March 6-11, 2016
Field assisted sintering technology (FAST) aka spark plasma sintering (SPS) has begun transitioning out of academic research institutions and into industry and government laboratories. With this transition, there has been considerable challenges in scaling up the sample sizes from ‘buttons’ to larger prototype parts. The primary challenges lie in areas such as temperature/density uniformity, tooling/die design, and near-net-shaping. This paper will report on the results of a 5-year manufacturing technology development program which scaled up parts from 30 mm diameter buttons to 250 mm x 200 mm tiles. We will discuss the influence of tooling material and geometry on the temperature distributions during sintering as well as the effect on resultant microstructure. We will highlight some localize overheating phenomena observed with certain die configurations and provide guidance for abatement. This paper will provide examples of near-net-shaped (NNS) parts and the added considerations which need to be addressed when NNS is desired. Lastly, we will highlight the numerous materials systems explored which included highly conductive metals, highly insulating ceramics, layered structures, composites, and functionally graded materials.
Christopher Haines, "Field assisted sintering: Challenges in scale–up from buttons to body armor" in "Electric Field Assisted Sintering and Related Phenomena Far From Equilibrium", Rishi Raj (University of Colorado at Boulder, USA) Thomas Tsakalakos (Rutgers University, USA) Eds, ECI Symposium Series, (2016). http://dc.engconfintl.org/efa_sintering/53