Oxidation and corrosion protection by halide treatment of powder metallurgy Ti and Ti6Al4V alloy Articles uri icon

publication date

  • November 2014

start page

  • 263

end page

  • 274

issue

  • November

volume

  • 88

international standard serial number (ISSN)

  • 0010-938X

electronic international standard serial number (EISSN)

  • 1879-0496

abstract

  • The aim of this work is to study the effect of halide treatment in powder metallurgy Ti-6Al-4V alloy, in order to improve high temperature oxidation and electrochemical corrosion resistance. Halide treatment was performed by immersing samples in a powder mixture containing 3 wt% NH4Cl, at 200 degrees C and 950 degrees C. Oxidation resistance was assessed by exposure to 600 degrees C for 300 h. The microstructure and phase constitution of the formed oxide layers was characterized. Corrosion resistance in aircraft simulated environment was evaluated with electrochemical impedance spectroscopy. Notable improvement in oxidation and corrosion resistance was observed for samples treated at 200 degrees C.

keywords

  • titanium; eis; thermodynamic diagrams; atmospheric corrosion; selective oxidation ; oxide coatings