A reasonable method to reduce the volume of the WC anvil.

With the continuous development of the diamond industry, the China-type cubic press (CCP) has gradually become larger. As a result, the volume of the tungsten carbide (WC) anvil has been increased. Considering that the WC anvil is sintered, a larger volume will deteriorate sintering quality, which could facilitate the formation of cracks during its operation.

Synthesis Optimization and Thermoelectric Properties of S-Filled and Te-Se Double-Substituted Skutterudite under High Pressure.

In recent years, skutterudite filled with electronegative elements (S, Se, Cl, Br) has attracted the extensive attention of researchers. By doping electron donors (Pb, Ni, or Te, S, Se) at the Co or Sb sites, the electronegative elements can form thermodynamically stable compounds in the intrinsic pores of the skutterudite, substantially expanding the research scope of skutterudite. In this study, SCoSbTeSe skutterudite was synthesized at high pressure and high temperature, with a pressure range of 2.

An Experiment Study on the Laminar Burning Velocity and Markstein Length of Chlorella Oil/RP-3 Kerosene Blends.

Experiments have been carried out in a constant volume chamber to investigate the effects of Chlorella oil addition on the laminar burning velocity and Markstein length of Chlorella oil/RP-3 kerosene blends at an initial pressure of 0.1 MPa and temperature of 450 K over a wide equivalence ratio range from 0.8 to 1.

HPHT Synthesis: Effects of the Synergy of Pressure Regulation and Atom Filling on the Microstructure and Thermoelectric Properties of Yb Ba GaGe.

Type-I clathrate compounds Yb Ba GaGe have been synthesized by the high-pressure and high-temperature (HPHT) method rapidly. The effects of the synergy of atom filling and pressure regulation on the microstructure and thermal and electrical properties have been investigated. With the content of Yb atom increasing, the carrier concentration is improved, the electrical resistivity and the absolute Seebeck coefficient are decreased, while the thermal conductivity is reduced significantly.

An effective method to improve the growth rate of large single crystal diamonds under HPHT processes: optimized design of the catalyst geometric construction.

In this work, we presented the influence of catalyst geometric construction on temperature distribution, flow structure, the transport processes of the carbon atoms, and the resulting diamond growth in the process of HPHT diamond synthesis. Several catalyst geometry models were tested, and the experimental results of growth rates were compared with numerical simulations. We revealed that increasing the protrusion diameter of the convex-shaped catalysts could significantly improve the growth rate of diamonds.

Effects of Pressure on the Microstructure and Simultaneous Optimization of the Electrical and Thermal Transport Properties of YbBaGaGe.

The thermoelectric (TE) properties of n-type polycrystalline YbBaGaGe bulks can be optimized by high-pressure and high-temperature (HPHT) sintering. After HPHT sintering, abundant nanograins are randomly distributed in the sample. Grains are refined by HPHT, with the grains being smaller with higher pressure.

High-Pressure and High-Temperature Synthesis and Pressure-Induced Simultaneous Optimization of the Electrical and Thermal Transport Properties of Nonstoichiometric TiO.

We developed suitable high-pressure and high-temperature (HPHT) conditions for improvement of the thermoelectric properties of nonstoichiometric TiO. X-ray diffraction, scanning transmission microscopy, transmission electron microscopy, and ultraviolet spectral measurements demonstrate that the crystal structures and microstructures are strongly modulated by our HPHT. The electrical properties and thermal conductivity are improved simultaneously by raising the reactive sintering pressure.

Ultrahard stitching of nanotwinned diamond and cubic boron nitride in C2-BN composite.

Materials combining the hardness and strength of diamond with the higher thermal stability of cubic boron nitride (cBN) have broad potential value in science and engineering. Reacting nanodiamond with cBN at moderate pressures and high temperatures provides a pathway to such materials. Here we report the fabrication of Cx-BN nanocomposites, measuring up to 10 mm in longest dimension, by reacting nanodiamond with pre-synthesized cBN in a large-volume press.

Experimental and modeling study on effects of N2 and CO2 on ignition characteristics of methane/air mixture.

The ignition delay times of methane/air mixture diluted by N2 and CO2 were experimentally measured in a chemical shock tube. The experiments were performed over the temperature range of 1300-2100 K, pressure range of 0.1-1.

Chemical kinetic simulation of kerosene combustion in an individual flame tube.

The use of detailed chemical reaction mechanisms of kerosene is still very limited in analyzing the combustion process in the combustion chamber of the aircraft engine. In this work, a new reduced chemical kinetic mechanism for fuel n-decane, which selected as a surrogate fuel for kerosene, containing 210 elemental reactions (including 92 reversible reactions and 26 irreversible reactions) and 50 species was developed, and the ignition and combustion characteristics of this fuel in both shock tube and flat-flame burner were kinetic simulated using this reduced reaction mechanism. Moreover, the computed results were validated by experimental data.

Finite element analysis and design of cubic high-pressure anvils based on the principle of lateral support.

This article theoretically investigates the lateral support on cubic high-pressure anvil using finite element analysis. The results show that to gain the same chamber pressure, the value of system oil pressure can be decreased by reducing the lateral support area and the anvils' lifetime is extended when the lateral support area grows. The optimal lateral support area to maximize anvils' lifetime is 27.

Hybrid-anvil: A suitable anvil for large volume cubic high pressure apparatus.

A hybrid-anvil used in cubic high pressure apparatus is presented, which makes it possible to pressurize samples of 36 mm(3) volume up to 5.5 GPa and to heat simultaneously up to 1350-1400 degrees C for routine operation. The hybrid-anvil has been designed based on the theory of multilayered pressure vessels and massive support, which can save weight about 60.

Finite element design of double bevel anvils of large volume cubic high pressure apparatus.

A double bevel anvil of the cubic high pressure apparatus (CHPA) was developed, adopting tungsten carbide as the anvil material. We have performed finite element analyses of conventional single bevel anvil and double bevel anvil. The results indicate that the double bevel anvil has two advantages.