Recubrimientos bioactivos: Hidroxiapatita y titania

Peer Reviewe

Ordering kinetics evaluation of FeAl powders

In this study, time resolved X-ray diffraction experiments using synchrotron X-ray radiation have been performed to get insight on the time and temperature dependent atomic ordering of an intermetallic Fe-40Al (at.%) ball-milled powder. The target of the present study is to gain knowledge on the rapid heating processes occurring during Thermal Spray coating processes. Present results show that in the temperature range 400 °C - 550 °C, the evolution of the order can be followed and modelled by fitting the powder diffraction patterns collected within the first minutes after fast heating. Reasonable refinements have been obtained by assuming the presence of two domains corresponding to the ordered and disordered lattices. The lattice constant changes from 0.29165 nm in the ball-milled powder at room temperature to 0.29281 nm in the ordered phase after 3000 s at 550 °C. The growth of the ordered phase is proposed to be a vacancy-related process with an activation energy of 1.04 eV. Above 550 °C, the ordering kinetics appears too fast to be resolved using the few seconds time scale of the present experiments which is in agreement to thermal spray results conditions.Peer ReviewedPostprint (author's final draft

Porous titanium-hydroxyapatite composite coating obtained on titanium by cold gas spray with high bond strength for biomedical applications

The lack of bioactivity of titanium (Ti) is one of the main drawbacks for its application in biomedical implants since it can considerable reduce its osseointegration capacities. One strategy to overcome this limitation is the coating of Ti with hydroxyapatite (HA), which presents similar chemical composition than bone. Nonetheless, most of the strategies currently used generate a non-stable coating and may produce the formation of amorphous phases when high temperatures are used. Herein, we proposed to generate a Ti-HA composite coating on Ti surface to improve the stability of the bioactive coating. The coating was produced by cold gas spraying, which uses relatively low temperatures, and compared to a Ti coating. The coating was thoroughly characterized in terms of morphology, roughness, porosity and phase composition. In addition, the coating was mechanically characterized using a tensile loading machine. Finally, biological response was evaluated after seeding SaOS-2 osteoblasts and measuring cell adhesion, proliferation and differentiation. The novel Ti-HA coating presented high porosity and high adhesion and bond strengths. No change in HA phases was observed after coating formation. Moreover, osteoblast-like cells adhered, proliferated and differentiated on Ti-HA coated surfaces suggesting that the novel coating might be a good candidate for biomedical applications.Peer ReviewedPostprint (author's final draft

Recubrimientos bioactivos: Hidroxiapatita y titania

Peer Reviewe

Mechanical and nanoindentation behavior of NiTi and NiTi-TiC coatings obtained by thermal spray

Postprint (published version

Process for obtaining a dense superhydrophobic or hydrophobic, icephobic and wear resistant coating by means of Cold Gas Spray technique

Process for obtaining a dense superhydrophobic or hydrophobic, icephobic and wear resistant coating by means of Cold Gas Spray technique The invention relates to a process of obtainment of a dense superhydrophobic or hydrophobic, icephobic and wear resistant coating by means of Cold Gas Spray technique, to the coatings obtained by said process, its use as coating in wind turbine blades, to a wind turbine blade comprising said coatings. Furthermore, the invention relates to the uses of said coatings as anti-fouling coatings, as self-cleaning architecture and as aircraft coatings, as well as the uses in the manufacture of civil engineering or machinery pieces and car, train or truck parts

TEM Study of the Orientation Relationship Between Cementite and Ferrite in a Bainitic Low Carbon High Strength Low Alloy Steel

Two different bainitic structures are observed in a steel depending on the sample heat treatment. The different types of bainitic structures exhibit different orientation relationships between cementite and the ferrite matrix. Upper bainite presents a Pitsch orientation relationship and lower bainite presents a Bagaryatski orientation relationship. Different heat treatments of low carbon HSLA steel samples have been studied using TEM in order to find the orientation relationship between the ferrite and carbide in the different bainitic structures and to determine if this relationship can identify the type of bainitic structure.Postprint (published version

Mechanicaland nanoindentation behavior of TiC-NiTi thermal spray coatings

Postprint (published version