Investigation of the microstructural evolution in Ti-6A1-4V alloy during cyclic hydrogenation and dehydrogenation heat treatment

The temporary alloying process involves a two stage heat treatment during which hydrogen is firstly introduced into the titanium sample (hydrogenation), and secondly removed from the sample under vacuum annealing (dehydrogenation), thereby completing the cycle. During the hydrogenation stage, the high diffusivity of hydrogen in titanium alloys at elevated temperatures is used to introduce hydrogen into the sample. Hydrogen being a stabilizing element of titanium alloys, lowers the β → (α+ β) transition temperature and slows the kinetics of the β → α phase transformation. This leads to the generation of new microstructures. Fine α-grain structures and martensitic plates were observed upon completion of the hydrogenation treatment.

Grantor dc:publisher.institution

Department of Mechanical Engineering

Year dc:date.issued

2008

Author dc:creator

• Oguh, Jeremiah Chika

Advisor dc:contributor.advisor

• Knutsen, Robert D

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/11427/5495

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/5495