The effects of sintering profiles on the densification behaviour of synthesized nanocrystalline hydroxyapatite (HA) powder were investigated in terms of phase stability and mechanical properties. A wet chemical precipitation method was successfully employed to synthesize a high purity and single phase HA powder. Green HA compacts were prepared and subjected to sintering in air atmosphere over a...

An investigation of the photoluminescent properties and crystalline morphology of blue emitting LiBa1-xPO4:xTm3+ phosphors with various concentrations (x = 0.005-0.030) of Tm3+ ions were synthesized by microwave sintering. For comparison, the LiBa1-xPO4:xTm3+ powders sintered at the same sintering condition but in a conventional furnace were also investigated. LiBaPO₄ without second phase was f...

The potential of a combination between single-step sintering and ZrO2 additive as a simple ceramic fabrication method to obtain dental porcelain-based ceramic-nanocomposites with good mechanical properties was demonstrated. Influences of sintering condition on phase formation, densification, microstructure and mechanical properties of these porcelain ceramics were examined via XRD, SEM-EDX and ...

Prealloyed powders usually melt over a range of temperatures. This feature is useful in performing supersolidus liquid phase sintering, where liquid forms inside the particles when heated just over the solidus temperature. Densification by supersolidus liquid phase sintering is sensitive to time-temperatures. A major difficulty arises when a narrow temperature range exists between densification...

We wrote two computer programs, 3D and BUMP, to interpret transmission electron microscope (TEM) micrographs made during a study of the initial stage sintering of ultrafine alumina particles (UFP’s, 20–50 nm in diameter). The first simulated the 3D geometric relationships of particles, from which we concluded that surface diffusion was the predominant sintering mechanism because no shrinkage oc...

Silicon nitride foams were prepared by direct foaming and subsequent rapid sintering at 1600 °C. The intense thermal radiation generated under the pressureless spark plasma sintering condition facilitated necking of Si3N4 grains. The prepared foams possessed a porosity of ∼80 vol% and a compressive strength of ∼10 MPa, which required only ∼30 min for the entire sintering processes. Rapid growth...

A two-stage sintering practice was applied to W­3.99Ni­1.71Fe (mass%) to control its microstructural evolution and, accordingly, mechanical properties under high strain rates. Unlike the traditional one-stage liquid phase sintering, the alloy was first solid-state-sintered to close to full densification, and then liquid-phase-sintered by induction heating where the cooling rate was fast. With t...

Ultra-refractory diborides are currently studied mainly as thermal protection materials for aerospace and military applications. However, their favourable properties (very high melting points and good thermo-mechanical properties at high temperatures) can be advantageously exploited to increase the operating temperature of thermodynamic solar plants in concentrating solar power systems. This pa...

A main obstacle in the rational development of heterogeneous catalysts is the difficulty in identifying active sites. Here we show metal/oxide interfacial sites are highly active for the oxidation of benzyl alcohol and other industrially important primary alcohols on a range of metals and oxides combinations. Scanning tunnelling microscopy together with density functional theory calculations on...

Output power of thermoelectric generators depends on device engineering minimizing heat loss as well as inherent material properties. However, the device engineering has been largely neglected due to the limited flat or angular shape of devices. Considering that the surface of most heat sources where these planar devices are attached is curved, a considerable amount of heat loss is inevitable. ...