This book reveals the history of metals and alloys and their importance in prosthodontics. This book covers the review of literature, classification, discuss the metals and alloys and also the recent alloys used in prosthodontics.This book also revels the recent classification of the alloys according to ADA. This book explains each alloys properties,uses, compositions, advantages and disadvantages of each alloy.
The Theory of Transformations in Metals and Alloys (Part I + II),
Nowadays, the use of pure metals is quite limited in dentistry because they appear to be soft and may tend to corrode rapidly.To optimize properties, most of the metals commonly used in dental applications are mixtures of two or more metallic elements or one or more metals and/or non-metals. Although such mixtures can be produced in a number of ways. The use of these cast metals has decreased because of increased consumer demand for aesthetics over durability. Knowledge of the structure and properties of cast metals and alloys is essential to ensure proper handling of these materials. Thus this book is a compilation of all dental casting alloys and their applications in clinical dentistry.
New contributions to the cyclic plasticity of engineering materials Written by leading experts in the field, this book provides an authoritative and comprehensive introduction to cyclic plasticity of metals, polymers, composites and shape memory alloys. Each chapter is devoted to fundamentals of cyclic plasticity or to one of the major classes of materials, thereby providing a wide coverage of the field. The book deals with experimental observations on metals, composites, polymers and shape memory alloys, and the corresponding cyclic plasticity models for metals, polymers, particle reinforced metal matrix composites and shape memory alloys. Also, the thermo-mechanical coupled cyclic plasticity models are discussed for metals and shape memory alloys. Key features: Provides a comprehensive introduction to cyclic plasticity Presents Macroscopic and microscopic observations on the ratchetting of different materials Establishes cyclic plasticity constitutive models for different materials. Analysis of cyclic plasticity in engineering structures. This book is an important reference for students, practicing engineers and researchers who study cyclic plasticity in the areas of mechanical, civil, nuclear, and aerospace engineering as well as materials science.
The growth of technology has placed rather severe demands on materials engineers to come up with novel materials at low cost to meet stringent and often contradictory property requirements which conventional materials cannot satisfy. In this respect,composite materials show great promise because of their superior stiness, high strength at elevated temperatures and better creep characteristics. Starting as early as 1906 the rotating isotropic disc has been studied by Grubler (1906)followed by Donatch (1912). Probably the first recognition given to the industrial importance of creep was by Dickenson in 1922. Experimental studies have demonstrated that steady state creep rate in aluminum or its alloys may be reduced by several orders of magnitude when it is reinforced with ceramic particles/whiskers like silicon carbide. The purpose of the present work is to study the isotropic and anisotropic properties with different distribution of material particulates. In many applications,rotating discs are exposed to elevated temperatures where creep deformation becomes important. From this point of view, an attempt has been made to analyze creep in rotating disc made of Al-SiC composites.
Metal ion release from metallic materials, e.g. metallic alloys and pure metals, implanted into the human body in dental and orthopedic surgery are becoming a major cause for concern. This book briefly provides an overview of both metallic alloys and pure metals used in implant materials in dental and orthopedic surgery. Additionally, a short section is dedicated to important biomaterials and their corrosive behavior in both real solutions and various types of media that model human biological fluids and tissues. The present book gives an overview of analytical methods, techniques and different approaches applied to measurement of in vivo trace metals released into body fluids and tissues from patients carrying metal-on-metal prosthesis and metal dental implants. Reference levels of ion concentrations in body fluids and tissues that have been determined by a host of studies are compiled, reviewed and presented in this paper. Finally, a collection of published clinical data on in vivo released trace metals from metallic medical implants is included.
Mechanical vibrations of ultrasonic frequency exert a considerable influence upon the mechanical properties of metals, in particular, their deformation characteristics. The following three phenomena are considered: ultrasonic softening, ultrasonic hardening and the influence of preliminary ultrasonic treatment upon the steady-state creep of metals. Ultrasonic softening takes place when a ultrasonic loading is superimposed upon a static one, which results in the decrease of static load needed to deform the metal. Ultrasonic hardening occurs during the sonication of annealed material without a static loading. The ultrasonic hardening manifests itself in the increase of the yield strength of material due to the defects of crystalline structure nucleated and developed in acoustic field. Ultrasonic treatment consists of the ultrasonic irradiation of material and subsequent annealing. Materials treated in such a way can offer a considerable resistance to creep deformation. However, this tendency is not a monotonic function of the preliminary sonification parameters. A new theory, the synthetic theory of irrecoverable deformation, is employed to model the phenomena discussed above.
The present book included three of the published papers, which have been chosen in CSA's Mechanical & Transportation Engineering Abstracts Database, America, 2005. Also, one of the published paper has the name of " New lead free solder alloy". Also one paper has been published in Key to metals,2012. In this book, we explained some basic concepts of metallic alloys, types and applications of metallic alloys. Furthermore we explained the types of solder alloys. In addition, illustration the importance of the rapid solidification technology that is used for producing alloys with improved properties.
This work presents a new formulation of the Boundary Element Method (BEM) for nonlinear time-dependent problems. An incremental process, in order to reach the steady state condition and the secondary steady stage for visco-plasticity and creep respectively, has also been developed. This research includes the development of a new Boundary Element Formulation for analysis of fracture problems related to visco-plasticity and creep. For the visco-plastic and creep crack analysis the Dual Boundary Element Method, (DBEM) is formulated. The implementation of visco-plasticity and creep in the formulation is taken into account by domain integrals in both boundary integral equations. The creep analysis is basically applied to metals, and this is confined to standard power law creep equations. Constant applied loads are used to demonstrate time and strain hardening effects. The calculation of the modified fracture parameter J-Integral, which is called C(t)-Integral for creep analysis, is obtained by applying this method to crack problems. This book is appropriate for researchers, Ph.D. and postgraduate students involved in modern numerical methods and non-linear analysis.
Positron annihilation spectroscopy is non-destructive method for studying defects in solid state materials. Binary alloys of iron and aluminium are industrially interesting materials and are suitable candidate for studying the behavior of intermetallics with vacancy concentrations several orders higher than in pure metals. Measuring of the positron lifetime enables to classify defects type, volume size and concentration. Measuring of coincidence Doppler broadening of annihilation peak carries information about chemical environment of a positron trapped at the defect. These measurements are supported by quantum-mechanics theoretical calculations which help us to interpret the measured data. Mechanical properties were studied simultaneously by the measuring of Vickers microhardness and compared with the positron annihilation spectroscopy results. The correlation of defect concentration with mechanical properties was observed in Fe-Al alloys with various composition and after various thermal treatments.
A filling is the repair of a damaged or decayed tooth, restoring it back to its normal shape, appearance and function. Amalgam Restoration is an example of the material giving its name to the process. Amalgam fillings are made up of mercury, powdered silver and tin. They are mixed and packed into cavities in teeth where it hardens slowly and replaces the missing tooth substance. The high copper have become material of choice as compared to low copper alloys nowadays because of their improved mechanical properties, corrosion resistance, better marginal integrity and improved performance in clinical trial. The high copper amalgam was used as a restorative material and was found to be much more useful than low copper amalgam. High copper had much more strength, corrosion resistance, durability and resistance to tarnish as compared to low copper amalgams. No marked expansion or condensation was noted in the amalgam restoration after its setting after 24 hrs. By using the high copper alloy, the chances of creep were also minimized in the restored tooth. No discomfort or any kind of odd sensation in the tooth was noted after few days of amalgam restoration in the tooth.
Summary: Materials are the essential part of our daily life and civilizations have been known by the materials they introduced. As the science progressed, scientists used the different combinations of material to enhance their properties to cope with new challenges and requirements. Alloys are also the combination of different materials specifically of metals. In early ages Iron and their alloys were used in the manufacturing heavy machineries. Gradually elements of lighter weight replaced the ferrous material like Alloys of Mg and Al. The main focus of this book will be on Aluminum Alloys specifically on Aluminum Alloy 2024. Aluminium alloys called super alloys because of their preferable mechanical and chemical properties for wide range of applications and uses. 2024 aluminium alloy was fabricated by taking percentage weight composition of Al-Cu-Mg-Zn.Corrosion tests were performed in 0.1M NaCl, 1% aqua regia and 5% aqua regia, 1% Potassium Dichromate solution and weight change was recorded in different intervals of time. Corrosion rate was studied by using Atomic Absorption Spectroscopy and morphological studies was accomplished by using Optical Microscopy.
A consideration has been given to dynamic models of formation of martensite plates with a fine structure of transformation twins, which are compatible with the supersonic growth rate of martensite crystals. Along with relatively long quasi-longitudinal waves, which determine the orientation of the habit plane, the control wave process includes relatively short longitudinal waves, which act in synchronism and control the growth of the main component of a regular twin structure. Preference is given to a model containing, at the initial moment of time, the only active dynamic cell capable of periodic reproduction in the interphase region at the stage of the martensite crystal growth. The calculated macroscopic morphological attributes, which were deduced from dynamic considerations, have been compared with the experimental data and crystallogeometrical calculation. Discussion of results and conclusions in a final part of the monography represent the independent interest. For scientific employees and experts in the field of metallography and physics of metals and alloys, as well as teachers, post-graduate students and the students who are specializing in materials technology.
With the advancements in technology more & more artificial metals, alloys and other implantable and non implantable materials are being used in the fields of medicine and dentistry. These materials directly or indirectly come in contact with skin, epithelium, connective tissue or bone. Given this long term intimate contact with vital tissues, it is paramount that alloy biocompatibility be investigated and understood. Moreover the oral and maxillofacial environment is complex and varied with different requirement and biocompatibility issues depending on the specific use. Unfortunately in our educational curriculums these important issues are not thoroughly understood, investigated or taught. In this book authors have made an utmost effort to make readers get a fair idea about these important issues and discuss the recent researches in this field. This will surely be a very useful piece of work for the medical and dental students, practitioners, assistants, technicians, manufacturer and many others who directly or indirectly come in contact with these materials.
Principles of MIC: Is introduction to corrosion, thermodynamic and kinetic of corrosion, corrosion rate, passivity and polarization. Corrosion types also mention in this book especially Microbiological Influenced Corrosion which discusses the mechanism of corrosion by living microorganisms especially in pipelines and how detect them, in addition to review some examples of this type of corrosion may be occur in metals and alloys.
The so-called creep strength enhanced ferritic 9-12% Cr steels have been identified as the most promising class of materials for some of the key components in ultra-supercritical fossil-fired power plants, including the main steam pipes, headers and superheater tubings. These steels are less costly, and they have a lower coefficient of thermal expansion and a higher thermal conductivity when compared with austenitic stainless steels, making them less susceptible to degradation through thermal fatigue. However, experience has shown that the weldments in these steels are particularly prone to premature creep failure, due to a localised form of cracking in the heat-affected zone, which is referred to as Type IV cracking. The work presented in this thesis is concerned with the effects of residual stresses and constraint on Type IV cracking. It was found that the highest as-welded tensile stresses resided near the outer boundary of the HAZ, and towards the weld root region and these were not fully relieved by the applied PWHT. In both conditions substantial tensile direct and hydrostatic stresses existed across the HAZ, including the fine-grained and intercritically-annealed regions.