an ultrafine grained dual phase (ufg dp) steel containing niobium was produced by a new routeutilizing simple cold-rolling and subsequent intercritical annealing of ferrite/martensite duplex startingstructures. the effects of intercritical holding time on the microstructural evolutions and mechanicalproperties were studied. the results showed that increasing intercritical holding time enhnaced ...

Grain boundary motion may be accompanied with vacancy generation [1–4]. A typical case where a moving grain boundary produces vacancies is in primary recrystallisation, when the growth of a recrystallised grain at the cost of a grain with a large dislocation density involves release of excess free volume. Vacancies are also generated during grain growth, when the total volume of the grain bound...

Ultrafine-grained (UFG) Ti for improved mechanical performance as well as its surface modification enhancing biofunctions has attracted much attention in medical industries. Most of the studies on the surface etching of metallic biomaterials have focused on surface topography and wettability but not crystallographic orientation, i.e., texture, which influences the chemical as well as the physic...

In the last three decades, several severe plastic deformation (SPD) procedures have been developed and applied in materials science to create bulk, ultrafine-grained (UFG) structures. As a consequence of SPD, not only submicron even nanometer grain sizes can be obtained, but also new boundaries with non-equilibrium structures material may formed. Therefore, both strength ductility UFG change si...

in this study, ultrafine grained 2024 al alloy based b4c particles reinforced composite was produced by mechanical milling and hot extrusion. mechanical milling was used to synthesize the nanostructured al2024 in attrition mill under argon atmosphere up to 50h. a similar process was used to produce al2024-5%wt. b4c composite powder. to produce trimodal composites, milled powders were combined w...

V.A. Andreyachshenko, Faculty of Nanotechnology and Metallurgy, Karaganda state technical University, Karaganda, Kazakhstan A.B. Naizabekov, Mining and Metallurgy Faculty, Rudny Industrial Institute, Rudny, Kazakhstan In the present research, equal channel angular pressing (ECAP) was conducted. The defectness degree of the alloy for one pass and maximum strain was determined. Ultra fine grained...

Ultrafine-grained Ti31Mo alloy and Ti31Mo5HA, Ti31Mo5HA-Ag (or Ta2O5, CeO2) composites with a grain size of approximately 2 μm were produced by the application mechanical alloying powder metallurgy. Additionally, surface was modified. In first stage, specimens immersed in 5M NaOH for 24 h at 60 °C. second hydroxyapatite (HA) deposited on sample surface. The cathodic deposition −5 V vs. open cir...

The tensile fractures of ultrafine-grained (UFG) Al-Mg alloy with a bimodal grain size were investigated at the microand macroscale using transmission electron microscopy (TEM), scanning electron microscopy (SEM) equipped with focused ion beam (FIB), and optical microscopy. The nanoscale voids and crack behaviors near the tensile fracture surfaces were revealed in various scale ranges and provi...