Effect of graphite die geometry on energy consumption during spark plasma sintering of zirconium diboride

Abstract

The present work aims to investigate the geometrical parameters of the graphite die on energy consumption needed for sintering of a ZrB2 sample. The Maxwell and electrical charge conservation equations are solved to obtain the electrical potential and current of the system. The governing equations are discretized by the Galerkin method and solved using the finite element method. The electric current distribution is obtained at each geometry and the temperature contours are obtained. The results showed that the height of die has a direct effect on power consumption. This can be attributed to the increased electric resistance and consequent increased Joule heating. On the other hand, increasing the die height resulted in more uniform temperature distribution through the sintered sample.

Role of Ti3AlC2 MAX phase on characteristics of in-situ synthesized TiAl intermetallics. Part I: sintering and densification

“…It should be noted that the melting temperature of aluminum is 660 °C but the temperature specified in the diagram, recorded by the thermocouple (an infrared sensor) located outside of the die, is different from the actual temperature inside the die and between the powder particles. Due to instantaneous plasma sparks, the local temperature between the particles in SPS method is much higher than the temperature measured by the thermocouple [34,35]. At 400 °C, the temperature rise slope suddenly increases to the final temperature of 900 °C.…”

Insights on Spark Plasma Sintering of Magnesium Composites: A Review

“…The study also shows the effect of the geometry of the die on power consumption. It reveals that an increase in the height of the graphite dies enhances the uniformity of temperature distribution and increases the power consumption rate [40].…”

“…There are four stages in the SPS process (i) maintaining atmospheric condition (vacuum/inert gas); (ii) compaction with the application of pressure; (iii) sintering by resistance heating; (iv) cooling [47]. The finite element simulation has been performed to understand the sintering mechanism, and the result shows that the heat conduction and Joule heating inside the sample are responsible sintering mechanisms [40]. The SPS of materials is completed based on various mechanisms, but the processes for the discharge and generation of plasma are extremely debatable within the research community.…”

On the oxidation behavior of ZrB2–SiC–VC composites

“…At high‐temperature applications, the devices must be made of a group of materials named ultrahigh‐temperature ceramics (UHTC). These materials are limited to less than 20 items such as ZrB 2 , 1–4 NbC, 5 TiC, 6,7 TaC, 8,9 TiB 2 , 10–12 etc. ZrB 2 ‐based ceramics and composites have a matchless combination of characteristics such as high melting points, high conductivities (thermal and electrical), low tendency to the chemical reactions with molten metals, and outstanding thermal shock resistance 13–15 …”