The formation of nano/ultrafine grained ferrite in low carbon steels containing different amounts of niobium was investigated using thermomechanical treatment which consisted of annealing of 85% cold rolled martensite with different parameters. The specimens were characterized by optical and scanning electron microscopy and Vickers hardness test. A lamellar dislocation cell structure was formed...

accumulative roll-bonding (arb) is a severe plastic deformation process that is using rolling to produce ultrafine grains in coarse grained metallic materials. in this study, arb has been applied on 70/30 brass up to 6 cycles at ambient temperature and non-lubricated conditions to apply a true strain up to 4.8 von mises strain. microstructures of arbed brass samples were characterized by scanni...

The processing of metals through the application of severe plastic deformation (SPD) techniques provides the potential for achieving exceptional grain refinement leading to ultrafine-grained (UFG) materials in bulk solids. These materials generally exhibit high strength but very limited ductility at room temperature (RT) leading to the so-called paradox of strength and ductility. The recent dev...

Supersaturated Al-Ti-Cr alloys were produced by a continuous electron beam evaporation technique. The as-deposited alloy sheets were fcc supersaturated solid solution with an average grain size of about 400 nm. Due to the fine grain size, the hardness of the alloy was as high as 270Hv. The sheet showed age hardening, and the peak hardness of 340Hv was obtained after aging at 623K for 900 s, in ...

Basic holographic characteristics of a newly developed panchromatic ultrafine grain silver halide light sensitive material for RGB recording of reflective holographic screen for autostereoscopic 3D display are presented. The average grain size is less than 10 nm which ensures high resolution, diffraction efficiency, and signal-to-noise ratio (more than 100 : 1) in a large dynamic range for RGB ...

Gonderman, Sean Robert. M.S.N.E., Purdue University, August 2014. Correlating Grain Size to Radiation Damage Tolerance of Tungsten Materials Exposed to Relevant Fusion Conditions. Major Professor: Jean Paul Allian. Tungsten remains a leading candidate for plasma facing component (PFC) in future fusion devices. This is in large part due to its strong thermal and mechanical properties. The ITER p...

The ultrafine grained (UFGed) 1050 Al plates with a thickness of 2 mm, which were produced by the accumulative roll bonding technique after five cycles, were friction stir butt welded to 2 mm thick 6061-T6 Al alloy plates at a different revolutionary pitch that varied from 0.5 to 1.25 mm/rev. In the stir zone, the initial nano-sized lamellar structure of the UFGed 1050 Al alloy plate transforme...

the study of nucleation mechanism of new grains during severe plastic deformation of magnesium alloys is of great importance to control the characteristics of final microstructures.  to investigate the role of discontinuous recrystallization, a wrought az31 magnesium alloy was deformed by accumulative back extrusion process at 330 °c.  the obtained microstructures were studied using optical and...

A large quantity of ultrafine tetragonal barium titanate (BaTiO3) nanoparticles is directly synthesized at room temperature. The crystalline form and grain size are checked by both X-ray diffraction and transmission electron microscopy. The results revealed that the perovskite nanoparticles as fine as 7 nm have been synthesized. The phase transition of the as-prepared nanoparticles is investiga...

In this work, we report on the electroplating of ultrafine and uniform magnesium (Mg) films on copper (Cu) and carbon nanotube (CNT) paper substrates. By controlling the process parameters and utilizing the pulsed deposition method, the average grain size of Mg was reduced to nanodimensions. Surface pretreatment of the substrates by depositing a seed layer was found to be an efficient strategy ...