Could face-centered cubic titanium in cold-rolled commercially-pure titanium only be a Ti-hydride?

TL;DR

This study confirms that the face-centered cubic phase observed in cold-rolled commercially pure titanium is actually a Ti hydride (TiHx), not a new titanium allotrope, using advanced microscopy and spectroscopy techniques.

Contribution

The paper provides definitive evidence that the FCC phase in cold-rolled titanium is a Ti hydride, clarifying previous ambiguities about its nature.

Findings

FCC phase is a Ti hydride (TiHx) with x>1.

Advanced microscopy confirms the chemical composition.

Hydride formation mechanisms are discussed.

Abstract

A face-centered cubic (FCC) phase in electro-polished specimens for transmission electron microscopy of commercially pure titanium has sometimes been reported. Here, a combination of atom-probe tomography, scanning transmission electron microscopy and low-loss electron energy loss spectroscopy is employed to study both the crystal structural and chemical composition of this FCC phase. Our results prove that the FCC phase is actually a TiHx (x>1) hydride, and not a new allotrope of Ti, in agreement with previous reports. The formation of the hydride is discussed.