Replacing of glass fibres with seed oil palm fibres for tribopolymeric composites

In the current study, the possibility of replacing woven glass fibres (WGFs) with seed oil palm fibres (SOPFs) as reinforcements for tribopolymeric composites is investigated. Mainly, two different polyester composites based on woven glass reinforced polyester (WGRP) and seed oil palm reinforced polyester (SOPRP) are developed. Different volume fractions (25, 35, and 45 vol.- %) of SOPFs were considered. The experiments were performed using a block on disc (BOD) machine and the tests were conducted under dry contact condition against smooth stainless steel counterface at 2?8 m s21 sliding velocity, 20 N applied load for different sliding distances (up to 5 km). The wear mechanism was categorised using a Scanning Electron Microscope (SEM). The results revealed that the steady state was reached after 4 km sliding distance for both WGRP and SOPRP composites. Seed oil palm reinforced polyester composites showed very high friction coefficient compared to WGRP. 35 vol.-% SOPRP composite exhibited a promising wear result, i.e. SOPFs are possible to replace WGFs in polymeric composites reinforcements whereas the wear resistance of the synthetic and natural composite were almost the same. The wear mechanisms for SOPRP composites were predominated by microcracks, deformation and pulled out of fibres while in the WGRP composite, abrasive nature was observed

Tribological investigation of frictional behaviour of mild steel under canola bio-lubricant conditions

In this study, two stock engine oils were developed using different blends of a vegetable oil (canola oil), mixed with fully synthetic oil (0 %, 20 %, 40 %, 60 %, and 80 % of synthetic oil). The viscosity of the prepared blends was determined at different temperatures (20 ºC – 80 ºC). Tribological experiments were conducted, according to the conditions of the prepared lubricants, to investigate the influence of the newly developed oil on the frictional characteristics of mild steel material against stainless steel subjected to adhesive wear loading. Scanning electron microscopy was used to examine the worn surface of the mild steel. The results revealed that blending the canola oil with synthetic oil increases the viscosity of the lubricants. Moreover, the viscosity of the canola oil and its blends with synthetic oil is controlled by the environmental temperature since increasing the temperature reduces viscosity. The experimental results revealed that the frictional coefficient of the mild steel was dependent on the applied load and velocity rather than the sliding distance. In addition, pure canola oil as a lubricant was able to compete in performance with a blend of 80 % synthetic and 20 % canola oils

Effect of SiC addition on mechanical and wear characteristics of WC-32(W-Ti)C-6Co cemented carbides

The effect of silicon carbide (SiC) addition on mechanical and wear properties of cemented carbides was investigated in this study. Different percentages (1-7 wt.%) of SiC were added to the cemented carbides mixture of WC/32 wt. % (Ti-W) C/6 wt.% Co. The microstructural characteristics of the developed materials was identified using scanning electron microscopy (SEM) and Rockwell-A macrohardness (HRA), Vickers microhardness (Hv) as well as transverse rupture strength (TRS) were measured. The experimental results revealed that inserting SiC inclusion into the cemented carbides is found to be useless for two reasons. First, the microstructure of the developed carbides has more aggregations of largely contiguous SiC grains led to presence of rich/poor regions and consequently poor compatibility between carbides and the binder. Second, all properties of the cemented carbides greatly declined with the addition of SiC particles

Theoretical Study of the Effect of Fibre Porosity on the Heat Conductivity of Reinforced Gypsum Composite Material

In recent years, there has been an increasing demand for engineering materials that possess good mechanical and thermal properties and are cheap and environmentally friendly. From an industrial and academic point of view, there is a need to study the heat conductivity of newly developed polymer composites and the influence of porosity on the insulation performance of polymer composites. Experimental and theoretical studies were conducted on mainly sisal/glass fibre gypsum composites with different fibre volumes (0, 20, 25, 30, and 35 wt.%). The outcomes from the theoretical model in ANSYS have shown that there is a high possibility to simulate the experimental work and high accuracy for reflecting the experimental findings. Moreover, the results show that natural fibre polymer composites with a high-volume fraction of natural fibres have higher insulation performance than synthetic polymer composites with the same volume fraction of synthetic fibres. Furthermore, the results suggest and support that the improved performance of natural fibre-based composites was due at least in part to the internal porosity of the fibres

Framework for orienting engineering undergraduate final year projects towards new product innovation process

The traditional framework for undergraduate final year project (FYP) has customarily focused on the sharpening of theoretical principles and the honing of fundamental practical skills. This work sees the pressing need for orienting FYPs at the undergraduate level towards new product innovation. Hence, an unconventional framework, incorporating new product development (NPD) processes and practices, is created, aiming to generate more balanced and productive graduates; and enabling them to contribute to the NPD innovation process. For the purpose of comparison, the traditional FYP framework is firstly introduced. Then, each phase in the new framework, which embodies the actual activities carried out in a customer-oriented organization, is presented in detail. In addition to that, a project was developed and the proposed framework was implemented. As a result, a potential was found for the new developed framework

Design of film thickness instrument for fibre polymer composites tribological experiments

New technique to measure film thickness in tribological experiments is presented in the current study. The technique is based on strain gauges circuit fixed on a lever of the block on ring (BOR) machine. Conversion of strain gauge readings was made to determine the film thickness values. For testing purposes, experiments were conducted using the new machine to investigate the wear performance of glass/polyester composites. The tests were performed against aluminium counterface at different applied loads (0.5 N to 3 N) for 10 minutes sliding time under wet contact conditions. From the results, the new technique highly assisted to analyise the tribological results. The SEM showed different damage features

Tribological studies of bamboo fibre reinforced epoxy composites using a BOD technique

To reduce the emission of harmful materials into the ecosystem, researchers have been exploring the potential of manufacturing polymeric composites based on natural fibres. Although the large area of application of these materials has encouraged investigations of their performance under various loading conditions, less research has been conducted on their tribological behaviour. Hence, in this study, tribological tests were conducted on epoxy composites based on bamboo fibres. The wear performance of bamboo fibre reinforced epoxy was tested using various operating parameters, and the worn surfaces were examined using optical microscopy. The results revealed that the specific wear rate of the composites reduced since the epoxy was reinforced with bamboo fibres. Scanning electron microscopy analysis showed different wear mechanisms and damages

Multiphoton radiative recombination of electron assisted by laser field

In the presence of an intensive laser field the radiative recombination of the continuum electron into an atomic bound state generally is accompanied by absorption or emission of several laser quanta. The spectrum of emitted photons represents an equidistant pattern with the spacing equal to the laser frequency. The distribution of intensities in this spectrum is studied employing the Keldysh-type approximation, i.e. neglecting interaction of the impact electron with the atomic core in the initial continuum state. Within the adiabatic approximation the scale of emitted photon frequencies is subdivided into classically allowed and classically forbidden domains. The highest intensities correspond to emission frequencies close to the edges of classically allowed domain. The total cross section of electron recombination summed over all emitted photon channels exhibits negligible dependence on the laser field intensity.Comment: 14 pages, 5 figures (Figs.2-5 have "a" and "b" parts), Phys.Rev.A accepted for publication. Fig.2b is presented correctl

IMECE2009-10160 NEW TECHNIQUE MEASURING FILM THICKNESS FOR TRIBOLOGICAL MACHINES

ABSTRACT In the present work, a prototype machine was developed for film thickness measurement for tribological tests. The configuration of the machine was based Block on Ring (BOR) technique. In the current machine, frictional forces and film thickness were measured using load cell and strain gauges, respectively. Calibration was made to determine the real film thickness. Experiments were conducted using the newly developed machine to investigate the film thickness during sliding of UHMWPE against aluminum alloy counterface. The tests were performed at applied loads (1.47 N -2.94 N). The results revealed that increases the applied load reduces the film thickness which in turn played a main role in controlling the surface characteristics of the polymer