High Entropy Alloys for Medical Applications
By Victor Geanta, Ionelia Voiculescu, Petrica Vizureanu and Andrei Victor Sandu
A wide variety of metallic biomaterials have been developed so far, including various types of alloys. However, there is a strong need in the medical field for new solutions in what concerns metallic biomaterials with superior biocompatibility and mechanical properties in order to meet future requirements, including the recently developed high entropy alloys (HEAs). This chapter presents some characteristics of high entropy biocompatible metallic alloys produced in an electric-arc remelting furnace in argon inert atmosphere. The effects of the chemical elements used, the microstructural features, and some mechanical characteristics, both in the cast state or after some heat treatments, are highlighted.
Part of the book: Engineering Steels and High Entropy-Alloys
Development of New Advanced Ti-Mo Alloys for Medical Applications
By Petrică Vizureanu, Mădălina Simona Bălțatu and Andrei Victor Sandu
The use of titanium and titanium-based alloys with applications in implantology and dentistry has made remarkable progress in the promotion of new technologies and new materials that have been developed in recent years. This is justified thanks to their excellent mechanical, physical, and biological performance. Today’s generation promotes new titanium alloys, with nontoxic elements and long-term performance and without rejection of the human body. This book chapter describes new original compositions of Ti-based alloys for medical applications, with improved properties compared to existing classical alloys (C.p. Ti, Ti6Al4V, CoCrMo, etc.). The addition of nontoxic elements such as Mo, Si, Zr, and Ta brings benefits as reduced modulus of elasticity, increased corrosion resistance, and improved biocompatibility.
Part of the book: Biomaterials
The Physical and Mechanical Characteristics of Geopolymers Using Mine Tailings as Precursors
By Petrica Vizureanu, Dumitru Doru Burduhos Nergis, Andrei Victor Sandu, Diana Petronela Burduhos Nergis and Madalina Simona Baltatu
Mine tailings are waste materials that resulted from the extraction and processing of raw materials to form mineral products. These dusty particles present negative environmental effects after being deposited in different types of dumping areas. Based on the circular economy concepts and the presently pushing need of identifying wastes as a potential replacement for natural resources, this chapter aims to present the physical (density, microstructure) and mechanical (compressive strength, flexural strength) characteristics of different types of geopolymers which use mine tailings as precursors or blended systems (mixes of different raw materials). The main reasons of approaching this topic are the need to decrease the consumption of natural resources, reduce environmental pollution and create an economic system aimed to capitalize the mining wastes. Accordingly, this chapter includes information regarding the availability of this waste and its potential utilization as a raw material in civil engineering applications. Therefore, reports of specific agencies and multiple research studies which approach tailing based geopolymers or blended systems have been summarized.
Part of the book: Advances in Geopolymer-Zeolite Composites
New Trends in Bioactive Glasses for Bone Tissue: A Review
By Petrică Vizureanu, Mădălina Simona Bălțatu, Andrei Victor Sandu, Dragos Cristian Achitei, Dumitru Doru Burduhos Nergis and Manuela Cristina Perju
Bioactive glasses are very attractive materials, used for tissue engineering materials, usually to fill and restore bone defects. This category of biomaterials, show considerable potential for orthopaedic surgery because they can promote bone tissue regeneration. Many trace elements have been incorporated in the glass network, an example is metallic glasses to obtain the desired properties. Because of tolerable mechanical properties, and because they are able to bond to living bone and stimulate its regeneration, this bioactive glasses have a particular interest and are in a continuous research and improvement. The chapter presents the history of bioactive glasses, classification, include a summary of common fabrication methods, applications, surface coatings, applications and future trends in relation to human bone. This review highlight new trends and areas of future research for bioactive glasses.
Part of the book: Current Concepts in Dental Implantology
Assessment of Solar Energy Potential Limits within Solids on Heating-Melting Interval View all chapters
By Petrica Vizureanu, Madalina-Simona Baltatu, Andrei-Victor Sandu, Dragos-Cristian Achitei, Dumitru-Doru Burduhos-Nergis and Manuela-Cristina Perju
The solar furnace works by using the electric energy produced by a photovoltaic system, which converts solar energy, solar radiation, into electric energy. The performances of the solar furnace used in various applications from industry are influenced by various factors. One of these factors imposes the acquisitions of certain large densities of the radiant power, and it requires a geometric form of the concentrator. The research is based on the behavior of some metallic alloys at elevated temperatures, for purifying some materials and for the achievement of some chemical synthesis. An important technological condition is a temperature which is achieved by concentrating solar radiation. This temperature is necessary to produce metallic material in the crucible, without other complementary energy for the thermal process. Steel or aluminum production requires very high quantities of thermal energy. Usually, this energy is given by electric power, natural gases, or conventional fuels. The solar furnace uses the energy given by the sun. For the manufacturing of the electrothermal furnaces, a series of specific materials are used, which are necessary for the obtaining of the furnace chamber, for the heating elements, as well as for the measurement systems of the temperature.
Part of the book: Latest Research on Energy Recovery