Numerical Simulation And Experimental Study Of Temperature Field In The Preheating Process Of SLS

Preheating powder bed is an important measure that carries on heat to the powder in the selective laser sintering(SLS), the result of which will directly influence the sintering time and warping, even the accuracy of parts fabricated in selective sintering technology. Most studies on numerical simulations of temperature field in SLS focuses on the sintering process, but the research of the preheating process still very not perfect.This dissertation presented the analysis that the mechanism, energy transmission and flux density etc. of tube-type and plank-type preheating equipment. The relation between the irradiator and the distribution of temperature field, heating efficiency in the preheating process was obtained. On the basis of these, the three-dimension calculating models of thermal distribution depicting the preheating process were reported, and the calculation of temperature field of powder bed was given by using Matlab. Then on different terms of preheating equipments, the test proves according to the model the calculating results is reasonably consistent with experimental data. In addition, according to the experiment data the thermal distribution of the tube-type and plank-type preheating equipment was analyzed in detail.On the foundation of simulation results, according to the characteristics of temperature field an excellent design scheme was chosen. The optimized preheating devices obviously affect the preheating effect. Under the premise of the heating step, uniformity of temperature field on the surface of powder bed is improved obviously.