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Showing 1 to 20 of 61 for “"Flow Stress"”.
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Thermal Reversibility of the Flow Stress in Single Crystal Titanium-56 Aluminum
The [021] oriented samples were also analyzed in order to observe ordinary dislocation motion without the presence of superdislocations. It was found that all ordinary dislocations observed were mostly 60°, mixed dislocations, with relatively few screw ordinary dislocations. At room …
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Relationship between flow stress recovery and dislocation structure in polycrystalline alpha-titanium
… were identified to be the {101̄0} type planes. Flow stress recovery of alpha titanium at 500 and 550ºC proceeded in two stages: (1) an initial rapid recovery during the first 6 hours and (2) a leveling off after 6 hours. Dislocation structure was studied by using transmission electron …
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The application of the soft impression technique to evaluate flow stress, creep and frictional deformation of polycrystalline diamond and cubic boron nitride
… of tool materials - e.g. the measurement of the flow stress of diamond single crystals at temperatures up to 1500°C (Brookes, 1992). In this work, the technique has been extended further in order to form a basis for the comparison and evaluation of ultra-hard materials. Three main aspects of the …
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Effect of Printing Parameters on the Structure and Properties of 316l Stainless Steel
… the perpendicular surface exhibited high maximum flow stress with a low strain whereas the parallel surface had lower maximum flow stress with a high strain. For the individual printing parameters, any combination of parameters that gives a finer microstructure showed higher flow stress with a low …
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Thermo-mechanical modelling of hot flat-rolling of components with curved profiles
… of separate submodels, such as, deformation, flow stress, roll force, temperature, etc., should be used, so that new development in each of these areas can be easily incorporated. A deformation submodel, based on the upper bound theorem, is given for the analysis of three-dimensional …
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High temperature flow behavior of titanium aluminide intermetallic matrix composites
… by powder metallurgy techniques. The compressive flow behavior of the Al₃Ti and Al₅CuTi₂, composites have been evaluated at temperatures ranging from 1000°C to 1200°C and strain rates of 0.0001 and 0.001 sec⁻¹. The results have been analyzed by a correlation to the resulting microstructure, …
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Alloying effects on high-temperature deformation behavior of nickel aluminide intermetallics
… 10 -6 to 10-3 s-1. At high temperatures, the flow stress becomes dependent on strain rate. The materials were evaluated by comparing the flow stress at various applied strain rates. The testing temperatures ranged from 850°C to 1200°C.
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Extending the annular in-plane torsional shear test specimen to applications at high strain rates
… future. An estimation method for steady-state flow stress is presented with the steady-state flow stress found to be rate dependant. Finally, a relationship between the steady-state flow stress and strain rate for all experimental results is proposed.
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Microstructural evolution of AISI304 stainless steel in the Steckel Mill rolling process
… rolling process. The strain, strain rates and stresses on the mill strip can be calculated from the mill logs. An understanding of the metallurgical changes during rolling process can be gained by analysing the mean flow stress trends that evolve during rolling. Microstructural examination of …
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Characterisation of metallurgical and mechanical properties of friction stir welded low alloy steels for marine applications
… material can be evaluated through the study of flow stress evolution. Novel flow stress data on DH36 steel were generated over a range of strain rates and temperatures by hot compression testing; these data and the subsequent innovative metallurgical examination of the tested samples will …
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High strain rate properties of structural aluminium.
… have been used in the past to determine the stress-strain relationship of metals and alloys at high strain rates of up to 2.2 x 10 per second; some of these were approximate whilst others required expensive equipment. In the present study three aluminium alloys, HE15, HE30TF and DTD5044 have …
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ANALYSIS OF MACHINING PROCESS USING THE FINITE ELEMENT METHOD
… and cutting conditions, the distribution of flow stress within the chip and workpiece is computed. Plastic and elastic tool-chip friction are accounted for. The distributions of tool-chip contact stresses and the cutting forces obtained in the present analysis agrees well with the …
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Plastic Deformation in Complex Crystal Structures
… is hoped that a general method for tailoring the flow stress of a material might be found. Present ductile-brittle criteria are based on simple ratios of polycrystalline elastic constants and are too limited to accurately capture flow behaviour. There are complex materials which, despite such …
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The prediction of applied force and torque during flat hot rolling.
… have been made that allow the use of a yield .stress which is dependent upon temperature, rate of deformation and extent of inhomogeneity of the deformation process. Like Alexander, the present model considers also the effect of both: the elastic zone at each end of the deformation region and …
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Mechanical Behavior of Metals Under Triaxial Stress: Apparatus and Experiments
Under combined axial-stress/external-pressure loadings, a solid specimen experiences a truly three-dimensional, homogenous stress state comprised of a uniform axial stress in conjunction with radial and circumferential stresses equal to the negative of the pressure, -P. Through independent computer …
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A thermo-mechanical finite element simulation of hot rolling for the prediction of roll forces
… stainless steel. In order to model the material flow stress accurately, uniaxial compression testing was conducted in the temperature range of 800-1250° at intervals of 50°C. The strain rates tested were 35, 10, 3.5, 1.0, 0.35, 0.1, 0.01s-1 and each temperature was tested within each strain rate. …
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An experimental and theoretical investigation of the reaming operation
… the cutting torque and thrust uses the variable flow stress theory of machining. In this work the reamer cutting edges are subdivided into individual cutting edge and analysed as a single point tool with a cutting geometry. The model predicts the values of thrust and cutting torque for each …
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Analytical modeling and simulation of metal cutting forces for engineering alloys
… model and the methodology to determine material flow data have been developed. The efforts have been made to address work hardening and thermal softening effects and allow the material to flow continuously through an opened-up deformation zone. Oxley's analysis of machining is extended to the …
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Elevated temperature mechanical properties of line pipe steels
… temperature. All steels exhibited a maximum in flow strength and average strain hardening rate as a function of temperature. The X52 steel exhibited maxima in flow strength and average strain hardening rate at lower temperatures than observed for the X70 steels. For all steels, the temperature …
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