Author: John Douglas PlummerPublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
On the Physical Aspects that Control Mechanical Deformation in Bulk Metallic Glasses
Author: John Douglas PlummerOn the Physical Aspects that Control Mechanical Deformation in Bulk Metallic Glasses
Author: John PlummerBulk Metallic Glasses
Author: C. SuryanarayanaPublisher: CRC Press
ISBN: 1498763685
Category : Technology & Engineering
Languages : en
Pages : 543
Book Description
Reflecting the fast pace of research in the field, the Second Edition of Bulk Metallic Glasses has been thoroughly updated and remains essential reading on the subject. It incorporates major advances in glass forming ability, corrosion behavior, and mechanical properties. Several of the newly proposed criteria to predict the glass-forming ability of alloys have been discussed. All other areas covered in this book have been updated, with special emphasis on topics where significant advances have occurred. These include processing of hierarchical surface structures and synthesis of nanophase composites using the chemical behavior of bulk metallic glasses and the development of novel bulk metallic glasses with high-strength and high-ductility and superelastic behavior. New topics such as high-entropy bulk metallic glasses, nanoporous alloys, novel nanocrystalline alloys, and soft magnetic glassy alloys with high saturation magnetization have also been discussed. Novel applications, such as metallic glassy screw bolts, surface coatings, hyperthermia glasses, ultra-thin mirrors and pressure sensors, mobile phone casing, and degradable biomedical materials, are described. Authored by the world’s foremost experts on bulk metallic glasses, this new edition endures as an indispensable reference and continues to be a one-stop resource on all aspects of bulk metallic glasses.
Bulk Metallic Glasses
Author: Michael MillerPublisher: Springer
ISBN: 9781441943132
Category : Technology & Engineering
Languages : en
Pages : 0
Book Description
Bulk metallic glasses are a new emerging field of materials with many desirable and unique properties. These amorphous materials have many diverse applications from structural applications to biomedical implants. This book provides a complete overview of bulk metallic glasses. It covers the principles of alloy design, glass formation, processing, atomistic modeling, computer simulations, mechanical properties and microstructures.
Structural Aspects of Deformation in Bulk Metallic Glasses
Author: Yang TongPublisher:
ISBN:
Category : Metallic glasses
Languages : en
Pages : 119
Book Description
Metallic glasses have liquid-like structure without well-defined topological defects like dislocations in metals and alloys. The unique disordered structure of metallic glasses leads to unique mechanical properties, such as inhomogeneous deformation at low temperature and homogeneous deformation at high temperature, and brittle behavior induced by annealing. This dissertation address three critical issues related to the mechanical behavior of metallic glasses: 1. Identification of deformation defects in metallic glasses. We have conducted high energy X-ray diffraction experiment -- using anisotropic pair distribution function -- to characterize the size and density of defects in metallic glasses activated by external stresses. Our results based on the characterization method reveal the microscopic origin of ductility in some metallic glasses. 2. Identification of two local stress relaxation modes that control macroscopic mechanical properties in metallic glasses. Using the defect characterization method we developed, we revealed two different local stress relaxation modes in defect regions, which are responsible for inhomogeneous and homogeneous deformation respectively. 3. We developed structural rejuvenation method to improve and recover the compressive plasticity. The microscopic mechanism of structural rejuvenation was unveiled by structural study and molecular dynamics simulation.
Metallic Glasses
Author: Hu HuangPublisher: BoD – Books on Demand
ISBN: 1789237203
Category : Technology & Engineering
Languages : en
Pages : 146
Book Description
Metallic glasses are very promising engineering and functional materials due to their unique mechanical, chemical, and physical properties, attracting increasing attention from both scientific and industrial communities. However, their practical applications are greatly hindered due to three main problems: dimensional limit, poor tension plasticity, and difficulty in machining and shaping. Therefore, further investigation of these issues is urgently required. This book provides readers with recent achievements and developments in the properties and processing of metallic glasses, including mainly thermoplastic forming of metallic glasses (Chapter 2), atomic-level simulation of mechanical deformation of metallic glasses (Chapter 3), metallic glass matrix composites (Chapter 4), and tribo-electrochemical applications of metallic glasses (Chapters 5 and 6).
Bulk Metallic Glasses
Author: C. SuryanarayanaPublisher: CRC Press
ISBN: 1439859698
Category : Technology & Engineering
Languages : en
Pages : 686
Book Description
In spite of the large amount of research activity in this subfield of materials science and engineering, there is no single book available that provides background information, methods of synthesis, characterization procedures, properties, and potential and existing applications.of bulk metallic glasses. Written in an easy-to-understand style by pioneering researchers in this field, Bulk Metallic Glasses is one of the first books to coherently discuss the synthesis, processing, properties, and applications of these unique materials. The book explores the differences between nanocrystalline, glassy, and amorphous solids as well as the thermodynamics and kinetics and various processing methods of glass formation. It critically compares the different criteria for glass formation, describes the advantages and limitations of experimental methods for synthesizing bulk metallic glasses in assorted sizes and shapes, and examines the kinetics of crystallization/devitrification and the mechanisms of transformations. It also covers the density, diffusivity, thermal expansion, electrical resistivity, specific heat, viscosity, corrosion resistance, mechanical behavior, and magnetic properties of bulk metallic glasses. After presenting a wide array of applications, the book concludes with a discussion on the future of these materials. The adoption of bulk metallic glasses into existing systems is besieged by many obstacles but due to their interesting combination of properties, future applications may be unlimited. A one-stop resource on all aspects of bulk metallic glasses, this book demonstrates the immense potential of these novel materials. It clearly elucidates the background, detailed methods of synthesis and characterization, structure, and properties of bulk metallic glasses.
Study of Mechanical Behaviors and Structures of Bulk Metallic Glasses with High-energy Synchrotron X-ray Diffraction
Author: Feng JiangPublisher:
ISBN:
Category :
Languages : en
Pages : 192
Book Description
This dissertation addresses two critical issues in the mechanical behaviors and structures of bulk-metallic glasses (BMGs): (1) the effect of composition, fabrication method, and pretreatment of plastic deformation on mechanical properties and structures of BMGs; (2) the mechanical response and structural evolution of BMGs in the elastic and plastic region. (Cu50Zr50)94Al6 and (Cu50Zr50)92Al amorphous alloys were used to study the effect of composition on mechanical properties and structures of BMGs. The (Cu50Zr50)94Al6 alloy exhibits lower yield stress and Young's modulus, higher Poisson's ratio, worse thermal stability, and better plasticity than (Cu50Zr50)92Al. Both the topological and chemical effects of Al addition account for the differences of mechanical and physical properties between them. A Zr55Ni5Al10Cu30 glass-forming alloy with injection casting (the melting temperatures are 1,550 K and 1,250 K, respectively) and with suction casting was fabricated. The results indicate that despite their amorphous structures, the suction-casting samples exhibit a lower yield stress, lower Young's modulus, and larger plastic strain than the injection-casting samples (the melting temperature is 1,550 K) due to more quenched-in free volumes in suction casting, which results from the higher cooling rate. The inhomogeneous plastic deformation in Zr50Cu40Al10 BMG samples was introduced by four-point-bend fatigue. There is almost no difference of the stress-strain behaviors between the deformed and undeformed samples. Elastostatic compression was used to introduce homogeneous deformation in Zr--0Cu6Ni16Al8 BMG samples. The preloaded samples are softer with decreases of yield strength and Young's moduli. Anisotropy was observed in the preloaded samples despite their small magnitudes, which even occurred at a relatively low temperature and applied stress level. The structural evolution of Zr--0Cu6Ni16Al8 BMG in the elastic region was analyzed with anisotropic pair density function. The analysis of the first shell of Zr--0Cu6Ni16Al8 glass confirms the structural changes in the elastic region. The bond reorientation leads to direction dependent changes in the chemical short-range order. The structural evolution in the plastic region of Zr--0Cu6Ni16Al8 BMG is investigated as well. The serrations were observed for both the stress-displacement and full width at half maximum-displacement curves. The excess free volume was measured, which increases with increasing the displacement.
Bulk Metallic Glasses
Author: C. SuryanarayanaPublisher: CRC Press
ISBN: 1420085972
Category : Technology & Engineering
Languages : en
Pages : 547
Book Description
In spite of the large amount of research activity in this subfield of materials science and engineering, there is no single book available that provides background information, methods of synthesis, characterization procedures, properties, and potential and existing applications.of bulk metallic glasses. Written in an easy-to-understand style by pioneering researchers in this field, Bulk Metallic Glasses is one of the first books to coherently discuss the synthesis, processing, properties, and applications of these unique materials. The book explores the differences between nanocrystalline, glassy, and amorphous solids as well as the thermodynamics and kinetics and various processing methods of glass formation. It critically compares the different criteria for glass formation, describes the advantages and limitations of experimental methods for synthesizing bulk metallic glasses in assorted sizes and shapes, and examines the kinetics of crystallization/devitrification and the mechanisms of transformations. It also covers the density, diffusivity, thermal expansion, electrical resistivity, specific heat, viscosity, corrosion resistance, mechanical behavior, and magnetic properties of bulk metallic glasses. After presenting a wide array of applications, the book concludes with a discussion on the future of these materials. The adoption of bulk metallic glasses into existing systems is besieged by many obstacles but due to their interesting combination of properties, future applications may be unlimited. A one-stop resource on all aspects of bulk metallic glasses, this book demonstrates the immense potential of these novel materials. It clearly elucidates the background, detailed methods of synthesis and characterization, structure, and properties of bulk metallic glasses.
Nanomechanical Studies of Metallic Glasses at Ambient and Elevated Temperatures
Author: Corinne E. PackardPublisher:
ISBN:
Category :
Languages : en
Pages : 129
Book Description
Bulk metallic glasses, though attractive for use in structural applications for their high strength and elastic limit, display several unacceptable features upon deformation, including quasi-brittle failure along shear bands, extremely limited tensile ductility, and propensity for fatigue under cyclic loading. Though researchers have studied metallic glasses for the last fifty years, several fundamental aspects of the mechanical deformation process in these materials have not been conclusively established. In this thesis, new instrumentation and techniques were developed to study the deformation mechanism of metallic glasses, enabling a focused, high-resolution method for probing nanomechanical behavior. A nanoindenter capable of sub-nanometer and sub-microNewton resolution was outfitted with a custom heating stage and installed in a controlled atmosphere chamber to allow for high fidelity testing in a non-oxidizing environment across a range of deformation regimes. Using this system, the process of shear band initiation near a stress concentration was investigated using a low load indentation technique, revealing that high stresses at a point directly beneath the contact are not sufficient to cause shear band release to the free surface, but instead the potential for material flow along a slip line to relieve stress must be considered. Additionally, the distribution of strengths associated with the yield event was identified and its origins were determined to be mainly structural by using a variety of specially designed loading functions to examine rate, stress, and dynamic loading dependencies. Elevated temperature testing in the custom indentation system allowed in situ observation of the transition from discrete accommodation of strain in shear bands to homogeneous flow as well as characterization of the main features of viscous flow above the glass transition temperature. With the development of these new high-resolution testing methods, new avenues of experimental investigation have been opened, allowing insight into the fundamentals of plastic flow in metallic glasses across a spectrum of conditions.