Accumulative roll-bonding process (ARB) is an important severe plastic deformation technique for production of the ultrafine grained, nanostructured and nanocomposite materials in the form of plates and sheets. In the present work, this process used for manufacturing Al/SiO 2 nanocomposites by using Aluminum 1050 alloy sheets and nano sized SiO 2 particles, at ambient temperature. After 8 cycle...

The main aim of this research was to find the mechanism for the failure of the CoCrMo porous nano-composite by characterizing microstructural changes and fractured surface after compression test. For this purpose, porous nano-composites were prepared with the addition of bioactive glass nano-powder to Co-base alloy with 22.5% porosity by the combination of space-holder and powder metallurgy tec...

a nano/ultra-fine grain al-0.2wt% zr alloy was produced by accumulated roll bonding (arb) processafter 10 cycles. the fraction of high angle grain boundaries increased from 8% to 65.4% during 10passes during arb process. this alloy was subjected to tensile test at different temperatures (523,573and 623 k) and strain rates (0.1 and 0.01 s-1). the optimum condition of temperature and strain rate ...

We have prepared and characterized a SnO2-decorated Pt-Sn(oxidized)/C cathode catalyst in a polymer electrolyte fuel cell (PEFC). Oxygen reduction reaction (ORR) performance of Pt/C (TEC10E50E) remained almost unchanged or even tended to reduce in repeated I-V load cycles, whereas the I-V load performance of the Pt-Sn(oxidized)/C prepared by controlled oxidation of a Pt-Sn alloy/C sample with t...

The tribological performances of the SiO₂/MoS₂ hybrids as lubricant additives were explored by a reciprocating ball-on-flat tribometer for AZ31 magnesium alloy/AISI 52100 bearing steel pairs. The results demonstrated that the introduction of SiO₂/MoS₂ hybrids into the base oil exhibited a significant reduction in the friction coefficient and wear volume as well as an increase in load bearing ca...

  Magnesium and its alloys are light, biodegradable, biocompatible metals that have promising applications as biomaterials. Magnesium is potentially useful for orthopedic and cardiovascular applications. However, the corrosion rate of this metal is so high that its degradation occurs before the end of the healing process. One of the ways to improve the corrosion rate is to compose it’s with cer...

It is well known that when coarse-grained metals undergo severe plastic deformation to be transformed into nano-grained metals, their ductility is reduced. However, there are no ductile fracture criteria developed based on grain refinement. In this paper, we propose a new relationship between ductile fracture and grain refinement during deformation, considering factors besides void nucleation a...

Diamond-like carbon (DLC) films have been successfully deposited on Ti-50.8 at.%Ni using plasma based ion implantation (PBII) technique. The influences of the pulsed negative bias voltage applied to the substrate from 12 kV to 40 kV on the structure, nano-indentation hardness and Young’s modulus are investigated by the X-ray photoelectron spectroscopy (XPS) and nano-indentation technique. The r...

In general, melting process is not a common method for the production of oxide dispersion strengthened (ODS) alloys due to agglomeration and coarsening of oxide particles. However, vacuum casting process has recently been employed as a promising process to produce micro-scale oxide dispersed alloys. In this paper, we report the process and characterization of in situ formation and uniform dispe...

High-frequency impacting and rolling was applied on AZ31B magnesium alloy to obtain a gradient nano-structured surface. Surface characteristics were experimentally investigated, and the nanocrystallization mechanism is discussed in detail. Results showed that the gradient nano-structure with the characteristics of work hardening, compressive residual stress and a smooth surface was induced on t...