Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 17 of 17 for “"hardening rate"”.
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FEM of nanoindentation on micro- and nanocrystalline Ni: Analysis of factors affecting hardness and modulus values.
… modulus to yield stress Eeff/σ and the work hardening behavior. Two separate cases of work hardening rates were considered; one with no work hardening rate and other with a linear work hardening rate. Specifically, it is observed that pile up is large only when hf/hmax is close to one and …
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Cavitation erosion of materials
… emulsions, Controlled cavitation was generated in the laboratory in a vibratory cavitation apparatus employing the stationery specimen system. The influence of separation distance between the drill tip and specimen and of varying medium temperature on cavitation erosion were also …
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Elevated temperature mechanical properties of line pipe steels
… behavior, ductility, strength, strain hardening rate, strain rate sensitivity, and fracture behavior were characterized at room temperature and in the temperature range of 200-350 °C, the potential operating range for steels used in oil production by the steam assisted gravity drainage …
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Ductile fracture after complex loading histories : experimental investigation and constitutive modeling
… angle parameter using the material's isotropic hardening law. Experimental results are presented for three different advanced high strength steels. For each material, the onset of fracture is characterized for five distinct stress states, including butterfly shear, notched tension, tension with …
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Mechanism-based constitutive modeling of L1₂ single-crystal plasticity
… of yield strength and strain hardening rate. To date, extensive research has been carried out to reveal the underlying mechanisms. However, none of the resulting models has satisfactorily quantified the macroscopic behavior based on microscopic phenomena. Mechanism-based …
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The Effect of Pre-strain and Strain Path Changes on Ductile Fracture
… void growth which was justified in terms work hardening rate in the sample. Scanning electron microscope images revealed that the ductility of the sample decreased with increasing pre-strain but only slightly compared to the large decrease in far field strain at failure. This suggests that …
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Abrasive wear resistance of ruthenium aluminide intermetallic and ferritic steels containing a sigma intermetallic phase
… the abrasion process. The corresponding work-hardening results showed that ruthenium aluminide had the highest work-hardening rate. It can be concluded that the work-hardening ability of the test materials correlates with their respective wear resistance properties.
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Modeling and Simulation of Viscoplasticity, Recrystallization, and Softening of Alloyed Steel During Hot Rolling Process
… curves at different temperatures and strain rates. An inverse finite element analysis was performed to calibrate the experimental curves. Viscoplastic models including a Johnson-Cook (JC) model, a Zerilli-Armstrong (ZA) model, and a combined JC and ZA model were developed. Dynamic …
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Co-deformation of an aluminum zinc alloy
… of 240nm.The material was tested using strain rate jump tests to determine the temperature sensitivity, tensile tested to determine work hardening and the temperature sensitivity, wire drawn to study the effect of large plastic deformation and finally tension compression tested to determine …
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Atomistic simulations of deformation in Metallic Nanolayered Composites
… by providing mobile dislocation sources to generate the plastic strain at the crack tip necessary for crack blunting. Increasing the layer thickness can further enhance the fracture resistance of both Cu and Nb layers, since the critical stress for activating dislocation motion decreases with …
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Ageing and strengthening of cold-rolled Al-Mg(-Cu)-Si-Mn alloys: experimental analysis and modelling
… alloys during ageing: solid solution, work hardening, recovery and precipitation. Microstructure analyses revealed the formation of undissolved particles consuming the small Si addition, which influences age hardening behaviour of the alloys. Tensile testing was performed to evaluate the …
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Role of toughness in abrasion, and impact-abrasion wear
… hardness, such as fracture toughness, the work hardening rate and microstructural considerations in determining wear resistance of steel. In the work presented in the thesis, a remarkable new steel has been studied to reveal the role of toughness on a particularly dramatic wear scenario …
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Understanding the role of slag on geopolymer hardening and microstructural development
… binder. The early age properties like hardening (stiffening) and setting will determine the removal of formwork and thus the time of construction. The study was performed on user-friendly geopolymers obtained by using Class F flyash/slag/K-silicate/H2O. This involves the use of low …
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A study of the microstructural and mechanical properties of novel spring steels.
… alloy systems based loosely around three separate microstructures, i.e. a fully pearlitic, bainitic and martensitic microstructure. In turn, each alloy was examined and assessed with respect to their suitability for the industrial application given their mechanical properties.From the initial …
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Effect of strain rates on tensile properties and fracture toughness determination of extruded Mg-Al-Zn alloys
… properties, tensile properties at high strain rates of extruded magnesium alloys and their fracture behaviour are some of the important parameters to be considered in design in ensuring the durability and reliability of automobile structures. In this study, the effect of strain rates on tensile …
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Mechanisms of deformation in beta-brass single crystals
… single crystals of β-brass when widely different rates of uninterrupted compressive loading were used. Under static loading (strain rates = 10-4 sec-1) the crystals workhardened in a parabolic manner, slip being confined to either of the two (101) [111] or (211) [111] systems. Cross-slip in the …
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Underlying deformation behavior of medium/high entropy alloys using advanced electron imaging and diffraction
… space that are little explored, have demonstrated unusual combinations of strength, ductility, and damage tolerance. Their complex chemistries create rich defect energy landscapes and multiple pathways for mechanical deformation, yet the link between local structure and deformation mechanisms …