Gradient Microstructure and Texture Formation in a Metastable Austenitic Stainless Steel during Cold Rotary Swaging.

The paper aimed to study the evolution of the microstructure and texture gradient of a 321-type metastable austenitic stainless steel during cold rotary swaging. Cold rotary swaging was carried out with a reduction of up to 90% at ambient temperature. Pronounced gradients of the α'-martensite volume fraction, the axial texture of austenite (⟨111⟩ and ⟨001⟩) and α'-martensite (⟨101⟩), and non-uniform microhardness distribution along the rod diameter were obtained after a reduction of 80-90%.

Effects of Various Ripening Media on the Mesoporous Structure and Morphology of Hydroxyapatite Powders.

Mesoporous hydroxyapatite (HA) materials demonstrate advantages as catalysts and as support systems for catalysis, as adsorbent materials for removing contamination from soil and water, and as nanocarriers of functional agents for bone-related therapies. The present research demonstrates the possibility of the enlargement of the Brunauer-Emmett-Teller specific surface area (SSA), pore volume, and average pore diameter via changing the synthesis medium and ripening the material in the mother solution after the precipitation processes have been completed. HA powders were investigated via chemical analysis, X-ray diffraction analysis, Fourier-transform IR spectroscopy, transmission electron microscopy (TEM), and scanning (SEM) electron microscopy.

Effect of Cold Swaging on the Bulk Gradient Structure Formation and Mechanical Properties of a 316-Type Austenitic Stainless Steel.

The present study aimed to discover the effect of cold swaging reduction on the bulk gradient structure formation and mechanical properties of a 316-type austenitic stainless steel. The initial rod was subjected to radial swaging until 20-95% reduction of initial rod diameter, at room temperature. According to finite element simulation, higher plastic strain was accumulated in the surface layer compared to the center region during swaging.

The Influence of Co Additive on the Sintering, Mechanical Properties, Cytocompatibility, and Digital Light Processing Based Stereolithography of 3Y-TZP-5AlO Ceramics.

Nanocrystalline 3 mol% yttria-tetragonal zirconia polycrystal (3Y-TZP) ceramic powder containing 5 wt.% AlO with 64 m/g specific area was synthesized through precipitation method. Different amounts of Co (0-3 mol%) were introduced into synthesized powders, and ceramic materials were obtained by heat treatment in the air for 2 h at 1350-1550 °C.

Influence of Al on the Structure and in Vitro Behavior of Hydroxyapatite Nanopowders.

Nanopowders of aluminum-substituted (0-20 mol %) hydroxyapatite (HA) with the average size of 40-60 nm were synthesized by the precipitation method from nitrate solutions. A series of samples were studied by various analytical tools to elucidate the peculiarities of Al introduction. Electron paramagnetic resonance and pulsed electron-nuclear double resonance data demonstrate that incorporation of Al resulted in a decrease in the concentration of impurity carbonate anions and lead to an increase in the number of protons in the distant environment of the impurity nitrogen species.

Solvothermal synthesis of Sm-doped FeO nanoparticles.

Magnetic iron oxide nanoparticles doped with samarium were prepared by solvothermal polyol method. An introduction of 2,2'-bipyridine during the synthesis reduces the particle diameter to about 9nm in average. The difference in physical and magnetic properties of the samples prepared with and without capping agent was outlined on the basis of complex characterization by a number of experimental techniques.