The Study Of The Preheating Temperature For Selective Laser Sintering Forming Machine

The selective laser sintering (SLS) is a new prototype manufacturing process among rapid prototyping (RP) techniques. In the SLS process,varieties of powder materials can be used to produce models and moulds for a wide range of applications. During the manufacturing period of SLS,temperature is one of the most important factors that affects the precision and intensity of the products. Now,the precision of the preheating temperature measurement,the uniform distribution of preheating temperature and the automation of temperature control are need to improve on. This dissertation includes the measurement and control of temperature,factors influencing energy distributing . Because the thickness of powder is just 0.1-0.3mm and a new layer of powder it will be paved above it with the drop of the bed of powder,by using the Thermocouple and Infrared temperature surveying to measure temperature, we doesn't achieve the wanted result successfully. This dissertation exposes the cause of the error and gives out the analysis and the discussion in the main factors. Also,the method of improving temperature measurement accuracy are presented. During the processing of SLS,the uniform distribution of temperature field is an important factor,which affects the precision and intensity of part. Through analyzing the energy delivery process and energy distributing, the factor influence the uniform distribution of preheating temperature field are obtained in this dissertation. Improving methods are put forward, such as setting the different goal temperature for different calefaction pipe and compensating the coefficient of calefaction pipe. The research gains good effect that controls the asymmetry of power bed inside 3℃. The SLS old temperature control software,when the temperature changes,needs to set the target temperature through handwork,and while the part character varies,it needs to increase heat intensity depending on experience,which not only makes worker feel much discommodiousness,but also leads temperature too high or too low with the neglect. This dissertation empolders an entire automatic control temperature software, the practice proves the new one doesn't need the handwork ,which make the temperature control process totally automatic.