In vivo oxide-induced stress corrosion cracking of Ti-6Al-4V in a neck-stem modular taper: Emergent behavior in a new mechanism of in vivo corrosion

Jeremy L. Gilbert, Sachin Mali, Robert M. Urban, Craig D. Silverton, Joshua J. Jacobs

Research output: Contribution to journalArticlepeer-review

49 Scopus citations

Abstract

In vivo modular taper corrosion in orthopedic total joint replacements has been documented to occur for head-neck tapers, modular-body tapers, and neck-stem tapers. While the fretting corrosion mechanism by which this corrosion occurs has been described in the literature, this report shows new and as yet unreported mechanisms at play. A retrieved Ti-6Al-4V/Ti-6Al-4V neck-stem taper interface, implanted for 6 years is subjected to failure analysis to document taper corrosion processes that lead to oxide driven crack formation on the medial side of the taper. Metallurgical sectioning techniques and scanning electron microscopy analysis are used to document the taper corrosion processes. The results show large penetrating pitting attack of both sides of the taper interface where corrosion selectively attacks the beta phase of the microstructure and eventually consumes the alpha phase. The pitting attack evolves into plunging pits that ultimately develop into cracks where the crack propagation process is one of corrosion resulting in oxide formation and subsequent reorganization. This process drives open the crack and advances the front by a combination of oxide-driven crack opening stresses and corrosion attack at the tip. The oxide that forms has a complex evolving structure including a network of transport channels that provide access of fluid to the crack tip. This emergent behavior does not appear to require continued fretting corrosion to propagate the pitting and cracking. This new mechanism is similar to stress corrosion cracking where the crack tip stresses arise from the oxide formation in the crack and not externally applied tensile stresses.

Original languageEnglish (US)
Pages (from-to)584-594
Number of pages11
JournalJournal of Biomedical Materials Research - Part B Applied Biomaterials
Volume100 B
Issue number2
DOIs
StatePublished - Feb 1 2012

Keywords

  • corrosion
  • failure analysis
  • hip prosthesis
  • modular
  • titanium (alloys)

ASJC Scopus subject areas

  • Biomaterials
  • Biomedical Engineering

Fingerprint Dive into the research topics of 'In vivo oxide-induced stress corrosion cracking of Ti-6Al-4V in a neck-stem modular taper: Emergent behavior in a new mechanism of in vivo corrosion'. Together they form a unique fingerprint.

Cite this