• sintering
• temperature distribution
• Finite Element Methods
• Field-Assisted Sintering Techniques
• tooling

Field-Assisted Sintering Techniques (FAST) have gained growing interest in the academic and industrial communities in the last decades, thanks to their outstanding characteristics in densifying powder materials with respect to the conventional sintering technologies.
The fundamental contribution of the electric field to the consolidation process is still under investigation, but its role in the production of intense Joule heating inside the powder specimen is well assessed.
This Joule heating is responsible for the obtainment of the temperatures necessary for the material densification, and its homogeneous distribution is a crucial requirement in order to attain satisfactory final outcomes, in terms of density and microstructure.
When increasing the size of the specimen to be sintered, thermal non-uniformities issues arise and become gradually more compromising.
During FAST procedures, the specimen is located inside a tooling setup constituted by a variable number of graphite components, whose significant effects on the current and temperature distributions is well known.
Being such tooling axisymmetric, two main cross-sections can be individuated when studying electrical and thermal gradients: axial and radial.
Both distributions have been thoroughly analyzed in our study. Problems of localized overheating and strong temperature inhomogeneities have been experimentally individuated and numerically addressed.
Finite Element Methods (FEM) have been selected as an optimal tool to reconstruct experimental processes, compensate for the lack of data on local temperatures (only measurable at one or two specific points in a FAST setup), and finally optimize the graphite tooling setup in order to mitigate the undesired thermal non-uniformities.
The FEM-suggested improvements led to the experimental implementation of novel tooling configurations, which successfully uniformized the axial and radial temperature distributions in a variety of macro-scale FAST configurations and finally allowed the production of sintered specimens endowed with a notable microstructural homogeneity.