Particularities of the selective laser sintering (SLS) on Nd +3:YAG laser and conditions of the polycarbonate (PC) destruction in the course of the manufacturing of porous three-dimensional parts made of the powdered metal-polymer compositions (MPC) were studied for their dependence on the laser influence (LI) parameters and the MPC composition. The initial powders of PC + Cu blend were prepared in the weight ratios 1:4, 1:6, and 1:10 for the micrometer-sized copper. To compare the SLS conditions, mixtures with proportions of 9:1, 7:3, 4:1 with nanosized copper additives were also provided. For the study, the scanning electron microscopy/energy dispersive X-ray spectroscopy analysis, IR spectroscopy, thermogravimetric analysis, and differential thermal analysis dates, and time-of-flight secondary ion mass spectrometry were carried out. The monitored parameter was the kinetics of a thermal destruction and thermo-oxidizing destruction of the PC evaluated by the change of the sol-gel fraction content, density, intrinsic viscosity, and molecular weight PC after the SLS process. It was shown that the activation energy of the PC destruction in nitrogen is higher than that in the air. The increase in the PC concentration in the MPC results in the decrease in the destruction processes activity. The metal inclusions have a shielding effect, thus moving the temperature range for the polymer destruction towards the region of higher temperatures, and therefore decreasing the rate of the PC decomposition under a fast temperature rise. The activation nature of the thermo-oxidizing destruction substantially goes down with the increase of the PC concentration in the MPC, and the comparison by the absolute values shows that the thermal destruction predominates over the oxidizing destruction during the SLS process.
|Журнал||International Journal of Advanced Manufacturing Technology|
|Состояние||Опубликовано - апр. 2014|
|Опубликовано для внешнего пользования||Да|