Effect of reinforcements on graphite/titania/aluminium nanohybrid composites

Aluminium alloys and their composites are often used in aerospace, automobile and biomedical applications. However, mechanical and surface properties of those alloys have not reached up to the expectation. This investigation focused to improve the wear resistance properties along with mechanical and surface properties of aluminium matrix composites. Here, novel aluminium matrix nanohybrid composites were developed using titanium oxide and graphite as reinforced via powder metallurgical route. The sintered samples were analysed by different tests such as, hardness, surface roughness, wear tests and other structural analyses. The obtained results showed that some new compounds formed during sintering were responsible for improved mechanical and surface properties for different applications. The wear test showed that there was rapid worn out of graphite from the composites having aluminium content more than 50 wt% due to the higher content of graphite (10 and 20 wt%, respectively). In addition, due to the increase of porosity in the different hybrid composites, there was an increase in coefficient of friction observed in some materials. The aluminium nanohybrid composite having 40 wt% titania and 10 wt% graphite showed best results compared with others. Therefore, the optimized hybrid composites with proper sintering condition would significantly help to get suitable structural, mechanical as well as tribological properties for many advanced applications.

Synthesis of PTFE based Air Cathode for Metal Air Battery

A large number of researchers devotes deep study to reducing the contact resistance and improving the durability of air cathode. Air cathode consists of gas diffusion layer, current collector and catalytic layers. The network structure (gas diffusion layer, GDL) of Air cathode plays an important role in metal-air battery. This GDL makes the air-cathode semi-permiable. It means that H2O does not pass through GDL layer but O2 moleecules can pass the layer. For that reason, the optimization of sintering condition is very important process in manufacturing Air cathode. This article is about the dependence of discharge property of magnesium air-battery to its sinter-ability. Thus in order to observe any changes in the discharge property, sinter-ability, a cost-effective method was designed in the air cathode production.

Development of Porous Titanium Sheet with High Porosity and Good Mechanical Properties

To respond to the requirements for porous Ti sheet with the balanced properties of high porosity and good mechanical properties, and to optimize the manufacturing conditions of the simple powder-filling plus sintering process, effects of sintering temperatures on density and bending strength in porous Ti sheet were investigated. The optimum sintering condition was 900-950 °C for 1h to obtain porous Ti sheet with the balanced density ratio (around 40%) and high bending strength. The polyhedron shape of HDH powders contributed to those balanced properties, in which localized sintering raised bending strength with keeping high porosity (low density). Using the optimum manufacturing conditions, large sized porous Ti sheet of 400 × 800 × 0.5 mm was successfully manufactured.