Materials Processing Defects


Book Description

The technological field of defects, and more appropriately, avoidance of them, is very current in perhaps all sectors of the manufacturing industry. This is particularly important to reduce/minimize waste everywhere to address lean production procedures. The recent advances in finite plasticity and visioplasticity, damage modelling, instability theories, fracture modelling, computer numerical techniques and process simulation etc. offer new approaches and tools for defect prediction, analyses and guidelines for designing components to be manufactured by traditional and emerging process technologies.This volume contains contributions from well known researchers and experts in the field presenting an up-to-date overview of advances in this area. Subjects covered include: micro- and macro-scale observation of defects; localization and instability analysis; damage modelling and fracture criteria; defect prediction methods; design considerations to avoid defects.




Advanced Methods in Materials Processing Defects


Book Description

This collection of papers focus on advanced methods for predicting and avoiding the occurrence of defects in manufactured products. A new feature is included, namely, the influence of the processing-induced defects on the integrity of structures.The following topics are developed: damage modeling; damage evaluation and rupture; strain localization and instability analysis; formability characterization; prediction of shape inaccuracies; influence of defects on structural integrity. The main manufacturing operations are covered and various materials are examined, such as new and conventional metal alloys, ceramics, polymers and composites.




Elements of Structures and Defects of Crystalline Materials


Book Description

Elements of Structures and Defects of Crystalline Materials has been written to cover not only the fundamental principles behind structures and defects, but also to provide deep insights into understanding the relationships of properties, defect chemistry and processing of the concerned materials. Part One deals with structures, while Part Two covers defects. Since the knowledge of the electron configuration of elements is necessary for understanding the nature of chemical bonding, it is discussed in the opening chapter. Chapter Two then describes the bonding formation within the crystal structures of varied materials, with Chapter Three delving into how a material's structure is formed. In view of the importance of the effects of the structure distortion on the material properties due to the fields, the related topics have been included in section 3.4. Moreover, several materials still under intensive investigation have been illustrated to provide deep insights into understanding the effects of the relationships of processing, structures and defects on the material properties. The defects of materials are explored in Part II. Chapter 4 deals with the point defects of metal and ceramics. Chapter 5 covers the fundamentals of the characteristics of dislocations, wherein physics and the atomic mechanics of several issues have been described in detail. In view of the significant influence of the morphologies including size, shape and distribution of grains, phases on the microstructure evolution, and, in turn, the properties of materials, the final chapter focuses on the fundamentals of interface energies, including single phase (grain) boundary and interphase boundary. - Discusses the relationship between properties, defect chemistry and the processing of materials - Presents coverage of the fundamental principles behind structures and defects - Includes information on two-dimensional and three-dimensional imperfections in solids




Computational Methods for Predicting Material Processing Defects


Book Description

The papers in this book deal with computational methods for predicting material processing defects. Using recent advances in finite strain plasticity and viscoplasticity, damage modelling, bifurcation and instability theory, fracture mechanics and computer numerical techniques, new approaches to mechanical defect analysis are proposed. Appropriate methods for explaining and avoiding the defects leading to fracture, high porosity, strain localization or undesirable geometrical imperfections are presented. In addition, some papers are devoted to new formulations and new calculation algorithms to be used for solving the forming problems. Finally, two papers deal with physical description of defects occurring in forming and cutting operations, focusing on the academic and practical interest of these topics.This is the first book to deal with the prediction of defects occurring in material forming processes; it contains much of interest from both a theoretical and a practical viewpoint.













Defects and Damage in Composite Materials and Structures


Book Description

The advantages of composite materials include a high specific strength and stiffness, formability, and a comparative resistance to fatigue cracking and corrosion. However, not forsaking these advantages, composite materials are prone to a wide range of defects and damage that can significantly reduce the residual strength and stiffness of a structure or result in unfavorable load paths. Emphasizing defect identification and restitution, Defects and Damage in Composite Materials and Structures explains how defects and damage in composite materials and structures impact composite component performance. Providing ready access to an extensive, descriptive list of defects and damage types, this must-have reference: Examines defect criticality in composite structures Recommends repair actions to restore structural integrity Discusses failure modes and mechanisms of composites due to defects Reviews NDI processes for finding and identifying defects in composite materials Relating defect detection methods to defect type, the author merges his experience in the field of in-service activities for composite airframe maintenance and repair with indispensable reports and articles on defects and damage in advanced composite materials from the last 50 years.







Charged Semiconductor Defects


Book Description

Defects in semiconductors have been studied for many years, in many cases with a view toward controlling their behaviour through various forms of “defect engineering”. For example, in the bulk, charging significantly affects the total concentration of defects that are available to mediate phenomena such as solid-state diffusion. Surface defects play an important role in mediating surface mass transport during high temperature processing steps such as epitaxial film deposition, diffusional smoothing in reflow, and nanostructure formation in memory device fabrication. “Charged Defects in Semiconductors” details the current state of knowledge regarding the properties of the ionized defects that can affect the behaviour of advanced transistors, photo-active devices, catalysts, and sensors. Features: group IV, III-V, and oxide semiconductors; intrinsic and extrinsic defects; and, point defects, as well as defect pairs, complexes and clusters.