Boron carbide is one of the lightest and hardest ceramics, but its applications are limited by its poor stability against a partial phase separation into separate boron and carbon. Phase separation is observed under high non-hydrostatic stress (both static and dynamic), resulting in amorphization. The phase separation is thought to occur in just one of the many naturally occurring polytypes in ...

Carbide tungsten cobalt alloys were deformed in compression or in three point bending in a temperature range 1000-1350°C and in a stress domain 30-1000MPa. In these conditions, the stress exponent n of WC-CO alloys is a function of only the cobalt volurnic ratio and tends tow rds n = 1 for pure B carbide. The apparent activation energy is 550 kj mole. T.E.M. investigations on pure carbide defor...

Abstract Early-age cement paste or mortar can be enhanced by curing it in a CO 2 chamber. The study was initiated with investigation on the optimum compressive strength replacing to carbide lime 0, 5, 10, 15 and 20% of Carbide Lime Waste (CLW) content. desired CLW at 28 normal age selected similar mix proportion again casted fresh cured for 1,3 7 days under controlled curing. concentration temp...

The precipitation behavior of carbides in modified 9Cr-1Mo steel (Grade 91) subjected to low-temperature tempering and the influence those on mechanical properties at room temperature were investigated. An as-quenched sample (AQ) contained a small amount metal carbide (MC) its martensite microstructure. On 300–500°C, intended suppress recovery growth dislocation substructure, three types formed...

The pressure-induced phase transition in silicon carbide is studied using a constant-pressure ab initio technique. The reversible transition between the zinc-blende structure and the rock-salt structure is successfully reproduced through the simulation. The transformation mechanism at the atomistic level is characterized, and it is found that the transition is based on a tetragonal and an ortho...

Introduction: The development of a self-limiting caries removal technique would be of great clinical importance. Smart bur II is a relatively new bur in the dental market and its manufacturer is claiming that it is the ultimate bur for selective caries removal. Objectives: The aim of this study was to evaluate caries removal time and efficacy of Smart bur II in comparison with conventional carb...

Findings of laser-assisted atom probe tomography experiments on boron carbide elucidate an approach for characterizing the atomic structure and interatomic bonding of molecules associated with extraordinary structural stability. The discovery of crystallographic planes in these boron carbide datasets substantiates that crystallinity is maintained to the point of field evaporation, and character...

This paper investigates the mechanisms of material removal in dynamic friction polishing of polycrystalline diamond composites through the analysis of polishing-produced debris. The specimens used were PCD compacts composed of diamond and silicon carbide. In order to uncover the debris’ structure, high-resolution transmission electron microscopy (HRTEM), electron diffraction and electron energy...

The effects of stoichiometry on the atomic structure and the related mechanical properties of boron carbide (B(4)C) have been studied using density functional theory and quantum molecular dynamics simulations. Computational cells of boron carbide containing up to 960 atoms and spanning compositions ranging from 6.7% to 26.7% carbon were used to determine the effects of stoichiometry on the ato...

The mobility of carriers in the channel of silicon carbide is significantly lower than in equivalent silicon devices. This results in a significant increase in on-state resistance in comparison to theoretical predictions and is hindering the uptake of silicon carbide technology in commercial circuits. The density of interface traps at the interface be‐ tween silicon carbide and the dielectric f...