Research On Preheating And Post-curing For Selective Laser Sintering With Dual Light Sources

At home and abroad, Selective Laser Sintering is the most widely used rapid prototypingtechnology, which are widely used in mold manufacturing, aerospace, crafts and other fields.The double light source selective laser sintering can one-off rapidly produce the large size ofthe parts, has the advantages of low cost, high efficiency, however, due to the increase in themolding area, put forward higher requirements for preheating and post-curing. Therefore, thispaper conducted in-depth research such as temperature uniformity, preheating process,microwave post-curing, which is full of important practical significance and application value.This paper analyzes the law of thermal radiation transfer between the heating tube andheating surface. This paper deduces the formula of thermal energy transfer between them andthe main factors that determine the impact of the distribution of temperature field uniformity.On this basis, put forward a method of unequal altitude preheating equipment to improve thepreheating uniformity, and using the finite element method to analyze the influence onpreheating temperature field when the heating tube at different heights and power, optimumdistribution of preheating temperature field are obtained with this method, and verified in theexperiment. By transition curve Act to determine the preheating system thermostat PIDparameters, and the infrared temperature sensor in the preheating system for proofreading.According to the actual industrial design uninterrupted temperature measurement methods.Analysis of how to get energy in the actual process and accumulation of the excess heat ofthe sintered layer, Through the sintered layer temperature curve, experimental accuracychange curve and the strength curve is recorded and analyzed in the experiment, presented agradual cooling of the production process, because the excess energy in the manufacturing, sothere should be steps to reduce preheating temperature, so that the machined surface energy isconsistent, verified by experiment, indicating that this preheating process can effectivelyimprove the accuracy and strength of parts.This paper presents a microwave post-curing method, because microwave thermal physics, to avoid heat loss in the transmission process, high energy efficiency, heating time is short.Through experiments to determine the relationship between the microwave power, temperatureand time in the microwave heating, prove the microwave curing parts in terms of strength,shrinkage superior to the traditional curing process and to develop the initial microwavepost-curing.