Nickel Metal and Alloys
Jurij J. Hostýnek, Howard I. Maibach in Nickel and the Skin, 2019
The individual elements must be mixed intimately to produce an alloy. This can be achieved by: Melting, which allows the elements to mix in the liquid phaseSintering of powders, which allows the constituents to interdiffuseMechanical alloying (high energy ball-milling, which causes repeated cold welding and fracture of the powder particles) followed by sinteringCo-deposition by electrolysisCo-deposition by vapor deposition
Industrial Applications
Vlado Valković in Low Energy Particle Accelerator-Based Technologies and Their Applications, 2022
Ranges of charged particles in different elements are well known and available information (Williamson et al. 1966) permit to select the appropriate particle energy for a specific problem. Ranges in compounds and alloys may be calculated according to Bragg's formula:where RA is the range in alloy, Ri, is the range in element i and Ci, is the concentration of element i. The depth of the radioactive layer depends on the particle energy and beam incidence angle:where E0 and Eth, are particle energy and reaction threshold, R is the particle range of energy E0 in a certain material and θ is the angle between the beam axis and the surface. The TLA technique allows to adjust the thickness of the label and thereby the sensitivity of the measurement. Q-reaction values and thresholds are tabulated in many books (see e.g. Qtool 2011: Calculation of Reaction Q-values and Thresholds) but one must bear in mind that real effective thresholds include the values of the Coulomb barrier.
Other Hazards in Clinical NMR Examinations
Bertil R. R. Persson, Freddy Ståhlberg in Health and Safety of Clinical NMR Examinations, 2019
There is another class of alloys called austenitic which has a characteristic grain structure first observed by Roberts-Austen. They have a stable structure consisting of uniform solid solution. Their elastic properties depend on cold-working and low-temperature heat treatment. Their corrosion resistance is notably higher than that of the martensitic type of stainless steel, hence they are the preferred type of alloy for human implantation. Although the raw material is nonmagnetic, cold-working, such as bending or cutting can induce significant ferromagnetic domains. Adding sufficient nickel (also nitrogen and carbon) to the alloy stabilizes iron in a nonmagnetic (γ) form at room temperature and reduces the magnetic susceptibility during cold working at room temperature. Thus, clips made of austenitic stainless steel with high nickel content (16 to 35% Ni) are found to have no ferromagnetism and are thus recommended to be used in NMR patients.16 Aneurysm clips made of tantalum or titanium are also nonferromagnetic and suitable to use in NMR patients.22
Discrepancy in alloy composition of imported and non-imported porcelain-fused-to-metal (PFM) crowns produced by Norwegian dental laboratories
Published in Biomaterial Investigations in Dentistry, 2020
Håvard Jostein Haugen, Brandon Michael Soltvedt, Peter N. Nguyen, Hans Jacob Ronold, Gaute Floer Johnsen
Subsequently, the crowns were grouped according to laboratories, alloy-type and organized in predetermined categories defined as: No deviation included crowns with only minor deviations in major constituents (elements that comprised >20 wt. %) and slight deviations in additional elements that comprised <10 wt. %. Small deviation included crowns with deviations <5 wt. percentage concerning major constituents and/or deviations >1 wt. % in additional elements that comprised <10 wt. %. Large deviation included deviations >5wt. % concerning major constituents and missing additional elements. This category also included crowns with elements that should not be found in the relevant alloys such as aluminum (Al) or were not specified. Incorrect alloy refers to crowns that comprised of elements similar to a different type of alloy. For example, a crown marked as CopraBond K with results showing elements such as silver (Ag) and palladium (Pd) and is likely an Argelite61 alloy. Unspecified alloy were crowns delivered without or with lacking alloy information.
Engineered titanium implants for localized drug delivery: recent advances and perspectives of Titania nanotubes arrays
Published in Expert Opinion on Drug Delivery, 2018
Shaheer Maher, Arash Mazinani, Mohammad Reza Barati, Dusan Losic
It is worth mentioning that, most of above-mentioned studies used pure titanium substrates in their experiments and only a few investigated titanium alloys. Titanium alloys are characterized by enhanced biomechanical properties as compared to pure Ti. In addition, most of implant devices, currently used in market, are made of Ti alloys. The incorporation of other metals, such as Al, V, Ta, Zr, etc. with Ti is found to add superior characteristics to the alloy such as more corrosion resistance, better hardness, lower elastic module, and higher withstand strength [38]. In one attempt, Liang et al. fabricated TNTs on Ti-4Zr-22Nb-2Sn alloy which were then tested for drug-delivery applications. Minocycline hydrochloride antibiotic was loaded onto TNTs and the release kinetics was compared for TNTs generated under different voltage [39].
Stress evaluation of different implant lengths on atrophic edentulous mandibles with fixed full-arch implant-supported prosthesis: a finite element analysis
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2020
Fernanda Benevides, Renata Cimões, André Vajgel, Ramiro Brito Wilmersdorf, Bruna de Carvalho Farias Vajgel
It is necessary to emphasize that for each simulated model, the components (implant, abutment, and prosthetic screw) were built and simulated as unitary bodies, while the coping was shaped as only a body with a metallic framework. This ensured that the models were developed within the necessary preconditions to obtain better representativeness of real models and provide better results on computational analysis, contrary to the other studies (Takahashi et al. 2010; Teixeira et al. 2010) that simplify the models, what can subsequently affect the achieved results. Co-Cr alloy properties were applied to the metallic framework since the studies demonstrated reduced stress with the use of this alloy due to its higher elastic modulus which permits better stress distribution (Weinberg 1993). The other components received Titanium alloy properties.
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