A double-layer heating method to generate high temperature in a two-stage multi-anvil apparatus*

Abstract

A new heating method is proposed to increase the cell temperature of the 6–8 type multi-anvil apparatus without reducing the volume of the sample chamber. The double-layer heater assembly (DHA) has two layers of heaters connected in parallel. The temperature of the cell was able to reach 2500 °C by using 0.025 mm rhenium foils, and the temperature limit was increased by 25% compared with that of the traditional single-layer assembly. The power–temperature relationships for these two assemblies with different sizes were calibrated by using W/Re thermocouple at 20 GPa. When the volume of samples was the same, the DHA not only attained higher temperature, but also kept the holding time longer, compared to the traditional assembly. The results of more than ten experiments showed that the new 10/4 DHA with a relatively large sample size (2 mm in diameter and 4 mm in height) can work stably with the center temperature of the sample cavity exceeding 2300 °C under the pressure of 20 GPa.

High-pressure and high-temperature sintering of pure cubic silicon carbide: A study on stress–strain and densification

“…The pressure was calibrated at ambient temperature using known phase transitions of Bi, Tl, and ZnS. [30] For the cold-pressing experiment, the SiC powder was compressed to the set pressure and held for 10 min, then the pressure was reduced to an ambient pressure and recovered for subsequent characterization. The SiC samples were sintered in a cubic press chamber under different temperature and pressure conditions and exposed isothermally for 10 min at a given temperature.…”