Study Of Temperature Compensation Of Selective Laser Sintering Processing Based On Temperature Field

Selective laser sintering (SLS) is one kind of rapid prototyping technologies, which sinters powdery material selectively to produce three-dimensional mechanical parts. During the manufacturing period of SLS, the preheating temperature is one of the most important factors that will affect the mechanical property of the products. Because the preheating temperature field of the powder bed surface is not uniform, the mechanical property of parts sintered in different area is very different. Temperature compensation study at low-temperature regions by increase heat sources in the powder bed surface at the basic research of preheat temperature field of powder bed. The study has important practical significance in enhance the mechanical properties and accuracy of selective laser sintering parts.First, Analysis of the SLS preheating mode and preheating heat transfer process. Calculation the heat flux of surface of powder bed which under thermal radiation. Analysis preheat devices and thermal radiation properties. A physical model for the steady-state preheating heat transfer of powder bed is established.Based on the physical model for the steady-state preheating heat transfer, the steady-state preheating temperature field of the powder bed surface is analyzed by finite-element method. And further research the selective laser sintering steady state temperature field which have point, line, box-type heat. Found that temperature compensation by increase heat in powder bed can significantly improve the temperature field. So as to avoid the situation that of insufficient strength and warp of parts due to preheat temperature is not high enough.At the basis of theoretical analysis, powder bed temperature compensation by add the heat source at the edge of the region is Proposed. The weight of the sample is used to measure the effect of temperature compensation. The optimum parameters of temperature compensation are studied by orthogonal design. Study the relationship between process factors and the effect of temperature compensation.