Spark Plasma Sintering of Commercial Zirconium Carbide Powders: Densification Behavior and Mechanical Properties

Abstract

Commercial zirconium carbide (ZrC) powder is consolidated by Spark Plasma Sintering (SPS). Processing temperatures range from 1650 to 2100 °C. Specimens with various density levels are obtained when performing single-die SPS at different temperatures. Besides the single-die tooling setup, a double-die tooling setup is employed to largely increase the actual applied pressure to achieve higher densification in a shorter processing time. In order to describe the densification mechanism of ZrC powder under SPS conditions, a power-law creep constitutive equation is utilized, whose coefficients are determined by the inverse regression of the obtained experimental data. The densification of the selected ZrC powder is shown to be likely associated with grain boundary sliding and dislocation glide controlled creep. Transverse rupture strength and microhardness of sintered specimens are measured to be up to 380 MPa and 24 GPa, respectively. Mechanical properties are correlated with specimens’ average grain size and relative density to elucidate the co-factor dependencies.

Zirconium Carbide Produced by Spark Plasma Sintering and Hot Pressing: Densification Kinetics, Grain Growth, and Thermal Properties

“…Densification mechanisms incorporated in control SPS and hot pressing of ZrC powders under similar heating and loading profiles were investigated to explain the observed different densification kinetics. An analytical/numerical approach for determining the creep coefficients of powder based materials subjected to hot consolidation in a rigid die has been developed recently, in which an analytical densification equation was derived based on the constitutive equation of sintering, as [8]: $\dot{\theta }=\frac{d\theta }{dt}=-\frac{A_0}{T}exp\left(-\frac{Q}{RT}\right){\left({\sigma }_z\right)}^{\frac{1}{m}}{\left(\frac{3\theta }{2}\right)}^{\frac{m+1}{2m}}{\left(1-\theta \right)}^{\frac{m-3}{2m}}$ where ${\sigma }_z$ is the applied axial pressure ( Pa ); T is specimen’s absolute temperature ( K ); m is the strain rate sensitivity; Q is the activation energy ( J / mol ); and $A_0$ is a combined material constant. The creep coefficients, m , Q , and $A_0,$ can be determined through numerically solving Equation (4) in regression to the experimental densification data.…”

Fully coupled electromagnetic‐thermal‐mechanical comparative simulation of direct vs hybrid microwave sintering of 3Y‐ZrO2

“…The densification part of the EMTM model is based on the continuum theory of sintering. 79 The rheological basis of this model has been initially developed by Skorokhod et al 80 In its present form, the continuum theory of sintering 79 is able to predict sintering utilizing both pressure [81][82][83] or pressureless 84,85 methods; and it is based on the consideration of the viscoplastic (nonlinear-viscous) porous material behavior.…”

Identification of the Norton‐Green Compaction Model for the Prediction of the Ti–6Al–4V Densification During the Spark Plasma Sintering Process

“…[3][4][5][6] They point out the concentration of heat in the punches and the important effect of electric and thermal contacts [7][8][9][10][11][12] on the temperature field. [14][15][16][17][18][19][20] Other authors substitute HIP tests by another type of mechanical test such as the determination of the radial strain rate in a cylindrical porous creep test, [21] or a die compaction test. This approach requires the identification of creep laws on both the dense and the porous material.…”

“…The main contribution of this work is then to adapt the classical methodology [15][16][17][18][19][20][21][22][23] to the SPS conditions (high heating rate and pressure) in the aim of being very close to the target application of the model. The proposed methodology is then perfectly suited to determine densification properties for potential applications using fine microstructures or for a preserved specific phase or microstructures.…”