Prvky vzácných zemin a jejich kvantifikace v Mg slitinách

Rare earth elements quantification in Mg alloys

abstrakt

en

Mg alloys are widely used in automotive and space industry due to their low specific mass and good mechanical properties. Alloying them with different rare earth elements (REE) can, increase structure homogeneity, corrosion resistance and mechanical properties (e.g. creep resistance). The research of biodegradable Mg alloys with addition of La, Ce and Nd for implants proved their effect on corrosion resistance1. Recently LIBS spectroscopy was used for the identification2, detection3 and quantification4 of REE’s content in different samples. In our experiment plasma was generated by Nd:YAG laser operating at 532 nm. The measured spectra were recorded by two spectrometers: broadband Mechelle spectrometer (230 nm – 975 nm, Andor Technology) equipped with iCCD camera (iStar DH743, Andor Technology) and a high resolution THR 1500 spectrometer (JobinYvon), coupled with the iCCD camera (iStar DH740, Andor Technology) for the separation of closed REE’s spectral lines. The measurements were taken under open air atmosphere at atmospheric pressures. The spectra were recorded in different gate dealys (200 ns, 500 ns, 1 µs, 2 µs, 5 µs and 7 µs). Gate width was always set to the same value as the gate delay. Electron density was determined using Stark broadening of H alpha spectral line at 656.23 nm and the electron temperature from Saha-Boltzmann plot of Zr I-II spectral lines. We measured the elemental composition of ZE41 Mg alloy. The average content of Mg, Zr, Zn and REE’s (La, Ce, Nd...) was determined using CF LIBS method by scanning accumulations over the sample surface. For the CF LIBS quantification the multiple Mg I-II, Zn I, Zr I-II, La II, Ce II and Nd II lines were used.

Mg slitiny jsou široce používány v automobilovém a kosmického průmyslu vzhledem k jejich nízké měrné hmotnosti a dobrým mechanickým vlastnostem. Jejich legováním s různými prvky vzácných zemin můžeme ovlivnit strukturu, homogenitu, odolnost proti korozi a mechanické vlastnosti (např. odolnost proti tečení) hořčíkových slitin. Výzkum biologicky rozložitelných slitin Mg s přídavkem La , Ce a Nd pro implantáty ukázalo jejich vliv na korozní odolnost. LIBS spektroskopie byla použita k identifikaci, detekci a kvantifikaci obsahu prvků vzácných zemin v různých vzorcích.

Mg alloys are widely used in automotive and space industry due to their low specific mass and good mechanical properties. Alloying them with different rare earth elements (REE) can, increase structure homogeneity, corrosion resistance and mechanical properties (e.g. creep resistance). The research of biodegradable Mg alloys with addition of La, Ce and Nd for implants proved their effect on corrosion resistance1. Recently LIBS spectroscopy was used for the identification2, detection3 and quantification4 of REE’s content in different samples. In our experiment plasma was generated by Nd:YAG laser operating at 532 nm. The measured spectra were recorded by two spectrometers: broadband Mechelle spectrometer (230 nm – 975 nm, Andor Technology) equipped with iCCD camera (iStar DH743, Andor Technology) and a high resolution THR 1500 spectrometer (JobinYvon), coupled with the iCCD camera (iStar DH740, Andor Technology) for the separation of closed REE’s spectral lines. The measurements were taken under open air atmosphere at atmospheric pressures. The spectra were recorded in different gate dealys (200 ns, 500 ns, 1 µs, 2 µs, 5 µs and 7 µs). Gate width was always set to the same value as the gate delay. Electron density was determined using Stark broadening of H alpha spectral line at 656.23 nm and the electron temperature from Saha-Boltzmann plot of Zr I-II spectral lines. We measured the elemental composition of ZE41 Mg alloy. The average content of Mg, Zr, Zn and REE’s (La, Ce, Nd...) was determined using CF LIBS method by scanning accumulations over the sample surface. For the CF LIBS quantification the multiple Mg I-II, Zn I, Zr I-II, La II, Ce II and Nd II lines were used.

Mg alloys, ZE41, REE, La, Ce, Nd, CF-LIBS

17.06.2015

Journées LIBS France 2015 (La LIBS pour les applications environnementales et industrielles)