Microscopic mechanisms of spark plasma sintering in a TiAl alloy

Zofia Trzaska (1) , Alain Couret (1) , Jean-Philippe Monchoux (1)

1 CEMES - Centre d'élaboration de matériaux et d'études structurales

A method to observe the mechanisms occurring at the neck between TiAl powder particles during interrupted spark plasma sintering (SPS) cycles has been developed. It is based on co- sintering of a mixture of equilibrated TiAl prealloyed powder with a small amount of Ti powder, the latter taking the place of the pores. Dense samples were obtained, which could be prepared for scanning and transmission electron microscopies (SEM, TEM) by standard procedures. TiAl- Ti reaction proved to be sufficiently limited to allow observations of necks between TiAl particles. Though the neck regions exhibit large deformations, clean and dislocation-free grains are observed by TEM in these regions. This is interpreted in terms of classical high temperature mechanisms: dislocation activity followed by dynamic recrystallization. No mechanisms specific to the SPS have been observed. Copyright © 2014 by The Minerals, Metals & Materials Society.

Mots clés: Dynamic recrystallization; Exhibitions; Mechanisms; Metallurgy; Spark plasma sintering; Titanium compounds; Transmission electron microscopy; Dislocation activity; Dislocation-free; High temperature; Microscopic mechanisms; Pre-alloyed powder; Scanning and transmission electron microscopy; Standard procedures; TiAl; Titanium alloys

Domaines: Physique [physics]

Zofia Trzaska, Alain Couret, Jean-Philippe Monchoux. Microscopic mechanisms of spark plasma sintering in a TiAl alloy. 5th International Symposium on High-Temperature Metallurgical Processing, 2014, San Diego, CA, Unknown Region. pp.329-336. ⟨hal-01726311⟩