Synthesis and flash sintering of zirconium nitride powder

Abstract

Zirconium nitride (ZrN) is a transition metal nitride of great interest due to its excellent physical and chemical properties. This study aims to synthesize ZrN fine powders by a facile and low‐cost urea route that avoids the use of any solvent. ZrCl4 and urea mixtures were heat‐treated at up to 1600˚C in nitrogen gas. The products were characterized by X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, energy‐dispersive X‐ray spectroscopy, and thermogravimetric analysis. The effects of different processing parameters such as metal to urea molar ratio, heat treatment temperature, and dwelling time on the product phase and stoichiometry were studied to understand the synthesis method. In addition, synthesized ZrN powder was consolidated into near fully dense single‐phase bulk ceramic with a homemade flash sintering setup. A constant DC electrical field of ∼80 V/cm and pressure of ∼14 MPa at room temperature triggered flash sintering without pre‐heating, and the entire process finished in 200 s. The composition, microstructure, density, hardness, and oxidation properties of the sintered pellet were also characterized.

A Perspective on Emerging and Future Sintering Technologies of Ceramic Materials

“…It has been demonstrated that FS can be applied to almost all oxides including ionic conductors, electronic conductors, insulators, and multicomponent oxides [5] and even synthesis of complex oxides in seconds by reactive FS is another promising kind of application. [37][38][39] FS of other material classes like nonoxide ceramics like nitrides, [40] carbides, [41][42][43][44][45] and even metals is currently under investigation.…”

Design Rules for a Wearable Micro-Fabricated Piezo-Resistive Pressure Sensor

“…At these conductivity values the high resistance of the elastomeric layer serves as a limit to the passing current between the layers and thus reducing the overall sensitivity of the sensor. For this reason, in order to achieve high sensitivity in piezo-resistive sensors, it is recommended that elastomeric layer be coated with a highly conductive layer like gold or as an example other novel conductive materials such as Zirconium nitride (~2 ×10 6 S/m [47]) with conductivity values higher than 10 S/m. In most cases, compositing the elastomeric layer with conductive materials leads to polymers that are not conductive enough which would adversely affect the sensitivity of the pressure sensor.…”

Effects of processing conditions on flash sintering of commercial ZrN

“…This configuration, also called pressure‐assisted flash sintering (PAFS), uses an electrical field as well as a low pressure (e.g., ∼10–50 MPa) to densify ceramic powders, even without preheating or pre‐compacting, 12–15 as shown in the schematic in Figure 1B 15 . Such PAFS has been adopted in several institutions and demonstrated for both oxides 15 and non‐oxides, such as transition metal carbides, borides, and nitrides 14,16–22 . Compared with classical FS with DC electrical field strength in the range of ∼10–1000 V/cm and current density in the range of ∼0.1–50 mA/mm, 2,23 sinter‐forging type FS has been applied to highly conductive ceramics such as hafnium–zirconium diboride 18 and tungsten carbide, 19–21 with low electrical field strength in the range of ∼1–30 V/cm and very high current density in the range of ∼10–50 A/mm 2 (or 10,000–50,000 mA/mm 2 ).…”