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This paper proposes the use of specific procedures of electromagnetic nondestructive testing method for evaluation of flaw severity in cylindrical products. The phenomena of mechanical and / or thermal fatigue as well as accidental handling can generate the appearance of flaws followed by the increase of these in the metal tubes. This paper proposes the use of specific procedures of electromagnetic nondestructive testing method for evaluation of flaw severity in cylindrical products, which included in a database, makes it useful for the operation of automatic classification of the severity of discontinuities, being based on the method of neural network “learning” to remain immune to certain signal-to-noise ratio. With this, inner circumferential discontinuities with 1mm depth can be detected with probability of detection more than 89% for 90% confidence level.

Bone injuries can be fixed and stabilized using degradable implants from magnesium - calcium alloys. Mg and Ca being natural elements in human body, they are easiest to be absorbed without causing toxicity problems. The aim of the paper is to present the effect of Gd and Mn addition in 0.5wt.% in order to improve elastic properties of Mg-Ca0.5-[E]x (E = Mn or Gd) and possibility to be used as biodegradable materials. The addition of Mn / Gd in the binary MgCa alloy modify the structural properties of the alloy (analyzed as elastic properties, respectively crystallographic structure). The measurements and the results calculus were carried out using the ultrasound methods and the Resonant Ultrasound Spectroscopy.

Zirconium oxide doped with rare earth elements (Y, Ce, etc.) is an important candidate material for incorporation in medical implants and prosthetics. Due to their mechanical properties, the doped compounds hold a unique place among the oxide ceramics since they can undergo phase transformations allowing a toughening mechanism. We aim to determine the influence of different types of thermal treatments for Zr1-xCexO2 (x=0.1; 0.15; 0.20) as well as the structural and mechanical properties of these materials using X-ray and Neutron Diffraction (ND) as well as high resolution of SEM imaging combined with Electron Backscattered Diffraction (EBSD). Our analyses have shown that, following the doping mechanism, the samples exhibit stable crystallographic structures but also improved material strengths, which can make these compounds suitable for a wide range of promising clinical applications.

Biodegradable materials are used as alternative implants for orthopedic applications due suitable strength, fatigue resistance, ductility and biocorrosion resistance which are features for biodegradable implants. Mechanical properties can be improved by adding alloying elements. The decrease of the corrosion rate of Mg can be induced by modifying the structure and phase distribution. Thus, Mg alloys have been designed to meet the requirements of bone repair implant materials by adding = Calcium and Yttrium or Gadolinium. Mg based alloy with Ca and Y/Gd had been proved to be a biocompatible material, osteoconductive and biodegradable and can be used in bone repairs. The system is defined as Mg100-(n+x) Ca(n) RE(x), varying the RE concentration in order to slow the degradation process. Beside morphological combining characterization SEM, EDX, with non-invasive testing is required to be carried out the determination of mechanical characteristics. The interest in this study is to analyze the influence of RE over elastic properties of these alloys in order to choose the best values appropriate with human bones, using Resonant Ultrasound Spectroscopy and ultrasound method.

The medical prosthesis components made from (ZrO2)-based ceramics present a good biocompatibility as well as especially mechanical properties. Much more, the problems of nondestructive evaluation for these elements, which assure both comfort and maximum safety to the patient, are imperative for these medical implants. In this study, we investigate the structure and the mechanical properties of Zr1-x(Ce/Y)xO2 , (x=0.0;0.09;0.13;0.17) materials as well as the modification of their crystallographic structure due to various thermal treatments and variation of Ce/Y concentrations in the samples. The substitution of Zr with Ce and the thermal treatment at 1000°C produced important transformation in the phase composition and the microstructure of the sample. A large decrease of the microstrains was observed at the treated samples. Combining characterization techniques based on XRD and ND with non-destructive evaluation methods based on Resonant Ultrasound Spectroscopy (RUS) and Acoustic Emission (AE), we emphasize a unique approach on evaluating the physical properties of these ceramics. Performed evaluation tests of Zr1-x(Ce/Y)xO2 ceramics have shown big influence of composition on their fracture behavior and resulting strength due to different damage mechanisms.

Protecting coatings as thermal barrier coating (TBC) are used for yield improvement of equipment working at high temperature. Zirconia doped with yttria ceramics are considered a good TBC material due of its low thermal conductivity, refractory, chemical inertness and compatible thermal expansion coefficient with metallic support. The paper proposes the use of an electromagnetic method for evaluation of coatings on stainless steel using a sensor with metamaterial lens and comparison of the results with those obtained by complementary methods.

The samples with the chemical composition LixCu1−2xFe2+xO4 were obtained starting from Li0.5Fe2.5O4 and CuFe2O4. X-ray investigations indicated that the sintered samples have spinel structure. Magnetic measurements were effected between 77 and 900 K and allowed us to determine the Curie temperatures and molecular magnetic moment.

Two series of perovskite type compounds (Sr2Mg1-xZnxMoO6 and Sr2Mg1-xNixMoO6) are characterized from the structural point of view. The synthesis conditions are briefly described. The cation distribution of the two series compounds were determined by X-ray diffraction.