The advanced structural materials for living beings implants

The paper deals with development of bioinert and bioactive biomaterials, different application of structural materials, including metallic materials, nanomaterials, nanostructured materials, biomaterials, ceramics, polymers, hybrid materials, functional graded materials, composites. Also are discussed multi-functional engineering materials with gradient properties, engineering materials for challenging application conditions, including aggressive environment and lightweight, multi-material (hybrid) systems where advanced materials are combined with more conventional / structural materials and materials production or joining technologies. Interdisciplinary approach to biomedicine materials research and production is very promising and horizontal cooperation of different national technology platforms is discusse

Coatings and Surface Modification of Alloys for Tribo-Corrosion Applications

This review of the tribocorrosion of coatings and surface modifications covers nearly 195 papers and reviews that have been published in the past 15 years, as compared to only 37 works published up to 2007, which were the subject of a previous review published in 2007. It shows that the research into the subject area is vibrant and growing, to cover emerging deposition, surface modification and testing techniques as well as environmental influences and modelling developments. This growth reflects the need for machines to operate in harsh environments coupled with requirements for increased service life, lower running costs and improved safety factors. Research has also reacted to the need for multifunctional coating surfaces as well as functionally graded systems with regard to depth. The review covers a range of coating types designed for a wide range of potential applications. The emerging technologies are seen to be molten-, solution-, PVD- and PEO-based coatings, with CVD coatings being a less popular solution. There is a growing research interest in duplex surface engineering and coating systems. Surface performance shows a strong playoff between wear, friction and corrosion rates, often with antagonistic relationships and complicated interactions between multiple mechanisms at different scale lengths within tribocorrosion contacts. The tribologically induced stresses are seen to drive damage propagation and accelerate corrosion either within the coating or at the coating coating–substrate interface. This places a focus on coating defect density. The environment (such as pH, DO2, CO2, salinity and temperature) is also shown to have a strong influence on tribocorrosion performance. Coating and surface modification solutions being developed for tribocorrosion applications include a whole range of electrodeposited coatings, hard and tough coatings and high-impedance coatings such as doped diamond-like carbon. Hybrid and multilayered coatings are also being used to control damage penetration into the coating (to increase toughness) and to manage stresses. A particular focus involves the combination of various treatment techniques. The review also shows the importance of the microstructure, the active phases that are dissolved and the critical role of surface films and their composition (oxide or passive) in tribocorrosion performance which, although discovered for bulk materials, is equally applicable to coating performance. New techniques show methods for revealing the response of surfaces to tribocorrosion (i.e., scanning electrochemical microscopy). Modelling tribocorrosion has yet to embrace the full range of coatings and the fact that some coatings/environments result in reduced wear and thus are antagonistic rather than synergistic. The actual synergistic/antagonistic mechanisms are not well understood, making them difficult to model

Novel Thin Film Technologies for Rapid Manufacture of Glassy Carbon and its Application in Printed Electronics and Energy Storage

This doctoral thesis is a research study into the thin film manufacture and applications ofglassy carbon. The aim of this research was to explore photonic curing as a novel rapidmanufacturing method to produce glassy carbon thin films and to expand the applicationsof glassy carbon in energy storage and printed electronics.Photonic curing was explored as a rapid method for producing glassy carbon coatings, reducing processing time from ~20 hours for conventional thermal processing down to ~1 minute. For both photonic and conventional thermal produced coatings, Raman spectroscopy and primary peak XPS data showed sp2 bonded carbon, indicative of bulk glassy carbon. XPS analysis indicated greater sp3 content at the immediate surface (5-10 nm) for photonic cured carbon compared with thermally cured carbon, likely due to the local environment (temperature, atmosphere) around the surface during conversion. The produced coatings were resilient, highly smooth, with no evidence of surface defects.The ability to rapidly manufacture glassy carbon coatings, by way of photonic curing, expands the potential window of applications of glassy carbons for high volume applications such as coatings for energy storage, rapid manufacture of complex electrically conductive shapes, and the opportunity to use temperature sensitive substrates.Photonic cured and thermal carbonized glassy carbon thin films were explored as electrode active materials. The glassy carbon thin films from both manufacturing methods showed comparable specific capacitances to one another and to the use of porous glassy carbon as a supercapacitor active electrode material in literature.Screen printed glassy carbon structures were made to explore potential applications for glassy carbon in printed electronics and sensors. These prints yielded electrical conductivities comparable to carbon based conductive inks, potentially expanding the applications window for glassy carbon for electronics devices with high chemical resistance, low reactivity and high thermal stability. Screen printed glassy carbon temperature and salinity sensors were produced and tested, glassy carbon as a temperature sensor yielded promising results whereas glassy carbon as a salinity sensor did not have a significant response with the investigated parameters

Optimization of Catalytic Microreactors for Ammonia Decomposition

Hydrogen is an attractive source for zero-emission energy because of its usefulness in fuel cell batteries. However, traditional methods to capture hydrogen for use in these cells, such as steam reforming, produce unwanted byproducts. Ammonia decomposition is a promising method to produce hydrogen, and our research explored the possibility of using catalyst-coated microreactors to improve the decomposition reaction. Microreactors have unique benefits over traditional reactors such as mass/heat transport properties, precision controls, and improved safety. Creation and characterization of thin films led to a design for a wall-coated nickel alumina catalyst microreactor. Our design was confirmed by testing various parameters of the microreactor by modeling heat transfer properties

Functional Ceramic Coatings

Ceramic materials in the form of coatings can significantly improve the functionality and applications of other engineering materials. Due to a wide range of controllable features and various deposition methods, it is possible to create tailored substrate–coating systems that meet the requirements of modern technologies. Therefore, it is crucial to understand the relationships between the structures, morphology and the properties of ceramic coatings and expand the base of scientific knowledge about them. This book contains a series of fourteen articles which present research on the production and properties of ceramic coatings designed to improve functionality for advanced applications

Non-Oxide Ceramics for Bone Implant Application: State-of-the-Art Overview with an Emphasis on the Acetabular Cup of Hip Joint Prosthesis

A rapidly developing area of ceramic science and technology involves research on the interaction between implanted biomaterials and the human body. Over the past half century, the use of bioceramics has revolutionized the surgical treatment of various diseases that primarily affect bone, thus contributing to significantly improving the quality of life of rehabilitated patients. Calcium phosphates, bioactive glasses and glass-ceramics are mostly used in tissue engineering applications where bone regeneration is the major goal, while stronger but almost inert biocompatible ceramics such as alumina and alumina/zirconia composites are preferable in joint prostheses. Over the last few years, non-oxide ceramics—primarily silicon nitride, silicon carbide and diamond-like coatings—have been proposed as new options in orthopaedics in order to overcome some tribological and biomechanical limitations of existing commercial products, yielding very promising results. This review is specifically addressed to these relatively less popular, non-oxide biomaterials for bone applications, highlighting their potential advantages and critical aspects deserving further research in the future. Special focus is also given to the use of non-oxide ceramics in the manufacturing of the acetabular cup, which is the most critical component of hip joint prostheses

Corrosion of bio implants

Chemical stability, mechanical behaviour and biocompatibility in body fluids and tissues are the basic requirements for successful application of implant materials in bone fractures and replacements. Corrosion is one of the major processes affecting the life and service of orthopaedic devices made of metals and alloys used as implants in the body. Among the metals and alloys known, stainless steels (SS), Co-Cr alloys and titanium and its alloys are the most widely used for the making of biodevices for extended life in human body. Incidences of failure of stainless steel implant devices reveal the occurrence of significant localised corroding viz., pitting and crevice corrosion. Titanium forms a stable TiO2 film which can release titanium particles under wear into the body environment. To reduce corrosion and achieve better biocompatibility, bulk alloying of stainless steels with titanium and nitrogen, surface alloying by ion implantation of stainless steels and titanium and its alloys, and surface modification of stainless steel with bioceramic coatings are considered potential methods for improving the performance of orthopaedic devices. This review discusses these issues in depth and examines emerging directions

Development of Low Temperature Alpha Alumina Coatings by AC Magnetron Sputtering

Alpha-phase aluminum oxide thin films were created using an Isoflux ICM-10 dual target inverted cylindrical magnetron sputtering system using mid-frequency AC power supplies. Alpha alumina films were deposited at a magnetron power of 6 kW, 50% oxygen partial pressure by volume, and -35 V DC bias. Film thickness, substrate material, and position and orientation within the deposition chamber were varied. To ensure the deposition conditions are suitable for alloys, the substrate temperature was measured using temperature indicating liquids. The experimental results, supported by Explicit Euler numerical analysis, revealed a steady state temperature of ~480°C at 6kW. Transmission electron microscopy (TEM) was used to study alumina films deposited on stainless steel with and without an alpha-phase chromium oxide template layer. The selected area electron diffraction (SAED) patterns indicate that, for both cases, the films tend be predominately alpha-phase with discernable gamma-phase components. Alpha alumina thin films were deposited on titanium to assess their viability as corrosion and wear resistant biomedical implants. Corrosion resistance tests indicated that the coated titanium had improved performance and stability compared to the uncoated titanium. However, the coefficient of friction increased with the applied film. Films were deposited on surgical stainless steel substrates to investigate the adsorption of a model protein (BSA, bovine serum albumin). Results indicate that there was a 50% reduction in protein adsorption for samples with the alumina coating compared to those with no coating