Tribological properties of PAANa/UHMWPE composite materials in seawater lubrication

To prepare a high-performance anti-friction and wear-resistant composite material for friction sub-components in marine equipment, a modification was made by adding different amounts sodium polyacrylate (PAANa) to ultra-high molecular weight polyethylene (UHMWPE). PAANa/UHMWPE-blended powders were prepared at individual weight ratios of 0/100, 3/97, 5/95, 8/92, 13/87, and 18/82 with hot-press molding. In seawater, experiments of PAANa/UHMWPE composites sliding against GCr15 have been conducted with a ball-on-disk configuration in this study. The results show the surface hardness of composites was almost the same with the increase in PAANa proportion, however, the friction coefficient and wear scars of PAANa/UHMWPE composites/GCr15 sliding pairs firstly decrease and then increase. Scanning electron microscopy (SEM) results show that wear mechanism of the composites is mainly plastic deformation and spalling. The composites with PAANa content of 3% and 5% achieves better tribological properties than the pure UHMWPE material.

Mechanically Resistant Composite Material Using Optimal Amount of Pre-Treated Hazardous Waste

The utilisation of a relatively high amount of hazardous waste such as neutralising sludge (NS), which is a by-product of galvanic metal plating, as filler in a mechanically resistant composite material with an epoxy matrix, appears to be a progressive approach for improving the environment aspects. Polymer composites containing a filler of pure finely-ground silica sand – silica flour (SF) and fine foam glass waste (FGW) with a particle size of less than 200 μm were used for comparison of the achieved mechanical parameters. Considering the required consistency of the composite, related to its intended application in practice, 40% of the epoxy resin fillings was tested. It was shown that the developed, mechanically-resistant composite exhibits very high impact and wear resistance. Based on the assessment of the results obtained, it was found that the composite containing pre-treated hazardous waste achieved only 20% lower compressive strength than the reference composite, which comprised only primary raw materials. It is thus claimed that specific pre-treated hazardous waste can be effectively used for the preparation of special repairing composite material, and also in areas with a significant mechanical load.

Justification of producing quality heat-resistant composite material using metals of platinum group by method of magnetic spray

In the work the technological scheme of manufacturing of a laminated composite material (SCM) by the method of magnetron sputtering is shown. This scheme consists of several successive steps: applying a protective coating to the mandrel, depositing the composite material to the required thickness, removing the mandrel. To implement this scheme, an experimental setup was made. Cathodes made of heat-resistant materials are made. A sample of the Ir - W - Nb system was obtained. His microstructure was studied. The conceptual model of the system of quantitative indicators of the quality of composite material production is developed. The system of indicators allows to obtain mathematical dependences of the product quality indicators on the indicators of technological operations at all production stages, and therefore to justify the optimal parameters of these modes.

Preparation and Properties of SiO2/Al2O3-SiO2 Fiber Mat Composite Materials

A light weight and heat-resistant composite material was successfully fabricated by impregnation-filtration process in which Al2O3-SiO2 fiber mat was used as the skeleton and silica was applied as reinforcing filler. The effects of both concentration of silica sol and sintering temperature on SiO2/Al2O3-SiO2 fiber composites were studied. The results indicated that the density of composites increased with the concentration of silica sol increasing. The heat-treatment temperature had little effect on the density of composites. As heat-treatment temperature increased, the compressive strength increased firstly and then decreased.

Processing of Zinc-Based MgAl2O4 Composite and Effect of Fly Ash Addition

The properties of ceramic-metal (Cermet) composites as tensile strength, hardness and resistance to corrosion and high temperature are superior than ceramics and metals. Because of the enhanced characteristics of cermets, they are commonly used in various applications and industries. The main objective of this study is to produce a cheap, easy produced, strong and high corrosion resistant composite material. For these purposes, zinc is used for its natural capacity against corrosion, low density, low melting point and softness. Magnesium aluminates spinel oxide (MgAl2O4) is chosen because of its high melting point and low density. Fly ash is a waste from coal power plant having puzzolanic properties. In this study, the effect of various amounts of zinc and fly ash addition on density and hardness behaviour of zinc-based MgAl2O4 composites was investigated. The experimental results showed that zinc and fly ash addition improved the hardness behavior of zincbased MgAl2O4 composite.