samples. Sometimes, attempts are made, due to economic reasons, to replace testing of the fracture toughness by a cheaper testing of notch toughness. Several empirical relations, pertaining to relations between fracture toughness and energy consumption in impact te...

an epoxy resin was modified by silica nanoparticles and cured with an anhydride. the particles with different batches of 12, 20, and 40 nm sizes were each distributed into the epoxy resin ultrasonically. electron microscopy images showed that the silica particles were well dispersed throughout the resin. tensile test results showed that young’s modulus and tensile strength increased with the vo...

The fracture toughness of snow in shear is one of the most relevant parameters when studying the mechanics of snow slab avalanche release. Double-cantilever snow beams were loaded asymmetrically to determine K(IIc). If crack surfaces touch under applied pressure, the fracture toughness in shear of snow (rho=247 kg m(-3)) is K(IIc)=680+/-60 Pa m(1/2). Screening of the stress intensity at the cra...

A high temperature cured self-healing epoxy is demonstrated by incorporating microcapsules of poly (dimethylsiloxane) (PDMS) resin and separate microcapsules containing an organotin catalyst. Healing is triggered by crack propagation through the embedded microcapsules in the epoxy matrix, which releases the healing agents into the crack plane initiating crosslinking reactions. A series of taper...

The effect of loading rate on the plane stress fracture toughness properties of a 3.2-mm thick 2219-T87 aluminum alloy plate was investigated with center-cracked panels. Plane-stress J-resistance curves were generated at a constant displacement rate of 10-6 and 5.7 m s-l. Dynamic fracture testing was performed with a coupled pressure plates technique. Fracture initiation and propagation toughne...

ID No. : FC-168 ABSTRACT Fiber-reinforced self-healing ceramic (shFRC) [1] is considered to be most attractive candidate of next generation structural materials using at high temperature, e.g. turbine blade, exhaust component of car engine etc. The shFRCs consist of three components, which are oxide fiber bundle, oxide matrix and self-healing agent interlayer. As the self-healing is generated a...

Bones are the principal structural components of a skeleton; they play unique roles in the body providing its shape maintenance, protection of internal organs and transmission of forces. Ultimately, their structural integrity is vital for the quality of life. Unfortunately, bones can only sustain loads until a certain limit, beyond which they fail. Understanding a fracture behaviour of bone is ...

The orientation dependence of Charpy toughness has been investigated in API-X80 linepipe steel. The occurrence of delamination and preferential alignment of {100} cleavage planes are found to contribute to the observed anisotropy in Charpy properties. Delamination is also related to the presence of banding in the hot–rolled alloy, and the additional plasticity it entails during the process of f...