Papers by Author: Qing Guo Chen

Abstract: Based on mechanism of SLS, the scanning speed, laser power, preheat temperature and thickness of spreading layer are main factors to part quality in Selective Laser Sintering(SLS). With manufactured specimen pieces by Molding machine AFS-450, orthogonal experimental design and analysis of variance were adopted to post-treatment. Three indexes, including sintering strength, constriction percentage and sintering density, were studied. So an optimized project can be determined. This work can provide process parameters in SLS for ABS power. It will be of benefit to improve the part dimensional precision and strength.

Abstract: Sintering temperature influences on sintering process essentially. Laser power and scanning speed determined sintering temperature. Preheat to powder is beneficial to improve the surface temperature uniformity. Stress concentration of part is various in different layer depth. Therefore, the influence of laser power, scanning speed, thickness of spreading layer and preheat temperature on part quality in selective laser sintering(SLS) are main factors. Based on laser energy in Gaussian distribution and mechanism of SLS, with manufactured specimen pieces by molding machine AFS-450, orthogonal experimental design and analysis of variance are adopted to post-treatment. The prototyping sintering parameters are optimized. The result and solution of the experiment are the preheat temperature of 100°C, the scanning speed of 2000 mm/s, the laser power of 24W, the thickness of single layer of 0.2mm for ABS resin. This work can provide optimized parameters in SLS for ABS resin. It will be of benefit to improve the part dimensional precision and strength.

Abstract: The vibrating roller crusher convert relative vibration generated by two rigid bodies to bring high-frequency impulse on grain layer (or granular) in chamber, which makes grain crush to particle. Based on the science of vibration, dynamics model in vibration-impact crushing system of a bilateral single-mass and vibration differential equations are established. By dynamic analysis, amplitude frequency curve, hysteresis impact curve and energy absorption curve are all founded. The curves on dynamic response are discussed. Under the consideration of their results, displacement, velocity and acceleration with the time history are induced. Impact on the left and right sides are unsymmetrical. Influence laws on amplitude frequency, impact, energy absorption from clearance and vibration frequency is also established.