We have conducted a study of toughening mechanisms in rubber modified polycarbonate systems in order to evaluate the sequence of deformation events which improve fracture toughness. We conclude that cavitation of the rubber particles occurs first, followed by massive shear yielding of the matrix material. The size and shape of the deformation zone created in front of the crack is governed by th...

In this paper, a systematic study on the effects of particle size and hybrid of two different size of silica nanoparticles on the toughening mechanisms of bisphenol-A epoxy was conducted. Nanosilica particles with mean diameter of 17 nm and 65 nm were blended into epoxy system. Probable synergy effects of these two nanoparticles on Young’s modulus and yield strength have been investigated. ...

This study examines the effects of different ZrB2 content on various mechanical properties and electrical conductivity of ZrB2/Y-TZP composite. Composites with ZrB2 content of up to 20 wt-% were particularly beneficial at the lower sintering temperature range by achieving greater densification and better hardness than Y-TZP monolith. In contrast to the trends estimated from rule of mixture, the...

3D X-ray computed tomography (CT) was used to study the effects of particle toughening within unidirectional carbon fibre reinforced polymer (CFRP) materials subjected to impact damage, followed by ex situ CT of compression after impact (CAI) tests at incremental loads. A multi-scale approach utilizing synchrotron radiation CT and laminography was used to study the damage micro-mechanisms of im...

The excellent mechanical properties of carbon nanotubes (CNTS) are driving research into the creation of new strong, tough nanocomposite systems. Here, the first evidence of toughening mechanisms operating in carbon-nanotube-reinforced ceramic composites is presented. A highly ordered array of parallel multiwall CNTs in an alumina matrix was fabricated. Nanoindentation introduced controlled cra...

Resin-based composites represent a unique class of restorative dental materials; however, these have severe shortcomings such as low wear resistance which is mainly responsible for the short life-span materials. Composites characteristics strength, stiffness, to abrasion, polymerisation shrinkage, thermal expansion coefficients and moisture absorption depend on filler particles coupling agents ...

The prospect of extending natural biological design to develop new synthetic ceramic-metal composite materials is examined. Using ice-templating of ceramic suspensions and subsequent metal infiltration, we demonstrate that the concept of ordered hierarchical design can be applied to create fine-scale laminated ceramic-metal (bulk) composites that are inexpensive, lightweight and display excepti...

Natural materials (e.g. nacre, bone, and spider silk) exhibit unique and outstanding mechanical properties. This performance is due to highly evolved hierarchical designs. Building a comprehensive understanding of the multi-scale mechanisms that enable this performance represents a critical step toward realizing strong and tough bio-inspired materials. This paper details a multi-scale experimen...