Synthesis and Characterization of Al–Al/(SiO<Subscript>2</Subscript>)<Subscript>np</Subscript> Composite by Powder-in-Tube Method

In this study, a macro-nanocomposite of Al–Al/(SiO₂)_np was synthesized using powder-in-tube method. Pure aluminum cylinders were cast and then machined to prepare tubes. Nanocomposite powders of Al/(SiO₂)_np were prepared by mixing 1 and 2 wt% SiO₂ nano-particle with aluminum. Then macro-nanocomposites were prepared by compaction of the nanocomposites inside the tubes. The effects of reinforcement weight fraction, volume fraction of nanocomposite in the macro-nanocomposites and hot extrusion on the microstructure and mechanical properties were investigated. Scanning electron microscope (SEM) and optical microscope (OM) were used for microstructural examinations. Mechanical properties were investigated using tensile and compression tests at room temperature. The results revealed that when 25 vol% of the powder-in-tube composite was the nanocomposite reinforced with 2 wt% of nano-particle, the tensile strength was increased by 10.8%. Tensile strength was improved by up to 24% when 64 vol% of nanocomposite reinforced with 1 wt% of nano-particle was employed. Additionally, significant increase in compressive strength was achieved. This is noteworthy that coupling of a pure aluminum sheath with the nanocomposite enhanced the strength with limited loss of ductility. Micrographs showed integrated composites in which the interface between the sheath and the core had no defects.     

Tailoring the Processing Route to Optimize the Strength–Toughness Combination of Pearlitic Steel

Metallurgical and Materials Transactions A - The present study fine tunes the processing route of a eutectoid steel to shape an optimum strength–toughness combination through appropriate...     

Self-adaptive query-broadcast in wireless ad-hoc networks using fuzzy best worst method

Wireless Networks - Various broadcasting schemes have been proposed for a unified routing approach in Wireless Adhoc Networks. In their efforts, the researchers mostly aim to minimize the...     

Effects of flash annealing and external magnetic field on magnetic properties of relatively high Nd content (37% by weight) NdFeB alloy

Journal of Materials Science: Materials in Electronics - Post modifications such as alloying element addition and/or heat treatment are applied to improve the magnetic properties of NdFeB permanent...     

Generalized differential quadrature analysis of electro-magneto-hydrodynamic dissipative flows over a heated Riga plate in the presence of a space-dependent heat source: The case for strong suction effect

The importance of including an electromagnetic actuator as a moving boundary on the dissipative flows of weakly conducting fluids had led to many published facts. But, nothing is known on the generalized differential quadrature analysis of magnetohydrodynamics over a Riga plate with emphasis on the case of viscous dissipation and space-dependent heat source. After deriving the simplified boundary layer equation that models the transport phenomenon, appropriate variables were used to non-dimensionalize and parameterize the partial differential equations. Thereafter, the resulting set of ordinary differential equations was solved numerically by applying a powerful differential quadrature algorithm. Based on the outcome of the simulation, it can be concluded that the viscous frictional effect can be minimized at the Riga plate either by weakening the suction process or by heightening the magnetic parameter. Moreover, the Lorentz forces have a hastening effect on the fluid motion, in the case when those magnetic causes are directed in the same sense of the developed flow.     

Settling characteristics of coal preparation plant fine tailings using anionic polymers

The objective of solid-liquid separation in thickeners in coal preparation plants is to obtain both a clear supernatant liquid with a low turbidity for reuse and a dense slurry. It is important for the smooth operation of the plant to produce good-quality recirculation water. In this study, settling characteristics of coal tailings (d₈₀=70 μm) taken from the thickener feed of Derekoy Coal Preparation Plant (Manisa, Turkey) were investigated with the use of anionic polymers. In the tests we determined the effects of the process parameters including polymer type, polymer dosage, temperature, suspension pH, and pulp density on the flocculation of the fine tailings of the coal preparation operation. Minefloc anionic polymer showed a better flocculation performance in comparison with other polymers. An optimum settling rate of 300 mm/min was reached at a dosage of 30 g/t-solids, a pulp density of 5%, pH 7.9, and temperature 25 °C using Minefloc polymer.