| Summary: | 碩士 === 國立雲林科技大學 === 機械工程系碩士班 === 95 === In recently years, the perfect attribute of Nano Composites has been emphasized, and it has raised the trend of nanotechnology in the worldwide. People expect the nanomaterial push forward the evolutional development in industry. Furthermore, the mechanical properties and tribological properties of Nano Composites are also concerned.
In the thesis, the polystyrene and multi-walled carbon nanotubes made by Chemical Vapour Dposition (CVD) are mixed to make Nano Composite. Nano Composite was dispensed to the materials in two kinds of weight ratios with 5%CNT and 95% PS, and pure PS with dimension of 2 x 2 mm. The sample in this experience is produced by Injection Molding Machine, which is the most popular process for polymers, The TGA and MDSC analyses show that the glass transition temperature of material is not affected while the decomposition temperature is increasing. Then the pin-on-disk tribometer is used the wear rate and wear depth under different conditions of loading and sliding velocity are observed. An eddy current sensor was used to record the change of coefficient of friction. Besides, a tank was added to the tribometer so that both the dry and wet tribological properties of the sample can be detected. To avoid the influence of temperature, a heater and a temperature sensor are also implemented.
The results of experience are as follows: first, after adding carbon nanotubes, the wear resistance is promoted up to 56.4% and 88.6 % under dry and wet lubrication respectively. While after adding lubricant in the wet wear experiment, the friction force is decreased; Secondly, the wear rate of the sample after adding the carbon nanotubes was small, and affected by the substrate. The condition in high temperature and continuous wear should be avoided when using the composite material. On the other hand, the nano-scratch test was conducted and the White-Light Interferometry was used to observe the surface morphology and surface roughness after the scratch tests.In the comparison of nanoindentor and pin-on-disk tribometers, the results of experiments are not in accordance due to different wear mechanisms and testing enviroments.
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