Affordable Access

Publisher Website

Transmission electron microscopy and 3D atom probe study of oxygen-induced fine microstructural features in as-sintered Ti-6Al-4V and their impacts on ductility

Authors
Journal
Acta Materialia
1359-6454
Publisher
Elsevier
Volume
68
Identifiers
DOI: 10.1016/j.actamat.2014.01.015
Keywords
  • Titanium Alloys
  • Atom Probe Tomography
  • Oxygen
Disciplines
  • Medicine

Abstract

Abstract Recent systematic experimental studies, involving the benchmark Ti-6Al-4V alloy fabricated from powder, have established that there exists a critical level of oxygen around 0.33 mass% beyond which the tensile ductility of the alloy drops dramatically until reaching total brittleness. To understand the fundamental mechanisms behind this critical oxygen content, three-dimensional atom probe tomography (3D-APT), transmission electron microscopy (TEM) and other analytical means have been used to identify and characterise the fine microstructural changes induced by the increased oxygen content beyond the critical level. Three fine microstructural features have been identified in as-sintered Ti-6Al-4V when the interstitial oxygen content was increased from 0.25 mass% to 0.49 mass%. These include (i) the formation of fine acicular α precipitates in the β phase, (ii) the formation of α2-type (Ti3Al) nanometric clusters in the α matrix, and (iii) grain boundary α-β-α layered structures between the α grains. The impacts of these microstructural changes on the tensile ductility are discussed.

There are no comments yet on this publication. Be the first to share your thoughts.