Abstract

Spark plasma sintering (SPS) has been employed to consolidate a micron-sized zirconium carbide (ZrC) powder. ZrC pellets with a variety of relative densities are obtained under different processing parameters. The densification kinetics of ZrC powders subjected to conventional hot pressing and SPS are comparatively studied by applying similar heating and loading profiles. Due to the lack of electric current assistance, the conventional hot pressing appears to impose lower strain rate sensitivity and higher activation energy values than those which correspond to the SPS processing. A finite element simulation is used to analyze the temperature evolution within the volume of ZrC specimens subjected to SPS. The control mechanism for grain growth during the final SPS stage is studied via a recently modified model, in which the grain growth rate dependence on porosity is incorporated. The constant pressure specific heat and thermal conductivity of the SPS-processed ZrC are determined to be higher than those reported for the hot-pressed ZrC and the benefits of applying SPS are indicated accordingly.

Highlights

  • Spark plasma sintering (SPS), known as field-assisted sintering or current-assisted sintering, is currently one of the most attractive rapid powder consolidation techniques

  • Attributed to the the because higher relative density is associated with the presence of fewerdensity pores, more thermal thermal conductivity is shown to increase with the relative because higher relative contributions of conduction electron bands and enhancing high phonon conductivity in ceramics materials pathways are present in the processed specimen

  • zirconium carbide (ZrC) pellets with high relative densities have been successfully produced by SPS

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Summary

Introduction

Spark plasma sintering (SPS), known as field-assisted sintering or current-assisted sintering, is currently one of the most attractive rapid powder consolidation techniques. Necessary to characterize these thermal effects before analyzing mass transfer and deformation mechanisms in SPS of powder materials Both partially and fully dense ZrC products can be utilized for various applications but the respective product service conditions are usually associated with high temperatures. The specimen’s temperature is determined using finite element method by correlating kinetics and microstructures are compared to these retrieved from SPS of ZrC under similar heating the simulated temperature inside the powder specimen with respect to the pyrometer measured and loading profiles. The resulting specimen’s temperature utilized to to investigate the grain correlating thedie simulated inside the powder specimen is with respect the pyrometer growth mechanism during the final stage of SPS Both densification and grain growth are studied measured temperature at the die surface.

Starting Powders
Consolidation of Zirconium Carbide Powder
Characterization of Processed Specimens
Temperature Evolution in SPS of ZrC
Densification Kinetics
Temperature
Densification
Grain Growth and Microstructures of SPS Processed Specimens
Thermal Properties of SPS-Processed Specimens
Findings
10. Heat capacities
Conclusions
Full Text
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