PM compaction equations applied for the modelling of titanium hydride powders compressibility data

ABSTRACT

The suitability of compaction equations commonly used in PM was investigated for the modelling of TiH₂ powder compaction. Compressibility data of TiH₂ powder fractions (<45, <150 and <355 μm) were obtained up to 800 MPa and fitted to the Heckel equation, as well as to the models of Gerdemann and Jablonski and Cooper and Eaton. Although a partial correlation was observed for the Heckel equation, the model provided a consistent approximation of TiH₂ powder yield strength. An accurate fit was observed for the Gerdemann and Jablonski equation; however, considering the brittleness of TiH₂, a more realistic depiction of the physical process was verified from the Cooper and Eaton model. By the addition of an exponential term to the original equation an excellent fit was attained, and compaction of TiH₂ powders could be appropriately described according to the mechanisms of initial density, particle rearrangement, fragmentation and plastic deformation.

KEYWORDS:

• Titanium powder metallurgy
• titanium hydride
• powder compaction
• compaction equations
• Heckel equation
• Gerdemann and Jablonski equation
• Cooper and Eaton equation

Disclosure statement

No potential conflict of interest was reported by the author.

Notes on contributor

Sergio Luis Graciano Petroni graduated in chemical engineering and PhD in nuclear technology at the University of Sao Paulo. Senior researcher at the Institute of Aeronautics and Space. Experienced in material characterization, metrology and laboratory quality management. Since 2008 developing research in titanium hydride powder metallurgy.

ORCID

Sergio Luis Graciano Petroni http://orcid.org/0000-0002-2074-5902