Anticorrosion properties of an epoxy zinc-rich composite coating reinforced with zinc,aluminum, and iron oxide pigments

The effects of lamellar aluminum (Al) and micaceous iron oxide (MIO) pigments on the anticorrosion properties of an epoxy zinc-rich coating were studied. To this end, the epoxy zinc-rich coatings containing 70% w/w spherical Zn particles, 60% w/w Zn + 10% w/w MIO, and 60% w/w Zn + 10% w/w Al were prepared. The electrochemical noise (ECN), potentiostatic polarization technique, and salt spray test were employed in order to investigate the anticorrosion performances of the zinc-rich coatings. The zinc-rich coatings morphologies were studied by scanning electron microscope (SEM) before and after the salt spray test. The open-circuit potential values were also measured at different immersion times. Results showed that MIO particles could enhance the cathodic protection duration of the zinc-rich coating by enhancing its barrier properties and reducing the zinc particles oxidation rate. It was also shown that Al particles reduced zinc-rich coating sacrificial behavior at short immersion times and increased it at long immersion times. Unlike MIO particles, Al particles behaved both as barrier and sacrificial pigment.     

Design,development and modelling of single actuated,compliant and symmetrical multi link hopping mechanism

Journal of Mechanical Science and Technology - In this study, we present the design and development of a compliant multi-link hopping mechanism actuated by a single DC motor. Mechanism consists of...     

Molasses and air blown coal tar pitch binders for the production of metallurgical quality formed coke from anthracite fines or coke breeze

The effect of the type and the amount of hardeners, such as ammonium nitrate, ammonium carbonate and nitric acid on the molasses bonded briquettes prepared from anthracite fines or coke breeze were investigated. Amongst the hardener studied the best results were obtained with 2.5% ammonium nitrate hardener. The briquettes produced with this hardener were highly water resistant but not waterproof and their tensile strengths were not adequate to be used as a substitute for the metallurgical coke. Therefore, the briquettes were prepared with molasses containing 2.5% ammonium nitrate hardener and air blown coal tar pitch blended binder. When the blended binder was used for the production of anthracite fines or coke breeze briquettes, after curing at 200 °C for 2 h, they became waterproof and their tensile strengths were found to be sufficient to be used as a substitute for coke oven coke. The briquettes after curing could be directly charged into the blast furnace without carbonizing them at high carbonization temperatures. Since molasses and coal tar pitch, are relatively cheap and readily available materials, the process investigated could be economical way of producing high quality formed coke.     

Mechanical and rheological behavior of highly filled polystyrene with lignin

The mechanical, rheological, and morphological properties of polystyrene (PS)/lignin blends over a wide range of lignin content (0–80 wt%) have been studied in this work. PS/lignin blends were compounded in an internal batch mixer with and without the addition of a linear triblock copolymer based on styrene, ethylene, and butylene (SEBS). A morphological analysis was carried out by scanning electron microscopy to determine the state of dispersion and the interfacial adhesion between the lignin particles and the PS matrix. It was found that the flexural and torsion moduli both increased, while the tensile properties decreased with increasing lignin content. Nevertheless, compatibilizer addition was found to improve the tensile properties of the lignin/PS blend. The shear rheological behavior of the lignin/PS blends was also studied in this work where viscosity, dynamic moduli, and activation energy were found to be very sensitive to both lignin and compatibilizer contents. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers     

Influence of prior cold working on the tribological behavior of Cu–0.65 wt.%Cr alloy

The influence of prior cold working on the friction and wear behavior of Cu–0.65 wt.%Cr alloy under dry sliding against a steel disk was investigated on a pin-on-disk wear tester. The worn surfaces and debrises of Cu–Cr alloy were analyzed by scanning electron microscope (SEM) and energy dispersive X-ray (EDX) spectrum. The results indicated that prior cold working and aging had an effect on the hardness and wear resistance of Cu–Cr alloy; in other words hardness and wear rate increased with the amount of cold working. At constant aging temperature, the wear rate of Cu–Cr alloys increase with cold working and reached maximum at 50% cold working. At constant amount of cold working aged specimens at 500 °C shows higher wear resistance than 450 °C. Crack initiation and propagation in the tribolayer and at the interface of subsurface and tribolayer was the dominant mechanism during the sliding process.