Study Of Changs In Intensity Of Selective Laser Sintering Processing Based On Temperature Field

Selective laser sintering (SLS) is one kind of rapid prototyping technologies, which sinterspowdery material selectively to produce three-dimensional parts. During the manufacturingperiod of SLS, the preheating temperature is one of the most important factors that will affect themechanical property of the products. Because the preheating temperature field of the powder bedsurface is not uniform, the mechanical property of parts sintered in different area is very different.This article based on the the research of preheating temperature field of the powder bed surface,and then 3D preheating temperature field generated by increasing heat sources under the powderbed to induce uneven preheating temperature is studied. Because of the nonuniform preheatingtemperature in the regions of the parts, the different areas have different intensity making thepart obtains a optimization mechanical performance. In order to produce the parts with changingintensity properties, right heat sources are needed to influence preheating temperature. The workdevelopmented in this article can extend the applications of the SLS, and have some innovation.First, introduce the SLS and its research status, analysis technologies of the SLS, and it'simpact factors. At the condition of other parameters unchanged, the preheating temperature willdecide the intensity of the partSecond, analysis of the SLS preheating mode and preheating heat transfer process. Analysispreheat devices and thermal radiation properties. A physical model for the steady-statepreheating heat transfer of powder bed is established.Third, based on a physical model for the steady-state preheating heat transfer of powder bed,the Finite Element Method is introduced to analysis the steady-state preheating heat transfer ofpowder bed, and the steady-state preheating temperature field of the powder bed surface isobtained, and then a 3D preheating temperature field is calculated. The results show that the increase of heat sources at the bottom of powder bed can apparently change the preheatingtemperature, thereby change the intensity of parts.Combined the results of the Finite Element Analysis and Experimental, the relationshipbetween preheating temperature, density and intensity is established, the experiment results ofvarying changing intensity specimens verify the method of using preheating temperature field tomanufacture changing intensity part is possible.