The objective of this work is to understand the influence of time on thermal oxidation of CP-Ti Grade II at 850 oC. Thermal treatments were performed for 5 minutes, 15 minutes, 30 minutes, 60 minutes and 120 minutes of isothermal stage. The response of titanium to oxidation at same temperatures and various timings has been investigated, in terms of layer thickness, phase evolution. A variety of experimental and analytical techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM) and ball cratering test have been used to characterize the result of thermal oxidized surfaces. The results showed that oxygen diffused on Ti structure can produce a thick oxide layer with rutile (TiO2) between 3,50 and 10,34 microns, which exhibited good adhesion with the substrate.

Titanium alloys corresponding to Ti-Nb-Zr-Ta system represent a new generation of biomaterials, which were developed for medical applications like metal-ceramic. They are composed of non-toxic and non-allergenic elements and have lower values of modulus of elasticity compared to that of the current biomaterials used in dentistry or orthopedics. In this paper are presented two new titanium alloys (Ti-21Nb-6Zr-15Ta and Ti-25Nb-10Zr-8Ta), which were characterized from structural aspect, mechanical and surface properties point of view using scanning electron microscopy, X-ray diffraction, wear properties, Vickers microhardness measurement. Also, was tested the cytotoxicity of these alloys using direct contact method. The results showed that the investigated alloys have a biphasic structure composed of β-solid solution with intragranular lamellar structures specific to α”. The experimental results shown that new titanium alloys from the system Ti-Nb-Zr-Ta present much better properties compared to that of the metallic biomaterials used currently.

This paper presents the results of dilatometry and DTA analyses performed on a Ni base super alloy sample on which a ZrO2/20%Y2O3 coating was deposited. The tests were done at similar temperatures as those present in a gas turbine engine at the inlet of the turbine. The purpose is to assess how a turbine blade with a ZrO2/20%Y2O3 coating would behave to changes in volume due to temperature and structural changes. The differential thermal analyses and thermo gravimetric analyses were performed on the DTA PT 1600 Linseis installation. The thermal dilatometry was performed on the L75HX XXXX installation.

This paper studies the way how a sample with a 40Cr130 coating behaves to contact fatigue wear from the perspective of plastic deformations. The sample is made of an 18MnCr11 alloy steel. The coating was deposited in electric arc using the Smart Arc 350 installation from Sulzer Metco. The samples was subjected to fatigue wear on the AMSLER installation in limit and mixed lubrication conditions. The samples were subjected to wear for 30 hours, at a loading force of 177 N. The moving sample had a rotational speed of 375 rot/min. Different combinations of contact materials were used for the test samples: coating coating and coating base material. The results were highlighted using the QUANTA 200 3D DUAL BEAM electron microscope.

This study presents the contact fatigue wear behavior of the cermet NiAlSi coating deposited by plasma spraying on alloyed steel. Wear is the failure cause for many component parts of the 4-stroke engine. For example the cylinders are subjected to wear caused by the sliding of the surfaces in EHD lubrication working conditions. Using the AMSLER test machine the rolls have been put to fatigue wear test for 5 hours in conditions of mixed friction. In order to make the results evident one carried out microscopic electronic scavenging analyses using the electronic microscope type QUANTA 200 3D DUAL BEAM.