Densification of zirconium nitride by spark plasma sintering and high voltage electric discharge consolidation: A comparative analysis

Abstract

The densification behavior of zirconium nitride powder is investigated for various temperature and pressure conditions imposed by spark plasma sintering and high voltage electric discharge consolidation techniques. The crystal structure, chemical composition, porosity, and grain size of the powders and processed specimens are analyzed by X-ray diffraction, scanning electron microscopy, and energydispersive X-ray spectroscopy. The outcomes of the two considered consolidation techniques are comparatively assessed. Vickers micro-hardness of the processed ZrN specimens is investigated, and hardness dependence on porosity is analyzed. The densification mechanism of ZrN consolidated by spark plasma sintering is revealed by applying the constitutive equation of the continuum theory of sintering, and it turns out to be a similar mechanism to hot pressing. Application of the sintering constitutive equations shows that the mechanism of ZrN densification by high voltage electric discharge consolidation method depends on the magnitude of the applied voltage.

Current understanding and future research directions at the onset of the next century of sintering science and technology

“…The technique is also gaining commercial importance as is evident from the large number of patents issued for this process . A schematic of the process is shown in Figure . SPS significantly shortens the processing of powder materials and improves the powder consolidation performance in terms of both time and quality.…”

“…(A) Schematic representation of the SPS process, (B) SPS tooling before an experiment . (Reprinted with permission from Elsevier)…”

“…242 A schematic of the process is shown in Figure 14. 243 SPS significantly shortens the processing of powder materials and improves the powder consolidation performance in terms of both time and quality. It has become especially useful for densifying hard to sinter ceramics including carbides, nitrides, borides, and composites.…”

Spark plasma sintering of structure‐tailored ultrahigh‐temperature components: First step to complex net shaping

“…Spark plasma sintering (SPS) has been shown to enable consolidation of numerous ‘poorly’ sinterable ultrahigh‐temperature ceramic (UHTC) powders into highly dense articles largely due to the coupled electro‐thermal‐mechanical effect . The SPS‐processed UHTCs have been shown to have better mechanical and thermal properties than those produced via conventional techniques suggesting the SPS technique can be utilized to fabricate components for high temperature and structural applications .…”

The Microstructure Evolution, Mechanical Properties and Densification Mechanism of TiAl-Based Alloys Prepared by Spark Plasma Sintering

“…To better understand the effect of sintering parameters on the densification of TiAl-based metallic powders during SPS, a model suggested by Bernard-Granger and Guizard [21] was used to analyze the sintering process. In this model, the flow stress for high-temperature deformation of the alloy is described as a function of strain rate ( ε ) and temperature (T) by Equation (1) [22].…”