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An Introduction to Bio-Implants and Biodegradable Materials
Published in Atul Babbar, Ranvijay Kumar, Vikas Dhawan, Nishant Ranjan, Ankit Sharma, Additive Manufacturing of Polymers for Tissue Engineering, 2023
Tapinderjit Singh, Sandeep Singh, Gurpreet Singh
Materials such as alumina and zirconia are often considered as bioinert. The implant gets the shield of a soft tissue interlayer which makes no direct bone–material interface. A successful bone ingrowth by fibrous tissue is achieved only under compression with a porous structure to fit with bone cavity. Since 1990, use of zirconia femoral heads (6 million) and alumina components (3.5 million) worldwide led to implantation-associated clinical success (Bahraminasab et al., 2012). The major drawback reports associated with bioceramics are due its intrinsic brittleness. Alumina has been used with a limited number of designs under low mechanical loads (Chevalier, 2006). The related mechanical properties of these materials are mentioned in Table 3.1 (Ruso et al., 2015). Moreover, yttria-stabilized zirconia (Y-TZP), due to high fracture toughness and strength, became in use having native structural similarity with alumina. Y-TZP enhanced new designs (knees and femoral heads) with improved mechanical properties which was previously not possible with alumina (Ruso et al., 2015). Figures 3.1–3.3 show the different sizes of femoral heads with the implant in the human body (Affatato, 2014b; Gautam and Malhotra, 2017; King and Phillips, 2016).
Thin Film Materials for Energy Applications
Published in Fredrick Madaraka Mwema, Tien-Chien Jen, Lin Zhu, Thin Film Coatings, 2022
Fredrick Madaraka Mwema, Tien-Chien Jen, Lin Zhu
Zirconium oxide was historically used as an electrolyte but has been overtaken by yttrium stabilised zirconia (YSZ), providing good conductivity at temperatures above 800°C. Cathode and anode performances are also improved with the use of strontium-doped lanthanum (LSM) and Ni-YSM cermet for former and later, respectively.
Fuel Cells
Published in Michael F. Hordeski, Emergency and Backup Power Sources:, 2020
The current technology employs several ceramic materials for the active SOFC components. The anode is typically constructed from an electronically conducting nickel/yttria-stabilized zirconia cermet (Ni/YSZ). The cathode is based on a mixed conducting perovskite, lanthanum manganate (LaMnO3). Yttria-stabilized zirconia (YSZ) is used for the oxygen ion-conducting electrolyte. To generate a suitable voltage, fuel cells are not operated as single units but as a series array of units or stack, with a doped lanthanum chromite (La0.8Ca0.2CrO3) interconnect joining the anodes and cathodes of adjacent units.
First-principles prediction of high oxygen-ion conductivity in trilanthanide gallates Ln3GaO6
Published in Science and Technology of Advanced Materials, 2019
Joohwi Lee, Nobuko Ohba, Ryoji Asahi
Oxygen-ion conductors with high oxygen-ion conductivities (σO) have been developed for important applications [1,2], such as electrolytes of solid oxide fuel cells (SOFC), oxygen separation membranes, and gas sensors. Currently, yttria-stabilized zirconia (YSZ) is widely used because of its advantages, such as abundance, chemical stability, non-toxicity, and low cost. This material is known to exhibit a σO of ~10−2 S/cm at a high temperature of 1000 K [2,3]. For useful industrial applications, it is necessary to be further improved to have similar σO values at lower temperatures or a higher σO at a similar temperature. Indeed, there are several oxides such as Gd-doped CeO2 (GDC) [4] and pure or Er-doped δ-phase of Bi2O3 [5,6], which have been reported to have higher σO at the same temperature than YSZ. However, there have been great efforts for the development of new oxygen-ion conductors that can substitute for YSZ with enough merits in practice.
Tribological behaviours of 8YSZ coating sliding against different counterparts
Published in Surface Engineering, 2021
Wen Deng, Lin Tang, Changfu Zhang, Hui Qi
The fatigue wear will lead to premature failure of mechanical components, and the failure of key parts of mechanical components may cause catastrophic consequences. Therefore, the lubrication and wear resistance of moving parts under extreme conditions has become a bottleneck affecting the reliability and life of mechanical systems. Recent years, with the emergence of advanced surface modification equipment and technology, all kinds of high-performance and functional coating materials are provided for the preparation of new coatings on metal substrates, which endows metal surfaces with good protection and improves their tribological performance as well as the efficiency of moving parts [1–4]. Ceramic materials with high hardness, good chemical stability, anti-corrosion and wear as well as other typical characteristics are widely used in the industrial field to protect metal parts from wear [5–8]. Zirconia is an important structural and functional material with excellent physical and chemical properties. Especially, yttria-stabilized zirconia possesses good toughness and strength as well as high-temperature resistance and corrosion resistance, which are widely used in the field of the thermal barrier coating [9–12]. Owing to the excellent service performance, zirconia-based ceramic coatings have been applied extensively in the field of tribology, but the research on friction is rare. Of various processing techniques for depositing ceramic coatings, atmospheric plasma spraying (APS) technology is very powerful and attractive due to its high deposition efficiency, low economic cost, widely used spraying materials and good adaptability to work size [13,14].