• Some of my recent and ongoing work is to understand and to discover a predictive theory for microstructure evolution. Most technologically useful materials are polycrystalline microstructures composed of a myriad of small monocrystalline grains separated by grain boundaries. The energetics and connectivity of the grain boundary network plays a crucial role in determining the properties of a m...

The evolution of texture was discussed during the formation of ultra-fine and nano grains in a magnesium alloy severely deformed through accumulative back extrusion (ABE). The microstructure and texture obtained after applying multiple deformation passes at temperatures of 100 and 250°C were characterized. The results showed that after single ABE pass at 100°C an ultrafine/nano grained microstr...

The evolution of microstructure and texture during isochronal annealing of a heavily cold rolled Al–0.3% Cu alloy has been characterized using electron backscatter diffraction. It is found that the rolling texture of this alloy is dominated by the Brass component and that recrystallization during annealing leads to the formation of a pronounced Goss texture. It is suggested that the development...

Direct Cu-to-Cu bonding was achieved at temperatures of 150-250 °C using a compressive stress of 100 psi (0.69 MPa) held for 10-60 min at 10(-3) torr. The key controlling parameter for direct bonding is rapid surface diffusion on (111) surface of Cu. Instead of using (111) oriented single crystal of Cu, oriented (111) texture of extremely high degree, exceeding 90%, was fabricated using the ori...

Residual stress was measured in sintered and heat-treated Fe2TiO5 samples with various grain sizes. The influence of texturing was assessed by comparing the residual stress states of samples having randomly oriented grains and highly oriented grains produced through magnetically assisted processing. The residual stress was measured with x-ray diffraction using Cr Ka radiation. Due to the signif...

The application of magnesium alloys is greatly limited because of their relatively low strength and ductility. An effective way to improve the mechanical properties of magnesium alloy is to refine the grains. As the race for better materials performance is never ending, attempts to develop viable techniques for microstructure refinement continue. Further refining of grain size requires, however...

Under standard processing conditions, many materials possess polycrystalline microstructures composed of a large number of small monocrystalline grains separated by grain boundaries. The energetics and connectivity of the grain boundaries network plays a crucial role in defining the properties of a material across a wide range of scales. A central problem in materials science is to develop tech...

A new statistical theory is introduced that takes into account the coupling between grain size, shape and crystallographic texture during deformation of polycrystalline microstructures. A “grain size orientation distribution function” (GSODF) is used to encode the probability density of finding a grain size D along a direction (given by unit vector n) in grains with orientation g. The GSODF is ...

A possible microstructural origin of the high critical current densities which have been obtained in c-axis-aligned, polycrystalline TlBa&a,Cu,Os +x deposits has been identified. The results of x-ray diffraction determinations of basal plane texture of Tl-1223 deposits prepared by spray pyrolysis are observed to depend on the size of the x-ray beam. Furthermore, most grain boundaries were found...