Quantitative analysis of TiO <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si42.svg" display="inline" id="d1e2226"> <mml:msub> <mml:mrow/> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msub> </mml:math> formation on TA6V terrestr

The Ti-6Al-4V ( TA6V ) titanium alloy is extensively used in aerospace applications, owing to its remarkable combination of low density, high mechanical strength, and excellent oxidation resistance. Understanding its oxidation behavior is therefore essential for assessing debris survivability during terrestrial atmospheric re-entry, where the material is exposed to air plasma conditions. This paper compares complementary experimental techniques: Scanning Electron Microscopy coupled with Energy-Dispersive X-ray Spectroscopy (SEM-EDS), X-ray Diffraction (XRD), Raman spectroscopy, and Calibration-Free Laser-Induced Breakdown Spectroscopy (CF-LIBS) on a TA6V sample oxidized under conditions representative of atmospheric re-entry. Conventional analyses (SEM-EDS, XRD, Raman) consistently confirm that the predominant oxide formed is rutile TiO 2 ( ∼ 6 μ m thick). Spectroscopic analysis of the LIBS plasma provides complementary depth-resolved insights. Elemental profiling, which is obtained by simulating the experimental spectra using the MERLIN code, shows that the O/Ti ratio sharply decreases from a stoichiometric value towards a residual null value. Using the measured laser ablation rate, the oxide thickness is found to be consistent with the SEM observations. This work demonstrates that LIBS enables quantitative depth-resolved measurements, providing direct access to oxygen gradients and oxide stoichiometry in a single experiment. • Oxidation layer on tank material (TA6V) representative of terrestrial re-entry conditions (inductive plasma torch). • (1) SEM-EDS : morphological and semi-quantitative analysis. • (2) XRD : crystalline phases identification. • (3) Raman spectroscopy : amorphous oxides identification. • (4) CF-LIBS : quantitative elemental analysis. • Cross comparison of measurements obtained from (1), (2), (3) & (4) : assessments and discussions of constistency and complementarity.