4:30 PM - 4:50 PM
[16B-T5-07] Observing the Impact of Electric Current Percolation in Ti-6Al-4V Powders during FAST/SPS Processing with XCT Analysis
Keywords:Titanium, Spark Plasma Sintering, Consolidation, Powder Metallurgy
A field assisted sintering technology (FAST) process at a range of temperatures under 20 MPa were interrupted at 0 s of dwell time to study early densification of Ti-6Al-4V samples. Powder compaction simulations were used for comparison to the early densification and quantitatively similar constructions observed to within 1.2% porosity variation. It was inferred from this validation, as well as XCT data that
the increased necking in the axial direction was a feature of early densification due to the pulsed electric current percolation through the powder and resulting localised heating at particle-particle boundaries. Columnar features created by this are observed, and some qualitative visual analysis performed to quantify this necking angular development. Additionally, for these 0 dwell time samples, a process lag time was proposed, also seen in FEM simulations from previous work due to heat conduction time from the displacement of the optical pyrometer.
the increased necking in the axial direction was a feature of early densification due to the pulsed electric current percolation through the powder and resulting localised heating at particle-particle boundaries. Columnar features created by this are observed, and some qualitative visual analysis performed to quantify this necking angular development. Additionally, for these 0 dwell time samples, a process lag time was proposed, also seen in FEM simulations from previous work due to heat conduction time from the displacement of the optical pyrometer.