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Showing 1 to 20 of 156 for “"Intergranular"”.
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Investigating intergranular fracture in nickel via atomistic simulations
… aspects of fracture properties in Ni, including intergranular fracture mechanisms, fracture toughness as well as crack healing. By performing statistical analysis on crack tip processes for fracture along different GBs, we revealed three distinct crack propagation mechanisms. For fracture along …
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Control of the intergranular glass phase in alumina ceramics
Includes bibliographical references.
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Microstructural study of intergranular M23C6 precipitates in Alloy 709
… and synchrotron X-ray diffraction (XRD). Intergranular M23C6 precipitates were first formed on high angle grain boundaries, followed by the formation of lamella-shaped M23C6 precipitates on twin boundaries. The precipitation time threshold of M23C6 was different from the known behaviors of …
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A Microscopic Approach to Intergranular Fatigue Fracture of Chemical Leadat Room Temperature
Made available in DSpace on 2014-12-12T00:25:49Z (GMT). No. of bitstreams: 1 7309969.pdf: 1211554 bytes, checksum: cac843e590e456729ef1d2717c94d1db (MD5) Previous issue date: 1972
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Thermodynamic calculations and model experiments on thin intergranular amorphous films in ceramics
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1997.
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Continuum models for intergranular films in silicon nitride and comparison to atomistic simulations
… for devising continuum models. The stability of intergranular films in CaO-doped Si₃N₄ is examined. A modified associate model that incorporates bulk-thermodynamic Gibbs free energy functions and treats non-bulk equilibrium compositions is developed. Kinetic equations are derived to solve for the …
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A Numerical Study of Intergranular and Oxidation-Driven Fracture in an Elastic-Viscoplastic Material
… response of high-temperature superalloys: intergranular fracture driven by the infiltration and embrittlement of grain boundaries by oxygen. A novel space-time finite element model is developed to study this mechanism. The numerical model provides the basis for generic investigations of the …
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Hydrogen effects on the evolution of plastic deformation in polycrystalline nickel: A mechanism for intergranular failure
… understood. The mechanism for hydrogen-induced intergranular failure of polycrystalline nickel was investigated in a series of uniaxial slow strain rate tensile tests in hydrogen-charged and uncharged specimens. The evolution of deformation microstructures was compared in the presence and …
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A Dislocation-Based Constitutive Model for Hydrogen-Deformation Interactions and a Study of Hydrogen-Induced Intergranular Fracture
This thesis presents two models of the effect of hydrogen on materials. Both models are intended to link experimental observations of material microstructure with macroscopically observable results. The first model creates a continuum, rate dependent plasticity model that incorporates the effect of …
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A dislocation-based constitutive model for hydrogen—deformation interactions and a study of hydrogen-induced intergranular fracture
This thesis presents two models of the effect of hydrogen on materials. Both models are intended to link experimental observations of material microstructure with macroscopically observable results. The first model creates a continuum, rate dependent plasticity model that incorporates the effect of …
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Application of Disorder-Induced Melting Concept to Fracture
… existing fracture problem: segregation-induced intergranular embrittlement. This is accomplished in the nickel-sulfur system by a comparison of the composition dependencies for polymorphous melting and intergranular fracture. The composition dependence for polymorphous melting is determined by …
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The role of microstructure in the temper embrittlement of low alloy steels.
… structures. It has been established that intergranular embrittlement in a quenched and tempered martensite microstructure was associated with the presence of P, whereas the initial intergranular embrittlement in a bainitic microstructure was associated with the segregation of Sb. It is …
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Origin of Creep-Fatigue Back Stress and its Effect on Deformation and Damage
… were employed to study the contributions of intergranular and intragranular incompatible strains to the back stress that is introduced in type 316H austenitic stainless steel under monotonic and cyclic loading at room and elevated temperatures. The scope of testing included load controlled …
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Phenomenology and kinematics of discrete plastic deformation events in amorphous silicon : atomistic simulation using the Stillinger-Weber potential
… the unique mechanical properties of disordered intergranular layers in nc-TiN/a-Si₃N₄ ceramic composites. Silicon was chosen as a model disordered network solid for the purpose of conducting feasible atomistic computer simulations of plastic deformation. Amorphous silicon structures were created …
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Stress relief cracking in creep resisting low alloy ferritic steels.
… and grain size in promoting high temperature intergranular failure could be identified. In particular, it is observed that although both steels exhibit very similar strength characteristics, the effect of grain size in promoting low ductility in association with intergranular failure is more …
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Modeling and simulation of creep rupture in high-temperature alloys
… causes of rupture in high-temperature alloys is intergranular cavitation: the nucleation, growth, and coalescence of voids along grain boundaries. It is also well known that intergranular voids grow under the influence of several physical processes, including matter diffusion along the void …
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