Preprint Article Version 1 Preserved in Portico This version is not peer-reviewed

On the Role of Grain Boundaries During Sintering

Version 1 : Received: 20 January 2021 / Approved: 21 January 2021 / Online: 21 January 2021 (14:19:33 CET)

How to cite: Staab, T.; Helm, R.; Diegeler, A. On the Role of Grain Boundaries During Sintering . Preprints 2021, 2021010422 (doi: 10.20944/preprints202101.0422.v1). Staab, T.; Helm, R.; Diegeler, A. On the Role of Grain Boundaries During Sintering . Preprints 2021, 2021010422 (doi: 10.20944/preprints202101.0422.v1).

Abstract

We present new results in positron annihilation lifetime spectroscopy (PALS), thermo-optical dilatometry and microscopy, which are indicating a strong correlation between grain-boundaries and mass transport during the sintering process of carbonyl iron powder. In this particular system we were able to show that the change in particle shape and size with increasing temperature yields an anisotropy in shrinkage, which manifests itself in a higher shrinkage perpendicular to the compaction axis. In the intermediate stage of sintering, where the major mass transport occurs, the average distance between two grain boundaries could be determined to (3,73 ± 0,18) μm at T = 744°C. This is in good agreement with previous calculations of positron pathways in defect free particles. Furthermore, due to sintering temperatures far above the annealing temperature of dislocations in iron, the existence of dislocations in the bulk of the particles is very unlikely. These claims are reflected by the collected positron data, which exhibit a clear grain boundary signal of ∼ 250ps while no vacancy or dislocation signal (typically ∼ 160 ps) is evident in the intermediate stage of sintering.

Keywords

Grain Boundaries

Comments (0)

We encourage comments and feedback from a broad range of readers. See criteria for comments and our diversity statement.

Leave a public comment
Send a private comment to the author(s)
Views 0
Downloads 0
Comments 0
Metrics 0


×
Alerts
Notify me about updates to this article or when a peer-reviewed version is published.
We use cookies on our website to ensure you get the best experience.
Read more about our cookies here.