Comparative study of Ti and Ti alloy for possible medical application

In the realm of modern medicine, the quest for innovation and improvement is relentless. One significant development that has transformed the landscape of medical devices and implants is the use of titanium and titanium alloys. Just as Titan stands as a resilient moon in the outer reaches of our cosmic neighborhood, titanium and its alloys have emerged as robust and versatile materials for a wide array of medical applications. From orthopedic implants to dental prosthetics, and even in cutting-edge biomedical engineering, titanium's exceptional combination of strength, biocompatibility, and corrosion resistance has made it an indispensable asset in modern medicine. Titanium and its alloys are not just elements on the periodic table; they are key elements in the quest for stronger, longer-lasting, and more effective medical treatments and devices

Dissimilar Laser Welding of AISI 321 and AISI 1010

This paper presents the dissimilar laser welding of AISI 321 stainless steel and AISI 1010 carbon steel thin sheets in butt joint geometry using a 1 kW diode laser. Influence of the welding speed on the geometry and microstructure of the joints is discussed. Structural characterisation of the welds is realised through optical, electron microscopy and EDS analysis, observing distinct mixed and unmixed areas in the weld bead because of the high cooling rate. The weld bead presents an austenitic-martensitic-ferrite structure, characterized by austenitic twin grains with ferrite particles precipitated on grain boundaries, and islands comprising a ferrite-martensite structure. Chromium and nickel migration in the weld bead area was observed. Good tensile behaviour of the dissimilar joints was obtained, as all the specimen failure occurs far-off the weld zone

Preliminary studies of new Ti alloys with different Mo content

This work aims to investigate the mechanical characteristics and biocompatibility of two novel titanium alloys, Ti15Mo7Zr15Ta1Si and Ti20Mo7Zr15Ta0,75Si.These samples have previously undergone cutting, grinding, polishing, and chipping. The studied samples were subjected to electrochemical, metallographic and corrosion behavior. Ti15Mo7Zr15Ta1Si and Ti20Mo7Zr15Ta0.75Si, the study samples, have demonstrated high corrosion potentials, lower corrosion rates, and consequently higher corrosion resistance. In summary, this study's data indicates that both alloys exhibit good corrosion behavior

Study of molybdenum stable oxide film in simulated body fluid

This study's main goal is to thoroughly compare the mechanical attributes and biocompatibility of the recently created titanium alloy Ti15Mo7Zr15Ta1Si (62% Ti, 15% Mo, 7% Zr, 15% Ta, 1% Si) to that of the pure metal Mo. The samples underwent a series of meticulous preparation procedures, including chip preparation, polishing, grinding, and cutting, to enable a thorough evaluation. These preparation steps were essential for ensuring the samples' consistency and uniformity, which allowed for accurate and reliable analyses of their mechanical and corrosionrelated properties. The samples' microstructure and surface morphology were also investigated using metallographic techniques, allowing a thorough examination of any potential flaws, grain boundaries, or phase compositions. Additionally, electrochemical tests were used to investigate the materials' corrosion resistance and electrochemical characteristics in environments that mimicked physiological conditions. The samples were subjected to a variety of electrochemical analyses, such as polarization curves and impedance spectroscopy, in order for the researchers to fully comprehend the corrosion behavior of the materials and their suitability for biomedical applications

Carbon Nanoparticle-Supported Pd Obtained by Solar Physical Vapor Deposition

Palladium supported on carbon nanoparticles has been obtained on a specially designed ceramic catalyst, obtained by thermal spraying on a copper substrate, starting from Pd/C targets. Solar physical vapor deposition in argon, an environment-friendly and energy-efficient alternative to arc or chemical vapor deposition, has been employed as a means of target vaporization at CNRS-PROMES facility in Odeillo, France. The obtained nanoparticles have a spherical-porous morphology with diameters ranging from 50 to 120 nm and specific sorption areas of 50,000 m2/g. The XRD diffractograms indicate the presence of dominatingly crystalline short-range ordered graphene oxide layers, in contrast with the amorphous Pd/C starting precursor. The presence of palladium (0.6% wt.) at the surface of the nanoparticles was proved by the EDX and XRD analyses, making the synthesized material useful in applications such as catalysis or gas sorption

Food Habits and Lifestyle of Romanians in the Context of the COVID-19 Pandemic

The pandemic caused by the SARS-CoV-2 virus has produced significant changes in socio-cultural life, diet, and interpersonal relationships across the world’s population. The present study aims to identify changes in lifestyle and diet among the Romanian population one year after the onset of the COVID-19 pandemic. An online questionnaire with 58 items (addressing the following aspects: socio-demographic and anthropometric data, current eating habits, and lifestyle changes) was distributed using institutional mailing lists and social media. A total number of 2040 respondents participated in the study, of whom 1464 were women, and 576 men. Among the respondents, 1598 came from urban areas and 442 from rural areas. The processing of the collected data showed significant changes in the behavior of the respondents caused by the pandemic situation with psycho-affective changes in some cases. The number of people who had anxiety, depression and nervousness increased by up to 20%. The majority of respondents (over 57%) were up to 30 years old, either students (43.50%) or employees going to workplaces (33.20%). Analyzing eating habits, we found that diet modification was needed to increase the daily consumption of fruits, vegetables, fish, and seafood. Regarding weight status during the pandemic, we noticed that 34.7% of normal-weight respondents said that they gained weight while 49.7% of overweight people and 52.5% of obese people said that they gained weight (p < 0.0001). Regarding psycho-emotional behavior, 11.81% of the surveyed women stated that they frequently had depressive states during the pandemic period and 11.63% of the men stated that they frequently presented depressive states during the pandemic (p = 0.005)

Corrosion Behavior of Coated Low Carbon Steel in a Simulated PEMFC Environment

Here, potential metallic bipolar plate (BP) materials were manufactured by laser coating NiCr-based alloys with different Ti additions on low carbon steel substrates. The titanium content within the coating varied between 1.5 and 12.5 wt%. Our present study focussed on electrochemically testing the laser cladded samples in a milder solution. The electrolyte used for all of the electrochemical tests consisted of a 0.1 M Na2SO4 solution (acidulated with H2SO4 at pH = 5) with the addition of 0.1 ppm F−. The corrosion resistance properties of the laser-cladded samples was evaluated using an electrochemical protocol, which consisted of the open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) measurements, and potentiodynamic polarization, followed by potentiostatic polarization under simulated proton exchange membrane fuel cell (PEMFC) anodic and cathodic environments for 6 h each. After the samples were subjected to potentiostatic polarization, the EIS measurements and potentiodynamic polarization were repeated. The microstructure and chemical composition of the laser cladded samples were investigated by scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectroscopy (EDX) analysis

Geometry Characterization of AISI 430 Stainless Steel Microstructuring Using Laser

Laser-generated surface patterns provide the means for local mechanical interlocking between the joined materials, tunes the wettability of surfaces that come in contact, and generally are the main factor for bonding strength enhancement, especially between dissimilar materials. This paper presents the influence of different patterning overlays generated with a pulsed laser on the surface of stainless-steel sheets. For all experiments, an overlapping degree of 90% has been chosen between three different patterns, while the engraving speed, pulse frequency and number of passes have varied. The textured surfaces’ morphology was assessed through optical microscopy, and the roughness of the surfaces was correlated with the corresponding experimental parameters. The results have indicated promising insights for joining stainless steel to plastic materials, which is otherwise difficult to assess through usual welding techniques

Functional Surfaces via Laser Processing in Nickel Acetate Solution

This study presents a novel laser processing technique in a liquid media to enhance the surface mechanical properties of a material, by thermal impact and micro-alloying at the subsurface level. An aqueous solution of nickel acetate (15% wt.) was used as liquid media for laser processing of C45E steel. A pulsed laser TRUMPH Truepulse 556 coupled to a PRECITEC 200 mm focal length optical system, manipulated by a robotic arm, was employed for the under-liquid micro-processing. The study’s novelty lies in the diffusion of nickel in the C45E steel samples, resulting from the addition of nickel acetate to the liquid media. Micro-alloying and phase transformation were achieved up to a 30 µm depth from the surface. The laser micro-processed surface morphology was analysed using optical and scanning electron microscopy. Energy dispersive spectroscopy and X-ray diffraction were used to determine the chemical composition and structural development, respectively. The microstructure refinement was observed, along with the development of nickel-rich compounds at the subsurface level, contributing to an improvement of the micro and nanoscale hardness and elastic modulus (230 GPa). The laser-treated surface exhibited an enhancement of microhardness from 250 to 660 HV0.03 and an improvement of more than 50% in corrosion rate