background: the aim of this study was to compare the effects of conventional acid etching and laser etching on the nano-mechanical properties of the dental enamel using nano-indentation test. materials and methods: in this experimental in vitro study, buccal surfaces of 10 premolars were divided into three regions. one of the regions was etched with 37% phosphoric acid and another etched with e...

Indentation is a remarkably flexible mechanical test due to its relative experimental simplicity. Coupled with advances in instrument development, ease of implementation has made indentation a ubiquitous research tool for a number of different systems across size scales (nano to macro) and scientific/engineering disciplines. However, the exploration of different materials systems and the potent...

introduction: nano-indentation has recently been employed as a powerful tool for determining the mechanical properties of biological tissues on nano and micro scales. a majority of soft biological tissues such as ligaments and tendons exhibit viscoelastic or time-dependent behaviors. the constitutive characterization of soft tissues is among very important subjects in clinical medicine and espe...

An analysis of the material properties of porcine corneas has been performed. A simple stress relaxation test was performed to determine the viscoelastic properties and a rheological model was built based on the Generalized Maxwell (GM) approach. A validation experiment using nano-indentation showed that an isotropic GM model was insufficient for describing the corneal material behaviour when e...

Multiple length-scale effects are demonstrated in indentation-strength measurements of a range of ceramic materials under inert and reactive conditions. Meso-scale effects associated with flaw disruption by lateral cracking at large indentation loads are shown to increase strengths above the ideal indentation response. Micro-scale effects associated with toughening by microstructural restraints...

Indentation methods are finding increasing use in the study of mechanical properties of bulk and thin-film materials over a wide range of size scales (e.g., [1,2]). With the increasing sophistication of instrumented, depth-sensing indentation equipment and of computational methods to model the deformation of materials subjected to indentation, there is growing interest in studying the elastopla...

Problem statement: Dammar is a natural resin that used anciently in varnish production. The use of dammar natural resin in coating is limited by undesirable properties for application in coating where it is considered very brittle. Due to dammar's brittle nature, an aged dammar coating can be easily scratched or abraded. Approach: Dammar natural resin could be modified into SiliconeDammar by us...

The scientific importance of nanocomposites are being increased due to their improvedproperties. This paper is divided into two parts. First, Al-Al2O3 nanocomposite wasproduced by using ball milling technique followed by cold compaction and sintering.Microstructure and morphology studies were done through SEM, TEM, and EDX anal-ysis on the produced powder. The mechanical properties of the produ...

The indentation slope curve from a spherical indentation on elastic-plastic materials is examined. By comparing it with that of an linear elastic material of the same elastic properties, we found that the start point of plastic yielding for an elastic-plastic material can be easily located from the indentation slope curve. Based on this analysis, a simple but effective method is proposed tomeas...