...Leila Ladani; Steven Nelson Mechanical fatigue crack nucleation and propagation is modeled in bimodal grain size aluminum alloy. A multiscale modeling approach in conjunction with a continuum based damage modeling technique, successive initiation, is used to determine microstructural site of crack...

... interiors in comparison to interfaces. If GBs are not accounted for, the second most influencing factor affecting fracture strength is the average grains size. Overall, it is mainly the GBs not the grain orientation distribution and grain size that significantly affects fracture strength. Slight variation...

.... The microstructure of the compacted and sintered HA and HA + ZrO 2 shows properties of a granular composite with grain size, which reduces with addition of ZrO 2 phase (AFM tests). Hydroxyapatite ceramic is one of the best implantation materials used for bone surgery and dentistry...

... investigated machining-induced workpiece microstructure variation using X-ray diffraction. It has been found that (1) under gentle cutting conditions, there was a 10% increase in the median grain size compared with unmachined ECAE NS/UFG copper bars. Increases in the arithmetic-, area-, and volume-weighted...

... on length scales up to a correlation length that is of the same order of magnitude as the grain size in the two directions. The difference in correlation lengths between the two directions is large for aluminum alloy and small for titanium alloy. Initially, the roughness values in the two directions remain...

... contributing to the grain refinement process. Examples are the ECAP with back pressure ( 5 ) and high pressure torsion test ( 31 ), where the grain size is smaller at equivalent strain compared with tests without hydrostatic stresses. (3) There is much more elongation in the grain shape in NECAP than in ECAP...

... for accurate material properties for finite element simulations of Mg structures. In this paper, we investigate the extent to which average grain size and postformed tensile properties vary across a Mg AZ31B hood inner component formed at 485 ° C for 20 min under a constant gas pressure. Tensile specimens were...

... the grain shape effect together with the new viscous parameter γ on the strain-stress behavior of aluminum and Waspaloy under tensile test. 07 01 2009 28 03 2009 03 11 2009 03 11 2009 elasticity grain size hardening plastic flow SCF calculations stress-strain relations...

... on sheared and on extruded samples confirms that the extrusion promotes massively simple shear. Besides, the grain refinement is measured with a dedicated transmission electron microscopy (TEM) attachment. It is shown that the grain size decreases regularly for a low carbon steel as well as for copper, down...

... to grain refinement, with the average grain size decreasing with temperature. Moreover, a steady state grain aspect ratio and inclination of the grain long axis with respect to the shear plane is observed. With increasing shear strain, the fraction of low angle grain boundaries goes over a maximum...

...Livan Fratini; Gianluca Buffa In this paper, the metallurgical phenomena occurring in friction stir welding processes of AA6082-T6 and AA7075-T6 aluminum alloys are investigated. In particular, to predict the local values of the average grain size, either a simple analytical expression depending...

... the localization strains when they straddle the localization band. 13 07 2007 21 11 2007 12 03 2008 aluminium grain size particle reinforced composites stress-strain relations strain localization damage finite element analysis aluminum particles grain structure Strain...

... pressing (ECAP) was used to produce a wide range of grain sizes, down to the submicrometer scale. The samples were heat treated before and after both processes to optimize tensile ductility. Implementation of the model to uniaxial tensile response of the conventionally rolled and the ECAP processed...

... and processes that exist over several size scales. Electron backscatter diffraction experiments were used for material structure characterization, which included crystallographic texture, distributions in grain sizes, and a distribution in intragrain misorientation. These distributions in structure were...

... density decreased. It was also observed that the grain sizes of polygonal ferrite with increased heat input. Accordingly, the decrease of the Charpy impact energy with the heat input is inevitable due to these microstructural changes. But, this does not mean that the acicular ferrite cannot be nucleated...

... of the TWBs. On the other hand, the results of uniaxial tensile tests clearly illustrated that there was no significant difference between the tensile strengths of the TWBs and those of the base metals. The metallographic study demonstrated a difference of grain size in the materials at base metal, heat...

... was between 3% and 5%. The films were synthesized using electrocodeposition. The grain size of the nanocomposite film was significantly smaller than the grain size of control films of pure copper. Electron backscatter diffraction (EBSD) experiments indicate that neither the nanocomposite thin films nor...

... fatigue cracks scanning electron microscopy bending elongation fracture mechanics grain size Mechanistic studies of fatigue crack nucleation have shown that surface or subsurface crack nucleation are likely to occur in α/β titanium alloys deformed under pure fatigue loading conditions 1 2...

... on Bergstrom’s model have been coupled for predicting temperature history, velocity and strain fields as well as phase transformations within the metal during and after hot forging. To verify the results of the model, theoretical predictions for loadstroke behavior and austenite grain size have been compared...

...Rui Wu; Rolf Sandstro¨m; Facredin Seitisleam With modern welding methods, satisfactory microstructures in 9%CrMoV (P91) steel can be obtained with a modest variation in hardness and prior austenite grain size. However, there is always a risk that significant deviations in the properties can...